Common Mistakes and Traps

Centrifugal force does NOT exist in the inertial frame — never add it to an FBD
Centripetal force is NOT a separate force — it is the net inward component of real forces
A body released from circular motion flies tangentially, NOT radially outward
At the top of a vertical circle, both T and mg point toward centre: T + mg = $mv^2$ /r
5gL is the minimum $v^2$ at the bottom for a STRING; for a ROD it is 4gL
Centripetal force does ZERO work (perpendicular to velocity)
v = sqrt(rg*tan(theta)) is the ONLY safe speed on a frictionless banked road
In non-uniform circular motion, the net force is NOT directed toward the centre