(a) A car is moving with a velocity of 10ms It then accelerates at 0.2ms for 100m. Find, correct to two decimal places the time taken by the car to cover the distance. (b) A particle moves along a straight line such that its distance S metres from a fixed point O is given by S = t - 5t + 6, where t is the time in seconds. Find its: (i) initial velocity; (ii) distance when it is momentarily at rest
Explanation
(a) u = 10ms, a = 0.2m, s = 100m, t = ? using S = ut + 100 = 10t + 100 = 10t + 0.1t 0.1t + 10t - 100 = 0 t = t = t = t = t = t = t = t = 9.15 seconds
(b)(i) S = t - 5 + 6 v = = 2t - 5 at t = 0, y = 2(0) - 5 = - 5ms The initial velocity is 5 in the negative direction
(ii) When t = 0, S = t - 5t + 6 S = 0 - 5(0) + 6 S = 6 The distance is 6m
