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

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.

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.

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

Agree A

For the first question about the astronaut and the anvil, the correct answer is option A - both the astronaut and the anvil accelerate in opposite directions at the same rate.

To explain why, we need to understand Newton's third law of motion, which states that every action has an equal and opposite reaction. When the astronaut pushes against the anvil, they exert a force on it, and according to Newton's third law, the anvil exerts an equal and opposite force on the astronaut. This force causes both the astronaut and the anvil to accelerate.

Since acceleration is directly proportional to force and inversely proportional to mass (using Newton's second law of motion, F = ma), we can see that the acceleration of the astronaut will be greater than the acceleration of the anvil. This is because the mass of the astronaut (75 kg) is smaller compared to the mass of the anvil (200 kg). Therefore, option D is incorrect.

For the second question about the person and the crate parachuting to Earth, the correct answer is option C - the person and the crate reach terminal velocity at the same time and hit the ground at the same time.

Terminal velocity is the constant speed reached by an object when the drag force acting up against it is equal to the force of gravity acting downward. Both the person and the crate experience the same force of gravity since they are in the same gravitational field. The air resistance (drag force) acting on them will also be equal since they have the same shape and size.

Therefore, both the person and the crate will experience the same terminal velocity and reach the ground at the same time. This makes option C the correct answer.

For the third question about the skydiver reaching terminal velocity, the correct answer is option B - the acceleration is constant.

When an object falls freely through the atmosphere, it initially accelerates due to the force of gravity. However, as the object gains speed, the air resistance acting against it increases. Eventually, a point is reached where the drag force equals the force of gravity, resulting in a net force of zero. At this point, the object reaches its terminal velocity, and its acceleration becomes constant.

In the case of the skydiver falling for 5 seconds before reaching terminal velocity, it means that during this time interval, the skydiver's acceleration remains constant. Therefore, option A is incorrect since the acceleration does not decrease. The acceleration is also not zero (option C) or increasing (option D) during this 5-second interval. Therefore, the correct answer is option B - the acceleration is constant.