Work Energy And Power Question 166
Question: A metal ball of mass 2 kg moving with a velocity of 36 km/h has an 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 [CBSE PMT 1997; AIIMS 2001]
Options:
A) 40 J
B) 60 J
C) 100 J
D) 140 J
Show Answer
Answer:
Correct Answer: B
Solution:
$ v=36km/h=10m/s $
By law of conservation of momentum $ 2\times 10=(2+3)V $
therefore $ V=4m/s $
Loss in K.E. $ =\frac{1}{2}\times 2\times {{(10)}^{2}}-\frac{1}{2}\times 5\times {{(4)}^{2}}=60J $
