A man pushes an 80-N crate a distance of 5.0 m upward along a frictionless slope that makes an angle of 30°with the horizontal.The force he exerts is parallel to the slope.If the speed of the crate is constant, then the work done by the man is:

Question

Quizplus · Accepted Answer

The work done by the man is calculated using the formula Work = Force x Distance. Since the force exerted is parallel to the slope and the motion is along the slope, the full force contributes to the work done. Given the force is 80 N and the distance is 5.0 m, the work done is $80 \, \text{N} \times 5.0 \, \text{m} = 400 \, \text{J}$. However, this calculation does not directly apply to the options provided, indicating a misunderstanding in the explanation process. The correct approach involves considering the component of the gravitational force along the slope, which the man's force must counteract to keep the speed constant. The correct calculation should involve the gravitational component parallel to the slope, but without additional information on the crate's mass or a direct calculation error, the correct answer is intended to reflect the work done against gravity or the force applied along the slope. Given the misunderstanding in the initial explanation, the correct approach involves calculating the work done by the man's force along the slope, considering the angle and the force applied. The correct answer, based on the options provided and the scenario of constant speed (implying no net work done on the crate's kinetic energy), would involve calculating the component of the force exerted in the direction of the slope and the distance moved. However, without the explicit calculation of the gravitational force component or the applied force's exact alignment with the slope in the provided options, the selection of "D" as the correct answer was based on an incorrect explanation. The actual work calculation should consider the force component along the slope and the distance, correctly applying the work formula and the angle's effect on the force's effective component in the work done equation.

A Man Pushes an 80-N Crate a Distance of 5