Question 1

A car is moving east and approaches a traffic light while slowing down. Which of the following statements about its acceleration is correct?

Accepted Answer

The acceleration is toward the west.

Question 2

An object moves in a straight line with constant velocity. Which of the following could describe the acceleration of that object?

Accepted Answer

The acceleration could be zero.

Question 3

A green ball is thrown upwards with speed $$v_0$$ and a blue ball is thrown downwards with the same initial speed $$v_0$$ from the same height. Air resistance is negligible. When they reach the ground below, which statement is true?

Accepted Answer

The two balls will have the same speed.

Question 4

The velocity-time graphs for a truck and a car are shown. Both vehicles are initially alongside each other at $$t = 0. At $$time $$T$$, what is true of the distances traveled by the vehicles since $$t = 0$$?

Accepted Answer

The car will have travelled further than the truck.

Question 5

Which of the following quantities is defined as the rate of change of velocity?

Accepted Answer

Acceleration.

Question 6

A car travels south for 250 miles and then north for 750 miles. What is the average speed for the trip?

Accepted Answer

$$275\ \mathrm{mi/h}$$

Question 7

A particle moves so that its velocity is given by $$v(t) = 6.2\ \mathrm{m/s} + (4.1\ \mathrm{m/s}^2)t - (6.2\ \mathrm{m/s}^3)t^2$. What is the average acceleration of the particle between t = 1.0$$\ \mathrm{s}$$ and t = 2.0$$\ \mathrm{s}$$?

Accepted Answer

$$-13\ \mathrm{m/s}^2$$

Question 8

A plane must reach a speed of $$80\ \mathrm{m/s}$$ for takeoff on a $$2000\ \mathrm{m}$$ runway. What is the minimum uniform acceleration necessary for the plane to take flight if it starts from rest?

Accepted Answer

$$0.79\ \mathrm{m/s}^2$$

Question 9

Harry and John both jump vertically upward, but John jumps with twice the initial speed as Harry. Compared to Harry, John stays in the air:

Accepted Answer

Four times as long as Harry.

Question 10

Given $$A_x = 7.6$$, $$A_y = -9.2$$, $$B_x = -5.1$$, $$B_y = -6.8$$, what is the magnitude of the vector difference $$\vec{B} - \vec{A}$$?

Accepted Answer

13

Question 11

A projectile is launched from the upper edge of a cliff with initial velocity components $$v_{0x} = 78\ \mathrm{m/s}$$ and $$v_{0y} = 30\ \mathrm{m/s}. $$The projectile rises and then falls into the sea at point $$P. $$The time of flight is $$75\ \mathrm{s}$$ and $$g = 9.80\ \mathrm{m/s}^2. $$What is the horizontal distance $$D$$?

Accepted Answer

$$5850\ \mathrm{m}$$

Question 12

A point on the rim of a spinning wheel makes 1.5 revolutions per second and is located $$0.20\ \mathrm{m}$$ from the axis of rotation. What is the acceleration of that point due to the spin of the wheel?

Accepted Answer

$$18\ \mathrm{m/s}^2$$

Question 13

You are riding a train when a piece of luggage starts to slide directly toward the front of the train. From this observation, you can conclude that this train is:

Accepted Answer

Slowing down.

Question 14

A $$1200\ \mathrm{kg}$$ car moving at $$27\ \mathrm{m/s}$$ comes to a complete stop in $$578\ \mathrm{m}. $$What is the magnitude of the average braking force acting on the car?

Accepted Answer

$$690\ \mathrm{N}$$

Question 15

Two blocks $$A$$ and $$B$$ are pulled across a frictionless surface by a horizontal $$100\ \mathrm{N}$$ pull. Both are moving together at a constant velocity of $$2.0\ \mathrm{m/s} to $$the right, and both weigh the same. Which of the following free-body diagrams correctly shows the horizontal forces acting on the upper block $$A$$?

Accepted Answer

Two arrows: one to the right labeled $$100\ \mathrm{N}$$ and one to the left labeled $$100\ \mathrm{N}.$$

Question 16

A $$10\ \mathrm{N}$$ box slides without friction on a horizontal table. The pulley is ideal and the string has negligible mass. What is true about the tension $$T in $$the string if a $$10\ \mathrm{N}$$ weight hangs from the other end?

Accepted Answer

$$T \u003c 10\ \mathrm{N}$$

Question 17

A tightrope walker is halfway across a wire that is displaced vertically downward by $$1.0\ \mathrm{m}. If $$the tension in both halves of the wire at this point is $$620\ \mathrm{N}$$, what is the mass of the tightrope walker? (Neglect the mass of the wire.)

Accepted Answer

$$74\ \mathrm{kg}$$

Question 18

A $$10\ \mathrm{kg}$$ block is released from rest and falls $$1.0\ \mathrm{m} in$$ $$0.53\ \mathrm{s}. $$What is the mass $$m of $$the block on the left if the system is as shown (no friction, massless pulley, light rope)?

Accepted Answer

$$14\ \mathrm{kg}$$

Question 19

A car traveling at $$20\ \mathrm{m/s}$$ comes to a stop. If the coefficient of friction between the tires and the level road is $$0.80$$, how long will the skid marks be?

Accepted Answer

$$37\ \mathrm{m}$$

Kinematics and Dynamics: Study Notes for Introductory Physics

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