In a closed system, an object with a mass of 10 kg moves at a velocity of 5.4 m/s. It collides with a second object that has a mass of 12 kg and that is moving in the opposite direction with a velocity of 3.5 m/s. What is the total momentum of the system after the collision? (1 point)

O 12 kg-m/s
• 66 kg-m/s
• 42 kg-m/s
• 54 kg-m/s

1 answer

To find the total momentum of the system after the collision, we first calculate the momentum of each object before the collision and then sum those values.

  1. Calculate the momentum of the first object (m1 = 10 kg, v1 = 5.4 m/s): \[ p_1 = m_1 \times v_1 = 10 , \text{kg} \times 5.4 , \text{m/s} = 54 , \text{kg-m/s} \]

  2. Calculate the momentum of the second object (m2 = 12 kg, v2 = -3.5 m/s, direction opposite to m1): \[ p_2 = m_2 \times v_2 = 12 , \text{kg} \times (-3.5 , \text{m/s}) = -42 , \text{kg-m/s} \]

  3. Combine the momenta to find the total momentum before the collision: \[ p_{\text{total}} = p_1 + p_2 = 54 , \text{kg-m/s} + (-42 , \text{kg-m/s}) = 54 - 42 = 12 , \text{kg-m/s} \]

Since momentum is conserved in a closed system, the total momentum after the collision will be the same as before the collision, which is 12 kg-m/s.

The total momentum of the system after the collision is 12 kg-m/s. Therefore, the answer is 12 kg-m/s (though, this option does not appear among the provided choices).