Newton's Second Law of Motion

MOMENTUM

Is the product of mass of a body and its velocity

The SI – Unit of momentum is Kilogram metre per second (Kgm/s) 

Example

The car of mass of 1000Kg is moving with a velocity of 40 m/s. Calculate the momentum of the car.

Solution

The momentum of the car = 40,000 Kg

THE NEWTON’S SECOND LAW OF MOTION

The Newton’s Second Law of Motion states that;

“The rate of change of linear momentum is directly proportional to the force applied and takes place in the direction of the force”

Example

What force is required to give a mass of 0.2 Kg an acceleration of 0.5 m/s².

Solution

The force required = 0.1 N

Example 2

What acceleration will be given to a body of mass 6 Kg by a force of 15 N?

Solution

The acceleration of a body will be 2.5 m/s²

Example 3

What mass will be given an acceleration of 5 m/s² by a force of 2 N

Solution

The acceleration of a body will be 0.4 m/s²

Application of Momentum and   Impulse in Our Daily Life

i)       While goalkeeper catching ball extends his hands forward so that he has enough room to let his hand move backward after impact to prevent bounce of ball

ii)     A person jump from a high ground to the floor bends his knees upon making contact otherwise his/she leg break

iii)   Glassware is wrapped in paper before packing to avoid breaking