Deck 3: Equilibrium and Linear Motion

Question 1

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

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

Answer 1

more than 100 m/s.

Question 2

Disregarding air resistance, objects fall with constant

A) speed.
B) acceleration.
C) velocity.
D) distances each successive second.

Answer 2

acceleration.

Question 3

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

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

Answer 3

is the same for each bullet.

Question 4

A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always

A) directed downward.
B) opposite its velocity.
C) directed upward.
D) in the direction of motion.

Question 5

Galileo's use of inclined planes allowed him to effectively

A) eliminate the acceleration of free fall.
B) increase the acceleration beyond that of free fall.
C) slow down the acceleration of free fall.
D) eliminate friction.

Question 6

While an object near the earth's surface is in free fall , its

A) velocity increases.
B) acceleration increases.
C) mass increases.
D) mass decreases.

Question 7

An object falls freely from rest on a planet where the acceleration due to gravity is twice as much as it is on Earth. In the first 5 seconds it falls a distance of

A) 250 m.
B) 150 m.
C) 100 m.
D) 500 m.
E) none of these

Question 8

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

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

Question 9

If a car accelerates from rest at 2 meters per second per second, its speed 3 seconds later will be about

A) 3 m/s.
B) 4 m/s.
C) 2 m/s.
D) 6 m/s.

Question 10

A pot falls from a ledge and hits the ground 45 m below. The speed with which it hits the ground is

A) about 120 m/s.
B) about 30 m/s.
C) about 60 m/s.
D) more than 120 m/s.

Question 11

If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting position is about

A) 2 seconds.
B) 10 seconds.
C) 20 seconds.
D) 1 second.
E) not enough information to estimate

Question 12

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?

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

Question 13

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?

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

Question 14

The two measurements necessary for calculating average speed are

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

Question 15

A man leans over the edge of a cliff and throws a rock upward at 4.9 m/s. How far below the level from which it was thrown is the rock 2 seconds later?

A) 19.6 m
B) 4.9 m
C) 14.7 m
D) 9.8 m

Question 16

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

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 17

A man leans over the edge of a cliff and throws a rock upward at 4.9 m/s. Neglecting air resistance, one second later the rock's speed is

A) zero.
B) 9.8 m/s.
C) 14.7 m/s.
D) 4.9 m/s.
E) none of the above.

Question 18

Consider drops of water that leak at a steady rate from a dripping faucet. As the drops fall they

A) get closer together.
B) remain at a relatively fixed distance from one another.
C) get farther apart.

Question 19

An apple falls from a tree and hits the ground 5 meters below. It hits the ground with a speed of about

A) 20 m/s.
B) 15 m/s.
C) 5 m/s.
D) 10 m/s.
E) not enough information given to estimate

Question 20

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

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

Question 21

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

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

Question 22

If an object falling freely were somehow equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be

A) greater than the second before.
B) constant.
C) less and less each second.
D) doubled.

Question 23

A ball is thrown upwards and returns to the same position. Compared with its original speed after release, its speed when it returns is about

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

Question 24

A bullet is dropped from the top of the Empire State Building while another bullet is fired downward from the same location. Neglecting air resistance, the acceleration of

A) the dropped bullet is greater.
B) each bullet is 9.8 meters per second per second.
C) the fired bullet is greater.

Question 25

A bullet is fired straight down from the top of a high cliff. Neglecting air resistance, the acceleration of the bullet in meters per second per second

A) is less than 9.8.
B) is more than 9.8.
C) is 9.8.
D) depends on the height of the cliff.

Question 26

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

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

Question 27

A ball is thrown upwards. Neglecting air resistance, what initial upward speed does the ball need to remain in the air for a total time of 10 seconds?

A) about 80 m/s
B) about 60 m/s
C) about 110 m/s
D) about 50 m/s
E) about 100 m/s

Question 28

Someone standing at the edge of a cliff throws one ball straight up and another ball straight down at the same initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the
Greater speed will be

A) the one thrown downward.
B) the one thrown upward.
C) neither - they will both hit with the same speed.

