Gravity Test

Michael is doing an experiment. He wants to drop a bowling ball and a stuffed bear out the window of a tall building. Under what conditions would they have the same acceleration?

• . If they had the same mass.

• B. If they had the same weight.

• C. If there was no air resistance.

• D. If there was no gravitational force.

A scientist, using a very precise scale, finds that a backpack full of heavy scientific textbooks weighs less on top of a high mountain than it does at sea level. What gravitational principle is this phenomenon illustrating?

• A. The gravitational force of Earth pulls objects towards the center of Earth.

• B. An object’s acceleration is equal to the force on the object divided by its mass.

• C. The gravitational force between two objects depends on the distance between them.

• D. The gravitational force between two objects depends on the mass of the two objects.

Satellite A is about to lose power while in orbit. It needs to immediately change course so it doesn’t hit Satellite B, a functioning satellite. The remaining fuel in Satellite A can be used to either thrust farther away from Earth or slow down. If it is thrust farther from Earth, it will be in orbit around Earth in the “graveyard orbit” far away from functioning satellites. If Satellite A uses its fuel to slow down, what will happen?

• A. The slower speed will make any collision with a functioning satellite unimportant.

• B. The gravitational force of the moon will exert more force, causing Satellite A to exit Earth’s orbit

• C. Without the horizontal force, the gravitational force of Earth will cause Satellite A to fall into the atmosphere, where it will burn up.

• D. The slower speed will make the gravitational force of Earth stronger, causing it to fall into the atmosphere, where it will burn up.

Astronauts visiting the moon collect and measure rock samples. Rock A is a 2 kg rock that weighs 1 N on the moon. Rock B is a 4 kg rock that weighs 2 N on the moon. How and why are the weights of these rocks likely to change once the rocks are brought back to Earth?

• A. Both rock samples are likely to weigh more on Earth because their masses will increase.

• B. Both rocks are likely to weigh less on Earth because their masses will increase.

• Both rocks are likely to weigh less on Earth because they are from the moon, which exerts a weaker gravitational force than Earth

• D. Both rocks are likely to weigh more on Earth because Earth exerts a stronger gravitational force on their respective masses than the moon

Which of the following describes gravitational force?

• A. contact, repulsive

• B. contact, attractive

• C. noncontact, attractive

• D. noncontact, repulsive

Which of the following describes the cause and effect relationship between gravity and falling objects?

• A. Gravity causes objects to fall toward the center of Earth.

• B. Gravity causes objects to repel from the center of Earth.

• C. Gravity is caused by objects’ attraction to the center of Earth.

• D. An object’s force is caused by gravity’s attraction to the center of Earth.

The strength of gravitational forces on an object near Earth’s surface depends on

• A. Earth’s mass.

• B. the object’s mass.

• C. the object’s speed.

• D. whether the object is falling.

What is likely to happen to the way an object moves if gravitational forces on the object do not change?

• A. The object will move in predictable ways.

• B. The object will move in unpredictable ways.

• C. The object will be pushed slightly away from Earth.

• D. The object will be pulled closer to the center of Earth.

Which object has greater acceleration when acted on by gravitational forces? A 2 kg apple, a 7 kg bowling ball, or a 20 kg rock?

• A. 5 m/s2

• B. 9.8 m/s2

• C. 15.2 m/s2

• D. 20 m/s2

Why doesn’t a feather fall at the same rate as an apple?

• A. Feathers are too light to be affected by gravitational forces.

• B. Gravitational forces affect different objects in different ways.

• C. Air resistance reduces an object’s downward acceleration and affects objects differently.

• D. Air resistance increases an object’s downward acceleration and affects objects differently.