Physics Chapter 3

b. 1 m/s2.

A cart changes its speed from 90 m/s to 100 m/s in 10 seconds. During this interval its acceleration is a. 10 m/s2. b. 1 m/s2. c. None of these d. zero.

b. zero

A cart maintains a constant velocity of 100 m/s for 10 seconds. During this interval its acceleration is a. 1 m/s2.Incorrect b. zero. c. 10 m/s2. d. None of these

c. acceleration

A freely-falling watermelon falls with constant Select one: a. velocity. b. speed. c. acceleration d. distances each successive second.

d. 10 km/h.

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. 20 km/h. b. 8 km/h. c. 6 km/h. d. 10 km/h.

c. 100 m farther south

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. 141 m farther b. due east of its starting point. c. 100 m farther south. d. None of these

a. All of these

A vehicle undergoes acceleration when it Select one: a. All of these b. gains speed. c. changes its direction. d. loses speed.

b. 100 km/h

An 80-km/h airplane caught in a 60-km/h crosswind has a resultant speed of Select one: a. 60 km/h. b. 100 km/h. c. 141 km/h. d. 80 km/h.

a. 141 km/h.

An airplane that flies at 100 km/h in a 100-km/h crosswind has a ground speed of Select one: a. 141 km/h. b. 0 km/h. c. 100 km/h. d. 200 km/h.

e. 10 m/s.

An apple falls from a tree and hits the ground 5 meters below with a speed of about Select one: a. not enough information b. 15 m/s. c. 20 m/s. d. 5 m/s. e. 10 m/s.

a. 20 m/s.

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. 20 m/s. b. 40 m/s. c. 10 m/s. d. 30 m/s.

a. 6 m/s2

If a car increases its velocity from zero to 60 m/s in 10 seconds, its acceleration is Select one: a. 6 m/s2. b. 600 m/s2. c. 3 m/s2. d. 60 m/s2.

a. 10 m/s

If a freely falling object were equipped with a speedometer, its speed reading would increase each second by about Select one: a. 10 m/s. b. a variable amount. c. 5 m/s. d. 15 m/s. e. depends on its initial speed

c. 10 m/s2

If you throw a ball straight downward (in the absence of air resistance), after leaving your hand its acceleration is Select one: a. less than 10 m/s2. b. greater than 10 m/s2. c. 10 m/s2.

b. 6 m/s

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. None of these b. 6 m/s. c. 10 m/s. d. 14 m/s.

a. 14 m/s.

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. 14 m/s. b. 10 m/s. c. 6 m/s. d. None of these

either depending on her running direction

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. 11 m/s. b. 5 m/s. c. None of these d. either depending on her running direction

c. 4.0 m/s2

Ten seconds after starting from rest, a car is moving at 40 m/s. What is the car's acceleration? a. 10 m/s2 b. 40 m/s2 c. 4.0 m/s2 d. 0.25 m/s2 e. 2.8 m/s2

b. from zero to g.

The accelerations possible for a ball on an inclined plane a. range from g to infinity. b. range from zero to g. c. have no limit.

c. increases

The distance a freely falling bowling ball falls each second Select one: a. is about 10 m. b. None of these c. increases. d. is about 5 m.

c. (100 - 5) m.

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. None of these b. 100 m. c. (100 - 5) m d. 5 m. e. (100 + 5) m.

c. instantaneous speed

The speedometer of an automobile reads Select one: a. average speed. b. accelerated speed. c. instantaneous speed.

c. 1.2 m.

The vertical height attained by a basketball player who achieves a hang time of a full 1 s is about Select one: a. 0.8 m. b. 2.5 m. c. 1.2 m. d. 1 m. e. more than 2.5 m.

c. 4 m/s2

What is the acceleration of a car that starts from rest and 5 seconds later reaches a speed of 20 m/s? a. 2 m/s2 b. 3 m/s2 c. 4 m/s2 d. 5 m/s2 e. 1 m/s2

d. speed

Which of the following is not a vector quantity? a. acceleration b. none are vector quantities. c. velocity d. speed e. all are vector quantities

c. None of these

While a car travels around a circular track at a constant speed, its Select one: a. inertia is zero. b. velocity is zero. c. None of these d. acceleration is zero.