Is this collision possible? Why or why not? Object A, initially travelling to th

Question

Is this collision possible? Why or why not? Object A, initially travelling to the right, collides withobject B, which is at rest. After the collision, object A movesback to the left and object B remains at rest.
(As far as I know is if object B has a really huge mass like awall then I think object A would move backwards if it collided intothe wall) Object A, initially travelling to the right, collides withobject B, which is at rest. After the collision, object A movesback to the left and object B remains at rest.
(As far as I know is if object B has a really huge mass like awall then I think object A would move backwards if it collided intothe wall)

Explanation / Answer

That collision is impossible provided object B has any finitemass and object A is travelling at non-relativistic speeds (speedsmuch less than the speed of light).
In order for object A to move backward after the collision, objectB must provide an impulse towards object A (a force over a certainperiod of time).
By Newton's III Law (which is valid for non-relativistic speeds),FAB = -FBA so the force exerted on object Afrom object B is also exerted on object B from object A, hence thesame force that pushed A backward will push B forward with equalmagnitude, so, as long as mass B isn't infinite, by conservation ofmomentum and NIII, it will indeed move forward (away from objectA). At relativistic speeds, you may need to consultEinstein.

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