Unit 1 MC Practice (AP Physics 1)

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) downward and constant

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.

An object is thrown with an initial speed u near the surface of Earth. Assume that air resistance is negligible and the gravitational field is constant.

If the object is thrown horizontally, 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) downward and constant

The graphs above represent the position x, velocity v, and acceleration 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) Rolling up a ramp and then rolling back down

A small cart is rolling freely on an inclined ramp with a constant acceleration of 0.50 m/s2 in the -x direction. At time t = 0, the cart has a velocity of 2.0 m/s in the +x-direction. If the cart never leaves the ramp, which of the following statements correctly describes the motion of the cart at a time t > 5 s?

A) The cart is traveling in the +x-direction and is slowing down.

B) The cart is traveling in the +x-direction and is speeding up.

C) The cart is traveling in the -x-direction and is slowing down.

D) The cart is traveling in the -x-direction and is speeding up.

D) The cart is traveling in the -x-direction and is speeding up.

A motion sensor is used to create the graph of a student's horizontal velocity as a function of time as the student moves toward and away from the sensor, as shown above. The positive direction is defined as the direction away from the sensor. Which of the following describes the student's final position xf in relation to the starting position x0 and the student's average horizontal acceleration ax between 0.0s and 3.0S?

A) Position xf is farther away from the sensor than x0, and ax is positive.

B) Position xf is farther away from the sensor than x0, and ax is negative.

C) Position xf is closer to the sensor than x0, and ax is positive.

D) Position xf is closer to the sensor than x0, and ax is negative.

B) Position xf is farther away from the sensor than x0, and ax is negative.

A solid metal ball and a hollow plastic ball of the same external radius are released from rest in a large vacuum chamber. When each has fallen 1 m, they both have the same

A) inertia

B) speed

C) momentum

D) kinetic energy

E) change in potential energy

B) speed

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 (20 m) by the time (4 s).

B) Yes, by determining the average speed while braking and doubling it.

C) No, because the acceleration is needed to use standard equations such as Δx = vot + 1/2 at2.

D) No, because the fundamental relationship that defines velocity contains acceleration.

B) Yes, by determining the average speed while braking and doubling it.

An object is sliding to the right along a straight line on a horizontal surface. The graph shows the object's velocity as a function of time. What is the object's displacement during the time depicted in the graph?

A) 0 m

B) 1 m

C) 8 m

D) 16 m

A) 0 m

A ball of mass m and momentum p has kinetic energy equal to which of the following?

A) (1/2)(p^2/m)

B) (p^2/m)

C) (2)(p^2/m)

D) (1/2)(m/p^2)

E) (2)(m/p^2)

A) (1/2)(P^2/m)

A ball is thrown with an initial speed of 20 m/s at an angle of 60° to the ground. If air resistance is negligible, what is the ball's speed at the instant it reaches its maximum height from the ground?

A) Zero

B) 10 m/s

C) 14 m/s

D) 17 m/s

E) 20 m/s

B) 10 m/s

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 for ball 2

E) Acceleration a--> Equal

Time to Hit Ground--> Equal

E) Acceleration a--> Equal

Time to Hit Ground--> Equal

An object starts from rest and slides with negligible friction down an air track tipped at an angle θ from the horizontal. A student records values of the object's position along the track at various times. The value of θ can best be determined from which of the following?

A) The y-intercept of a graph of position as a function of time

B) The y-intercept of a graph of position as a function of the square of time

C) The slope of a graph of position as a function of time

D) The slope of a graph of position as a function of the square of time

D) The slope of a graph of position as a function of the square of time

A block is projected up a frictionless plane with an initial speed vo. 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 vo

B) 5 m/s2 down the incline

A rock of mass m is thrown horizontally off a building from a height h, as shown above. The speed of the rock as it leaves the thrower's hand at the edge of the building is vo

How much time does it take the rock to travel from the edge of the building to the ground?

