A 79-kg worker at the Burj Khalifa, the tallest building in the world with its roof 828 m above the ground below, rides a series of elevators from the ground level to the roof. What is the worker's change in gravitational potential energy?

Worker's change in gravitational potential energy = 641.69 kJ

Explanation:

Potential energy = Mass x Acceleration due to gravity x Height

PE = mgh

Mass, m = 79 kg

Acceleration due to gravity, g = 9.81 m/s²

Height, h = 828 m

Potential energy, PE = 79 x 9.81 x 828 = 641691.72 J = 641.69 kJ

Worker's change in gravitational potential energy = 641.69 kJ