1.5: Displacement, velocity and acceleration

4PM1/2/June/2022 — Question 2 · 6 marks

A particle P\displaystyle P moves along the x\displaystyle x-axis. At time t\displaystyle t seconds, the displacement, x\displaystyle x metres, of P\displaystyle P from the origin O\displaystyle O is given by
x=t413.5t+12.x=t^4-13.5t+12.
(a) Find the velocity, in ms1\displaystyle \mathrm{m\,s^{-1}}, of P\displaystyle P when t=3\displaystyle t=3.
(2)
(b) Find the value of t\displaystyle t for which P\displaystyle P is instantaneously at rest.
(2)
(c) Find the acceleration, in ms2\displaystyle \mathrm{m\,s^{-2}}, of P\displaystyle P when t=2\displaystyle t=2.
(2)