A Perfect Wat to Answer This... (1 Viewer)

[Ajihood]

Can someone tell me the perfect way to answer this, im in Year 11, so it should be easy for you year 12ers out there

Explain why momentum is conserved in collisions in terms of Newton's Third Law of motion.

Thanks for any help. Its a 5 marks question too.

 

[Ajihood]

No one able to help me?

 

[helper]

F₁=-F₂
so m₁a₁=-m₂a₂
m₁(v₁-u₁)/t=-m₂(v₂-u₂)/t
t is common so cancels
m₁(v₁-u₁)=-m₂(v₂-u₂)
m₁v₁+m₂v₂=m₁u₁+m₂u₂
So momentum before equals momentum after

 

[Forbidden.]

F₁=-F₂
so m₁a₁=-m₂a₂
m₁(v₁-u₁)/t=-m₂(v₂-u₂)/t
t is common so cancels
m₁(v₁-u₁)=-m₂(v₂-u₂)
m₁v₁+m₂v₂=m₁u₁+m₂u₂
So momentum before equals momentum after

Exactly the same way Mr. P taught us in the Preliminary year, I forgot it all.
The equal and opposite part, "m₁a₁=-m₂a₂" is crucial to this.