# Stem 9 Practice Final

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Sit back, relax and have fun with this Physical Science Practice quiz.

• 1.

### Which of the following units is an SI base unit?

• A.

Centimeter

• B.

Kilogram

• C.

Cubic meter

• D.

Liter

D. Liter
Explanation
The liter is not an SI base unit. The SI base units are the units from which all other units are derived. The SI base units include the meter for length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for temperature, the mole for amount of substance, and the candela for luminous intensity. The liter is a unit of volume, but it is not one of the SI base units.

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• 2.

### In a controlled experiment,

• A.

The outcome is controlled.

• B.

Results are obtained by computer models.

• C.

One variable is fixed while all others are changed.

• D.

One variable is changed while all others remain fixed.

D. One variable is changed while all others remain fixed.
Explanation
In a controlled experiment, one variable is changed while all others remain fixed. This is done to determine the specific effect of the variable being tested on the outcome or results of the experiment. By keeping all other variables constant, researchers can isolate the impact of the variable they are interested in studying. This allows for a more accurate understanding of the relationship between the variable and the outcome, and helps to establish cause-and-effect relationships.

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• 3.

### Matter is

• A.

Any visible solid that has mass.

• B.

Any liquid that takes up space and has mass.

• C.

Anything that takes up space and has mass.

• D.

Any liquid or solid that takes up space.

C. Anything that takes up space and has mass.
Explanation
The correct answer is "anything that takes up space and has mass." This answer is the most comprehensive and inclusive definition of matter. It encompasses all forms of matter, including both solids and liquids, and emphasizes the key characteristics of matter, which are occupying space and having mass. This definition allows for the inclusion of gases as well, which may not be visible but still possess mass and occupy space.

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• 4.

### What i the chemical formula for iron (III) oxide?

• A.

Fe2+

• B.

NaCl

• C.

I2

• D.

Fe2O3

D. Fe2O3
Explanation
The chemical formula for iron (III) oxide is Fe2O3. This is because iron (III) indicates that iron has a +3 charge, and oxygen has a -2 charge. To balance the charges, two iron atoms with a +3 charge each combine with three oxygen atoms with a -2 charge each, resulting in the formula Fe2O3.

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• 5.

### Which of the following is a mixture?

• A.

Air

• B.

Salt

• C.

Water

• D.

Sulfur

A. Air
Explanation
Air is a mixture because it is composed of various gases such as nitrogen, oxygen, carbon dioxide, and trace amounts of other gases. These gases are not chemically combined and can be separated by physical means. Therefore, air is considered a mixture rather than a pure substance.

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• 6.

### Compounds and elements are

• A.

Always solids.

• B.

Mixtures.

• C.

Pure substances.

• D.

Dense.

C. Pure substances.
Explanation
Compounds and elements are classified as pure substances because they are composed of only one type of atom or molecule. Unlike mixtures, which contain different substances that can be separated physically, pure substances have a uniform composition and cannot be separated into simpler components by physical means. While compounds and elements can exist in different states of matter, such as solids, liquids, or gases, their fundamental characteristic is that they are pure and homogeneous throughout. Therefore, pure substances is the correct answer.

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• 7.

### Which of the following is a physical change?

• A.

Melting ice cubes

• B.

Burning paper

• C.

Rusting iron

• D.

Burning gasoline

A. Melting ice cubes
Explanation
Melting ice cubes is a physical change because it is a change in the state of matter from solid to liquid. The molecules in the ice cubes rearrange themselves as heat is applied, causing the ice to melt and become water. This change is reversible, as the water can be frozen again to form ice cubes.

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• 8.

### If you add oil to water and shake the two liquids together, you will form a

• A.

Heterogeneous mixture.

• B.

Homogeneous mixture.

• C.

Miscible liquid.

• D.

Pure substance.

A. Heterogeneous mixture.
Explanation
When oil is added to water and shaken together, they do not mix completely and form separate layers. This indicates that the oil and water do not dissolve in each other and remain as distinct phases. Therefore, the resulting mixture is heterogeneous, meaning it contains visibly different components.

