(i)[2]
Determine v when t = 8 and hence determine k.
(ii)[2]
Determine the maximum velocity of P.
(iii)[3]
Determine the displacement of P from its starting position when t = 18.
Mathematics 9709 · AS & A Level · Kinematics of motion in a straight line
Kinematics of motion in a straight line — practice question
A particle P leaves from rest and travels in a straight line for 18 s. During the first 8 s, P has constant acceleration 0.25 m s^-2. After that, P’s velocity, v m s^-1 at time t seconds after the motion began, is given by v = -0.1t^2 + 2.4t - k, where 8 ≤ t ≤ 18 and k is a constant.