A) √hv0

B) h/v0

C) hv0/g

D) 2h/g

E) √2h/g

E) √2h/g

A student throws a rock horizontally from the edge of a cliff that is 20 m high. The rock has an initial speed of 10 m/s. If air resistance is negligible, the distance from the base of the cliff to where the rock hits the level ground below the cliff is most nearly

A) 5 m

B) 10 m

C) 20 m

D) 40 m

E) 200 m

C) 20 m

Object A is released from rest at height h. At the same instant, object B is thrown downward from the same location. Which of the following graphs of speed of v as a function of time t is correct for the two objects?

(I can't add pictures so ill describe the graphs)

A) B and A start at origin and B line is above A line

B) B starts above A on the y- axis and they have the same slope

C) B starts above A on the y- axis and has a steeper slope

D) B starts above A on the y- axis and A has a steeper slope

E) A starts before B on the x- axis and they're slopes are equal

B) B starts above A on the y- axis and they have the same slope

For which of the following motions of an object must the acceleration always be zero?

I. Any motion in a straight line

II. Simple harmonic motion

III. Any motion in a circle

A) I only

B) II only

C) III only

D) Either I or III, but not II

E) None of these motions guarantees zero acceleration.

E) None of these motions guarantees zero acceleration.

A cart is constrained to move along a straight line. A varying net force along the direction of motion is exerted on the cart. The cart's velocity v as a function of time t is shown in the graph above. The five labeled points divide the graph into four sections.

For which segment does the cart move the greatest distance?

A) AB

B) BC

C) CD

D) DE

A) AB

An object is thrown with a horizontal velocity of 20 m/s from a cliff that is 125 m above level ground. If air resistance is negligible, the time that it takes the object to fall to the ground from the cliff is most nearly

A) 3 s

B) 5 s

C) 6 s

D) 12 s

E) 25 s

B) 5 s

A 10 kg block is attached to a light cord that is wrapped around the pulley of an electric motor,as shown above. At what rate is the motor doing work when it is pulling the block upward with an instantaneous speed of 3 m/s and an upward acceleration of 2 m/s2 ?

A) 120 W

B) 240 W

C) 300 W

D) 360 W

E) 600 W

D) 360 W

An object undergoes an acceleration as it travels along a straight, horizontal section of a track. Which of the following graphs could represent the motion of the object? Select two answers.

(I can't add pictures so i'll describe the graphs)

A) speed v time, the line starts above the origin on the y-axis

B) position v time, the line starts at the origin

C) position v time squared, the line starts above the origin on the y-axis

D) velocity v time, the line starts above the origin on the y-axis and is a straight horizontal line

A) speed v time, the line starts above the origin on the y-axis

AND

C) position v time squared, the line starts above the origin on the y-axis

A person throws a marble straight up into the air, releasing it a short height above the ground and catching it at that same height. If air resistance is negligible, which of the following graphs of position y versus time t is correct for the motion of the marble as it goes up and then comes down?

(I can't add pictures so i'll describe the graphs)

A) straight up then straight down with a point at the top

B) Straight up then straight down with a curve at the top

C) concave curved up then concave curved down with a point at the top

D) convex curve up then concave curve down with a point at the top

E) concave curve up then convex curve down with a point at the top

B) Straight up then straight down with a curve at the top

An object is released from rest near a planet's surface. A graph of the acceleration as a function of time for the object is shown for the 4 s4 s after the object is released. The positive direction is considered to be upward. What is the displacement of the object after 2 s2 s?

A) -20 m

B) −10 m

C) 10 m

D) 20 m

B) −10 m

An object attached to one end of a string moves in a circle at constant speed. Which of the following is correct?

A) The object is accelerating as it moves.

B) The object's velocity is the same as its speed.

C) The object does not require a force to keep its state of circular motion.

D) If the string breaks, the object will keep its circular motion.

E) If the string breaks, the object will move radially away from the center of the circle.

A) The object is accelerating as it moves.

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) None of the above

A car goes from rest to 30 m/s in 12 s with constant acceleration. How long does it take the car to go from rest to 15 m/s with the same acceleration?

