PSSI: Chapter 2 Quiz

A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is about

10

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

10 m/s/s

Action and reaction forces comprise the parts of

A single interaction

Disregarding air resistance, objects fall at constant

Acceleration

If the mass of an object does not change, a constant net force on the object produces constant

Acceleration

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

At the same time as the lighter object

Earth pulls on the Moon. Similarly the Moon pulls on Earth, evidence that - Earth's and Moon's pulls comprise an action-reaction pair - Earth and the Moon are simply pulling on each other - Both of these

Both of these

If an object falls with constant acceleration, the velocity of the object must

Continually change by the same amount each second

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

Directed downward

An object is propelled along a straight-line path by a force. If the net force were doubled, its acceleration would

Double

An elephant and a feather fall from a tree through the air to the ground below. The amount of air-resistance force is greater on the

Elephant

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

Exactly below the midpoint of the ceiling

A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the

Force the glove exerts on the ball

A large and a small person wish to parachute at equal terminal velocities. The larger person will have to

Get a larger parachute

Consider drops of water that leak from a dripping faucet. As the drops fall, they

Get father apart

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

Greater than the second before

An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much, its acceleration

Halves

An object following a straight-line path at constant speed

Has zero acceleration

Two objects of the same size, but unequal weights are dropped from a tall tower. Taking air resistance into consideration, the object to hit the ground first will be the

Heavier object

A heavy block at rest is suspended by a vertical rope. When the block is accelerated upward by the rope, the rope tension

Increases

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

Increasing

If you are carrying a heavy bag of groceries and bang your hand against the wall, the concept that most explains why you are hurt is

Inertia

A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is

Its weight

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

Less than the speed it had when thrown upwards

A force is a vector quantity because it has both

Magnitude and direction

An object maintains its state of motion because it has

Mass

While a car travels around a circular track at constant speed, its - Acceleration is zero - Both of these - Velocity is zero - None of these

None of these

The maximum acceleration of a car while towing a second car twice its mass, compared to no towing, is

One-third

A heavy rock and a light rock in free fall have the same acceleration. The reason the heavy rock doesn't have a greater acceleration is that the

Ratio of force to mass is the same

The force exerted on the tires of a car to directly accelerate it along a road is exerted by the

Road

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

Same for each

Two factors that greatly affect air resistance on falling objects are the size and

Speed of the object

A light woman and a heavy man jump from an airplane at the same time and open their same-size parachutes at the same time. Which person will get to a state of zero acceleration first?

The light woman

A rocket becomes progressively easier to accelerate as it travels upward from the ground mainly because

The mass of the rocket decreases as fuel is burned

The brakes are slammed on a speeding truck and it skids to a stop. If the truck were heavily loaded so it had twice the total mass, the skidding distance would be

The same

Neglecting friction, a large block of ice and a small block of ice start sliding down an incline together. The heavier block will get to the bottom

The same time as the light block

The force required to maintain an object at a constant velocity in free space is equal to

Zero

When a falling object has reached its terminal velocity, its acceleration is

Zero

When a rock thrown straight upwards gets to the exact top of its path, its velocity is - About 10 m/s and its acceleration is about 10m/s/s - None of these - Zero and its acceleration is zero - About 10 m/s and its acceleration is zero - Zero and its acceleration is about 10 m/s/s

Zero and its acceleration is zero