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• 9.

### During which change of state do atoms or molecules become more ordered?

• A.

Boiling

• B.

Condensation

• C.

Melting

• D.

Sublimation

B. Condensation
Explanation
During condensation, atoms or molecules transition from a gaseous state to a liquid state. This change of state leads to the formation of liquid droplets or solid particles, causing the particles to become more ordered and closely packed together. As the gas cools and loses energy, the random motion of the particles decreases, resulting in a more organized arrangement. Therefore, condensation is the process in which atoms or molecules become more ordered.

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• 10.

### Which of the following describes what happens as the temperature of a gas in a balloon increases?

• A.

The volume of the gas increases and the speed of the particles in increases.

• B.

The speed of the particles decreases.

• C.

The volume decreases.

• D.

The pressure decreases.

A. The volume of the gas increases and the speed of the particles in increases.
Explanation
As the temperature of a gas in a balloon increases, the volume of the gas increases. This is because at higher temperatures, the gas molecules gain more energy and move faster, causing them to spread out and occupy a larger volume. Additionally, the speed of the particles in the gas also increases. This is because the increase in temperature leads to an increase in the kinetic energy of the particles, resulting in faster movement.

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• 11.

### Materials that can flow to fit their containers include

• A.

Gases.

• B.

Liquids.

• C.

Both gases and liquids.

• D.

Neither gases or liquids.

C. Both gases and liquids.
Explanation
Both gases and liquids can flow to fit their containers because they are both considered fluids. Gases are able to flow and fill their containers because their particles are not held together tightly and are able to move freely. Liquids, on the other hand, have particles that are held together more closely, but they are still able to flow and take the shape of their containers due to their ability to slide past one another. Therefore, both gases and liquids have the ability to flow and adapt to the shape of their containers.

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• 12.

### Which statement is NOT true of Bohr's model of the atom?

• A.

The nucleus can be compared to the sun.

• B.

Electrons orbit the nucleus.

• C.

An electron's path is not known exactly.

• D.

Electrons exist in energy levels.

C. An electron's path is not known exactly.
Explanation
Bohr's model of the atom states that electrons orbit the nucleus in specific energy levels. This model compares the nucleus to the sun, suggesting that it is the central and most massive part of the atom. However, it also acknowledges that an electron's path cannot be known exactly, as it only provides information about the probability of finding an electron in a particular region of space. Therefore, the statement "An electron's path is not known exactly" is true of Bohr's model.

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• 13.

### According to the moderns model of the atom,

• A.

Moving electrons form an electron cloud.

• B.

Electrons and protons circle neutrons.

• C.

Neutrons have a positive charge.

• D.

The number of protons an atom has varies.

A. Moving electrons form an electron cloud.
Explanation
According to the modern model of the atom, moving electrons form an electron cloud. This means that electrons do not orbit the nucleus in fixed paths, but rather exist in a cloud-like region around the nucleus. The electron cloud represents the probability of finding an electron at a particular location. This model is supported by quantum mechanics and explains the behavior and properties of electrons in atoms.

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• 14.

### If an atom has a mass of 11 amu and contains five electrons, it's atomic number must be

• A.

55.

• B.

16.

• C.

6.

• D.

5.

D. 5.
Explanation
An atom's atomic number represents the number of protons in its nucleus. Since the atom in question has five electrons, it must also have five protons to maintain a neutral charge. Therefore, the atomic number of this atom is 5.

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• 15.

### Which statement about atoms of elements in the same group of the periodic table is true?

• A.

They have the same number of protons.

• B.

They have the same mass number.

• C.

They have similar chemical properties.

• D.

They have the same number of total electrons.

C. They have similar chemical properties.
Explanation
Atoms of elements in the same group of the periodic table have similar chemical properties because they have the same number of valence electrons. Valence electrons are the outermost electrons involved in chemical bonding, and they determine the reactivity and chemical behavior of an element. Since elements in the same group have the same number of valence electrons, they exhibit similar chemical properties and tend to form similar types of compounds.

