A crate on a motorized cart starts from rest and moves with a constant eastward acceleration of a = 2.50m/s^2 . A worker assists the cart by pushing on the crate with a force that is eastward and has magnitude that depends on time according to F(t) = (5.40\;{\rm N/s})t. Part
A What is the instantaneous power supplied by this force at t = 4.20s?