Question Detail
Question
A 3-kg block is pulled up a frictionless inclined plane by a 30 N force parallel to the incline. If the plane is inclined at 35° to the horizontal, calculate the work done by the weight of the block as it moves a distance of 3 m up the incline. (acceleration due to gravity, g = 10 m/s²)
Correct Answer
Option A is the correct answer.
Detailed Explanation
Work done by weight = -mgh, where h is the vertical height gained. h = 3 sin 35° = 3 × 0.574 = 1.722 m. Work = -3 × 10 × 1.722 = -51.66 J. Magnitude = 51.6 J.
Hint
Work by gravity = -mg × (vertical height gained).