Question

A particle moves along a straight line such that its displacement at any time t is given by s = (t³ – 6t² + 3t + 4) metres.The velocity when the acceleration is zero is(a) 3 ms⁻¹ (b) – 12 ms⁻¹(c) 42 ms⁻² (d) – 9 ms⁻¹

Answer 1

v=ds/dt
a=dv/dt
=6t-12=0 given
IE. t=2
therefore,

v= 3t²-12t+3

since t=2

v = 3*4 - 12*2 +3
v = 12+3-24
ie v= -9m/s