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• 16.

### The majority of elements in the periodic table are

• A.

Nonmetals.

• B.

Conductors.

• C.

Synthetic.

• D.

Noble gases.

B. Conductors.
Explanation
The majority of elements in the periodic table are conductors. Conductors are materials that allow the flow of electric current. In the periodic table, the majority of elements are metals, and most metals are good conductors of electricity. Therefore, it can be concluded that the correct answer is conductors.

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• 17.

### An atom of which of the following elements is unlikely to form a positively charged ion?

• A.

Potassium, K

• B.

Selenium, Se

• C.

Barium, Ba

• D.

Silver, Ag

B. Selenium, Se
Explanation
Selenium is unlikely to form a positively charged ion because it is located in Group 16 of the periodic table, also known as the oxygen family. Elements in this group tend to gain two electrons to achieve a stable electron configuration, forming negatively charged ions. Therefore, it is unlikely for selenium to lose electrons and form a positively charged ion.

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• 18.

### Which of the following statements about krypton is NOT true?

• A.

Its molar mass is 83.79 g/mol Kr.

• B.

Its atomic number is 36.

• C.

One mole of krypton atoms has a mass of 41.90 g.

• D.

It is a noble gas.

C. One mole of krypton atoms has a mass of 41.90 g.
Explanation
The molar mass of krypton is 83.79 g/mol Kr. The atomic number of krypton is 36, indicating that it has 36 protons in its nucleus. Krypton is a noble gas, belonging to Group 18 of the periodic table. However, one mole of krypton atoms does not have a mass of 41.90 g. The molar mass of krypton is given as 83.79 g/mol, which means that one mole of krypton atoms has a mass of 83.79 grams.

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• 19.

### Compounds are different from mixtures because

• A.

Compounds are held together by chemical bonds.

• B.

Each substance in a compound maintains its own properties.

• C.

Each original substance in a compound remains chemically unchanged.

• D.

Mixtures are held together by chemical bonds.

A. Compounds are held together by chemical bonds.
Explanation
Compounds are different from mixtures because they are held together by chemical bonds. In a compound, the atoms of different elements are chemically bonded to form a new substance with unique properties. This is in contrast to mixtures, where the substances are physically mixed together but retain their individual properties and can be separated by physical means.

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• 20.

### Which substance has ionic bonds?

• A.

CO

• B.

CO2

• C.

KCl

• D.

O2

C. KCl
Explanation
KCl has ionic bonds. Ionic bonds occur between a metal and a nonmetal, where one atom transfers electrons to the other, resulting in the formation of ions with opposite charges. In the case of KCl, potassium (K) donates an electron to chlorine (Cl), forming K+ and Cl- ions. These ions are held together by electrostatic attraction, creating an ionic bond. On the other hand, CO and CO2 have covalent bonds, where electrons are shared between atoms, and O2 consists of a diatomic molecule held together by a double covalent bond.

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• 21.

### In an exothermic reaction,

• A.

Energy is conserved.

• B.

The formation of bonds in the product releases more energy than is required to break the bonds in the reactants.

• C.

Energy is released as bonds form.

• D.

All of the above.

D. All of the above.
Explanation
In an exothermic reaction, energy is conserved because it cannot be created or destroyed, only transferred or converted. Additionally, the formation of bonds in the product releases more energy than is required to break the bonds in the reactants, resulting in a net release of energy. This energy is released as bonds form, further supporting the idea that all of the statements are correct.

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• 22.

### Which of the following is a homogeneous mixture?

• A.

• B.

Soil

• C.

Salt water

• D.

Vegetable soup

C. Salt water
Explanation
Salt water is a homogeneous mixture because it has a uniform composition throughout. In a homogeneous mixture, the different components are evenly distributed and cannot be easily distinguished. In the case of salt water, the salt particles are dissolved uniformly in the water, resulting in a solution where the salt is evenly spread out and cannot be seen or separated easily. This is in contrast to the other options given, such as tossed salad or vegetable soup, where the different components can be visually distinguished and are not evenly distributed.

