Question

A 40 ton rail car and a 100 ton rail car, initially at rest, are connected together with a giant but massless compressed spring between them. When released, the 40 ton car is pushed away at a speed of 3.3 m/s relative to the 100 ton car. What is the speed of the 40 ton car relative to the ground?

Answer 1

The speed of the 40 ton rail car relative to the ground after the spring is released is also 3.3 m/s due to the conservation of momentum

Step-by-step explanation:

The question at hand involves the concept of conservation of momentum, which is a fundamental principle in Physics. When the compressed spring between the two rail cars is released, the cars push away from each other, and their momenta are equal and opposite due to the law of conservation of momentum. The 40 ton (which is 40,000 kg) car is moving at a speed of 3.3 m/s relative to the 100 ton (100,000 kg) car. Because both cars start from rest, the speed of the 40 ton car relative to the ground is also 3.3 m/s, as there is no additional external force applied to the system.