Two hockey players are about to collide on the ice. One player has a mass of 66 kg and is traveling at 1.5 m/s north. The other has a mass of 75 kg and is
traveling at 1.2 m/s south. The system consists of the two tlockey players.
According to the law of conservation of momentum, what is the total
momentum of the system after they collide? Assume the collision is an
elastic collision.
A. 189 kg-m/s south
O B. 9 kg-m/s north
C. 189 kg. m/s north
D. 9 kg m/s south

Option B: 9 kg.m/s North

Explanation:

We are told;

One player has a mass of

66 kg and is traveling at 1.5 m/s north.

Thus, velocity is positive since it's acting in the positive direction upwards.

Thus;

m1 = 66 kg

v1 = 1.5 m/s

Also, The other has a mass of 75 kg and is traveling at 1.2 m/s south.

Since it's traveling south, it means that velocity is negative. Thus;

m2 = 75 kg

v2 = -1.2 m/s

From conservation of mass, total momentum is;

m_total = m1•v1 + m2•v2

m_total = (66 × 1.5) + (75 × -1.2)

m_total = 99 - 90

m_total = 9 kg.m/s

This is positive and thus it will be in the direction of the north.

b.

explanation: