Which is an example of a transverse wave? A. an ultrasound that transmits sound waves
B. crowd doing the wave at a sporting event
C. the waves formed by an earthquake
D. the movement of a spring in a pogo stick

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)