A fighter plane is moving in a vertical circle of radius r . Its minimum velocity at the highest point A of the circle will be

Step-by-step solution

When a body tied to the end of a string is revolved in a vertical circle, the speed of the body is different at different points of the circular paths. The resultant of tension (T) and weight ( mg ) provides the necessary centripetal force i.e., T+m g= m v_A^2 r Tension ( T ) becomes zero at the points of minimum velocity, therefore aligned & & 0+m g & = m v_A^2 r & & v_A & = g r aligned