Question

What happens to the speed of the rail cart as sand pours out?

Answer 1

In order to solve this question, we are going to first consider the movement of the rail cart and on which type of surface it is moving. After that the case of the sand pouring out and its impact on the speed of the rail cart are discussed. Then, a final conclusion about motion is discussed.

Complete step-by-step solution:
Let us consider the rail cart to be moving with a constant speed which is carrying sand. It is moving on a straight frictionless level track. Now because the surface is frictionless, this means that the speed remains the same irrespective of the sand pouring out. The speed depends more on the nature of the surface and the external forces that are present and not the sand pouring out. Therefore, the speed of the rail cart remains the same as sand pours out or is not changed due to the sand pouring out. Thus, it can be concluded that the momentum of the cart alone, if considered, remains constant following the law of conservation of momentum. This is because the momentum directly depends on the speed of the cart which is constant.

Note: It is important to note that we need to confirm the type of surface on which the cart or any vehicle is moving. This determines all kinds of the external forces that are acting on the vehicle. This gives the impact of the movement of the internal bodies that are present in it on the speed of the vehicle.