Circular motion requires a continuous inward (centripetal) force. In uniform circular motion (UCM), speed is constant but velocity changes direction, producing centripetal acceleration $a_c$ = $v^2$/r = r*$omega^2$ toward the centre. The centripetal force $F_c$ = $mv^2$/r is NOT a separate force — it is the net radial component of real forces (tension, gravity, friction, normal force).

Non-uniform circular motion adds a tangential component $a_t$ = $\frac{dv}{dt}$, making $a_{net}$ = sqrt($a_c^2$ + $a_t^2$). The net force is NOT purely radial.

Vertical circle is the most tested topic. For a mass on a string: v_{top}_{min} = sqrt(gL), v_{bottom}_{min} = sqrt(5gL), and $T_{bottom}$ - $T_{top}$ = 6mg always. For a rigid rod: $v_{top}$ = 0 is allowed, so v_{bottom}_{min} = 2*sqrt(gL).

Banked roads: Without friction, tan(theta) = v^$\frac{2}{rg}$ gives one safe speed. With friction, a speed range [$v_{min}$, $v_{max}$] exists. A conical pendulum has period T = 2pisqrt$\frac{L*cos(theta}{g}$).

Key approach: identify real forces, resolve into radial and tangential, set net radial force = $mv^2$/r. Never add centrifugal force in the inertial frame.