Question

A 75 kg astronaut in space pushes against a 200 kg anvil. When the astronaut lets go of the anvil while pushing it: My answer is D (Just checking my work)

A. both astronaut and anvil accelerate in opposite directions at the same rate
B. neither the astronaut nor the anvil will accelerate since net force equals zero
C. both accelerate, but the anvil accelerates more than the astronaut
D. both accelerate, but the anvil accelerates less than the astronaut


A 75 kg person and a 200 kg crate are each parachuted to earth from a plane. Which statement is correct? My answer is C

A. the crate will reach terminal velocity las, but hit the ground first
B. the person will reach terminal velocity last, but hit the ground first
C. the person and crate reach terminal velocity at the same time and hit the ground at the same time
D. ther person and crate reach terminal velocity at the same time but the crate wiill hit the ground first

A skydiver steps from a helicopter and falls for 5 seconds before reaching her terminal velocity. During this 5 second interval, her acceleration: My answer is A

A. decreases
B. is constant
C. is zero
D. increases

Answer 1

If there is no force on something it does not accelerate.
F = m a
if the astronaut is not pushing the anvil, neither will accelerate further.

Answer 2

There is more net force up on the person/parachute than on the crate/parachute at every speed.
Therefore the crate accelerates down faster and has higher terminal velocity.
Therefore I would say A.

Answer 3

Net down force on diver is less and less, so acceleration down is less and less.
Agree A