Question

Luz, who is skydiving, is traveling at terminal velocity with her body parallel to the ground. She then changes her body position to feet first toward the ground. What happens to her motion? She will continue to fall at the same terminal velocity because gravity has not changed. She will slow down because the air resistance will increase and be greater than gravity. She will speed up because air resistance will decrease and be less than gravity. She will begin to fall in free fall because she will have no air resistance acting on her.

Answer 1

Answer:

She will speed up because air resistance will decrease and be less than gravity.

Explanation:

While Luz was falling initially, she was experiencing a gravitational force downwards, and air resistance that arise from the drag force on her body

Her gravitational force downwards is constant, and she fall down with a net force of

$F_{net}$ = $F_{g}$ - $F_{d}$

where $F_{net}$ is the net force on Luz downwards

$F_{g}$ is the gravitational force on Luz

$F_{d}$ is the drag force on Luz

The drag force on on Luz is proportional to her attack surface area.  When Luz changes her body position from her frontal area, parallel to the ground to falling with her feet first, she reduces the area available for drag force from her whole frontal area to just about a little more than the areas of the sole of her feet. This action reduces the drag force due to air resistance on her body.

Answer 2

Answer:

The correct answer to the question is the third statement.

Explanation:

She will speed up because air resistance will decrease and be less than gravity. Changing position during skydiving is one of the factors affecting the speed. Since the cross section area is smaller than the first position, she experiences lesser air resistance, which causes her to speed up.