Question

A bag of sand of mass $98\, kg$ is suspended by a rope A bullet of $200\, g$ travelling with speed $10\, ms ^{-1}$ gets embedded in it, then loss of kinetic energy will be

• A. $4.9 J$
• B. $9.8 J$
• C. $14.7 J$
• D. $19.6 J$

Answer 1

Answer: (B)

$9.8 J$

Answer 2

Pi​=Pf​ ( no any external force )
0.2×10=10×v
v=0.2m/sec
Loss in K.E. =21​×(0.2)×102−21​×10(0.2)2
=21​×10×(0.2)[10−0.2]
=9.8J