How would i solve these problems, nobody in my class understands and there is a substitute

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?

Asap and show ! a 14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earths velocity. earth mass is 6.0 * 10^24 kg. show your work assuming the rock earth system is closed.

Difference between series and parallel circuits