AP Physics 1 1.1 - 2.3

A book is at rest on the top of a table. A student makes the following claim: “An attractive electromagnetic force is exerted on the book from the table, and this force can also be classified as the normal force.” Which of the following statements correctly justifies the student's claim?

• The claim is correct because the charged particles of the table exert a downward attractive force on the charged particles of the book.

• The claim is correct because the charged particles of the table exert a downward repulsive force on the charged particles of the book.

• The claim is incorrect because the charged particles of the table exert an upward repulsive force on the charged particles of the book.

• The claim is incorrect because the charged particles of the table exert an upward attractive force on the charged particles of the book.

Two bricks are stacked on a floor. A student draws the force diagram for brick 2, as shown above. The forces are an upward normal force, a downward force exerted by brick 1, and a downward gravitational force. How many of the forces, if any, in the force diagram are contact forces caused by microscopic interactions?

• Zero

• Only one

• Only two

• All three

A block slides to the right on a rough horizontal surface. The forces exerted on the block are shown above. Which of the following statements about the frictional force Ff exerted on the block is true?

• It is the only force acting on the block that is caused by microscopic interactions.

• It does not depend on the materials that the block and the surface are made of.

• It is caused by gravitational interactions between the atoms in the block and the atoms in the surface.

• It is the sum of all the microscopic contact forces between the bottom of the block and the surface.

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?

• Object X is moving at the same speed as object Y.

• Object X is moving four times faster than object Y.

• Object X has traveled the same distance as object Y.

• Object X has traveled twice as far as object Y.

• Object X has traveled four times as far as object Y.

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 x and vertical position y as a function of time t. In Experiment 2, the student horizontally rolls the same ball off a table, and uses video analysis to plot the ball’s horizontal position x and vertical position y as a function of time t 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?

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

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

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

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

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?

• Between 10 s and 20 s

• Between 20 s and 30 s

• At 30 s exactly

• Between 30 s and 40 s

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 horizontally, the direction and magnitude of its acceleration while it is in the air is

• upward and decreasing

• upward and constant

• downward and decreasing

• downward and increasing

• downward and constant

The graph shows the acceleration as a function of time for an object that is at rest at time t = 0s. The distance traveled by the object between 0 and 2s is most nearly

• 1 m

• 2 m

• 3 m

• 4 m

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.

• 
• 
• 
• 

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 greatest?

• A

• B

• C

• D

• E