Question

what is the conservation of momentum? ​

Answer 1

Answer:

Definition of conservation of momentum

Definition of conservation of momentum:

a principle in physics: the total linear momentum of a system of particles not acted upon by external forces is constant in magnitude and direction irrespective of any reactions among the parts of the system.

Answer 2

Heya mate :)

First we go through momentum !

Momentum ^^

➡️Momentum measures the quantity of motion possessed by a body . It is defined as the product of mass and velocity of the body . Besides magnitude , momentum also has a direction . At any instant , it's direction is the same as the direction of the velocity .

If a body of mass

$m$

moves with a velocity

$v$

, then momentum ' p ' is given by

$p = mv$

The S.I unit of momentum is Kg -m/s.

➡️If a body is in rest , it's velocity , v = 0 and so momentum , p =0

Laws of conservation of momentum :-

laws of conservation of momentum is a result of Newton's third law of motion . According to this law , the total momentum of a system of objects remains conserved before and after their interaction or collision provided that there is no external unbalanced force acting on them .

➡️Total initial momentum of system is given by

= mA uA + mB uB

➡️Total final momentum of system is given by

= mA vA + mB vB

See the above attachment and try to understand the points which I have written :)

To prove :- mA uA + mB uB = mA vA + mB vB

Proof from Newton's third law of motion , force exerted by mA on mB = - (force exerted by mB on mA )

From Newton's second law

mB (vB - uB / t ) = -mA( vA-uA / t )

Therefore Acceleration , a = final velocity - initial velocity / time taken )

=> mB vB - mB uB / t = ( - mA vA + mA uA / t

=> mB vB - mB uB = - mA vA + mA u A

or , mA vA + mB vB = mA uA + mB uB

Where ( mA uA + mB uB ) is the total momentum of two objects before collision and ( mA vA + mB vB ) is their total momentum of two objects is unchanged or conserved before and after the collision !

Hence Proved !

Application of law of conservation of momentum

Some practical application based on the law of conservation of linear momentum are as follows :

I. While firing a bullet , the gun should be held tight to the shoulder due to recoil the gun.

II. When a man jumps out of a boat to the shore then the boat slightly moves away from the shore to conserve the momentum

III. Rocket and jet plane work on the principle of conservation of momentum

IV. An astronaut in open space , who wants to return to the spaceship , throws some objects in a direction opposite to the direction of motion of the spaceship .

Hope it will help you :)

Thankyou !