Question

When the string of a suspending bob is cut off, the bob falls onto the
ground. Why

Answer 1

Answer:

If the string of a pendulum were cut when the bob is at its central position, the bob would fall to the earth due to the absence of the force exerted by the string in the upward direction. At that time, only weight of the bob is acting in downward direction so pendulum falls down.

Answer 2

Answer:

force exerted by the string in the upward direction

Explanation:

If the string of a pendulum were cut when the bob is at its central position, the bob would fall to the earth due to the absence of the force exerted by the string in the upward direction. At that time, only weight of the bob is acting in downward direction so pendulum falls down.