What is it asking mathphys im sorry i dont know but i tried teaching myself physics but i cant

The puck B remains at the point of collision.

Explanation:

This is an elastic collision, so both momentum and energy are conserved.

The mass of both pucks is m.

The velocity of puck B before the collision is vb.

The velocity of puck A and B after the collision is va' and vb', respectively.

Momentum before = momentum after

m vb = m vb' + m va'

vb = vb' + va'

Energy before = energy after

½ m vb² = ½ m vb'² + ½ m va'²

vb² = vb'² + va'²

Substituting:

(vb' + va')² = vb'² + va'²

vb'² + 2 va' vb' + va'² = vb'² + va'²

2 va' vb' = 0

va' vb' = 0

We know that va' isn't 0, so:

vb' = 0

The puck B remains at the point of collision.

a

explanation:

because they are cartillidge

force tends to be low and long diustance masses are high