How much work is done by a person lifting a $10\mathrm{lb}$ bucket $4\mathrm{ft}$ off the ground?

• A. $100\mathrm{ft}\cdot \mathrm{lb}s$
• B. $0\mathrm{ft}\cdot \mathrm{lb}s$
• C. $40\mathrm{ft}\cdot \mathrm{lb}s$
• D. $400\mathrm{ft}\cdot \mathrm{lb}s$

Answer: (C)

Verified step by step guidance

1. Understand the problem: Work is defined as the product of force and displacement in the direction of the force. Here, the force is the weight of the bucket (10 lb), and the displacement is the vertical distance the bucket is lifted (4 ft).
2. Express the formula for work: Work = Force × Displacement. In this case, the force is constant because the weight of the bucket does not change as it is lifted.
3. Substitute the given values into the formula: Force = 10 lb and Displacement = 4 ft. Therefore, Work = 10 × 4.
4. Recognize the units: The work will be expressed in foot-pounds (ft⋅lb), which is the standard unit for work in this context.
5. Perform the multiplication to find the work done: Multiply the force (10 lb) by the displacement (4 ft) to calculate the total work. The result will be in ft⋅lb.