Question

Luz, who is skydiving, is traveling at terminal velocity when she changes position by going headfirst toward the ground. What happens to her motion?

Answer 1

Answer:

The velocity would increase as the surface area decreases

Explanation:

The force on a person falling is given by

$F=\dfrac{1}{2}\rho CAv^2\\\Rightarrow v=\sqrt{\dfrac{2F}{\rho CA}}$

where,

$\rho$ = Density of air

A = Surface are

C = Drag coefficient

v = Terminal velocity

F = Drag force

It can be seen that the terminal velocity of a body is inversely proportional to the surface area.

Hence, the velocity would increase as the surface area decreases.

Answer 2

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

Explanation:

The reason is because her mass and her weight are stronger than the air resistance which makes gravity pull her down.