The motion is upwards, the direction is downwards.brainpushups said:In what direction is the force YOU exert? Compare this with the direction of motion.
AAAA said:upwards
AAAA said:You move a textbook from a high shelf to a low shelf. Is the work you do on it positive or negative?
brainpushups said:That's not how you phrased the question:
From a high to a low shelf means the motion is downward. The force you exert is upward. Therefore the work you do is negative (force and displacement are in the opposite direction i.e. θ = 180)
Work on an object moving downwards is the force applied to an object in the direction of its motion as it moves in a downward direction.
The amount of work done on an object moving downwards is affected by the magnitude of the force applied, the distance over which the force is applied, and the angle at which the force is applied.
The work done on an object moving downwards is calculated by multiplying the force applied to the object by the distance over which the force is applied, multiplied by the cosine of the angle between the force and the direction of motion.
Yes, work on an object moving downwards can be negative if the force applied is in the opposite direction of the object's motion. This indicates that the object is losing energy as it moves downwards.
According to the work-energy theorem, the work done on an object moving downwards is equal to the change in the object's kinetic energy. This means that as work is done on an object to increase its speed while moving downwards, the object's kinetic energy also increases.