The position of a particle moving along the $x$ -axis varies with time according to $x(t)=5.0 t^{2}-4.0 t^{3} \mathrm{m} .$ Find (a) the velocity and acceleration of the particle as functions of time, (b) the velocity and acceleration at $t=2.0 \mathrm{s},(\mathrm{c})$ the time at which the position is a maximum, (d) the time at which the velocity is zero, and (e) the maximum position.