Question

A railroad car (with a mass of 3250 kg) moves at 8.1 m/s . It collides with and couples to another car that was initially at rest. After the collision, the two cars move together at a speed of 4.50 m/s. What is the mass of the second car?

Answer 1

m_2 = 2600kg

Step-by-step explanation:

P_1 = P_2

P = (m_1)*(v_1)+(m_2)(v_2)

P_1 = (3250kg)(8.1m/s)+(m_2)(0m/s)

P_1 = 26,325 kg*m/s

P_2 = (3250kg)(4.5m/s)+(m_2)(4.5m/s)

P_2 = 14,625kg*m/s+(4.5m/s)m_2

26,325 kg*m/s = 14,625kg*m/s+(4.5m/s)m_2

11,700kg*m/s = (4.5m/s)m_2

m_2 = 2600kg