Question

A 14,000-kg boxcar is coasting at 1.50 m/s along a horizontal track when it suddenly hits and couples with a stationary 10,000-kg boxcar. What is the speed of the cars just after the collision?

Answer 1

Explanation:

It is given that,

Mass of a box car, $m_1=14000\ kg$

Initial speed of a box car, $u_1=1.5\ m/s$

Initial speed of another stationary car is 0 as it was stationary

Mass of another box car is 10,000 kg

Let V is the speed of the cars just after the collision. It is based on the concept of inelastic collision. So, using the conservation of linear momentum we get :

$m_1u_1+m_2u_2=(m_1+m_2)V\\\\m_1u_1=(m_1+m_2)V\\\\V=\dfrac{m_1u_1}{(m_1+m_2)}\\\\V=\dfrac{14000\times 1.5}{(14000+10000)}\\\\V=0.875\ m/s$

So, the speed of the cars just after the collision is 0.875 m/s.