Answer:
mv^2 / R
Explanation:
If a particle of mass m is going in a circle of radius R with velocity v, then the centripetal force is
[tex]F=\frac{mv^2}{R}[/tex]
Now, the force that counters centripetal force is the normal force ( which is the result of Newton's third law - every force comes with an equal and opposite force) and its magnitude is exactly to that of the centripetal force.
[tex]F_N=-\frac{mv^2}{R}[/tex]
