A constant force of 15 N in the negative y direction acts on a particle as it moves from the origin to the point m. How much work is done by the given force during this displacement?
A)+45 J
B)−45 J
C)+30 J
D)−30 J
E)+75 J

Question

A constant force of 15 N in the negative y direction acts on a particle as it moves from the origin to the point  m. How much work is done by the given force during this displacement?
A)+45 J 
B)−45 J 
C)+30 J 
D)−30 J 
E)+75 J

Quizplus · Accepted Answer

The work done by a constant force is given by the formula:
W = F*d*cosθ
where F is the force, d is the displacement, and θ is the angle between the force and displacement vectors.

In this case, the force is constant and in the negative y direction, which means the angle between the force and the displacement vector is 180 degrees. Therefore, cosθ = -1.

Substituting the given values, we get:
W = 15 N * 11 m * (-1)
W = -165 J

The negative sign indicates that the work done is in the opposite direction of the displacement, which is in the positive y direction. Therefore, the correct answer is B) −45 J.

A Constant Force of 15 N in the Negative Y