A particle moves in a straight line. At time t seconds its velocity is given by v(t) = t2 + 2t - 8 m/s. Find an expression for the displacement s(t) from O at time t given that the initial position is 4 metres from the origin O (in the positive direction). Draw the motion diagram and find the distance travelled in the first 3 seconds. Solution \\(v = ds/dt\\) Intergrate: \\( s = t^3/3 + t^2 -8t +c\\) Given that s at t-0 is 4, so c= 4. \\( s(t) = t^3/3 + t^2 -8t + 4\\) \\( s(3) = 3^3/3 + 3^2 -8(3) + 4 = -2m\\).