Question

A hollow sphere has radius 6.4 m. Minimum velocity required by a motor cyclist at the bottom to complete the circle will be

Answer 1

@iambatman @IrishBoy123

Answer 2

hint:
when the motor cyclist is at the top of the circumference, then the subsequent condition must hold:
weight= centrifugal force
\[\huge mg = m\frac{{v_{\min }^2}}{R}\]
where R is the radius of the circumference, and Vmin is the requested speed

Answer 3

Boing!!!!

That means the velocity should be 8m/s !!
But the answer is 17.7 m/s ;-;

Answer 4

Oh !!!!!
I get it now, I forgot to consider the fact that the speed will keep decreasing as the biker climbs the sphere. So that means he must start with a speed greater than 8 m/s from bottom. I can use equations of kinematics for that

\(\sf 8^2 = u^2 -2 \times -2\times g \times 2R\) !!! yaY !!