Question

A body moves in a straight line so that its distance 'x' from a fixed point after 't' seconds is given by the formula x=9t^2÷2-t^3÷2 find: a; its velocity after 2 seconds b; its velocity when the acceleration is 0???

Answer 1

x(t) = 9t^2/2 - t^3/2
v(t) = 9t - 3t^2/2
a(t) = -3t

Now it should be easy to answer the questions.