You have a light string. At one end of the string there is a ball modelled as a particle. The string has negligible mass. The other end of the string is fixed at a point and the ball is undergoing circular motion.
At the bottom, the centripetal force = mg - T. At the top, the centripetal force = T + mg.
m = mass of ball
g = gravitational field strength
T = tension
If an exam asks you: What is the reaction force at the bottom? What is the reaction force at the top?
Ball goes in a vertical circular path. Resistive forces = 0.
Is the reaction force always 0? The ball isn't in contact with anything but the string. Isn't the centrifugal force fictitious? Thanks.
Edit: Velocity is not constant due to conservation of energy, so the centripetal force is not constant. I was wondering if there is a reaction force acting on the ball, and if so, what is the value of that reaction force.