Question

Find the minimum speed of a bike at higher point of a globe of diameter 19.6m?

Answer 1

Answer:

A. The forces on the roller coaster are ( in the absence of air friction and friction between rails and the car)

a. Weight mg downwards

b. Normal force N by the rails on the car, also downwards

From Newton's second law N + mg = (mv2 )/ r = centripetal force to execute the circle with velocity v

Min speed at the top = (rg)-2 where r is the radius of the loop

This speed is derived from conservation of energy. If air friction is taken into account, then v must be greater than (rg)-2 as part of the energy will be used to overcome friction.

Outward force or cetrifugal force is a pseudo force which needs to be taken into account if we describe the motion of the car on the roller coaster from a rotating frame which is non inertial and still use Newton's laws. As we are observing the roller coaster from the ground frame, which is inertial, there is no pseudo force.

Explanation:

may be right ho