Ap Physics 1 Midterm

Unit 1 test Q20 The graph below shows velocity v as a function of time t for a 0.50 kg object traveling along a straight line. The graph has three segments labeled 1, 2, and 3. A rope exerts a constant force of magnitude FT on the object along its direction of motion the whole time. During segment 2 only, a frictional force of magnitude Ff is also exerted on the object. Which of the following correctly ranks the displacement ∆x for the three segments of the object's motion? A. ∆x3 > ∆x2 > ∆x1 > 0 B. ∆x1 = ∆x2 = ∆x3 > 0 C. (∆x1 = ∆x3) > ∆x2 > 0 D. (∆x1 = ∆x3) > 0 > ∆x2

A.

An object is thrown with an initial speed v near the surface of Earth. Assume that air resistance is negligible and the gravitational field is constant. If the object is thrown vertically upward, the direction and magnitude of its acceleration while it is in the air is A. upward and decreasing B. upward and constant C. downward and decreasing D. downward and increasing E. downward and constant

E.

Balls 1 and 2 are each thrown horizontally from the same height above level ground, but ball 2 has a greater initial velocity after leaving the thrower's hand. If air resistance is negligible, how do the accelerations of the balls and the times it takes them to hit the ground compare? A. Acceleration a- greater for ball 2; time to hit ground- greater for ball 2 B. Acceleration a- greater for ball 2; time to hit ground- equal C. Acceleration a- equal; time to hit ground- greater for ball 2 D. Acceleration a- equal; time to hit ground- less foe ball 2 E. Acceleration a- equal; time to hit ground- equal

E.

On Earth, when a box slides across a horizontal board, the board exerts a frictional force of magnitude F0 on the box. The board and the box are moved to a planet with twice the radius but one-third the mass of Earth. When the box slides across the board, the frictional force exerted by the board on the box is now A. 1/12 F0 B. 1/6 F0 C. 2/3 F0 D. F0

A.

Unit 1 test Q13 A lion is running at constant speed toward a gazelle that is standing still, as shown in the top figure above. After several seconds the gazelle notices the lion and accelerates directly toward him, hoping to pass the lion and force him to reverse direction. As the gazelle accelerates toward and past the lion, the lion changes direction and accelerates in pursuit of the gazelle. The lion and the gazelle eventually each reach constant but different speeds. Which of the following sets of graphs shows a reasonable representation of the velocities of the lion and the gazelle as functions of time? A. B. C. D.

A.

Unit 2 Quiz Q5 A block of mass m is at rest on a rough incline, as shown in the figure above. Which of the following forces must have a magnitude equal to mg? Choose two answers. A. The total force exerted on the block by the incline B. The normal force exerted on the block by the incline C. The force of friction exerted on the block by the incline D. The gravitational force exerted on Earth by the block

A. and D.

A block is projected up a frictionless plane with an initial speed v0. The plane is inclined 30° above the horizontal. What is the approximate acceleration of the block at the instant that it reaches its highest point on the inclined plane? A. zero B. 5 m/s2 down the incline C. 10 m/s2 down the incline D. 10 m/s2 up the incline E. It cannot be calculated without knowing the value of v0

B.

Unit 1 test Q4 A student sets an object attached to a spring into oscillatory motion and uses a motion detector to record the velocity as a function of time. A portion of the recorded data is shown in the figure. The total change in the object's speed between 1.0s and 1.1s is most nearly? A. zero B. 5 cm/s C. 10 cm/s D. 15 cm/s

B.

A toy doll and a toy robot are standing on a frictionless surface facing each other. The doll has a mass of 0.20 kg, and the robot has a mass of 0.30 kg. The robot pushes on the doll with a force of 0.30 N. The magnitude of the acceleration of the robot is A. zero B. 0.60 m/s2 C. 1.0 m/s2 D. 1.5 m/s2

C.

Unit 1 test Q11 The motion of a particle along a straight line is represented by the position versus time graph above. At which of the labeled points on the graph is the magnitude of the acceleration of the particle the greatest. A. a B. b C. c D. d E. e

C.

Unit 1 test Q15 The graphs above represent the position x, velocity v, and acceleration a as a function of time t for a marble moving in one dimension. Which of the following could describe the motion of the marble? A. Rolling along the floor and then bouncing off a wall B. Rolling down one side of a bowl and then rolling up the other side C. Rolling up a ramp and then rolling back down D. Falling and then bouncing elastically off a hard floor

C.

