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An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms–1 and the second part of mass 2 kg moves with speed 8 ms–1. If the third part flies off with speed 4 ms–1 then its mass is
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- 5 kg
- 7 kg
- 17 kg
- 3 kg
Correct Option: A
Presultant = √12² + 16²
= √144 + 256 = 20
m3v3 = 20 (momentum of third part)
| m3 = | = 5 kg | |
| 4 |
