Question

What is the momentum of an object of mass m and moving with velocity v?

Answer 1

Hint: Momentum is simply defined as the mass in motion. All the objects have mass, so if the object is moving it possesses momentum. Momentum of a body is the product of its mass and the velocity by which the object is moving and mathematically it is represented as \[p=mv\]. We will see momentum, its type and example in brief.

Complete step by step answer:
Let us first define the motion.
Motion: Motion is described as the change in the position of the body with respect to time.
Force: Force is the agent which changes the position of the body or the direction of motion of the body.
According to Newton’s Second Law of motion, force if the product of mass and acceleration i.e. \[\overrightarrow{F}=m\overrightarrow{a}\].

Momentum:
a. Momentum of the body is the quantity of motion possessed by it or the momentum of a body is the product of its mass and velocity.
b. It is a vector quantity which means it has both magnitude and direction. The direction of momentum is the direction of velocity of the object.
c. Momentum possessed by linear motion is called linear momentum, given by $\overrightarrow{p}=m\overrightarrow{v}$ where p is the linear momentum.
d. Units of momentum: SI unit \[kgm{{s}^{-1}}\] and CGS unit \[gcm{{s}^{-1}}\].
Example of linear momentum, a bullet can penetrate a wooden block due to its high momentum. Even though the bullet is very lighter, the velocity is very high which makes the momentum higher.

Additional Information:
Another type of momentum is angular momentum which deals with rotational motion. Angular momentum of an object is the product of its linear momentum and perpendicular distance to a fixed point (from where angular momentum is to be determined). It is generally represented by L or J.
\[L=m(r\times v)\]

Note: Most of the times we are dealing with conservation of momentum, to determine the velocity after collision or before collision. In such a case momentum is always conserved i.e. the initial momentum of the body before collision is equal to final momentum after collision.