1.
During nuclear decay, a new isotope is created. How is the nucleus of the new isotope different from the parent if the parent isotope has undergone beta decay?
Correct Answer
C. The atomic number increases by 1 and the mass remains the same.
Explanation
During beta decay, a neutron in the nucleus is converted into a proton, causing the atomic number to increase by 1. However, the mass of the nucleus remains the same because the proton and neutron have nearly the same mass. Therefore, the correct answer is "the atomic number increases by 1 and the mass remains the same."
2.
Which statement is true regarding the relationship between distance and displacement?
Correct Answer
D. Distance is always greater than or equal to displacement.
Explanation
Distance is a scalar quantity that refers to the total path length traveled, regardless of direction. Displacement, on the other hand, is a vector quantity that refers to the straight-line distance between the initial and final positions, taking into account direction. Since displacement is the shortest distance between two points, it can never be greater than the distance traveled. Therefore, distance is always greater than or equal to displacement.
3.
The calculation of kinetic energy uses the formula, KE = 1 2 mv2. Identify the unit that is required for mass and velocity, respectively, to determine the kinetic energy in Joules.
Correct Answer
B. Mass in kg, velocity in m s
Explanation
The correct unit for mass in the formula for kinetic energy is kilograms (kg) and the correct unit for velocity is meters per second (m/s). This is because the formula KE = 1/2 mv^2 requires mass to be in kilograms and velocity to be in meters per second in order to calculate kinetic energy in Joules.
4.
If F = force, which equation illustrates the Law of Conservation of Momentum?
Correct Answer
B.
F1 = -F2
Explanation
The equation F1 = -F2 illustrates the Law of Conservation of Momentum. According to this law, the total momentum of a closed system remains constant if no external forces act on it. In this equation, F1 and F2 represent the forces exerted by two objects on each other. The negative sign indicates that the forces are equal in magnitude but opposite in direction, which ensures that the total momentum of the system remains unchanged.
5.
Consider the free body diagram. If the sum of the tension forces is equal to the force of gravity,
which description BEST applies?
Correct Answer(s)
D. A girl hangs by both hands, motionless, from a trapeze.
E. A girl hangs by both hands, motionless, from a trapeze.
Explanation
The free body diagram shows that the tension forces acting on the girl hanging from the trapeze are equal to the force of gravity pulling her down. This means that the forces are balanced and there is no net force acting on the girl. As a result, she remains motionless and does not move in any direction.
6.
Describe how resistance affects the flow of current in a circuit.
Correct Answer
D. The flow of current in a circuit is reduced by resistance from collisions of the electrons within the wire.
Explanation
Resistance in a circuit refers to the opposition that the flow of current faces. When there is resistance in a circuit, the flow of current is reduced. This is because resistance causes collisions between the electrons within the wire, hindering their movement and slowing down the flow of current. Therefore, the correct answer states that the flow of current in a circuit is reduced by resistance from collisions of the electrons within the wire.
7.
The change in electric potential energy per unit charge is
Correct Answer
D. Voltage
Explanation
The change in electric potential energy per unit charge is known as voltage. Voltage is a measure of the electric potential difference between two points in an electric circuit. It represents the amount of work done to move a unit charge from one point to another. The unit for voltage is volts (V). Amperes, current, and gravity are not measures of the change in electric potential energy per unit charge.
8.
Most radiation is released as particles. Identify the type radiation that is not a particle.
Correct Answer
C. Gamma
Explanation
Gamma radiation is not a particle but rather a form of electromagnetic radiation. Unlike alpha and beta particles, which are made up of particles (helium nuclei and electrons, respectively), gamma radiation consists of high-energy photons. These photons do not have mass or charge, making gamma radiation distinct from the other options listed.
9.
Which student correctly identifies a similarity and a difference between vector quantities and scalar quantities?
Correct Answer
B.
Carlita
Explanation
Carlita correctly identifies a similarity between vector quantities and scalar quantities, which is that both types of quantities can be measured and have units. She also correctly identifies a difference between the two, which is that vector quantities have both magnitude and direction, while scalar quantities only have magnitude.
10.
A 10.0 kilogram mass of iron on earth exerts a downward force of 98 Newtons. On the moon this same 10.0 kilograms of iron is weighed and found to exert a downward force of 16.3 Newtons. How is this possible?
