2.9 Acceleration and Free Fall

What happens to the velocity of a ball as it is dropped off a cliff? 

• It decreases.

• It increases.

• It is constant.

In a normal environment, why does a bowling ball and feather hit the ground at different times when dropped from the same height?

• They don't; they hit the ground at the same time.
• One is more dense than the other.
• One is heavier than the other.
• Air resistance 

Which would hit the ground first if dropped from the same height in a vacuum—a feather or a metal bolt?

• the feather
• the metal bolt
• They would hit the ground at the same time.
• They would be suspended in a vacuum.

Which would fall with greater acceleration in a vacuum—a leaf or a stone?

• the leaf
• the stone
• They would accelerate at the same rate.
• It is difficult to determine without more information.

If you throw a baseball straight up, what is its velocity at the highest point?

• 9.8 m/s²
• 9.8 m/s
• 0 m/s²
• 0 m/s

A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of the ball when caught would be 

• less than the speed it had when thrown upwards.
• more than the speed it had when thrown upwards.
• the same as the speed it had when thrown upwards.

A skydiver jumps out of a plane and is falling towards the Earth before she opens her parachute.

• She is in free fall because nothing is holding her up.

• She is in free fall because gravity is pulling her down.

• She is not in free fall because skydiving is an expensive hobby.

• She is not in free fall because gravity is not the only force she is experiencing.

A textbook is dropped from a second floor window and falls to the ground. What happens to the velocity as the book falls to the ground

• the velocity increases

• the velocity decreases

• the velocity remain constant

A textbook is dropped from a second floor window and falls to the ground. What happens to the acceleration as the book falls to the ground

• the acceleration increases

• the acceleration decreases

• the acceleration remains constant

A baseball is thrown up into the air. What happens to the velocity as the ball rises in the air?

• the velocity increases

• the velocity decreases

• the velocity remains constant