Question

What happens to the velocities of the two objects when a high-mass object hits a low-mass object head-on? When a low-mass object hits a high-mass object head-on?

Short answer

When a high-mass object hits a low-mass object head-on, the velocity of the low-mass object increases but the velocity of the high-mass object remains the same. On the other hand, when a low-mass object hits a high-mass object head-on, the low-mass object rebounds with the same speed but the velocity of the high-mass object remains the same.

Step-by-step solution

Significance of the law of conservation of momentum of a system

This law states that the momentum of a particular system before and after the collision is constant if no external force acts on the system.

The law of conservation of momentum gives the velocities of the light and the heavy objects after the collision.

Determination of the velocities of the light and the heavy object

From the law of conservation of momentum, when a high mass object hits a low mass object, the low mass object moves with a higher speed and also with higher acceleration. As the force exerted is directly proportional to the acceleration, so, when force is exerted then the velocity of the low-mass object also increases but the high-mass object remains the same as there is no effect of force on that due to the reason that the mass of the heavy object is large.

Apart from that, when a low-mass object hits a high-mass object, the low-mass object rebounds with the same speed but the velocity of the high-mass object does not change. This is also due to the difference in mass. So, the low-mass object will not affect the high-mass object.

Thus, when a high-mass object hits a low-mass object head-on, the velocity of the low-mass object increases but the velocity of the high-mass object remains the same. On the other hand, when a low-mass object hits a high-mass object head-on, the low-mass object rebounds with the same speed but the velocity of the high-mass object remains the same.