Problem 1.97

At the moment \(t=0\) a stationary particle of mass \(m\) experiences a time-dependent force \(\mathbf{F}=\mathbf{a} t(\tau-t),\) where a is a constant vector, \(\tau\) is the time during which the given force acts. Find: (a) the momentum of the particle when the action of the force discontinued: (b) the distance covered by the particle while the force acted.