Question

A springboard diver intending to do a somersault brings her knees and arms closer to her body during the dive. What effect does this have?
It makes her fall more slowly.

It decreases her moment of inertia.

It decreases her angular velocity.

It increases her angular momentum.

Answer 1

During the diving when a diver jumps off from platform he brings her knees and arms closer to the body

This is because when diver is in air he don't have any torque about his center of mass which shows that angular momentum of his body will remain constant during his motion in air

Now we can say product of his moment of inertia and his angular speed will remain constant always

So here if we decrease the moment of inertia of the body during our motion then angular speed will increase so that product will remain constant

and this is what the diver use during his diving

so correct answer will be

It decreases her moment of inertia.