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• 23.

### A solution is _________ if it contains as much dissolved solute as it will hold under a given set of  conditions.

• A.

Saturated.

• B.

Dilute.

• C.

Supersaturated.

• D.

Concentrated

A. Saturated.
Explanation
A solution is saturated when it cannot dissolve any more solute under the given conditions. This means that the solution is at its maximum capacity for holding the solute. Dilute refers to a solution that has a low concentration of solute, while concentrated refers to a solution that has a high concentration of solute. Supersaturated refers to a solution that has more solute dissolved than it would normally hold under the given conditions.

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• 24.

### Gases are more soluble in liquids when the pressure is __________ and the temperature is _________.

• A.

High, high

• B.

High, low

• C.

Low, high

• D.

Low, low

B. High, low
Explanation
Gases are more soluble in liquids when the pressure is high because high pressure increases the number of gas molecules in contact with the liquid, allowing for more opportunities for the gas to dissolve. Additionally, gases are more soluble in liquids when the temperature is low because low temperature decreases the kinetic energy of the gas molecules, reducing their ability to escape from the liquid and increasing their solubility.

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• 25.

### Which ions does an acid form in solution?

• A.

Oxygen

• B.

Hydronium

• C.

Hydroxide

• D.

Sulfur

B. Hydronium
Explanation
An acid is a substance that donates a proton (H+) in solution. When an acid dissolves in water, it forms hydronium ions (H3O+). These hydronium ions are responsible for the acidic properties of the solution. Oxygen, hydroxide, and sulfur are not ions that an acid typically forms in solution.

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• 26.

### Which ions does a base form in solution?

• A.

Oxygen

• B.

Hydronium

• C.

Hydroxide

• D.

Sulfur

C. Hydroxide
Explanation
A base is a substance that accepts protons or donates pairs of electrons. In solution, a base forms hydroxide ions (OH-) by accepting a proton from water molecules. This process increases the concentration of hydroxide ions in the solution, making it basic. Therefore, the correct answer is hydroxide.

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• 27.

### When a solution of nitric acid is added to a solution of calcium hydroxide, the salt formed has the formula

• A.

Ca(NO3)2.

• B.

Ca(OH)2.

• C.

H2O

• D.

CaH

A. Ca(NO3)2.
Explanation
When nitric acid (HNO3) reacts with calcium hydroxide (Ca(OH)2), a double displacement reaction occurs. The nitrate ion (NO3-) from nitric acid combines with the calcium ion (Ca2+) from calcium hydroxide to form the salt calcium nitrate (Ca(NO3)2). The other options are not correct because they do not represent the correct combination of ions formed during the reaction.

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• 28.

### Which of the following ionic equations best represents a neutralization reaction?

• A.

Na + H2O --> Na+ + OH- + H2

• B.

HNO3 + H2O --> H3O+ + NO3-

• C.

2OH- + NH4Cl --> Cl- + H2O + NH3

• D.

OH- + H3O+ --> 2H2O

D. OH- + H3O+ --> 2H2O
Explanation
The given equation OH- + H3O+ --> 2H2O represents a neutralization reaction because it involves the combination of a hydroxide ion (OH-) and a hydronium ion (H3O+) to form water molecules (H2O). In a neutralization reaction, an acid and a base react to form a salt and water. In this case, the hydronium ion acts as the acid and the hydroxide ion acts as the base, resulting in the formation of water.

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• 29.

### Bleach removes stains by

• A.

Changing the color of the stain.

• B.

Covering the stain.

• C.

Removing the stain-causing substances.

• D.

Disinfecting the stain.

A. Changing the color of the stain.
Explanation
Bleach removes stains by changing the color of the stain. Bleach contains chemicals, such as sodium hypochlorite, that have the ability to break down or oxidize the pigments in the stain, causing them to lose their color. This chemical reaction helps to remove the visible stain from the surface. By changing the color of the stain, bleach effectively eliminates the discoloration and makes it less noticeable.

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• 30.

### A neutron decays to form a proton and a(n)

• A.

