Question

A vehicle is travelling at uniform speed $36kmph$ along a fly-over bridge and a person of mass $50kg$ in the vehicle experiences a normal reaction $390N$ as the vehicle crosses the highest point. The radius of curvature of the fly-over bridge is:

• A. $40m$
• B. $50m$
• C. $80m$
• D. $100m$

Answer 1

The correct option is B $50m$

$V=36km/h$

$=36\times \frac{5}{18}$

$=10m/s$

$mg-390=\frac{m{V}^2}{R}$

$490-390={\frac{50\times 10}{R}}^2$

$100=\frac{5000}{R}$

$R=50m$