a 1.0 kg ball is dropped from a 20 m tall building. how long will it take for the ball to hit the ground?

Imagine you are standing in the antarctic during the southern hemisphere summer. the sky is clear and blue. there are no clouds in the sky. your shadow is cast on the icy ground. what is the color of the shadow?

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down, 7.00 s after it was thrown. what is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? ignore air resistance.

Achild has maximum walking speed of 1.6 m/s. what is the length of the child's legs? 0.26 m