The gravity on the moon is one sixth the gravity of Earth.
Correct Answer
D. The gravity on the moon is one sixth the gravity of Earth.
Explanation
The force of gravity is directly proportional to the mass of an object. Since the mass of the iron is the same on both Earth and the moon, the difference in the downward force is due to the difference in gravity between the two celestial bodies. The moon has only one sixth the gravity of Earth, which means that the force of gravity exerted on the iron is also one sixth of what it is on Earth. This explains why the iron weighs less on the moon compared to Earth.
11.
You are sitting in a car that isn't moving; suddenly, the car quickly accelerates. Your body seems to be pushed back against the seat. Which word best explains why your body seemed to be pushed backward against the seat?
Correct Answer
C. Inertia
Explanation
When the car quickly accelerates, your body tends to resist the change in motion due to its inertia. Inertia is the tendency of an object to resist changes in its state of motion. Therefore, your body seems to be pushed backward against the seat because of inertia.
12.
Mutt and Jeff are running along a path each pushing a cart loaded with rocks. If Mutt's wagon has a mass two times greater than Jeff's and they want to stay together, arriving at their destination at the same time, what must happen?
Correct Answer
C. Mutt must use twice as much force to push his cart.
Explanation
If Mutt's wagon has a mass two times greater than Jeff's, then according to Newton's second law of motion (F = ma), Mutt would need to apply a greater force to push his cart. This is because the force required to accelerate an object is directly proportional to its mass. Therefore, Mutt must use twice as much force to push his cart in order to stay together with Jeff and arrive at their destination at the same time.
13.
The gravitational force between Earth and the Sun is a two-way force. Both the planet and the Sun attract each other. However, Earth revolves around the Sun rather than the Sun revolving around Earth. Which statement BEST explains the orbit of the Earth around the Sun?
Correct Answer
B. The Sun’s mass is much greater than Earth’s.
Explanation
The statement "The Sun's mass is much greater than Earth's" best explains the orbit of the Earth around the Sun because the force of gravity between two objects depends on their masses. The Sun's much greater mass means that it exerts a stronger gravitational pull on the Earth, causing the Earth to orbit around the Sun. This is consistent with the understanding that objects with larger masses exert a greater gravitational force.
14.
A 16N force is applied to an object and 96J of work is done. How far was the object moved?
Correct Answer
A. 6 meters
Explanation
When a force is applied to an object, work is done on the object. The work done is equal to the force multiplied by the distance moved in the direction of the force. In this case, the work done is given as 96J and the force applied is 16N. To find the distance moved, we can rearrange the formula for work done and solve for distance. Distance = Work / Force = 96J / 16N = 6 meters. Therefore, the object was moved a distance of 6 meters.
15.
A 0.5kg ball of clay originally moving at 6 m/s strikes a wall and comes to rest in 0.25s, what is the magnitude of the impulse given to the ball of clay?
Correct Answer
C. 3.0 kg m/s
Explanation
The magnitude of impulse can be calculated using the equation Impulse = Change in momentum. The initial momentum of the ball of clay is given by p = mv = 0.5kg * 6 m/s = 3 kg m/s. Since the ball comes to rest, the final momentum is 0 kg m/s. Therefore, the change in momentum is 0 kg m/s - 3 kg m/s = -3 kg m/s. The magnitude of the impulse is the absolute value of the change in momentum, so it is 3 kg m/s.
16.
As you tune your radio to a higher frequency, from 88.5 FM to 103.3 FM, the wavelength of the wave that you are tuning in
Correct Answer
B. Decreases
Explanation
As you tune your radio to a higher frequency, the wavelength of the wave that you are tuning in decreases. This is because wavelength and frequency are inversely proportional to each other. When the frequency increases, the wavelength decreases and vice versa. Therefore, as you move to a higher frequency on your radio, the wavelength of the wave becomes shorter.
17.
Using your knowledge of the properties of the different states of matter, determine which state of matter would travel the fastest.
Correct Answer
C. Dry ice – solid carbon dioxide
Explanation
Dry ice is the solid form of carbon dioxide. In general, sound travels faster in solids compared to liquids and gases. This is because the particles in solids are closely packed together, allowing sound waves to propagate more efficiently. In liquids, the particles are more spread out, causing sound waves to travel slower. In gases, the particles are even more spread out, resulting in the slowest speed of sound transmission. Therefore, dry ice, being a solid, would travel the fastest.
