Question

A circular disc of radius r = 5m is rotating in horizontal plane about y-axis. Y-axis is vertical axis passing through the centre of disc and x-z is the horizontal plane at ground. The height of disc above ground is h = 5 m. Small particles are ejecting tangentially from disc in horizontal direction with speed 12 m/s from the circumference of disc then the distance of these particles from origin when they hits the x-z plane is –

• A. 12 m
• B. 13 m
• C. 5 m
• D. None of these

Answer 1

Answer: (B)

13 m

Answer 2

R = $u \sqrt { \frac { 2 h } { g } }$ therefore l = $\sqrt { \mathrm { r } ^ { 2 } + \mathrm { R } ^ { 2 } }$