How much work is done by the string of a pendulum on its bob as it swings back and forth?(1 point) Responses a negative amount a negative amount zero zero negative when going up and positive when going down negative when going up and positive when going down a positive amount
The correct response is "zero." The work done by the string on the bob of a pendulum is zero because the force exerted by the string is always perpendicular to the displacement of the bob. In other words, there is no component of the force parallel to the displacement, so no work is done.
