A body is initially at rest. It under goes one-dimension motion with constant acceleration. The power delivered to it at time t is proportional to

power =force . velocity---(1) but acceleration =velocitytime ⇒a t = velocity ---(2) substitute eqn(2) in (1) power P=F(at) given acceleration is constant, hence force will be constant ⇒power α time ⇒P α t