Question

Why do we use momentum?

Answer 1

The importance of momentum

1. Momentum is a vector quantity since it has a direction it can be used to predict the direction and speed of the objects after they collide.
2. From the second law of motion, the rate of change of momentum is termed as a force.
3. The more momentum a body has the more force it can generate.

Rate of change of momentum $=\frac{mv-mu}{t}$

Here,

$$\begin{gathered} v=finalvelocity \\ u=initialvelocity \\ m=massoftheobject \\ a=accelerationofthebody \end{gathered}$$

$$\begin{gathered} =m\left(\frac{v-u}{t}\right) \\ =ma\left[\because acceleration,a=\frac{v-u}{t}\right] \\ =force\left[\because Force=ma\right] \end{gathered}$$

Second law motion proved.

Hence, momentum is used to predict the direction and speed of the objects.