A stone is thrown into a pond. Five waves were made from the same source in 10 seconds. help me plz

Energy is the ability to do work which measures what

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)

Why does a collision with an airbag cause less damage than a collision with a steering wheel