Unit 1 test Q7 An engineer measures the velocity v of a remote-controlled cart on a straight track at regular time intervals. The data are shown in the graph above. During which of the following time intervals did the cart return to its position at time t=0s? A. 3s ≤ t < 5s B. 5s ≤ t < 7s C. 7s ≤ t < 10s D. 10s ≤ t < 12s

C.

Unit 2 Quiz Q10 The system shown above is released from rest. If friction is negligible, the acceleration of the 4.0 kg block sliding on the table shown above is most nearly A. 0 B. 1.7 m/s2 C. 3.3 m/s2 D. 5.0 m/s2 E. 10.0 m/s2

C.

Unit 2 Quiz Q7 Two students need to move two identical boxes of mass M0M0 across a room where friction between the floor and the boxes cannot be neglected. One student moves the first box by pushing with a force of magnitude F0 at an angle θ from the horizontal, as shown in the figure for scenario 1. The other student moves the second box by pulling with a force of magnitude F0 at the same angle θ from the horizontal, as shown in the figure for scenario 2. Which of the following graphs could describe the motion of the two boxes as they are moved across the room? A. B. C. D.

C.

Unit 2 Quiz Q9 In a lab, a block weighing 80 N is attached to a spring scale, and both are pulled to the right on a horizontal surface, as shown above. Friction between the block and the surface is negligible. What is the acceleration of the block when the scale reads 32 N? A. 2.0 m/s2 B. 2.5 m/s2 C. 4.0 m/s2 D. 6.0 m/s2 E. 8.0 m/s2

C.

Unit 1 test Q18 Two astronauts are connected by a taut cable and are initially at rest with respect to a nearby space station. Astronaut X throws a large container to Astronaut Y. Figure 1 above shows the astronauts immediately after the container is thrown by Astronaut X, and Figure 2 shows the astronauts immediately after the container is caught by Astronaut Y. Which of the following describes the motion of Astronaut Y in Figures 1 and 2 ? * A. Figure 1: Does not Move, Figure 2: Moves to the Right B. Figure 1: Moves to the Left, Figure 2: Moves to the Right C. Figure 1: Does not Move, Figure 2: Does not Move D. Figure 1: Moves to the Left, Figure 2: Does not move

D.

Unit 1 test Q3 A student sets an object attached to a spring into oscillatory motion and uses a motion detector to record the velocity as a function of time. A portion of the recorded data is shown in the figure. The acceleration of the object at time t=0.7 is most nearly equal to which of the following? A. The value of the graph where it crosses the 0.7s grid line B. The slope of the line connecting the origin and the point where the graph crosses the 0.7s grid line C. The area under the curve between where the graph crosses the time axis near 0.63s and time 0.7s D. The slope of the tangent to a best-fit sinusoidal curve at 0.7s

D.

Unit 1 test Q5 The graph above represents position x versus time t for an object being acted on by a constant force. The average speed during the interval between 1s and 2s is most nearly? A. 2 m/s B. 4 m/s C. 5 m/s D. 6 m/s E. 8 m/s

D.

A kitten sits in a lightweight basket near the edge of a table. A person accidentally knocks the basket off the table. as the kitten and basket fall, the kitten rolls, turns, kicks, and catches the basket in its claws. The basket lands on the floor with the kitten safely inside. If air resistance is negligible, what is the acceleration of the kitten-basket system while the kitten and basket are in midair A. The acceleration is directed downward with magnitude less than g because the basket is light B. The acceleration is directed downward with magnitude equal to g because the system is a projectile C. The acceleration fluctuates because of the rolling, turning, and kicking motion of the kitten D. The acceleration cannot be determined without knowing how hard the basket is pushed

B.

Unit 1 test Q17 An object's velocity as a function of time t is given in the graph above. Which of the following statements is true about the motion of the object. A. The object is not moving from t=4s to t=10s B. The object's initial and final positions are the same C. The object is slowing down from t=14s to t=16s D. The average acceleration of the object from t=0s to t=4s is different from the acceleration from t=34s to t=36s

B.

Unit 1 test Q6 In a classroom at time t=0, a sphere is thrown upward at a 45° angle to the horizontal. At time t1, while the sphere is still rising, it bounces off the ceiling elastically and with no friction. Which of the following pairs of graphs could represent the sphere's horizontal velocity and vertical velocity as functions of time t? A. B. C. D.

