Question

A ball thrown in air follows a path given byy = $\frac{x}{\sqrt{3}} - \frac{3g}{8}$x²m, where x-axis is taken along the horizontal and y-axis along the vertical. The maximum displacement of the ball along
x-direction for which displacement along y is zero equals to –

• A. 15$\sqrt{3}$m
• B. $(4/15\sqrt{3})$ m
• C. 4/3 m
• D. Data insufficient

Answer 1

Answer: (B)

$(4/15\sqrt{3})$ m

Answer 2

On comparing the given equation with the standard equation of a projectile

y = x tanq – $\frac { \mathrm { gx } ^ { 2 } } { 2 \mathrm { u } ^ { 2 } \cos ^ { 2 } \theta }$

q = 30º and u = 4/3 m/s

\ R = $\frac { u ^ { 2 } \sin 2 \theta } { g } = \frac { ( 4 / 3 ) ^ { 2 } \sin 2 \left( 30 ^ { \circ } \right) } { 10 } = \frac { 4 } { 15 \sqrt { 3 } } \mathrm {~m}$