Question 1

A football player moves along the x-axis, and you record their position at several times. From 1s to 2s, the player moves from $$x = 0 m to$$ $$x = 8 m. $$Which statement is correct about the player's motion during this interval?

Accepted Answer

The player's start to finish displacement magnitude and total distance travelled are equal.

Question 2

What is the magnitude of the player's average velocity from 1s to 3s if their position changes from $$x = 0 m at 1s to$$ $$x = 0 m at 3s$$?

Accepted Answer

$$0 m/s$$

Question 3

A $$7 kg $$bowling ball is dropped from a $$20 m $$high balcony. Simultaneously, a $$4.5 kg $$golf ball is thrown upward at $$4 m/s $$from the ground toward the balcony. Air resistance is negligible. Which statement is correct?

Accepted Answer

The sign of acceleration for the bowling ball and golf ball is the same.

Question 4

How long does it take for the bowling ball to hit the floor if dropped from $$20 m$$? (Use $$g = 9.8 m/s$^2)$$

Accepted Answer

$$2.02 s$$

Question 5

A $$60 kg $$person stands in an elevator that moves upward while accelerating downward at $$2 m/s$^2. $$Which statement best describes the situation?

Accepted Answer

The speed of the person in the elevator is decreasing.

Question 6

Calculate the magnitude of the normal force acting on the $$60 kg $$person in the elevator accelerating downward at $$2 m/s$^2$$. ($$g = 9.8 m/s$^2)$$

Accepted Answer

$$468 N$$

Question 7

A ball is kicked into the air from ground level with an initial velocity $$30^	ext{o}$$ above the horizontal and a horizontal component of $$4 m/s. $$Which statement is correct about the ball's motion?

Accepted Answer

The net force on the ball points downward during the ball's entire motion.

Question 8

What was the ball's magnitude of velocity when kicked if its horizontal component is $$4 m/s $$and the angle is $$30^	ext{o}$$?

Accepted Answer

$$4.62 m/s$$

Question 9

A $$20 kg $$block on a frictionless incline is connected to a $$15 kg $$mass by an ideal string over a pulley. Both are motionless. Which force diagram pair is correct for the block and the mass?

Accepted Answer

Block: down the incline and perpendicular to incline; Mass: vertical up and down

Question 10

What is the weight of the $$15 kg $$mass hanging from the pulley? ($$g = 9.8 m/s$^2)$$

Accepted Answer

$$147 N$$

Question 11

You wish to move a $$50 kg $$box over a horizontal rough surface. You push with $$40 N of $$force directed $$30^	ext{o}$$ below the horizontal and observe that it doesn't move. In which situation might it be possible for the box to move?

Accepted Answer

You apply $$40 N of $$force $$10^	ext{o}$$ below the horizontal to the box above.

Question 12

When you first tried to move the box, how much friction did the floor apply to it?

Accepted Answer

$$35 N$$

Question 13

A $$0.003 kg $$coin does not slide while sitting on a disk that turns about its center. The coin is $$0.2 m $$away from the disk's center and moves at a constant $$12 m/s. If $$the coin's distance from the center and its speed are both doubled, which is correct?

Accepted Answer

The coin feels more friction and accelerates faster.

Question 14

What is the magnitude of friction acting on the coin if $$m = 0.003 kg$$, $$r = 0.2 m$$, $$v = 12 m/s$$?

Accepted Answer

$$2.16 N$$

Question 15

While riding in a roller coaster car, you enter a circular loop with a radius of $$20 m. $$You travel at $$20 m/s at $$the topmost point. Which statement is correct concerning the topmost point of the loop?

Accepted Answer

The net force acting on the roller coaster is perpendicular to its velocity.

Question 16

What is the magnitude of the normal force exerted on a $$70 kg $$passenger by the roller coaster car at the topmost point of the loop? ($$g = 9.8 m/s$^2$$, $$v = 20 m/s$$, $$r = 20 m)$$

Accepted Answer

$$714 N$$

Question 17

An airplane travels horizontally at constant velocity at an altitude of $$1960 m $$above the ground. A package is dropped from the airplane and lands $$1000 m $$right of where it was released. What is the airplane's speed?

Accepted Answer

$$50 m/s$$

Question 18

An $$82 kg $$warehouse crate is initially at rest when a fork truck begins to push it across the floor. After $$6 s$$, the crate slides at $$3 m/s. If $$the fork truck applies $$55 N of $$force horizontally to the crate, what force of friction acts on the crate?

Accepted Answer

$$14 N$$

Question 19

A $$35 kg $$loudspeaker is suspended a distance $$h = 1.2 m $$below the ceiling by two cables that make equal angles with the ceiling. Each cable has a length of $$l = 3.6 m. $$What is the tension in the cable on the right?

Accepted Answer

$$515 N$$

Question 20

A ball with mass $$m = 0.2 kg is $$suspended from a fixed point by an ideal string. The ball swings in a horizontal circle of radius $$r = 0.6 m so $$that the string makes an angle $$	heta = 20^	ext{o}$$ with the vertical. What is the ball's speed as it swings?

Accepted Answer

$$4.08 m/s$$

Fundamental Concepts in Introductory Physics: Kinematics, Dynamics, and Circular Motion

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