# Gravitational Potential Energy Formula | Problems

Gravitational potential energy or gravitational energy (PEG) is the product of mass (m), gravitational acceleration (g) and the distance (Δh). Using the formula of gravitational potential energy: PEG = m g Δh, the value of gravitational potential energy of an object can be calculated.

Let’s solve some problems based on this formula, so you’ll get a clear idea.

## Gravitational Potential Energy Practice Problems

Problem 1: Calculate the gravitational potential energy of a 10 kg box which is lifted to a height of 5 m above the ground. (Take the value of gravitational acceleration, g = 9.81 m/s2)

Solution:

Given data:
Gravitational potential energy of a box, PEG = ?
Mass of a box, m = 10 kg
Distance above the surface of ground, Δh = 5 m
Gravitational acceleration, g = 9.81 m/s2

Using the formula of gravitational potential energy,
PEG = m g Δh
PEG = 10 × 9.81 × 5
PEG = 490.5 J

Therefore, the gravitational potential energy of a box is 490.5 J.

Problem 2: A 5 kg trolley is lifted to a height of 15 m above the ground. Calculate the gravitational potential energy of a trolley. (Take the value of gravitational acceleration, g = 9.81 m/s2)

Solution:

Given data:
Mass of a trolley, m = 5 kg
Distance above the surface of ground, Δh = 15 m
Gravitational potential energy of a trolley, PEG = ?
Gravitational acceleration, g = 9.81 m/s2

Using the formula of gravitational potential energy,
PEG = m g Δh
PEG = 5 × 9.81 × 15
PEG = 735.75 J

Therefore, the gravitational potential energy of a trolley is 735.75 J.

Problem 3: What is the gravitational potential energy of a 24 kg wooden block which is lifted to a height of 20 m above the floor. (Take the value of gravitational acceleration, g = 9.81 m/s2)

Solution:

Given data:
Gravitational potential energy of a wooden block, PEG = ?
Mass of a wooden block, m = 24 kg
Distance above the surface of ground, Δh = 20 m
Gravitational acceleration, g = 9.81 m/s2

Using the formula of gravitational potential energy,
PEG = m g Δh
PEG = 24 × 9.81 × 20
PEG = 4708.8 J

Therefore, the gravitational potential energy of a wooden block is 4708.8 J.

Problem 4: A player throws a football in the upward direction to the height of 8 m above the ground. Calculate the gravitational potential energy of a football, if the mass of a football is 450 gm. (Take the value of gravitational acceleration, g = 9.81 m/s2)

Solution:

Given data:
Distance above the surface of ground, Δh = 8 m
Gravitational potential energy of a football, PEG = ?
Mass of a football, m = 450 gm = 0.45 kg
Gravitational acceleration, g = 9.81 m/s2

Using the formula of gravitational potential energy,
PEG = m g Δh
PEG = 0.45 × 9.81 × 8
PEG = 35.31 J

Therefore, the gravitational potential energy of a football is 35.31 J.

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