A body of mass 10,kg moving with speed of 3 ,ms ^{-1} collides with another stationary body of mass

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5.Work, Energy, Power and Collision

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A body of mass $10\,kg$ moving with speed of $3 \,ms ^{-1}$ collides with another stationary body of mass $5 \,kg$. As a result, the two bodies stick together. The $KE$ of composite mass will be .......... $J$

A

$60$

B

$30$

C

$90$

D

$120$

Solution

(b)

Using momentum conservation

$10(3)=15 \,V$

$V=2 \,m / s$

$K . E .=\frac{1}{2} m v^2=\frac{1}{2}(15)(2)^2$

$=30 \,J$

Standard 11

Physics

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