A bob of a simple pendulum of mass ' m ' is displaced through 90^ from mean position and released. When the bob is at lowest position, the tension in the string is

Step-by-step solution

When it is displaced through 90^ from mean position, it is at a height ' r ' and has potential energy mgr. At the lowest position this potential energy is converted into kinetic energy. aligned & 1 2 mv ^2= mgr & mv ^2= mgr aligned At the lowest position the tension in the string T = mg + mv ^2 r = mg +2 mg =3 mg