A body of mass m1 , moving with velocity u1 collides head on with a body of mass m2 moving with a velocity u2 the two bodies stick together after the collision the loss of kinetic energy after the collision is ?Ans) Initial KE of the system= 1/2 [ m1.u1^2 + m2.u2^2 ]applying conservation of momentum we get new velocity of the new body= (m1.u1-m2.u2) / (m1+m2)new KE of the Body= [ (m1.u.1 - m2.u2) / 2.(m1+m2) ]^2Subtracting and simplyfing we get the loss in KE after Collision= [ m1.m2. (u1 + u2)^2 ] / [ 2.(m1 + m2) ]
Since the objects stick together they will be a part of plastic collision...so. conservation of kinetic energy cannot be applied...Apply conservation of linear momentum and then find individual velocitiesthen loss of kinetic energy will be change in kinetic energy......So,it will become equal to amount of work done.