JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
If momentum of a body is increased by \(20 \%\), then its kinetic energy increases by\(....\%\)
- A \(36\)
- B \(40\)
- C \(44\)
- D \(48\)
Answer & Solution
Correct Answer
(C) \(44\)
Step-by-step Solution
Detailed explanation
\(P ^{\prime}= P +\frac{20}{100} P =1.2 P\) \(\%\) change in \(KE =\frac{ K ^{\prime}- K }{ K } \times 100\) \(=\left(\frac{\frac{ P ^{2}}{2 m }-\frac{ P ^{2}}{2 m }}{\frac{ P ^{2}}{2 m }}\right) \times 100\) \(= {\left[(1.2)^{2}-1\right] \times 100 }\) \(= 44\%\)
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