Question

A motor cyclist rides around the well with a round vertical wall and does not fall down while riding because:

• A. the force of gravity disappears
• B. he loses weight some how
• C. he is kept in this path due to the force exerted by surrounding air
• D. the frictional force of the wall balances his weight

Answer 1

The correct option is D the frictional force of the wall balances his weight

as we can see in the diagram(FBD), if we don't let the motor cyclist fall then

$\Rightarrow f=mg\Rightarrow \mu N=mg$

the frictional force $f$ balances his weight