A rock is thrown into a swimming pool that is filled with water at a uniform temperature. As the rock moves beneath the pool's surface and sinks to the bottom of the pool, which of the following statements is true? a. The buoyant force on the rock increases as it sinks.
b. The buoyant force on the rock decreases as it sinks.
c. The buoyant force on the rock is zero as it sinks.
d. The buoyant force on the rock is constant as it sinks.
e. The buoyant force on the rock as it sinks is nonzero at first but becomes zero once the terminal velocity is reached.

A50 kg student climbs 3 m to the top of a set of stairs. calculate the change in the student’s gravitational potential energy from the bottom to the top of the stairs. show your calculations and include units in your answer. how much total work does the student do while climbing the stairs? show your calculations or explain your reasoning. include units in your answer. it takes the student 30 s to climb to the top of the stairs. what is the average power generated by the student climbing the stairs? show your calculations and include units in your answer. the next day the student carries a 10 kg backpack up the same stairs and again takes 30 s to reach the top of the stairs. is the average power you calculated in part (c) greater than, less than, or equal to the average power the student generated the next day? explain your answer.