Question 1187897
A particle travels in a straight line in such a way that; t seconds after passing through a fixed point 0, its displacement from 0 is s metres. 
Given that s=4-8/(t+2) find:

i) Expression in terms of t, for the velocity and acceleration of the particle.
Speed is the first derivate of displacement.
{{{s=4-8/(t+2) = 4 - 8(t+2)^-1}}}
{{{ds/dt = -8*(-1)*(t+2)^-2 = 8/(t+2)^2}}}
=======================
ii) The value of t when the velocity of the particle is 0.125m/s
{{{8/(t+2)^2 = 0.125}}}
{{{8 = 0.125(t+2)^2}}}
(t+2)^2 = 64
t+2 = 8
t = 6
================
iii) The acceleration of the particle when it is 3.5m from 0.
accel is the 2nd derivative of displacement.