A particle is projected with speed u making an angle 30o with the horizontal from a point A on the ground. The vertical wall is smooth. The particle hits the wall at highest point of its trajectory, after which it rebounds from the smooth ground and reaches point A as shown in the diagram. If coefficient of restitution e is same for all the collision then find the value of 10e.

Engineering

Physics

Collision

Question

LiveFree JEE Main Previous Year Online Papers Live Free JEE Advance Previous Year Online Papers

College PredictorLive

Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.

Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA

Total return distance = $\frac{R}{2}$

$\Rightarrow \frac{R}{2} = eucos 30^{\circ} \times \frac{2 eusin 30^{\circ}}{g} + eucos 30^{\circ} \sqrt{\frac{2 H}{g}}$

$\frac{2 ucos 30^{\circ} usin θ}{2 g} = \frac{2 ucos θ 2 eusin 30^{\circ}}{g} + eucos 30^{\circ} \frac{usin 30^{\circ}}{g}$

$\Rightarrow 2 e^{2} + e = 1$

$\Rightarrow e = \frac{1}{2} \Rightarrow 10 e = 5$

Please subscribe our Youtube channel to unlock this solution.