B.

A vehicle lands on Mars and explores its surface. The average gravitational field on the surface of Mars is 3.7 N kg . The weight of the vehicle is defined as the gravitational force exerted on it. Which of the following statements are true about the vehicle's weight? Select two answers. A. The vehicle's weight was constant until it reached the surface of Mars. B. The vehicle's weight increased while it was descending to the surface of Mars. C. The vehicle's weight always equals the normal force exerted by Mars on the vehicle while it is landing. D. The vehicle weighs less on the surface of Mars than on the surface of Earth

B. and D.

Unit 2 Quiz Q1 Figure 1, cart Y is connected to cart X by a tight string and is also connected to the hanging block of mass m0 by a light string that passes over a pulley. Figure 2 shows a system that is identical except for one change: cart Y and X are connected by a spring at its equilibrium length. Both systems are released from rest. Is the hanging block's acceleration as a function of time the same in both systems, and why or why not? A. Yes, because the net external force exerted on both systems is the same. B. Yes, because the tension in the string connecting the block to cart Y is determined by the masses of cart Y and the block C. No, because the net external force exerted on each system is different. D. No, because the tension in the string connected to the block is constant in one system but not in the other.

D.

A ball is thrown straight up in the air. When the ball reaches its highest point, which of the following is true? A. It is in equilibrium B. It has zero acceleration C. It has maximum momentum D. It has maximum kinetic energy E. None of the above

E.

Unit 2 Quiz Q8 Two students need to move two identical boxes of mass M0M0 across a room where friction between the floor and the boxes cannot be neglected. One student moves the first box by pushing with a force of magnitude F0 at an angle θ from the horizontal, as shown in the figure for scenario 1. The other student moves the second box by pulling with a force of magnitude F0 at the same angle θ from the horizontal, as shown in the figure for scenario 2. Which of the following is a correct expression for the acceleration of the box in scenario 2? A. F0 cosθ−μ(M0 g−F0 sinθ)/M0 B. F0 cosθ−μ(M0 g+F0 sinθ)/M0 C. F0 cosθ+μ(M0g−F0 sinθ)/M0 D. F0 cosθ+μ(M0g+F0 sinθ)/M0

A.

Unit 1 test Q9 An object begins at position x = 0 and moves one-dimensionally along the x-axis with a velocity v expressed as a function of time t according to the graph above. At what time does the object pass through x = 0 again? A. Between 10s and 20s B. Between 20s and 30s C. At 30s exactly D. Between 30s and 40s E. After 40s

B.

A person driving a car suddenly applies the brakes. The car takes 4 s to come to rest while traveling 20 m at constant acceleration. Can the speed of the car immediately before the brakes were applied be determined without first determining the car's acceleration? A. Yes, by dividing the distance (20m) by the time (4s) B. Yes, by determining the average speed while braking and doubling it. C. No, because the acceleration is needed to use standard equations D. No, because the fundamental relationship that defines velocity contains acceleration.

B.

Unit 1 test Q14 A hollow plastic ball is projected into the air. There is significant air resistance opposing the ball's motion, so the magnitude of the ball's acceleration is not equal to g. At time t, the ball is moving up and to the right at an angle of 45° to the horizontal, as shown above. Which of the following best shows the magnitude a and the direction of the ball's acceleration at time t? A. B. C. D.

B.

Unit 2 Quiz Q4 Blocks X and Y are glued together and released from rest on a ramp with negligible friction, as shown in trial 1. The blocks are then separated and connected by a light spring, as shown in trial 2. The spring is compressed and the blocks are again released from rest on the ramp. Immediately after the blocks are released, is the net force on the two-block system the same or different between trial 1 and trial 2? Immediately after the blocks are released, is the net force on block Y the same or different between trial 1 and trial 2? A. Force on System- Different; Force on Block Y- Different B. Force on System- Different; Force on Block Y-The same C. Force on System- The same; Force on Block Y-Different D. Force on System- The same; Force on Block Y- The same4

C.

Two objects, X and Y, accelerate from rest with the same constant acceleration. Object X accelerates for twice the time as object Y. Which of the following is true of these objects at the end of their respective periods of acceleration? A. Object X is moving at the same speed as object Y B. Object X is moving four times faster than object Y C. Object X has traveled the same distance as object Y D. Object X has traveled twice as far as object Y E. Object X has traveled four times as far as object Y

E.