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(a) What is the speed of the four cars after the collision? m/s (b) How much mec

ID: 2142909 • Letter: #

Question

    (a) What is the speed of the four cars after the collision?
          m/s
    
    (b) How much mechanical energy is lost in the collision?
          J

A railroad car of mass 2.48 times 104 kg is moving with a speed of 3.94 m/s. It collides and couples with three other coupled railroad cars, each of the same mass as the single car and moving in the same direction with an initial speed of 1.97 m/s. What is the speed of the four cars after the collision? How much mechanical energy is lost in the collision?

Explanation / Answer

a.)applying conservation of momentum


2.48*10^4*(3.94+1.97+1.97+1.97)=4*2.48*10^4*v


v=2.46 m/s



b.)loss in mechanical energy


=1/2*2.48*10^4*3.94^2+3*2.48*10^4*1.97^2-(4*1/2*2.48*10^4*2.46^2)


=121.13 KJ ans