Question

A circular disc of radius r = 5 m is rotating in horizontal plane about y-axis. y-axis a 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 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 x – z plane is –

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

Answer 1

Answer: (C)

13 m

Answer 2

R = $u \sqrt { \frac { 2 h } { g } }$ = $12 \sqrt { \frac { 2 \times 5 } { 10 } }$ = 12 m

\ Distance from origin = $\sqrt { 5 ^ { 2 } + ( 12 ) ^ { 2 } }$ = 13 m