Work Energy And Power Question 130
Question: A body of mass m moving with velocity v makes a head-on collision with another body of mass 2 m which is initially at rest. The loss of kinetic energy of the colliding body (mass m) is [MP PMT 1996]
Options:
A) $ \frac{1}{2} $ of its initial kinetic energy
B) $ \frac{1}{9} $ of its initial kinetic energy
C) $ \frac{8}{9} $ of its initial kinetic energy
D) $ \frac{1}{4} $ of its initial kinetic energy
Show Answer
Answer:
Correct Answer: C
Solution:
$ \frac{\Delta K}{K}=[ 1-{{( \frac{m_1-m_2}{m_1+m_2} )}^{2}} ]=[ 1-{{( \frac{m-2m}{m+2m} )}^{2}} ] $
$ =\frac{8}{9} $
$ \Delta K $ = $ \frac{8}{9}K $ i.e. loss of kinetic energy of the colliding body is $ \frac{8}{9} $ of its initial kinetic energy.