Alpha particle.

• B.

Beta particle.

• C.

Gamma ray.

• D.

Emitted neutron.

B. Beta particle.
Explanation
A neutron decays to form a proton and a beta particle. During beta decay, a neutron in the nucleus of an atom is converted into a proton, and a high-energy electron, known as a beta particle, is emitted. This process occurs when there is an excess of neutrons in the nucleus, and it helps to restore the balance between protons and neutrons.

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• 31.

### The strong nuclear force

• A.

Attracts protons to electrons.

• B.

Holds molecules together.

• C.

Hold the atomic nucleus together.

• D.

Attracts electrons to neutrons.

C. Hold the atomic nucleus together.
Explanation
The strong nuclear force is responsible for holding the atomic nucleus together. This force is extremely powerful and overcomes the electrostatic repulsion between positively charged protons in the nucleus. It acts between protons and neutrons, keeping them bound together and forming a stable nucleus. Without the strong nuclear force, the nucleus would not be able to stay intact, leading to the disintegration of atoms.

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• 32.

### The amount of energy produced during nuclear fission is related to

• A.

The temperature in the atmosphere during nuclear fission.

• B.

The masses of the missing nuclei and particles released.

• C.

The volume of the nuclear reactor.

• D.

The square of the speed of sound.

B. The masses of the missing nuclei and particles released.
Explanation
The amount of energy produced during nuclear fission is related to the masses of the missing nuclei and particles released. This is because during nuclear fission, a heavy nucleus is split into two smaller nuclei, releasing a large amount of energy. The mass of the missing nuclei and particles is converted into energy according to Einstein's famous equation, E=mc^2, where E is the energy, m is the mass, and c is the speed of light. Therefore, the more mass that is converted into energy, the greater the amount of energy produced during nuclear fission.

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• 33.

### Which of the following is NOT a use for radioactive isotopes?

• A.

As tracers for diagnosing disease

• B.

As an additive to paints to increase their durability

• C.

As a way of treating forms of cancer

• D.

As a way to study biochemical processes in plants

B. As an additive to paints to increase their durability
Explanation
Radioactive isotopes are commonly used in various fields, including medicine and scientific research. They are used as tracers in diagnosing diseases, as they can be easily detected and tracked within the body. Radioactive isotopes are also used in cancer treatment, as they can target and destroy cancer cells. Additionally, they are used to study biochemical processes in plants, providing insights into their growth and development. However, radioactive isotopes are not used as additives to increase the durability of paints. This is because the radioactivity could pose health and safety risks to individuals exposed to the painted surfaces.

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• 34.

### A car travels a distance of 210 mi in exactly 4 h.  The driver calculates that he has traveled 52.5 mi/h.  Which of the following terms most nearly describes his calculation?

• A.

Average speed

• B.

Instantaneous speed

• C.

Instantaneous acceleration

• D.

Displacement

A. Average speed
Explanation
The driver's calculation of 52.5 mi/h represents the average speed because it is the total distance traveled divided by the total time taken.

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• 35.

### Which of the quantities below represents velocity?

• A.

25 m/s

• B.

10 km/min

• C.

15 mi/h eastward

• D.

3 mi/hr

C. 15 mi/h eastward
Explanation
Velocity is a vector quantity that represents the rate at which an object changes its position in a specific direction. It includes both the speed and the direction of motion. In this case, the quantity "15 mi/h eastward" represents velocity because it includes both the speed (15 mi/h) and the direction (eastward). The other quantities listed only provide the speed of the object but do not specify the direction, so they do not represent velocity.

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• 36.

### Which of the following is NOT accelerating?

• A.

A ball being juggled

• B.

A woman walking 2.5 m/s along a straight road

• C.

A satellite circling Earth

• D.

A braking cyclist

B. A woman walking 2.5 m/s along a straight road
Explanation
The woman walking 2.5 m/s along a straight road is not accelerating. Acceleration is the rate at which an object's velocity changes over time. In this case, the woman's velocity is constant at 2.5 m/s, so there is no change in her velocity and therefore no acceleration.

