Question

A flatcar of mass m_o starts moving to the right due to a constant horizontal force F (Fig: 1.46). Sand spills on the flatcar from a stationary hopper. The velocity of loading is constant and equal to μ kg/s. Find the time dependence of the velocity and the acceleration of the flatcar in the process of loading. The friction is negligibly small.

Answer 1

Let the car be moving in a reference frame to which the hopper is fixed and at any instant of time, let its mass be m and velocity vector v.

Then from the general equation, for variable mass system