Question

A pilot of mass $m$ can bear a maximum apparent weight $7$ times of $mg$. The aeroplane is moving in a vertical circle. If the velocity of aeroplane is $210m/s$ while driving up from the lowest point of vertical circle, the minimum radius of vertical circle should be:

• A. $375m$
• B. $420m$
• C. $750m$
• D. $840m$

Answer 1

The correct option is C $750m$

Given maximum apparent weight is $7mg$
Apparent weight at the lowest point is ($mg+m\frac{v^2}{r}$)
So, $7mg=mg+m\frac{v^2}{r}$
or, $6mg=m\frac{v^2}{r}$
or, $r=\frac{v^2}{6g}$
or, $r=\frac{{210}^2}{6g}$
or, $r=750m$
So , minimum radius of circle is $750m$