Work Energy And Power Question 164
Question: If a skater of weight 3 kg has initial speed 32 m/s and second one of weight 4 kg has 5 m/s. After collision, they have speed (couple) 5 m/s. Then the loss in K.E. is [CPMT 1996]
Options:
A) 48 J
B) 96 J
C) Zero
D) None of these
Show Answer
Answer:
Correct Answer: D
Solution:
Loss in K.E. = (initial K.E. - Final K.E.) of system $ \frac{1}{2}m_1u_1^{2}+\frac{1}{2}m_2u_2^{2}-\frac{1}{2}(m_1+m_2)V^{2} $
$ =\frac{1}{2}3\times {{(32)}^{2}}+\frac{1}{2}\times 4\times {{(5)}^{2}}-\frac{1}{2}\times (3+4)\times {{(5)}^{2}} $ = 986.5 J
