Movement is a part of our day-to-day lives. But what is it that measures our movement? It’s momentum. In Physics, Momentum refers to the quantity of motion that an object has. It can be defined as “mass in motion”. Any slightest of object that has mass and moving is said to have momentum. The higher the momentum of the body, the higher force is required in the negative direction to stop it. We might have heard a person is on roll. It means, in an ironic way, if a person has gained momentum its difficult to bring him down.
PRINCIPLE OF CONSERVATION OF MOMENTUM:
Conservation of momentum is derived from conservation of energy. It states that when two bodies collide with each other, the net amount of momentum of the system remains intact and fixed. The combination of momentum of both the bodies remains same before and after the collision. In an isolated system, after collision, momentum gets transferred from one body to another but is not destroyed. For example, while playing cricket when you catch the ball, ball becomes stationary. The momentum of the ball is transferred from the ball to your body. That’s why players often fall down after catching the ball as huge quantity of momentum is transferred to their body. How momentum is transferred to the body depends on the type of collision, which can be of three types – elastic collision, partially inelastic collision and perfectly inelastic collision.
As mentioned above, when you catch a ball, momentum gets transferred to you. If you catch a ball, even you tend to fall back with it. Since the velocity of the ball was high when it reached to you, that velocity got transferred to you. Velocity is major deciding factor of momentum. Now consider, one table tennis ball and a cricket ball both travelling at the speed of 10 meters per second. Is the force required to stop the ball same in both cases? No. It takes lesser effort and energy to stop the table tennis ball than to stop the cricket ball. Therefore, other important aspect of momentum is mass. Momentum can be calculated as –
p = m * v
Where p is momentum of the body, m is mass of the body and v is velocity of the moving body. The SI unit of measurement of momentum is kilogram meter per second.