Question 29

An airplane flies at 100 km/h in still air.. If it flies into a 10 km/h headwind, its groundspeed is

A) 90 km/h.
B) 120 km/h.
C) 110 km/h.
D) 100 km/h.

Question 30

The vertical height attained by a basketball player who achieves a hang time of a full 1 s is

A) about 1.2 m.
B) about 2.5 m.
C) about 0.8 m.
D) about 1 m.
E) more than 2.5 m.

Question 31

While a car travels around a circular track at a constant speed its

A) acceleration is zero.
B) inertia is zero.
C) velocity is zero.
D) none of the above

Question 32

An object covers a distance of 8 meters in the first second of travel, another 8 meters during the next second , and 8 meters again during the third second. Its acceleration in meters per second per
Second is approximately

A) 0.
B) 24.
C) 8.
D) 5.

Question 33

If a car increases its velocity from zero to 60 km/h in 10 seconds, its acceleration is

A) 600 km/h/s.
B) 10 km/h/s.
C) 60 km/h/s.
D) 3 km/h/s.
E) 6 km/h/s.

Question 34

When a rock thrown straight upwards gets to the exact top of its path, its

A) velocity is about 10 m/s and its acceleration is about 10 meters per second per second.
B) velocity is about 10 m/s and its acceleration is zero.
C) velocity is zero and its acceleration is about 10 meters per second per second.
D) velocity is zero and its acceleration is zero.
E) none of these

Question 35

If an object moves with constant acceleration, its velocity must

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 36

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

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

Question 37

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?

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

Question 38

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

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 39

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

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

Question 40

In each second of fall, the distance a freely falling object will fall is

A) about 5 m.
B) the same, but not 5 m or 10 m.
C) about 10 m.
D) increasing.
E) none of these.

Question 41

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

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

Question 42

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

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 43

If a projectile is fired straight up at a speed of 10 m/s, the time it takes to reach the top of its path is about

A) 2 seconds.
B) 10 seconds.
C) 1 second.
D) not enough information to estimate

Question 44

Distance is to displacement as

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 45

The muzzle velocity of a bullet fired from a new rifle is 100 m/s. Neglecting air resistance, at the end of one second a bullet fired straight up into the air will have traveled a distance of

A) (100 - 4.9) m.
B) 100 m.
C) (100 + 4.9) m.
D) 4.9 m.
E) none of these

Question 46

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?

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

Question 47

At one instant a heavy object in air is moving upward at 50 meters per second. One second later its speed in meters per second is approximately

A) 55 m/s.
B) 40 m/s.
C) 60 m/s.
D) 50 m/s.

Question 48

Which of the following is not a vector quantity?

A) speed
B) velocity
C) acceleration
D) All are vector quantities.

Question 49

A ball is thrown 125 meters upward and then falls the same distance back to Earth. Neglecting air resistance, its total time in the air is

A) about 5 seconds.
B) about 15 seconds.
C) about 10 seconds.
D) more than 20 seconds.

Question 50

An object, at rest near the surface of a distant planet, starts to fall freely . If the acceleration there is twice that of the earth, its speed one second later would be

A) 40 m/s.
B) 10 m/s.
C) 20 m/s.
D) 30 m/s.

Question 51

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

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

Question 52

If you drop an object, it will accelerate downward at a rate of 9.8 meters per second per second. If you instead throw it downwards, its acceleration (in the absence of air resistance) will be

A) greater than 9.8 meters per second per second.
B) less than 9.8 meters per second per second.
C) 9.8 meters per second per second.

Question 53

Starting from rest, the distance a freely-falling object will fall in 0.5 second is about

A) 1 m.
B) 1.00 m.
C) 10 m.
D) none of the above

Question 54

A man leans over the edge of a cliff and throws a rock upward at 4.9 m/s. Neglecting air resistance, two seconds later the rock's speed is

A) zero.
B) 9.8 m/s.
C) 4.9 m/s.
D) 14.7 m/s.
E) none of the above.