Question

A ball is projected from point A with a velocity, $10 \, m \, s^{- 1}$ perpendicular to the inclined plane as shown in the figure. Range of the ball on the inclined plane is :

• A. $\frac{4 0}{3} m$
• B. $\frac{2 0}{13} m$
• C. $\frac{13}{20} m$
• D. $\frac{13}{40} m$

Answer 1

Answer: (A)

$\text{T} = \frac{\text{2u sin 90}^{\text{o}}}{\text{g cos 30}^{o}}= \frac{2 \text{u}}{\text{g} \text{cos} 3 0^{\text{o}}}$
$R=\frac{1}{2} \times\left(g \sin 30^{\circ}\right) \times \frac{4 u^2}{g^2 \cos ^2 30^{\circ}}$
$\text{R} = \frac{2 \text{u}^{2} \times 4}{2 \times 1 0 \times 3} = \frac{2 \times 1 0 \times 1 0 \times 4}{2 \times 1 0 \times 3} = \frac{4 0}{3} m$