Quiz 2

as soon as it leaves the barrel.

A bullet fired from a rifle begins to fall

True

An Earth satellite is simply a projectile freely falling around the Earth.

beneath the plane

An airplane flies at 40 m/s at an altitude of 50 m. The pilot drops a heavy package, which falls and strikes the ground. Where, approximately, does the package land?

has a velocity that changes 9.8 m/s each second.

An object in free fall

10 m/s

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

10 m/s/s.

If you drop an object, it will accelerate downward at a rate of about 10 m/s/s. If you instead throw it downwards, its acceleration (in the absence of air resistance) will be

500 m

Starting from rest, the distance a freely falling object will fall in 10 s is about

100 m/s

Ten seconds after starting from rest, a freely falling object will have a speed of about

10 m/s

The gain in speed each second for a freely falling object is about

direction

Unlike scalars, vectors have which of the following?

0 m/s^2

What is the acceleration of a car that maintains a constant velocity of 100 km/h for 10 s?

zero and its acceleration is about 10 m/s/s.

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

same for each

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, acceleration is greatest for the

6 m/s

A car accelerates from rest at 2 m/s/s. What is its speed 3 s after the car starts moving?

220

A car traveling at 22 m/s comes to an abrupt halt in 0.1 s when it hits a tree. What is the deceleration in meters per second per second of the car?

50 m/s

A projectile is launched vertically at 50 m/s. If air resistance is negligible, its speed upon returning to its starting point is

5 m

A stone is thrown horizontally from the top of a cliff. One second after it has left your hand its vertical distance below the cliff is

exactly below the midpoint of the ceiling.

A truck is moving at constant velocity. Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor

velocity

Acceleration is the time rate of change of what?

60 m/s

An object is in free-fall. At one instant, it travels at a speed of 50 m/s. Exactly 1 s later, its speed is about

velocity increases

As an object freely falls, its

acceleration

Disregarding air resistance, objects fall at constant

a change in position.

Motion necessarily involves

5 m/s

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

distance and time

The two measurements necessary for calculating average speed are