Momentum in a simple way is a quantity of motion. Here quantity is measurable because if an object is moving and has mass, then it has momentum. If an object does not move then it has no momentum. However, in everyday life it has an importance but many people didn’t recognize it. Momentum is just about every activity that involves motion. It is an essential concept of physics. In sports momentum term is commonly used. Like, if a team has the momentum then it is on the move and is going to take some effort to stop. But if a team has lot of momentum then it is really on the move and is going to be hard to stop. This article deals with the concept of momentum with examples and its importance in everyday life.
What is momentum?
The momentum of a body is defined as the product of its mass and velocity. This we can better understand with the help of an example: Cricket ball is much more heavy than a tennis ball. Suppose we throw a cricket ball and a tennis ball, both with the same speed or velocity. It will be found that more force is required to stop the cricket ball which has more mass and less force is required to stop the tennis ball which has less mass. Therefore, we can say that the force required to stop a moving body is directly proportional to its mass.
When we throw two cricket balls of the same mass but with different speed or velocities then it will be found that more force is required to stop that cricket ball which is moving with higher speed or velocity than another with lower speed or velocity. So, we can say that the force required to stop a moving body is also directly proportional to its velocity. Thus, the quantity of motion in a body depends on the mass and velocity of the body. Momentum is a vector quantity and takes place in the direction of velocity. SI unit of momentum is kilogram metres per second or kgms-1.
Momentum = mass x velocity
Or, p = m x v
Where p = momentum
v= velocity or speed
If a body is at rest, its velocity is zero and so its momentum will also be zero.
Why bursting of Balloon makes sound when pricked with a needle?
Importance of momentum in everyday life
Do you know that every moving body possesses momentum. This we can see with various examples:
- In everyday life momentum is used many a times. Like, I say that I run every day, mostly i.e. I run every day and so I have built a momentum for this. If I didn’t run with consistency or not exercise then I have built up negative momentum that would make it even harder to get started.
- A karate player break a pile of tiles or a slab of ice with a single blow of his hand. This is because a karate player strikes the pile of tiles or the slab of ice with his hand very very fast. In doing so, the large momentum of the fast moving hand is reduced to zero in a very, very short time. This exerts a very large force on the pile of tiles or the ice slab which is sufficient to break them apart.
- We have seen that road accidents at high speeds are very much worse than accidents at low speeds. This is because the momentum of vehicles running at high speeds is very high and causes a lot of damage to the vehicles and injuries to passengers during the collision.
- A bullet, although small in mass, has a large momentum because of an extremely large velocity.
Therefore, we can conclude that the combined effect of mass and velocity of a body is taken in to account by a physical quantity called momentum and is considered to be a measure of the quantity of motion of a moving body.