Change in gravitational potential energy formula

Steps:

• Recall the formula for change in gravitational potential energy: ΔPE = m g Δh, where Δh is the vertical displacement change.
• Recognize that weight W equals m g, so ΔPE = W Δh.
• Identify that W and Δh directly substitute into the formula for calculation.
• Confirm uniform field assumes constant g, making these quantities sufficient.

Why D is correct:

• ΔPE = weight × change in vertical displacement, per the definition of gravitational potential energy.

Why the others are wrong:

• A: Mass and g yield weight but omit displacement change.
• B: Mass and displacement change omit g for force magnitude.
• C: "Change of free fall" is undefined; weight needs displacement.

Final answer: D