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• 37.

### A book is siting still on your desk.  Which of the following best describes this situation?

• A.

There are no forces acting on the book.

• B.

The book is moving compared to the reference frame.

• C.

There are balanced forces acting on the book.

• D.

There are unbalanced forces acting on the book.

C. There are balanced forces acting on the book.
Explanation
The book is sitting still on the desk, which means it is not moving. If there were unbalanced forces acting on the book, it would be in motion. However, since the book is stationary, it suggests that there are balanced forces acting on it. Balanced forces occur when the forces pushing or pulling on an object are equal in magnitude and opposite in direction, resulting in no net force and thus no movement.

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• 38.

### Newton's first law of motion states tat an object

• A.

At rest remains at rest unless it experiences an unbalanced force.

• B.

In motion maintains its velocity unless it experiences an unbalanced force.

• C.

Will tend to maintain its motion unless it experiences an unbalanced force.

• D.

All of the above.

D. All of the above.
Explanation
The correct answer is "All of the above." This is because Newton's first law of motion states that an object at rest remains at rest unless it experiences an unbalanced force, an object in motion maintains its velocity unless it experiences an unbalanced force, and an object will tend to maintain its motion unless it experiences an unbalanced force. Therefore, all three statements are true and encompass the complete explanation of Newton's first law of motion.

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• 39.

### A measure of inertia is an object's

• A.

Mass.

• B.

Weight.

• C.

Velocity.

• D.

Acceleration.

A. Mass.
Explanation
Mass is a measure of inertia because it quantifies the amount of matter an object contains. Inertia refers to an object's resistance to changes in its motion, and mass directly determines this resistance. Objects with more mass have greater inertia, meaning they require more force to accelerate or decelerate. Weight, on the other hand, is a measure of the force exerted on an object due to gravity and can vary depending on the gravitational field. Velocity and acceleration are related to an object's motion, but they are not measures of inertia.

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• 40.

### An example of action-reaction forces is

• A.

Air escaping from a toy balloon.

• B.

A rocket traveling through the air.

• C.

A ball bouncing off a wall.

• D.

All of the above.

D. All of the above.
Explanation
All of the given options demonstrate action-reaction forces. In the case of air escaping from a toy balloon, the action force is the air being forced out of the balloon, and the reaction force is the balloon moving in the opposite direction. Similarly, when a rocket travels through the air, the action force is the expulsion of gases from the rocket's engines, and the reaction force is the rocket moving forward. Lastly, when a ball bounces off a wall, the action force is the ball hitting the wall, and the reaction force is the ball bouncing back in the opposite direction. Therefore, all of the options involve action-reaction forces.

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• 41.

### __________ is defined as force acting over a distance.

• A.

Power

• B.

Energy

• C.

Work

• D.

Potential energy

C. Work
Explanation
Work is defined as the force acting over a distance. In physics, work is calculated by multiplying the force applied to an object by the distance the object moves in the direction of the force. It is a measure of the energy transfer that occurs when an object is moved by a force. Work is expressed in units of joules (J) and is a scalar quantity. It is an important concept in understanding the relationship between force, distance, and energy.

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• 42.

### Which of the following situations does NOT involve potential energy being changed into kinetic energy?

• A.

An apple falling from a tree

• B.

Shooting a dart from a spring-loaded gun

• C.

Pulling back the string of a bow

• D.

A creek flowing downstream

C. Pulling back the string of a bow
Explanation
Pulling back the string of a bow does not involve potential energy being changed into kinetic energy. When the string of a bow is pulled back, potential energy is stored in the bow due to the tension in the string. However, this potential energy is not directly converted into kinetic energy. Instead, when the string is released, the potential energy is transferred to the arrow, which then moves forward and gains kinetic energy. Therefore, the act of pulling back the string of a bow does not involve the direct conversion of potential energy into kinetic energy.

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• 43.

### Energy that involves the large-scale motion or position of objects in a system is called

• A.

Potential energy.

• B.

Mechanical energy.

