A pendulum of length L with a bob of mass m is released from the vertical position without initial speed. Under the suspension point, a nail is fixed at a distance of L − x. The thread of the pendulum gets stuck in the nail during its motion so that the bob starts to move on a circular path of radius x after it has reached its lowest position. a) At most how large should x be if the bob executes a complete circle? b) If x = L/3, calculate the tension in the thread when the bob reaches its highest position during the motion after the thread gets stuck in the nail.

A pendulum of length L with a bob of mass m is released from the vertical position without initial speed. Under the suspension point, a nail is fixed at a distance of L − x. The thread of the pendulum gets stuck in the nail during its motion so that the bob starts to move on a circular path of radius x after it has reached its lowest position. a) At most how large should x be if the bob executes a complete circle? b) If x = L/3, calculate the tension in the thread when the bob reaches its highest position during the motion after the thread gets stuck in the nail.