BHU PMT BHU PMT (Screening) Solved Paper-2008

  • question_answer
    The maximum height attained by a projectile is increased by 5%. Keeping the angle of projection constant, what is the percentage increase in horizontal range?

    A)  5%                                        

    B)  10%

    C)  15%                                      

    D)  20%

    Correct Answer: A

    Solution :

                     Let h be the maximum height attained by the projectile. Then \[h=\frac{{{u}^{2}}{{\sin }^{2}}\theta }{2g}\] \[R=\frac{{{u}^{2}}\sin 2\theta }{g}\] \[\therefore \]  \[\frac{R}{h}=\frac{{{u}^{2}}\sin 2\theta }{g}/\frac{{{u}^{2}}{{\sin }^{2}}\theta }{2g}\]                 \[=\frac{2\sin \theta \cos \theta }{({{\sin }^{2}}\theta )/2}\] Therefore, \[\frac{\Delta R}{R}=\frac{\Delta h}{h}\] Hence, percentage increase in R = percentage increase in height\[h=5\text{ }%\]


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