Question 1

It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft?

Accepted Answer

A)  about 60 m 
B)  about 180 m 
C)  about 120 m 
D)  more than 200 m

Question 2

At one instant an object in free fall is moving downward at 50 meters per second. One second later its speed should be about

Accepted Answer

A)  100 m/s. 
B)  55 m/s. 
C)  50 m/s. 
D)  25 m/s. 
E)  60 m/s.

Question 3

A ball is thrown upwards and caught when it comes back down. In the presence of air resistance, the speed with which it is caught is always

Accepted Answer

A)  more than the speed it had when thrown upwards. 
B)  the same as the speed it had when thrown upwards. 
C)  less than the speed it had when thrown upwards. 
D)  impossible to determine.

Question 4

A car accelerates from rest for 5 seconds until it reaches a speed of 20 m/s. What is the car's acceleration in meters per second per second?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 5

A horse gallops a distance of 10 kilometers in a time of 30 minutes. It's average speed is

Accepted Answer

A)  40 km/h. 
B)  30 km/h. 
C)  20 km/h. 
D)  15 km/h.

Question 6

Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car's acceleration in meters per second per second?

Accepted Answer

A)  10 
B)  40 
C)  0.25 
D)  4.0 
E)  2.8

Question 7

If a rocket initially at rest accelerates at a rate of 50 m/s2 for one minute, its speed will be

Accepted Answer

A)  3600 m/s. 
B)  50 m/s. 
C)  3000 m/s. 
D)  500 m/s.

Question 8

The two measurements necessary for calculating average speed are

Accepted Answer

A)  velocity and time. 
B)  distance and acceleration. 
C)  distance and time. 
D)  velocity and distance. 
E)  acceleration and time.

Question 9

Drop a rock from a 5-m height and it accelerates at 10 m/s2 and strikes the ground 1 s later. Drop the same rock from a height of 2.5 m and its acceleration of fall is about

Accepted Answer

A)  twice as much. 
B)  four times as much. 
C)  the same amount. 
D)  half as much.

Question 10

If an object moves with constant acceleration, its velocity must

Accepted Answer

A)  change by varying amounts depending on its speed. 
B)  be constant also. 
C)  change by the same amount each second. 
D)  always decrease.

Question 11

A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun, straight down towards the water. Neglecting air resistance, the acceleration just before
Striking the water

Accepted Answer

A)  is greater for the fired bullet. 
B)  is the same for each bullet. 
C)  is greater for the dropped bullet. 
D)  depends on how high they started. 
E)  none of these

Question 12

One half second after starting from rest, a freely-falling object will have a speed of about

Accepted Answer

A)  2.5 m/s. 
B)  5 m/s. 
C)  10 m/s. 
D)  20 m/s. 
E)  none of these

Question 13

A heavy object and a light object are dropped at the same time from rest in a vacuum. The heavier object reaches the ground

Accepted Answer

A)  sooner than the lighter object. 
B)  later than the lighter object. 
C)  almost immediately 
D)  at the same time as the lighter object.

Question 14

Distance is to displacement as

Accepted Answer

A)  speed is to velocity. 
B)  impulse is to momentum. 
C)  force is to weight. 
D)  velocity is to acceleration. 
E)  None of the above choices are correct

Question 15

Disregarding air drag, how fast must you toss a ball straight up in order for it to take 2 seconds to return to the level from which you tossed it?

Accepted Answer

A)  10 m/s 
B)  20 m/s 
C)  15 m/s 
D)  5 m/s 
E)  7.5 m/s

Question 16

A car accelerates at 2 meters per second per second. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 30 m/s?

Accepted Answer

A)  2 seconds 
B)  15 seconds 
C)  60 seconds 
D)  30 seconds 
E)  none of these

Question 17

A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is

Accepted Answer

A)  equal to its weight. 
B)  equal to its weight divided by its mass. 
C)  zero. 
D)  equal to the product of its mass times its weight.

Question 18

An object falls freely from rest on a planet where the acceleration due to gravity is 20 meters per second squared. After 5 seconds, the object will have a speed of

Accepted Answer

A)  10 m/s. 
B)  5 m/s. 
C)  20 m/s. 
D)  100 m/s. 
E)  50 m/s.

Question 19

Twelve seconds after starting from rest, an object falling freely will have a speed of

Accepted Answer

A)  10 m/s. 
B)  100 m/s. 
C)  50 m/s. 
D)  more than 100 m/s.

Question 20

A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval it acceleration is

Accepted Answer

A)  zero. 
B)  1000 km/hr. 
C)  110 km/hr. 
D)  10 km/hr.

Exam 3: Equilibrium and Linear Motion