F2LT1 (Gravity)

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.
• If they had the same weight.
• If there was no air resistance.
• If there was no gravitational force.

Which of the following describes gravitational force?

• contact, repulsive
• contact, attractive
• noncontact, attractive
• noncontact, repulsive

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?

• the 2 kg apple
• the 7 kg bowling ball
• the 20 kg rock
• they all have the same acceleration when acted on by gravitational forces.

Why is the moon never pulled into the Earth despite gravitational forces that pull it toward Earth?

• The moon has enough of its own gravity to avoid being pulled to Earth.
• The moon is so large that gravity repels it from Earth rather than pulls it.
• The moon is pulled toward the sun with a force equal to Earth’s pull on it.
• The moon falls forward fast enough so that it is never pulled into Earth.

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?

• The gravitational force of Earth pulls objects towards the center of Earth.
• An object’s acceleration is equal to the force on the object divided by its mass.
• The gravitational force between two objects depends on the distance between them.
• The gravitational force between two objects depends on the mass of the two objects.

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?

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

Two satellites are orbiting Earth in opposite directions at the same altitude. They collide head-on and stick together, completely stopping their motion forward or backward. What will most likely happen to the wreckage immediately after the collision?

• The wreckage will remain floating in place where the collision happened.
• The wreckage will continue orbiting Earth, just at a slower speed.
• The wreckage will fall straight down toward Earth due to gravity.
• The wreckage will be pushed outward into space, away from Earth.

Which of the following is true of the strength of gravitational forces between two objects in relation to mass?

• Gravitational forces are greater when objects have a large mass.
• Gravitational forces are weaker when objects have a large mass.
• Gravitational forces are greater when objects have a small mass.
• Gravitational forces are the same regardless of the mass of the objects.

The strength of gravitational force on an object at Earth's surface depends on the Earth's mass and...

• the object’s mass
• the object’s speed
• whether the object is falling
• the object’s color

Choose the statement that correctly defines mass and weight.

• Mass is the amount of matter in an object, whereas weight is the force of gravity acting on that object.
• Mass is the force of gravity acting on an object, whereas weight is the amount of matter in an object.
• Mass is the size of an object, whereas weight is the amount of desity it has
• Mass is the speed at which an object moves, whereas weight is the distance between the object and Earth.