A mover pushes a 245 kg piano so that it accelerates uniformly from rest to 1.5 m/s in 5.00 s. What is the power delivered by the mover in this time interval? A 55W B 110W C 280W D 540 W

B, 110 W

Explanation:

we can use the equation P = Fv

P = Fv

P = mav

m = 245 kg

a = (vf - vo)/t

a = (1.5 - 0)/5

a = 0.3 m/s^2

v = 1.5 m/s

P = 245 * 0.3 * 1.5

P = 110 W

answer choice B

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.