Question

Three balls projected upwards with the same initial
speed at angle 0 = 30°, 45° and 60° respectively. Let
the range of the ball be expressed by Ro. Then :
(a) R30° > R45° > R60° (b) R60° > R45° > R30°
(C) R45° > R30°
(d) R45° <R60°.​

Answer 1

Answer:

C is the correct answer

Answer 2

Answer: the correct option is (C) R45° > R30°

Explanation: Range of a projectile motion is

R= $\frac{u^{2}sin2\alpha }{g}$

where u is initial velocity, α is angle of projection and g is acceleration due to gravity.

case I For α=30° , sin 2α = sin 60° = $\frac{\sqrt{3} }{2}$

case II For α = 45° , sin 90° = 1

case III For α= 60°, sin 120° = $\frac{\sqrt{3} }{2}$

R(α= 30°) = $\frac{u^{2} \frac{\sqrt{3} }{2} }{g}$

R(α= 45°) = $\frac{u^{2} }{g}$

R(α=60°) =$\frac{u^{2} \frac{\sqrt{3} }{2} }{g}$

So, R45°> R30°