Question

Explain conservation of momentum......9th std in simple words.​

Answer 1

Answer:

When to (or more) bodies act upon one another, their total momentum remains constant (or conserved) provided no external forces are acting.

Explanation:

Suppose a car named A of mass 1500 kg, travelling at 25m/s collides with another car B of mass 1000 kg travelling at 15m/s in the same direction. After collision the velocity af car A becomes 20m/s .Then how will we Calculate the velocity of car B after the collision?

(a) Momentum of car A(before Collision) = Mass of car A x Velocity of car A =1500x25 = 37500 Kg. m/s.

Momentum of car B (before Collision) = Mass of car B x Velocity of car B =1000x15 =15000 kg. m/s.

Total Momentum of car A and car B(before Collision) =37500+15000= 52500 kg. m/s.

(b) After collision, the velocity of car A of mass 1500 kg becomes 20m/s.

So, Momentum of car A(after Collision) = 1500x20= 30000 kg. m/s .

After collision, suppose the velocity of car B of mass 1000kg becomes v m/s.

So, Momentum of B(after Collision) = 1000x v= 1000v kg. m/s.

Total Momentum of car A and car B (after collision) = 30000+1000 v.

Now according to the law of conservation of Momentum :

Total Momentum before collision = Total Momentum after Collision

That is, 52500= 30000+ 1000v

1000v= 52500-30000

1000v= 22500

v = 22500/1000

v= 22.5 m/s.