AP Physics C: Mechanics Unit 3 Practice Test & Exam | 18 Questions

Questions 1-2 refer to the following information.

1. What is the net work done on the block as it moves the distance $d$?

(A)$Fd$(B)$(F - mg\sin\theta - \mu_k mg\cos\theta)d$(C)$0$(D)$mgd\sin\theta$

2. What is the work done by the force of gravity on the block?

(A)$-mgd$(B)$-mgd\sin\theta$(C)$-mgd\cos\theta$(D)$0$

3. Two objects, A and B, have masses $mA$ and $mB$ respectively, with $mA > mB$. They both have the same kinetic energy. Which of the following statements is true about their speeds, $vA$ and $vB$?

(A)$vA > vB$(B)$vA < vB$(C)$vA = vB$(D)The relationship cannot be determined without knowing the exact masses.

Questions 4-5 refer to the following information.

4. What is the force acting on the particle at $x = 2$ m?

(A)$-24$ N(B)$-12$ N(C)$12$ N(D)$24$ N

5. At which of the following positions is the particle in stable equilibrium?

(A)$x = -1$ m(B)$x = 0$ m(C)$x = 1$ m(D)$x = 2$ m

6. A force $\vec{F} = (3\hat{i} + 4\hat{j})$ N acts on an object that undergoes a displacement $\Delta\vec{r} = (2\hat{i} - 2\hat{j})$ m. What is the work done by the force on the object?

(A)$-2$ J(B)$2$ J(C)$14$ J(D)$10$ J

7. The graph above shows the magnitude of a force exerted on an object as it moves along the x-axis. What is the work done by the force as the object moves from $x = 0$ m to $x = 5$ m?

(A)10 J(B)25 J(C)50 J(D)100 J

8. A 2 kg block is released from rest at the top of a frictionless ramp of height 3 m. The ramp merges smoothly with a horizontal surface. The block slides along the horizontal surface and compresses a spring with spring constant $k = 200$ N/m. What is the maximum compression of the spring? (Use $g = 10$ m/s²)

(A)$\sqrt{0.3}$ m(B)$\sqrt{0.6}$ m(C)$0.3$ m(D)$0.6$ m

9. An engine lifts a 100 kg crate at a constant velocity of 2 m/s. What is the instantaneous power supplied by the engine? (Use $g = 9.8$ m/s²)

(A)200 W(B)490 W(C)980 W(D)1960 W

10. A satellite of mass $m$ is in a circular orbit of radius $R$ around a planet of mass $M$. What is the total mechanical energy of the satellite?

(A)$-G\frac{Mm}{R}$(B)$-G\frac{Mm}{2R}$(C)$G\frac{Mm}{2R}$(D)$G\frac{Mm}{R}$

11. A particle moves along the x-axis under the influence of a force given by $F(x) = 3x^2 + 2x$. How much work is done by this force as the particle moves from $x=1$ m to $x=2$ m?

(A)10 J(B)12 J(C)16 J(D)20 J

12. The graph shows the potential energy $U(x)$ of a particle as a function of its position $x$. The particle has a total mechanical energy $E_{total}$ as indicated by the dashed line. Which of the following statements is true?

(A)The particle's kinetic energy is greatest at $x=3$.(B)The particle is not allowed in the region between $x=1$ and $x=5$.(C)The force on the particle is zero at $x=1$ and $x=5$.(D)The particle's kinetic energy is zero at $x=0$.

13. A car's engine provides a constant power of $P$. The car is moving on a flat road and air resistance is negligible. How does the car's acceleration $a$ depend on its instantaneous speed $v$?

(A)$a$ is constant(B)$a \propto v$(C)$a \propto v^{-1}$(D)$a \propto v^{-2}$

14. A 0.5 kg pendulum bob is released from rest at an angle of 60° with respect to the vertical. The length of the pendulum string is 2.0 m. What is the speed of the bob at the lowest point of its swing? (Use $g = 9.8$ m/s²)

(A)3.1 m/s(B)4.4 m/s(C)6.3 m/s(D)19.6 m/s

15. The work done by a conservative force on a particle moving between two points is -10 J. What is the change in the potential energy of the system, $\Delta U$?

(A)-10 J(B)0 J(C)10 J(D)The change cannot be determined without knowing the path.

16. A block of mass $m$ is initially at rest on a frictionless horizontal surface. At time $t=0$, a horizontal force $F(t) = ct$ is applied, where $c$ is a positive constant. What is the kinetic energy of the block at time $t=T$?

(A)$\frac{c^2T^2}{2m}$(B)$\frac{c^2T^3}{3m}$(C)$\frac{c^2T^4}{8m}$(D)$\frac{cT^2}{2}$

17. A force $\vec{F} = (2t)\hat{i}$ N acts on a particle with velocity $\vec{v} = (3)\hat{i} + (4t)\hat{j}$ m/s. What is the instantaneous power delivered by the force at $t=2$ s?

(A)4 W(B)12 W(C)24 W(D)32 W

18. An observer on the ground sees a ball of mass $m$ thrown horizontally with speed $v$ from a height $h$. A second observer is in a car moving with velocity $\vec{v}$ in the same direction as the ball. From the point of view of the observer in the car, what is the initial kinetic energy of the ball?

(A)$\frac{1}{2}mv^2$(B)$0$(C)$mgh$(D)$mgh + \frac{1}{2}mv^2$

AP Physics C: Mechanics Unit 3: Work, Energy, and Power Practice Exam

Exam Details

A. Multiple-Choice Questions (18 Questions)

AP Physics C: Mechanics Unit 3: Work, Energy, and Power Practice Exam

Exam Details

A. Multiple-Choice Questions (18 Questions)