Question

a body of mass 1kg moving with the velocity 5 m/s collides with another body of masses 2kg moving with the velocity of 1.5m/s in opposite direction. if the coefficient of resistution is 0.8 their velocities after collosion will be ?

Answer 1

Explanation:

Given : m1=2kg m2=1kg u1=3 m/s u2=4 m/s

Let the common velocity of the combined body be V

Mass of combined body M=2+1=3kg

Applying conservation of momentum :

2×3−1×4=3×V ⟹V=32 m/s

Momentum of the system P=2×3−1×4=2 kg m/s

Loss in kinetic energy of the system due to collision ΔK.E=K.Ei−K.Ef

ΔK.E=21(2)×32+21(1)×42−21(3)×(32)2

⟹ΔK.E=349 J