Problemas
Can work ever be negative? If so, give an example of a force that produces negative work. I Instructions square
Roztwór
Carmen
veterano · Tutor durante 10 años
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(219 Votos)
Respuesta
Work can indeed be negative. Work is defined as the product of the force applied to an object and the displacement of the object in the direction of the force. Mathematically, work
is given by:
where:-
is the magnitude of the force,-
is the displacement of the object,-
is the angle between the force and the displacement.When the force and displacement are in opposite directions, the angle
is 180 degrees, and the cosine of 180 degrees is -1. This results in negative work.### Example of Negative WorkConsider a person pushing against a wall. The force exerted by the person on the wall is directed towards the wall, while the displacement of the person's hand is away from the wall. Since the force and displacement are in opposite directions, the angle
between them is 180 degrees, and the cosine of 180 degrees is -1. Therefore, the work done by the person's force on the wall is negative.In this scenario:- The force
is the force exerted by the person on the wall.- The displacement
is the distance the person's hand moves away from the wall.- The angle
is 180 degrees.Thus, the work done
is:
This negative work indicates that the force exerted by the person on the wall does not contribute to moving the wall but instead opposes the displacement of the hand.