Question 1

The force exerted on the tires of a car to directly accelerate it along a road is exerted by the

Accepted Answer

A) engine. 
B) tires. 
C) air. 
D) road. 
E) none of the above

Question 2

The net force on any object moving at constant velocity is

Accepted Answer

A) zero. 
B) 10 meters per second squared. 
C) equal to its weight. 
D) less than its weight.

Question 3

A skydiver who weighs 500 N reaches terminal velocity at 90 km/h. The air resistance on the skydiver is

Accepted Answer

A) 90 N. 
B) 250 N. 
C) 410 N. 
D) 500 N. 
E) none of the above

Question 4

When an object falls through the air and gains velocity, the net force actually

Accepted Answer

A) increases. 
B) decreases. 
C) remains the same whether in air or in a vacuum.

Question 5

A sheet of paper can be pulled from beneath a box of cereal without toppling it if the paper is jerked quickly. This best demonstrates that

Accepted Answer

A) the box has no acceleration. 
B) there is an action-reaction pair of forces. 
C) gravity tends to hold the box secure. 
D) the box has inertia.

Question 6

A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. Air resistance just before they hit is actually greater for the

Accepted Answer

A) regular ball. 
B) lead-filled ball. 
C) same for both

Question 7

An archer shoots an arrow. If the action force is the bowstring on the arrow, the reaction is the

Accepted Answer

A) weight of the arrow. 
B) air resistance on the bow. 
C) friction of the ground on the archer's feet. 
D) grip of the archer's hand on the bow. 
E) arrow's push on the bowstring.

Question 8

Action and reaction forces comprise the parts of

Accepted Answer

A) a single interaction. 
B) two interactions. 
C) multiple interactions.

Question 9

If an object falls with constant acceleration, the velocity of the object must

Accepted Answer

A) be constant also. 
B) continually change by the same amount each second. 
C) continually change by varying amounts, depending on its speed. 
D) continually decrease. 
E) none of the above

Question 10

As a ball falls, the action force is the pull of Earth's mass on the ball. The reaction force is the

Accepted Answer

A) air resistance acting against the ball. 
B) acceleration of the ball. 
C) pull of the ball's mass on Earth. 
D) nonexistent. 
E) none of the above

Question 11

A light woman and a heavy man jump from an airplane at the same time and open their same-size parachutes at the same time. Which person will get to a state of zero acceleration first?

Accepted Answer

A) the light woman 
B) the heavy man 
C) both should at the same time 
D) not enough information

Question 12

A roller coaster car at an amusement park carrying 1 passenger takes 3 min to make its ride from start to finish. Neglecting friction, a car with 5 passengers would take

Accepted Answer

A) less time. 
B) the same time. 
C) more time.

Question 13

Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the rock tends to

Accepted Answer

A) continue in a circular path. 
B) follow a straight-line path. 
C) spiral inward. 
D) fall straight downward.

Question 14

A rock is thrown vertically into the air. At the top of its path, its acceleration is

Accepted Answer

A) 0 m/s2. 
B) 10 m/s2. 
C) between 0 m/s2 and 10 m/s2. 
D) greater than 10 m/s2. 
E) none of the above

Question 15

A 10-kg block is pushed across a horizontal surface with a horizontal force of 30 N against a friction force of 10 N. The acceleration of the block is

Accepted Answer

A) 1 m/s2. 
B) 2 m/s2. 
C) 5 m/s2. 
D) 10 m/s2. 
E) none of the above

Question 16

A rock is thrown vertically upward. At the top of its straight-line path, its velocity is

Accepted Answer

A) 0 m/s. 
B) 10 m/s. 
C) between 0 m/s2 and 10 m/s2. 
D) greater than 10 m/s. 
E) none of the above

Question 17

Drop a rock from a 5-m height and it accelerates at 10 m/s2 and strikes the ground in

Accepted Answer

A) 1/5 s. 
B) 1/2 s. 
C) 1 s. 
D) 2 s.

Question 18

A ball is thrown vertically upward. Because of air resistance, its speed when returning to its starting level compared with its initial speed is

Accepted Answer

A) less. 
B) the same. 
C) more.

Question 19

When you toss a ball upward, after the ball leaves your hand

Accepted Answer

A) the force of your hand moves it up and gradually changes direction. 
B) the upward force changes direction at the top of the path. 
C) we see that force and velocity are essentially the same thing. 
D) none of the above

Question 20

A tow truck exerts a force of 3000 N on a car that accelerates at 2 m/s2. The mass of the car must be

Accepted Answer

A) 500 kg. 
B) 1000 kg. 
C) 1500 kg. 
D) 3000 kg. 
E) none of the above

Exam 2: Newtons Laws of Motion