A body of mass 10kg moving with a velocity of 5\(ms^{-1}\) collides with another body of mass 15kg moving in the same direction as the first with a velocity of 2\(ms^{-1}\). After collision, the two bodies move together with a common velocity v\(ms^{-1}\).
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3.2
- 5.3
- 7.0
- 8.0
The correct answer is: A
Explanation
Momentum of bodies with common velocity = \(m_{1}v_{1} + m_{2}v_{2} = (m_{1} + m_{2})v\)
\((10 \times 5) + (15 \times 2) = (10 + 15)v\)
\(50 + 30 = 25v \implies v = \frac{80}{25} = 3.2ms^{-1}\)