You lower a 2.50 kg textbook (remember when textbooks used to be made out of paper instead of being digital?) from a height of 1.85 m to 1.50 m. What is its change in potential energy?

Change in potential energy = 8.58 J

Explanation:

Potential energy = Mass x Acceleration due to gravity x Height

Potential energy = mgh

m = 2.50 kg

g = 9.81 m/s²

Initial height, h₁ = 1.85 m

Final height, h₂ = 1.50 m

Change in potential energy = mgh₁ - mgh₂

Change in potential energy = 2.5 x 9.81 x 1.85 - 2.5 x 9.81 x 1.50

Change in potential energy = 8.58 J