A) 3.0 s

B) 12/√2 s

C) 6.0 s

D)12√2 s

E) 24 s

C) 6.0s

Using a force probe, a student generates the graph above of the force exerted on a small wagon as a function of time. The wagon starts from rest and rolls with negligible friction in the axles. Which of the following graphs best represents the wagon's momentum as a function of time?

(I can't add my own pictures so i'll describe the graphs)

A) constant slope up from 0-2, levels off from 2-4, constant slope up from 4-6

B) level from 0-2, drops down to 0 and levels off from 2-4, shoots back up to the same place and levels off from 4-6

C) constant slope up from 0-2, constant but less steep slope up from 2-4, back to first constant slope up from 4-6

D) constant slope up from 0-2, more steep slope up from 2-4, a steeper slope up from 4-6

D) constant slope up from 0-2, more steep slope up from 2-4, a steeper slope up from 4-6

A student is provided with a battery-powered toy car that the manufacturer claims will always operate at a constant speed. The student must design an experiment in order to test the validity of the claim. Which of the following measuring tools can the student use to test the validity of the claim? Select two answers.

A) Photogates placed at the beginning, end, and at various locations along the track that the car travels on

B) A meterstick to measure the distance of the track that the car travels on

C) A motion detector that is oriented perpendicular to the direction that the car travels

D) A mass balance to determine the mass of the car

A) Photogates placed at the beginning, end, and at various locations along the track that the car travels on

AND

B) A meterstick to measure the distance of the track that the car travels on

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?

(i can't add pictures and i can't describe all of the graphs so ill just describe the answer)

A) same graphs but the lion starts negative and the gazelle starts at zero for a little before it accelerates

A bowling pin is thrown vertically upward such that it rotates as it moves through the air, as shown in the figure. Initially, the center of mass of the bowling pin is moving upward with a speed vivi of 10 ms10 ms. The maximum height of the center of mass of the bowling pin is most nearly

A) vi^2/2g

B) 2g/vi^2

C) The answer cannot be determined without knowing how long it takes the bowling pin to reach its maximum height.

D) The answer cannot be determined because an irregularly shaped object is too complex to treat as a single point mass.

A) vi^2/2g

A compressed spring mounted on a disk can project a small ball. When the disk is not rotating, as shown in the top view above, the ball moves radially outward. The disk then rotates in a counterclockwise direction as seen from above, and the ball is projected outward at the instant the disk is in the position shown above. Which of the following best shows the subsequent path of the ball relative to the ground?

(I can't ad pictures and i can't describe all of the graphs so i'll describe the answer)

E) the right most arrow is pointed up and right as a STRAIGHT LINE

A student wants to investigate the motion of a ball by conducting two different experiments, as shown in Figure 1 and Figure 2 above. In Experiment 1, the student releases a ball from rest and uses a slow-motion camera to film the ball as it falls to the ground. Using video analysis, the student is able to plot the ball's horizontal position xx and vertical position yy as a function of time tt. In Experiment 2, the student horizontally rolls the same ball off a table, and uses video analysis to plot the ball's horizontal position xx and vertical position yy as a function of time tt starting from the instant the ball leaves the table. The graphs from each experiment are shown above along with each graph's best-fit curve line.

In Experiment 1, what is the speed of the ball the instant it makes contact with the ground?

A) 0 m/s

B) 0.55 m/s

C) 1.5 m/s

D) 5.4 m/s

D) 5.4 m/s

A student wants to investigate the motion of a ball by conducting two different experiments, as shown in Figure 1 and Figure 2 above. In Experiment 1, the student releases a ball from rest and uses a slow-motion camera to film the ball as it falls to the ground. Using video analysis, the student is able to plot the ball's horizontal position xx and vertical position yy as a function of time tt. In Experiment 2, the student horizontally rolls the same ball off a table, and uses video analysis to plot the ball's horizontal position xx and vertical position yy as a function of time tt starting from the instant the ball leaves the table. The graphs from each experiment are shown above along with each graph's best-fit curve line.

Which of the following conclusions can the student draw from the graphs, and why?

