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A metal ball of mass 2 kg moving with a velocity of 36 km/h has a head on collision with a stationary ball of mass 3 kg. If after the collision, the two balls move together, the loss in kinetic energy due to collision is
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- 140 J
- 100 J
- 60 J
- 40 J
Correct Option: C
Applying conservation of momentum, m1v1 = (m1 + m2)v
| = | ||
| (m1 + m2) |
Here, v1 = 36 km/hr = 10 m/s
m1 = 2 kg, m2 = 3 kg
| v = | = 4 m/s | |
| 5 |
| K.E. (initial) = | × 2 × ( 10 )2 = 100 J | |
| 2 |
| K.E. (Final) = | × (3 + 2) × ( 4 )2 = 40 J | |
| 2 |
Loss in K.E. = 100 – 40 = 60 J
