Any help please? I differentiate and integrate using the usual methods to find acceleration and displacement respectively. Since the particle is 18m from O, it could mean that s, displacement = both -18m and 18m. Hence, I have two probable equations for the displacement, and 2 e.qs for velocity and acceleration with three unknowns. Then, I'm unable to get anywhere.A particle moving in a straight line passes through a fixed point O such that it's velocity, v m/s is given by v=6+pt-qt^2, where t is the time in seconds after passing through O, and p and q are constants. when the acceleration is zero, it's velocity is 10 m/s and the particle is 18m from O after 2 seconds.

Find

(i) the values if p and q,

(ii) the interval of t when the velocity is decreasing.

Answer:

(i) p=6, q=9/4

(ii) t>4/3

A quick answer would be much appreciated, as I need this in time in about 6 more hours. TIA.

EDIT: Added a new question.

The answer is 16.5 m, but I'm getting a different answer.A particle moving in a straight line passes through a fixed point, O. It's velocity, v m/s at the time seconds is given by v=2t^2-6t-8. Given that after 3 seconds, the particle is 4m to the left of O.

Find the distance traveled from the beginning until when the acceleration is zero.