Question

In the figure shown, a particle is released from the position Aon a smooth track. When the particle reaches at $B$, then normal reaction on it by the track is

• A. $m g$
• B. $2 mg$
• C. $\frac{2}{3} m g$
• D. $\frac{m^{2} g}{h}$

Answer 1

Answer: (A)

Using Mechanical energy conservation
$m g(3 h)=m g(2 h)+\frac{1}{2} m u^{2}$
$m g h=\frac{1}{2} m v^{2}$
$v^{2}=2 g h$
$m g+ N=\frac{m v^{2}}{h}=\frac{m(2 g h)}{h}$
$N=m g$