What is the amount of work required to raise a 120-pound weight vertically by 3 feet (ignoring friction)?

What is the amount of work required to raise a 120-pound weight vertically by 3 feet (ignoring friction)?

• A. 360 foot-pounds
• B. 120 foot-pounds
• C. 3600 foot-pounds
• D. 60 foot-pounds

Answer: (A)

Work against gravity is calculated as weight times the vertical distance moved. The force you must overcome is the weight, 120 pounds, and you raise it 3 feet, so the work done is 120 × 3 = 360 foot-pounds. Ignoring friction means no extra work from other forces. The other numbers would correspond to different distances or weights (for example, 3600 would require a larger distance or weight, and 60 would come from a 0.5-foot lift), which isn’t the situation here.

Work against gravity is calculated as weight times the vertical distance moved. The force you must overcome is the weight, 120 pounds, and you raise it 3 feet, so the work done is 120 × 3 = 360 foot-pounds. Ignoring friction means no extra work from other forces. The other numbers would correspond to different distances or weights (for example, 3600 would require a larger distance or weight, and 60 would come from a 0.5-foot lift), which isn’t the situation here.