1.
Mass is anything that takes up space.
Correct Answer
B. False
Explanation
The statement given in the question is incorrect. Mass is not related to taking up space. Mass is a measure of the amount of matter in an object, while volume is the measure of the space occupied by an object. Therefore, the correct answer is False.
2.
A vacuum is the absence of matter.
Correct Answer
A. True
Explanation
A vacuum refers to a space that is completely empty, devoid of any matter or particles. It is characterized by the absence of air or any other substance. Therefore, the statement that a vacuum is the absence of matter is true.
3.
You weigh more at the top of a mountain than you would at sea level.
Correct Answer
B. False
Explanation
At higher altitudes, such as the top of a mountain, the gravitational force acting on an object decreases slightly compared to sea level. This is because the distance between the object and the center of the Earth increases as you move higher. As a result, your weight would actually be slightly less at the top of a mountain than it would be at sea level. Therefore, the statement that you weigh more at the top of a mountain is false.
4.
What is the word that scientists use for the amount of matter a thing at rest has?
Correct Answer
mass
Explanation
Scientists use the term "mass" to refer to the amount of matter a thing has when it is at rest. Mass is a fundamental property of an object and is measured in units such as kilograms or grams. It represents the quantity of matter present in an object and is different from weight, which is the force exerted on an object due to gravity. Mass remains constant regardless of the location or gravitational field, making it an important concept in physics and scientific calculations.
5.
Always remember that unlike mass, the weight of a thing at rest is always the same even when floating in space and doesn't weigh anything at all.
Correct Answer
B. False
Explanation
The statement is false because weight is a measure of the force of gravity acting on an object, and it can vary depending on the gravitational field. In space, where there is no gravity, an object would not have any weight. Therefore, the weight of a thing at rest is not always the same and can be zero when floating in space.
6.
The formula for speed is Speed= -------- divided by ----------.
Correct Answer
distance, time
7.
Scientists often use a special unit called a_________ to measure forces.
Correct Answer
newton.
Explanation
Scientists often use a special unit called a newton to measure forces. The newton is the standard unit of force in the International System of Units (SI). It is named after Sir Isaac Newton, the renowned physicist who formulated the laws of motion. The newton is defined as the force required to accelerate a one-kilogram mass by one meter per second squared. By using the newton as a unit of measurement, scientists can accurately quantify and compare the forces acting on objects in various experiments and studies.
8.
If you are by the seashore and you pile 10 lbs of sand on your stomach, how much force is your stomach putting on the sand?
Correct Answer
10 lbs
10 pounds
Explanation
When you pile 10 lbs of sand on your stomach, the force exerted by your stomach on the sand is equal to the weight of the sand, which is 10 lbs. This is because according to Newton's third law of motion, for every action, there is an equal and opposite reaction. So the force exerted by your stomach on the sand is equal to the force exerted by the sand on your stomach, which is 10 lbs.
9.
In physics, ______ is only being done when something is being moved.
Correct Answer
work
Explanation
Work in physics is defined as the transfer of energy that occurs when a force is applied to an object and it causes the object to move. Therefore, work is only being done when something is being moved.
10.
What is the difference between work and energy?
Correct Answer
to have energy a thing does not have to move
Explanation
Energy is the ability to do work or cause change. While work is the transfer of energy that occurs when a force is applied to an object and the object moves in the direction of the force, energy does not require movement. An object can possess energy even if it is not in motion. For example, a compressed spring or a charged battery both have potential energy stored in them, even though they are not actively moving.
11.
When energy moves things, it's called ______ energy.
Correct Answer
Kinetic
Explanation
Kinetic energy is the correct answer because it refers to the energy possessed by an object due to its motion. When energy is transferred to an object and causes it to move, it is known as kinetic energy. This type of energy can be observed in various forms such as the movement of vehicles, the motion of wind, or the flow of water. Therefore, kinetic energy accurately describes the situation when energy is responsible for moving objects.
12.
The energy a thing has before it moves is called ______ energy.
Correct Answer
potential
Explanation
The energy a thing possesses before it starts moving is referred to as potential energy. It is the stored energy that an object has due to its position or condition. Potential energy can exist in various forms such as gravitational potential energy, elastic potential energy, or chemical potential energy.
13.
Energy is expressed in the foot, pounds, or ______
Correct Answer
joules
Explanation
Energy is commonly expressed in the unit of joules. Joules is the standard unit of energy in the International System of Units (SI). It is used to measure various forms of energy such as mechanical, thermal, electrical, and chemical energy. The foot-pound is another unit used to measure energy, but it is not as widely used or recognized as the joule. Therefore, the correct answer to this question is joules.
14.
What are the three phases or states of matter?
Correct Answer
liquids
solids
gases
gas
liquid
solid
Explanation
The three phases or states of matter are liquids, solids, and gases. Liquids have a definite volume but no definite shape, solids have both a definite shape and volume, and gases have neither a definite shape nor volume. The additional options of gas, liquid, and solid are just variations of the correct answers.
15.
Matter can be made to change phases by adding or taking away _____
Correct Answer
energy
Explanation
Matter can change phases, such as from solid to liquid or liquid to gas, by adding or taking away energy. This is because the different phases of matter are characterized by the arrangement and movement of particles. When energy is added, the particles gain more kinetic energy and move faster, causing the substance to change phases. Conversely, when energy is taken away, the particles lose kinetic energy and slow down, leading to a phase change. Therefore, the addition or removal of energy is the key factor in causing matter to change phases.
16.
The melting point and freezing point of a substance are the same temperatures of 0 degrees Celsius.
Correct Answer
A. True
Explanation
The melting point and freezing point of a substance are the same temperatures of 0 degrees Celsius because both processes involve a change in state from solid to liquid or vice versa. At the melting point, a solid substance turns into a liquid, and at the freezing point, a liquid substance solidifies. Since these processes involve the same temperature change, the melting point and freezing point are the same.
17.
The boiling point of water is?
Correct Answer
C. 100 degrees C
Explanation
The boiling point of water is 100 degrees Celsius. This is the temperature at which water changes from a liquid state to a gaseous state, forming steam. It is a well-known and widely accepted fact in science.
18.
In a steam engine, the combustion ( burning) takes place inside the engine.
Correct Answer
B. False
Explanation
The combustion in a steam engine does not take place inside the engine. Instead, the combustion occurs in a separate furnace or boiler, where fuel is burned to produce heat. This heat is then used to generate steam, which is sent into the engine to produce mechanical work.
19.
A current that moves from the - to the + pole and keeps going in the same direction is called a _______ current.
Correct Answer
direct
DC
dc current
direct current
Explanation
A current that moves from the - to the + pole and keeps going in the same direction is called a direct current (DC). DC current refers to the flow of electric charge in a single direction, typically produced by batteries or power supplies. It is characterized by a constant magnitude and unidirectional flow, making it suitable for many electronic devices and systems.
20.
The electricity that runs refrigerators, televisions, stereos, and washing machines moves back and forth, changing the direction of flow sixty times a second is called a ________ current.
Correct Answer
alternating
AC
AC current
alternating current
ac current
ac
Explanation
The electricity that powers household appliances such as refrigerators, televisions, stereos, and washing machines is called alternating current (AC). AC current moves back and forth, changing its direction of flow sixty times a second. The terms "alternating," "AC," "AC current," "alternating current," "ac current," and "ac" all refer to the same type of electrical current.