Question

If the overbridge is concave instead of being convex, the thrust on the road at the lowest position will be

• A. $mg+\frac{m{v}^2}{r}$
• B. $mg-\frac{m{v}^2}{r}$
• C. $\frac{m^2{v}^{2}g}{r}$
• D. $\frac{v^{2}g}{r}$

Answer 1

The correct option is A $mg+\frac{m{v}^2}{r}$

Let the normal reaction (thrust) applied by the bridge be $N$.

Circular motion equation : $m{a}_r=N-mg$

$\therefore$ $\frac{m{v}^2}{r}=N-mg$

$⟹N=\frac{m{v}^2}{r}+mg$