• C.

Nonmechanical energy.

• D.

Conserved energy.

B. Mechanical energy.
Explanation
Mechanical energy refers to the energy associated with the motion or position of objects in a system. It includes both kinetic energy, which is the energy of motion, and potential energy, which is the energy stored in an object due to its position. Therefore, mechanical energy encompasses the large-scale motion or position of objects in a system, making it the correct answer.

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• 44.

### Which of the following can a machine not do?

• A.

Change the direction of a force

• B.

Multiply or increase force

• C.

Redistribute force

• D.

Increase the total amount of work done

D. Increase the total amount of work done
Explanation
A machine cannot increase the total amount of work done because it follows the principle of conservation of energy. According to this principle, energy cannot be created or destroyed, only transferred or transformed. Therefore, a machine can only transfer or transform energy from one form to another, but it cannot create additional energy to increase the total amount of work done.

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• 45.

### A machine with a mechanical advantage of less that one

• A.

Increases speed and distance.

• B.

Multiplies force.

• C.

Increases output force.

• D.

Reduces distance and speed.

A. Increases speed and distance.
Explanation
A machine with a mechanical advantage of less than one increases speed and distance because it allows for a smaller input force to produce a larger output force. This means that the machine is able to achieve a greater speed and cover a longer distance with the same amount of input force.

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• 46.

### Temperature is proportional to the average kinetic energy of particles in an object.  Thus an increase in temperature results in a(n)

• A.

Increase in mass.

• B.

Decrease in average kinetic energy.

• C.

Increase in average kinetic energy.

• D.

Decrease in mass.

C. Increase in average kinetic energy.
Explanation
An increase in temperature causes an increase in the average kinetic energy of particles in an object. This is because temperature is directly proportional to the average kinetic energy. As the temperature rises, the particles gain more energy and move faster, resulting in an increase in their average kinetic energy.

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• 47.

### The temperature at which the particles of a substance have mo more kinetic energy to transfer is

• A.

-273 K.

• B.

0 K.

• C.

0 degrees K.

• D.

273 K.

B. 0 K.
Explanation
The temperature at which the particles of a substance have no more kinetic energy to transfer is 0 K. This is because 0 K, also known as absolute zero, is the lowest possible temperature that can be reached. At this temperature, the particles of a substance have minimal or no kinetic energy, meaning they have stopped moving. As a result, there is no further energy available for transfer.

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• 48.

### The type of energy transfer that takes place between objects in direct contact is

• A.

Conduction.

• B.

Convection.

• C.

Contraction.

• D.

A. Conduction.
Explanation
Conduction is the correct answer because it refers to the transfer of heat or energy between objects that are in direct contact with each other. In this process, the heat is transferred through molecular collisions from a region of higher temperature to a region of lower temperature. Convection, on the other hand, involves the transfer of heat through the movement of fluids or gases. Contraction is not a type of energy transfer, and radiation refers to the transfer of heat through electromagnetic waves.

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• 49.

### Which type of energy transfer can occur in empty space?

• A.

Convection

• B.

Contraction

• C.

Conduction

• D.

Explanation
Radiation is the correct answer because it is the only type of energy transfer that can occur in empty space. Convection requires the movement of particles, which is not possible in a vacuum. Conduction involves the transfer of heat through direct contact between objects, which is also not possible in empty space. Contraction is not a type of energy transfer. Radiation, on the other hand, is the transfer of energy through electromagnetic waves, which can propagate through empty space.

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• 50.

### Which of the following would be an example of a very good conductor of heat energy?

• A.

Liquid

• B.

Wood

• C.

Air

• D.

Metal

D. Metal
Explanation
Metal would be an example of a very good conductor of heat energy because metals have high thermal conductivity. This means that heat can easily flow through metals due to the movement of free electrons within their atomic structure. In contrast, liquids, wood, and air have lower thermal conductivity and are not as efficient at conducting heat.

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• Current Version
• Mar 20, 2023
Quiz Edited by
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• May 24, 2018
Quiz Created by
J Wells

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