Deck 3: Linear Motion

Question 1

Jogging Jake runs at 4 m/s along a train flatcar that moves at 10 m/s in the same direction. Jake's speed relative to the ground is

A)6 m/s.
B)10 m/s.
C)14 m/s.
D)none of the above

Answer 1

14 m/s.

Question 2

A rock dropped from a 5-m height accelerates at 10 m/s² and strikes the ground 1 s later. If the rock is dropped from a height of 2.5 m, its acceleration of fall is

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

Answer 2

the same.

Question 3

When you walk at an average speed of 4 m/s, in 5 s you'll cover a distance of

A)2 m.
B)10 m.
C)15 m.
D)20 m.

Answer 3

20 m.

Question 4

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

A)3 m/s².
B)6 m/s².
C)60 m/s².
D)600 m/s².

Question 5

The two measurements necessary for calculating average speed are

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

Question 6

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

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

Question 7

A cart maintains a constant velocity of 100 m/s for 10 seconds. During this interval its acceleration is

A)zero.
B)1 m/s².
C)10 m/s².
D)none of the above

Question 8

You're at rest in a hammock when a hungry mosquito sees an opportunity for lunch. A mild 2-m/s breeze is blowing. If the mosquito joins you for lunch it should hover over you by flying

A)against the breeze at 2 m/s.
B)with the breeze at 2 m/s.
C)a bit faster than wind speed.
D)none of the above

Question 9

The speedometer of an automobile reads

A)average speed.
B)instantaneous speed.
C)accelerated speed.

Question 10

Katelyn runs along the aisle of a train that moves at 8 m/s. Her speed relative to the floor is 3 m/s. Her speed relative to an observer at rest on the ground is

A)5 m/s.
B)11 m/s.
C)either depending on her running direction
D)none of the above

Question 11

A ball rolls along a horizontal track in a certain time. If the track has a dip in it, the time to roll the length of the track will be

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

Question 12

Jogging Jake runs at 4 m/s along a train flatcar that moves at 10 m/s in the opposite direction. Jake's speed relative to the ground is

A)6 m/s.
B)10 m/s.
C)14 m/s.
D)none of the above

Question 13

If an object moves with constant acceleration, its velocity must

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

Question 14

A ball rolls along a horizontal track in a certain time. If the track has a small upward dent in it, the time to roll the length of the track will be

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

Question 15

A mosquito flying at 3 m/s that encounters a breeze blowing at 3 m/s in the opposite direction has a speed of

A)0 m/s.
B)3 m/s.
C)4 m/s.
D)6 m/s.

Question 16

A mosquito flying at 3 m/s that encounters a breeze blowing at 3 m/s in the same direction has a speed of

A)0 m/s.
B)3 m/s.
C)4 m/s.
D)6 m/s.

Question 17

A vehicle undergoes acceleration when it

A)gains speed.
B)loses speed.
C)changes its direction.
D)all of the above

Question 18

The average speed of a horse that gallops 10 kilometers in 30 minutes is

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

Question 19

A cart changes its speed from 90 m/s to 100 m/s in 10 seconds. During this interval its acceleration is

A)zero.
B)1 m/s².
C)10 m/s².
D)none of the above

Question 20

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 is

A)0 m/s².
B)5 m/s².
C)8 m/s².
D)24 m/s².

Question 21

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

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

Question 22

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

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

Question 23

If a freely falling object were equipped with a speedometer, its speed reading would increase each second by about

A)5 m/s.
B)10 m/s.
C)15 m/s.
D)a variable amount.
E)depends on its initial speed

Question 24

The distance a freely falling bowling ball falls each second

A)is about 5 m.
B)is about 10 m.
C)increases.
D)none of the above

Question 25

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

A)0.25 m/s²
B)2.8 m/s²
C)4.0 m/s²
D)10 m/s²
E)40 m/s²

Question 26

The accelerations possible for a ball on an inclined plane

A)range from zero to g.
B)range from g to infinity.
C)have no limit.

