I need the answers to these questions

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

Agroup of students were investigating the force of gravity. they began by dropping a foam ball from a height of 3 meters into a bucket of sand. the ball hit the sand in 0.306 seconds. they dropped additional balls of approximately the same diameter, but of different masses. here is the data they collected. based on this experiment and the collected data, what would their conclusion be?