A) \[{{25}^{o}}\] and \[{{65}^{o}}\]
B) \[{{35}^{o}}\] and \[{{75}^{o}}\]
C) \[{{10}^{o}}\] and \[{{50}^{o}}\]
D) None of these
Correct Answer: A
Solution :
Range of a projectile (R) is given by \[R=\frac{{{u}^{2}}\,\sin \,2\theta }{g}\] where \[\mu \] is velocity of projection and 9 the angle of projection. Substituting \[({{90}^{o}}-\theta )\] in place of \[\theta ,\] we get \[R=\frac{{{u}^{2}}\sin \,\,({{90}^{o}}-\theta )}{g}\] \[=\frac{{{u}^{2}}\sin ({{180}^{o}}-2\theta )}{g}=\frac{{{u}^{2}}\,\sin \,2\theta }{g}\] Hence horizontal range is same whether the body is projected at \[\theta \] or \[{{90}^{o}}-\theta \]. \[\therefore \] Therefore, \[{{25}^{o}}\] or \[{{({{90}^{o}}-25)}^{o}}={{65}^{o}}\]You need to login to perform this action.
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