I need help in Physics pls help me!

20 points for CORRECT ANSWER!!!

Astone is dropped with no initial velocity from the top of a cliff and hits the ground a time of 3.9 s later. what is the height of the cliff, in units of meters? you may assume that air resistance is negligible. give the answer as a positive number question 15 a figure skater is rotating at a rate of 200 revolutions per minute. what is the angular speed, in units of rad/s? 200 o 20.9 12000 o 3.33

If a balloon is taken outside on a very cold day, what will occur?

The combining of light nuclei is called blank. blank as in not actually blank. you know what im tryin to say.