The distance covered by a moving particle through point O is given by the equation, s = t^3- 15t^2+ 63t -10.

Question

Find:
(a) distance covered when t = 2

(b) the distance covered during the 3rd second;


(c) the time when the particle is momentarily at rest;


(d) the acceleration when t = 5

Answer 1

b. distance during third second: s(4)-s(3)=4^3-3^3-15(4^2-3^2)+63(4-2)
c. when at rest ds/dt=0 or 3t^2-30t+63=0
solve the quadratic, solve for time t.
d. s"=6t-30 at t=5, zero.