NEET AIPMT SOLVED PAPER 2002

  • question_answer
                    If kinetic energy of a body is increased by 300% then percentage change in momentum will be:

    A)                                                                                                                                                                                            100%  

    B)                150%     

    C)                 265%  

    D)                 73.2%

    Correct Answer: A

    Solution :

                    Key idea: The relation between momentum p and kinetic energy K is \[K=\frac{1}{2\,m}({{p}^{2}})\]                 Kinetic energy                 \[K=\frac{1}{2m}({{p}^{2}})\]                 or            \[p=\sqrt{2m\,K}\]                 If kinetic energy of a body is increased by 300%, let its momentum becomes p?.                 New kinetic energy                 \[K'=K+\frac{300}{100}K=4K\]                 Therefore, momentum is given by                 \[p'=\sqrt{2m\times 4K}=2\sqrt{2mK}=2p\]                 Hence, % change (increase) in momentum                 \[\frac{\Delta p}{p}\times 100=\frac{p'-p}{p}\times 100%\]                 \[=\left( \frac{p'}{p}-1 \right)\times 100%\]                 \[=\left( \frac{2p}{p}-1 \right)\,\times 100%\]                 = 100%


You need to login to perform this action.
You will be redirected in 3 sec spinner