Page:Calculus Made Easy.pdf/86

 Find an expression for the velocity and the acceleration at any time. Find the velocity and acceleration after $$10$$ seconds.

(10) A body moves in such a way that the spaces described in the time $$t$$ from starting is given by $$s=t^n$$, where $$n$$ is a constant. Find the value of $$n$$ when the velocity is doubled from the $$5$$th to the $$10$$th second; find it also when the velocity is numerically equal to the acceleration at the end of the $$10$$th second.