A railway carriage of mass 9000 kg moving with a speed of 36kmh^(-1) collides with a stationary carriage of same mass. After the collision, the carriages get coupled and move together. What is their common speed after collision? What type of collision is this?

A railway carriage of mass 9000 kg moving with a speed of 36kmh^(-1) c

1.	A railway carriage of mass 9000 kg moving with a speed of 36kmh^(-1) collides with a stationary carriage of same mass. After the collision, the carriages get coupled and move together. What is their common speed after collision? What type of collision is this?
Answer» Solution :`m_(1)=9000kgkg,u_(1)=(36km)/H=(10 m)/s` `m_(2)=9000KG, u_(2)=0,v=v_(1)=v_(2)= ?` BY conservation of momentum : `m_(1)u__(1)+m_(2)u_(2)=(m_(1)+m_(2))v` `therefore v=(5m/s)` `"total K.E. before collision"=1/2m_(1)u_(2)^(2)+1/2m_(2)u_(2)^(2)=45000J` `"Total K.E. after collision =1/2(m_(1)+m_(2))v_(2)=225000J` `"As total K.E. after collision" lt "total K.E.before collision"` `therefore "collision is INELASTIC".`