Question 27

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)in the direction of motion.
B)opposite its velocity.
C)directed upward.
D)directed downward.
E)none of the above

Question 28

A ball starting from rest at the top of an inclined plane accelerates at 2 m/s² and reaches the bottom of the plane in 3 seconds. What is the length of the plane?

A)2 m
B)3 m
C)5 m
D)9 m

Question 29

A freely-falling watermelon falls with constant

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

Question 30

If a freely falling object were equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s², then its speed reading would increase each second by

A)10 m/s.
B)20 m/s.
C)30 m/s.
D)40 m/s.
E)depends on its initial speed

Question 31

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

Question 32

A ball is thrown upwards and returns to the same location. Compared with its initial speed its speed when it returns is about

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

Question 33

A car's speed 3 seconds after accelerating from rest at 2 m/s² is

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

Question 34

While an iron block near the Earth's surface is in free fall, it undergoes an increase in

A)speed.
B)acceleration.
C)both of these
D)neither of these

Question 35

What is the acceleration of a car that starts from rest and 5 seconds later reaches a speed of 20 m/s?

A)1 m/s²
B)2 m/s²
C)3 m/s²
D)4 m/s²
E)5 m/s²

Question 36

Twelve seconds after starting from rest, a freely-falling cantelope has a speed of

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

Question 37

If a stone falls to the bottom of a mineshaft in 6 seconds, then the depth of the shaft is about

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

Question 38

The time it takes a car to attain a speed of 30 m/s when accelerating from rest at 2 m/s² is

A)2 s.
B)15 s.
C)30 s.
D)60 s.
E)none of the above

Question 39

A ball starting from rest at the top of an inclined plane gains a speed of 2 m/s for each second it rolls. What is its acceleration down the incline?

A)0.5 m/s²
B)1 m/s²
C)2 m/s²
D)4 m/s²

Question 40

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

Question 41

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

A)1 s.
B)2 s.
C)10 s.
D)not enough information

Question 42

Neglecting air resistance, a ball projected straight upward so it remains in the air for 10 seconds needs an initial speed of

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

Question 43

An object falls freely from rest on a planet where the acceleration due to gravity is 20 m/s². After 5 seconds, the object will have a speed of

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

Question 44

A bullet is dropped into a river from a very high bridge at the same time as another bullet is fired straight downward from a rifle. Neglecting air resistance, the acceleration just before striking the water is

A)greater for the dropped bullet.
B)greater for the fired bullet.
C)the same for each bullet.
D)none of the above

Question 45

At one instant an object in free fall is moving downward at 50 m/s. One second later its speed is

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

Question 46

Phil Physiker standing at the edge of a cliff throws one ball straight up and another ball straight down, both with the same speed. Neglecting air resistance, which ball hits the ground below with the greater speed?

A)the one thrown upward
B)the one thrown downward
C)neither, both hit with the same speed

Question 47

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

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

Question 48

Neglecting air resistance, how fast must you toss a ball straight up in order for it to take 6 seconds to return to its initial level?

A)5 m/s
B)10 m/s
C)20 m/s
D)30 m/s
E)more than 30 m/s

Question 49

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 - 5)m.
B)(100 + 5)m.
C)100 m.
D)5 m.
E)none of the above

Question 50

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

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

Question 51

A pot that falls from a ledge and hits the ground 45 m below hits the ground at

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

Question 52

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

A)2 m/s.
B)5 m/s.
C)10 m/s.
D)20 m/s.
E)none of the above

Question 53

The total time it takes a projectile fired straight up at 10 m/s to reach the top of its path and return to its starting point is about

A)1 s.
B)2 s.
C)10 s.
D)20 s.

Question 54

Neglecting air resistance, a bullet fired straight down from the top of a high cliff has an acceleration of

A)less than 10 m/s².
B)10 m/s².
C)more than 10 m/s².
D)depends on the height of the cliff.