18.
What is the voltage of a battery that powers a light with 0.43 A and has a resistance of 3.5 ohms?
Correct Answer
A.
1.505 V
Explanation
The voltage of a battery can be calculated using Ohm's Law, which states that voltage is equal to current multiplied by resistance. In this case, the current is 0.43 A and the resistance is 3.5 ohms. By multiplying these values together, we get a voltage of 1.505 V.
19.
What is the approximate equivalent resistance between points A and D?
Correct Answer
B. 410 Ω
Explanation
The approximate equivalent resistance between points A and D is 410 Î©.
20.
There are three ways to give an object a static charge. They are friction, conduction, and induction. Two pieces of cellophane tape are stuck to a lab table. Each piece is quickly ripped off the table. What prediction would you make about what happens when the two pieces of tape are brought near one another?
Correct Answer
B. The two pieces of tape will repel as both have obtained a static charge.
Explanation
When the two pieces of tape are brought near each other, they will repel each other because both pieces have obtained a static charge. This repulsion occurs because objects with the same charge (in this case, both pieces of tape have the same static charge) repel each other.
21.
What generates the magnetic field that surrounds a wire carrying an electric current?
Correct Answer
A. Compasses placed near a long straight current-carrying wire indicate that field lines form circular loops centered on the wire.
Explanation
When a wire carries an electric current, it generates a magnetic field around it. This is indicated by the compasses placed near a long straight current-carrying wire, which show that the field lines form circular loops centered on the wire. The magnetic field is created due to the movement of electric charges in the wire, which creates a circular magnetic field around it. This phenomenon is described by Ampere's law and is a fundamental principle of electromagnetism.
22.
750 million years ago, there was enough Uranium-235 present in Oklo, Gabon to have a natural fission reaction occur and generate a chain reaction. If there is currently 50kg of U-235 present in Oklo, how much must have been present 750 million years ago when the reaction took place?
Correct Answer
B. 100 kg
Explanation
In a natural fission reaction, uranium-235 undergoes a chain reaction and releases energy. To sustain such a reaction, a certain amount of uranium-235 is required. Since there was enough uranium-235 present 750 million years ago to generate a chain reaction, it means that there must have been at least the same amount of uranium-235 present at that time as there is currently, which is 50 kg. Therefore, the amount of uranium-235 present 750 million years ago when the reaction took place must have been 100 kg.
23.
Alpha radiation is another type of radiation. Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus. They have much less energy than either beta particles of gamma waves. Suppose a Geiger counter was placed 10 cm from an alpha emitter, and clicks were recorded for three minutes. Based on the recorded data, predict the number of clicks you would detect on the far side of the aluminum shield.
Correct Answer
A.
0 clicks
Explanation
Alpha particles have a large mass and a positive charge, which makes them highly ionizing and easily absorbed by materials. The aluminum shield would effectively block the alpha particles, preventing them from reaching the far side and causing any clicks on the Geiger counter. Therefore, no clicks would be detected on the far side of the aluminum shield.
24.
While texting his girlfriend that he was running late for their date, Jordan rear-ended a car stopped at a red light. Since this was clearly an inelastic collision, some of his car's kinetic energy was transformed to other types of energy. What types of energy are most likely to result from such a collision?
Correct Answer
B. Thermal and mechanical
Explanation
In an inelastic collision like the one described, some of the car's kinetic energy is transformed into other types of energy. Thermal energy is likely to be produced due to the friction and heat generated during the collision. Additionally, mechanical energy is also likely to result from the collision, as the impact causes deformation and damage to the cars involved. Therefore, the most likely types of energy to result from such a collision are thermal and mechanical.
25.
The calculation of kinetic energy uses the formula, KE = ½ mv2. Identify the unit that is required for mass and velocity, respectively, to determine the kinetic energy in Joules
Correct Answer
C. Mass in kg, velocity in m/s
Explanation
The correct answer is Mass in kg, velocity in m/s. This is because the formula for kinetic energy requires the mass to be in kilograms and the velocity to be in meters per second in order to calculate the energy in Joules.