A car of mass M is free to move on a frictionless horizontal surface. A gun fires bullets on the car. The bullets leave the stationary gun with speed `u` and mass rate `b kg s^(-1)`. The bullets hit the vertical rear surface of the car while travelling horizontally and collisions are elastic. If the car starts at rest find its speed and position as a function of time. Mass of the car `M gt gt` mass of each bullet.

Answer

`v=(u)/(1+(M)/(2bt))`