Work Energy And Power Question 45
Question: If the linear momentum is increased by 50%, the kinetic energy will increase by [CPMT 1983; MP PMT 1994; MP PET 1996, 99; UPSEAT 2001]
Options:
A) 50%
B) 100%
C) 125%
D) 25%
Show Answer
Answer:
Correct Answer: C
Solution:
Let $ P_1=P $ , $ P_2=P_1+50% $ of $ P_1 $ = $ P_1+\frac{P_1}{2}=\frac{3P_1}{2} $
$ E\propto P^{2} $
therefore $ \frac{E_2}{E_1}={{( \frac{P_2}{P_1} )}^{2}}={{( \frac{3P_1/2}{P_1} )}^{2}}=\frac{9}{4} $
therefore $ E_2=2.25E $
$ =E_1+1.25E_1 $
$ E_2=E_1+125$ % $\text{of }E_1 $
i.e. kinetic energy will increase by 125%.
