A person pushes a 72 kg patient on a 15 kg trolley, producing an acceleration of `0.60m//s^2` (a) How much work does the person do by pushing the patient and the trolley through a distance of 2.5m ? Assume the trolley moves without friction. (b) How far must the person push the trolley to do 140J of work. (c) Does the work done by the person depends on the speed of the trolley?

Explanation

(a) `F = ma = (72 kg + 15kg)(0.60 m//s^2) = 52N`
W = F s =(52N)(2.5m) =130J
(b) As W = F s, `s = (W)/(F) = (140J)/(52N) = 2.7m `
(c ) No, the work done on an object W = F s, does not depends on whether the object moves through
the distance s quickly or slowly.