Momentum is the term which measure the quantity of motion the body has. It relies on mass the body  has the velocity with which the body moves.If the mass and velocity of a body is constant Any body in motion the momentum is inbuilt in it. Hence we can define momentum as mass in motion.
Momentum
The momentum formula is given by,
Momentum = mass $\times$ velocity
or
p = m $\times$ v.
Where, p = momentum, m = mass, v = velocity.

Momentum is a vector quantity and its SI unit of  it is a kilogram meter per second (Kg m/s).

Below are given some examples on momentum:

Question 1: A truck of mass 800 kg moves with velocity 30 m/s. Calculate its momentum.
Solution:
Given: Mass m = 800 kg, velocity v = 30 m/s

The momentum is given by,
p = m $\times$ v
p = 800 kg $\times$ 30 m/s
p = 24000 kgm/s

Therefore, the truck moves with 24000 kgm/s of momentum.

Question 2: A rock of mass 10 kg falls from hill with velocity 5 m/s. Calculate its momentum.
Solution:
Given: Mass m = 10 kg, velocity v = 10 kg

The momentum is given by,
p = m $\times$ v
p = 10 kg $\times$ 5 m/s
p = 50 kgm/s.

Therefore, the rock falls with momentum of 50 kgm/s.