You have two balls of equal size and smoothness, and you can ignore air resistance. One is heavy, the other is much lighter. You hold one in each hand at the same height above the ground. You release them at the same time. What will happen?

They will hit the ground at the same time.

Explanation:

By ignoring the opposing forces i.e. air resistant, both the heavy and light balls will fall with same acceleration due to gravity (g=9.8 m/s²) and g is independent of mass of the objects. Thus both will hit the ground at the same time.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.