What does newton's third law say about why momentum is conserved in collisions?

1. equal forces act for unequal times, so the change in momentum for both objects must be equal.
2. unequal forces act for unequal times, so the change in momentum for both objects must be unequal.
3. unequal forces act for unequal times, so the change in momentum for both objects must be equal.
4. equal forces act in equal times, so the change in momentum for both objects must be equal.

Option 4 is the correct answer.

Explanation:

I think you've heard that for every force, there is equal and opposite force.

So, option 2 and 3 will be wrong because unequal force is included in the answer.

Actually, both objects are exerting equal magnitude of force to each other throughout the duration of contact.

Now,

For forces to be equal, time of contact must also be equal.

So, option 4 is right.

option 4 is correct

Explanation:

Equal forces acts in equal times,so the change in momentum for both objects must be equal

the displacement produced by the body.  

the amount of force subjected to the body.  

the angle between the direction of force and displacement

so easy. just google the electromagnetic waves and it’ll pop up.