Question 55

Compared with hang time on Earth, hang time on the Moon would be

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

Question 56

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

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

Question 57

The distance a freely falling object falls from rest in one-half second is

A)2 m.
B)4 m.
C)6 m.
D)none of the above

Question 58

A ball is projected 125 meters straight upward and then falls the same distance back to its starting point. Neglecting air resistance, its total time in the air is about

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

Question 59

When a ball thrown straight upwards reaches the very top of its path, its acceleration is

A)zero.
B)5 m/s².
C)10 m/s².
D)none of the above

Question 60

If you throw a ball straight downward (in the absence of air resistance), after leaving your hand its acceleration is

A)less than 10 m/s².
B)10 m/s².
C)greater than 10 m/s².

Question 61

A river 100 m wide flows due south at 1 m/s. A boat that travels 1 m/s relative to the water is pointed due east as it crosses from the west bank. The boat reaches the east bank

A)due east of its starting point.
B)100 m farther south.
C)141 m farther south.
D)none of the above

Question 62

An 80-km/h airplane caught in a 60-km/h crosswind has a resultant speed of

A)60 km/h.
B)80 km/h.
C)100 km/h.
D)141 km/h.

Question 63

A river 100 m wide flows 1 m/s due south. A boat that travels 1 m/s relative to the water is pointed due east as it crosses from the west bank. Relative to its starting point, the boat travels

A)nowhere.
B)100 m.
C)141 m.
D)200 m.
E)more than 200 m.

Question 64

Phil leans over the edge of a cliff and throws a rock upward at 5 m/s. Neglecting air resistance, one second later the rock's speed is

A)zero.
B)5 m/s.
C)10 m/s.
D)15 m/s.
E)none of the above

Question 65

A seagull flying at 10 km/h in a 10-km/h crosswind has a resultant speed of

A)10 km/h.
B)about 14 km/h.
C)20 km/h.
D)more than 20 km/h.

Question 66

An airplane that flies at 100 km/h in a 100-km/h crosswind has a ground speed of

A)0 km/h.
B)100 km/h.
C)141 km/h.
D)200 km/h.

Question 67

As water drops fall at a steady rate from a leaking faucet they

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

Question 68

A humming bird flying at 4 km/h that gets caught in a 3-km/h crosswind has a resultant speed of about

A)3 km/h.
B)4 km/h.
C)5 km/h.
D)more than 5 km/h.

Question 69

A motorboat that normally travels at 8 km/h in still water heads directly across a 6-km/h flowing river. The resulting speed of the boat is about

A)6 km/h.
B)8 km/h.
C)10 km/h.
D)20 km/h.

Question 70

A bird flying at 8 km/h in a 6-km/h crosswind has a resultant speed of

A)6 km/h.
B)8 km/h.
C)10 km/h.
D)14 km/h.

Question 71

An 80-km/h airplane flying in the same direction as a 10 km/h tail wind has a groundspeed of

A)10 km/h.
B)70 km/h.
C)80 km/h.
D)90 km/h.

Question 72

Phil leans over the edge of a cliff and throws a rock upward at 5 m/s. How far below the level from which it was thrown is the rock 2 seconds later?

A)5 m
B)10 m
C)15 m
D)20 m

Question 73

An 80-km/h airplane flying against a 10-km/h head wind has a groundspeed of

A)10 km/h.
B)70 km/h.
C)80 km/h.
D)90 km/h.

Question 74

Phil leans over the edge of a cliff and throws a rock upward at 5 m/s. Neglecting air resistance, two seconds later the rock's speed is

A)zero.
B)5 m/s.
C)10 m/s.
D)15 m/s.
E)none of the above

Question 75

Which of the following is not a vector quantity?

A)velocity
B)speed
C)acceleration
D)all are vector quantities
E)none are vector quantities.