Momentum is the power of motion of an object.
The product of velocity and mass is called the momentum. Momentum is denoted by 'p'.
Therefore, Momentum of the object = Mass x Velocity
\[p=m\times v\]
Where, p= momentum, m = mass of the object and v = velocity of the object
Consider the following explanations to understand the momentum:
- A person get injured in the case of hitting by a moving object, such as stone, pebbles or anything because of momentum of the object.
- Even a small bullet is able to kill a person when it is fired from a gun because of its momentum due to great velocity.
- A person get injured severely when hit by a moving vehicle because of momentum of vehicle due to mass and velocity.
Since momentum is the product of mass and velocity (p = m x v) of an object. This means momentum is directly proportional to mass and velocity. Momentum increases with increase of either mass or velocity of an object.
This means if a lighter and a heavier object is moving with same velocity, then heavier object will have more momentum than the lighter one.
If a small object is moving with great velocity, it has tremendous momentum. And because of momentum, it can harm an object more severely. For example, a small bullet having a little mass even kills a person when it is fired from a gun. Usually, road accidents prove more fatal because of high speed than in slower speed. This happens because vehicles running with high speed have greater momentum compared to a vehicle running with slower speed.
Momentum of an object which is in the state of rest:
Let an object with mass 'm' is in the rest.
Since, object is in rest, therefore, its velocity, v = 0
Now, we know that
Momentum = mass x velocity
Or p =m x v = 0 x 0 = 0
p = 0 kg m/s
Thus, the momentum of an object in the rest i.e., non-moving, is equal to zero.
Unit of momentum:
We know that
SI unit of mass = kg
SI unit of velocity = meter per second i.e., m/s
Momentum (p) = m x v
Therefore,
p = kg x m/s = kg m/s
Therefore, SI unit of momentum = kg m/s