A) The horizontally rolled ball travels a greater horizontal distance and takes a longer amount of time to reach the ground.

B) The released ball travels with a slower speed and takes a longer amount of time to reach the ground.

C) Since both balls have zero horizontal acceleration, they reach the ground at the same time.

D) Since the balls have the same vertical position at any given time, they reach the ground at the same time.

D) Since the balls have the same vertical position at any given time, they reach the ground at the same time.

A student wants to investigate the motion of a ball by conducting two different experiments, as shown in Figure 1 and Figure 2 above. In Experiment 1, the student releases a ball from rest and uses a slow-motion camera to film the ball as it falls to the ground. Using video analysis, the student is able to plot the ball's horizontal position xx and vertical position yy as a function of time tt. In Experiment 2, the student horizontally rolls the same ball off a table, and uses video analysis to plot the ball's horizontal position xx and vertical position yy as a function of time tt starting from the instant the ball leaves the table. The graphs from each experiment are shown above along with each graph's best-fit curve line.

Suppose that Experiment 1 and Experiment 2 are conducted at the same time; one student drops the ball from rest at the same instant that a second student horizontally rolls an identical off the table. After both balls have traveled half their vertical distance to the floor, what is the acceleration of the center of mass of the two-ball system relative to Earth?

A) Greater than g

B) Equal to g

C) Less than g, but not zero

D) Zero

B) Equal to g

Two students want to determine the speed at which a ball is released when thrown vertically upward into the air. One student throws the ball into the air while the other student measures the total time that the ball is in the air. The students use a meterstick to measure the release height of the ball. Which of the following equations should the students use to determine the speed at which the ball was released?

A) Use y=y0+vy0t+1/2at^2 from the moment in time in which the ball was released to the moment in time in which the ball reaches its highest point.

B) Use y=y0+vy0t+1/2at^2 from the moment in time in which the ball was released to the moment in time in which the ball hits the ground.

C) vy^2=vy0^2+2ay(y−y0) from the moment in time in which the ball was released to the moment in time in which the ball reaches its highest point.

D) vy^2=vy0^2+2ay(y−y0) from the moment in time in which the ball was released to the moment in time in which the ball hits the ground.

B) Use y=y0+vy0t+1/2at^2 from the moment in time in which the ball was released to the moment in time in which the ball hits the ground.

An object's velocity v 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 = 4 s to t = 10 s.

B) The object's initial and final positions are the same.

C) The object is slowing down from t = 14 s to t = 16 s.

D) The average acceleration of the object from t = 0 s to t = 4 s is different from the acceleration from t = 34 s to t = 36 s.

B) The object's initial and final positions are the same.

At time t=0t=0, a moving cart on a horizontal track is at position 0.5m0.5m. Using a motion detector, students generate a graph of the cart's velocity as a function of time, as shown above. At t=2.5st=2.5s, the cart's position is most nearly

A) 0.5 m

B) 1.25 m

C) 1.75 m

D) 2 m

C) 1.75 m

A ball is released from rest from the twentieth floor of a building. After 1 s1 s, the ball has fallen one floor such that it is directly outside the nineteenth-floor window. The floors are evenly spaced. Assume air resistance is negligible. What is the number of floors the ball would fall in 3s after it is released from the twentieth floor?

A) 3 floors or less

B) 4 to 6 floors

C) 7 to 10 floors

D) 11floors or more

C) 7 to 10 floors

A car initially at rest accelerates at 10ms210⁢ms2. The car's speed after it has traveled 2525 meters is most nearly

A) 0.0 m/s

B) 10.0 m/s

C) 22.0 m/s

D) 25.0 m/s

C) 22.0 m/s

The displacement x with respect to time t of a particle moving in simple harmonic motion is given by x = 5cos(16πt), where x is in millimeters and t is in seconds. If the particle starts at x = 5 mm and t = 0 s, at what time t does it first pass through its equilibrium position?

A) 1/32 s

B) 1/16 s

C) 1/5 s

D) 4 s

E) 8 s

A) 1/32 s