A 5 kg toy car with a speed of 6 m/s collides head-on with a stationary 1 kg car. After the collision, the cars are locked together with a speed of 5.00 m/s. How much kinetic energy is lost in the collision?

Answer 1

conservation of momentum
5*6+0=6*5

final energy=1/2 m v^2=3*25
initial KE=1/2 m v^2=2.5*36
amountlost is difference