AP Physics 1 Quiz: Power

What this quiz covers

This quiz focuses on Power, giving you a quick way to practice the rules, question types, and explanations that matter most for AP Physics 1.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Trial 1, because it has more work
2. Trial 2, because it takes less time
3. They have equal average power (correct answer)
4. Cannot be determined without the force

Question 2

1. $\dfrac{F}{v}$
2. $Fv$ (correct answer)
3. $\dfrac{1}{2}mv^2$
4. $F\Delta x$

Question 3

1. First student, because power depends on time only
2. Second student, because more energy is transferred in the same time (correct answer)
3. They have the same average power because they both climb stairs
4. Cannot be determined without knowing their masses

Question 4

1. The first trial, because the distance is the same.
2. The second trial, because average power scales as $W/t$ and both $W$ and $1/t$ increase. (correct answer)
3. They have equal average power because both are constant-speed motions.
4. They have equal average power because power depends only on force.

Question 5

1. $mgv$
2. $mg$
3. $0$ (correct answer)
4. $mgh$

Question 6

1. $\displaystyle \frac{f_k d}{t}$ (correct answer)
2. $\displaystyle f_k t$
3. $\displaystyle f_k d$
4. $\displaystyle \frac{f_k}{d}$

Question 7

1. $mgv$ (correct answer)
2. $mg/v$
3. $mg$
4. $mgh$

Question 8

1. $\Delta U_g t$
2. $\dfrac{\Delta U_g}{t}$ (correct answer)
3. $\dfrac{t}{\Delta U_g}$
4. $\Delta U_g$

Question 9

1. $P_B = 2P_A$ because more energy is transferred.
2. $P_B = \dfrac{1}{2}P_A$ because the time is longer.
3. $P_B = P_A$ because energy and time both double. (correct answer)
4. Cannot be determined without the elevator's speed.

Question 10

1. doubled
2. halved
3. unchanged (correct answer)
4. quadrupled

Question 11

1. Trial 1, because less energy means greater power
2. Trial 2, because more work always means more power
3. Trial 1, because $\frac{W}{t} > \frac{2W}{4t}$ (correct answer)
4. They have the same average power because both involve constant force

Question 12

1. Power is the same because the force is constant.
2. Power at $2t$ is twice that at $t$ because $P=Fv$. (correct answer)
3. Power at $2t$ is four times that at $t$ because kinetic energy quadruples.
4. Power at $2t$ is half that at $t$ because the acceleration decreases.

Question 13

1. Machine 1, because it uses less power to store the same energy.
2. Machine 2, because it transfers the same energy in less time. (correct answer)
3. They have equal power because the energy change is the same.
4. Machine 1, because power depends on energy only, not time.

Question 14

1. Cyclist A, because less speed means more time resisting the force.
2. Cyclist B, because $P=F_r v$ and tripling $v$ triples power. (correct answer)
3. They require equal power because the resistive force is the same.
4. They require equal power because both move at constant speed.

Question 15

1. It doubles because $P=Fv$ and $F$ doubles while $v$ stays the same. (correct answer)
2. It stays the same because the speed is unchanged.
3. It halves because more force means less speed.
4. It becomes zero because constant speed implies zero power.

Question 16

1. Trial 2 has greater power because it acts longer
2. Trial 1 has twice the average power of Trial 2 (correct answer)
3. They have equal average power because $mgh$ is the same
4. Trial 2 has twice the average power of Trial 1

Question 17

1. $Ft$
2. $Fv$ (correct answer)
3. $F/v$
4. $F$

Question 18

1. It doubles because the time doubles
2. It halves because power is inversely proportional to time
3. It stays the same because $P=Fv$ and both are unchanged (correct answer)
4. It quadruples because work doubles and time doubles

Question 19

1. It doubles because more energy is transferred
2. It halves because the time is longer
3. It stays the same because $\frac{E}{5} = \frac{2E}{10}$ (correct answer)
4. It cannot be determined without the force

Question 20

1. The first motor, because it does less work.
2. The second motor, because it does more work.
3. The first motor, because $\frac{W}{t} > \frac{2W}{4t}$. (correct answer)
4. They have equal average power because both involve work and time.