**Potential energy** (PE) is the product of **mass **(m), **gravitational acceleration** (g) and the **height** (h). Using the formula of potential energy: **PE = m g h**, the value of potential energy of an object can be calculated.

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

## Potential Energy Practice Problems

**Problem 1:** Calculate the potential energy of a 1.5 kg book which is about to fall from the top of a 2.65 m bookshelf. (Take the value of gravitational acceleration, g = 9.8 m/s^{2})

Solution:

Given data:

Mass of a book, m = 1.5 kg

Height of a book, h = 2.65 m

Potential energy of a book, PE = ?

Gravitational acceleration, g = 9.81 m/s^{2}

Using the formula of potential energy,

PE = m g h

PE = 1.5 × 9.81 × 2.65

PE = 38.99 J

Therefore, a book has the potential energy of **38.99 J**, before it falls from the top of a bookshelf.

**Problem 2:** A stone of mass 4 kg, resting at the edge of the hill having a height of 50 m is about to fall. Calculate the potential energy of a stone right before it falls off the hill. (Take the value of gravitational acceleration, g = 9.8 m/s^{2})

Solution:

Given data:

Mass of a stone, m = 4 kg

Height of a stone, h = 50 m

Potential energy of a stone, PE = ?

Gravitational acceleration, g = 9.81 m/s^{2}

Using the formula of potential energy,

PE = m g h

PE = 4 × 9.81 × 50

PE = 1962 J

Therefore, a stone has the potential energy of **1962 J**, right before it falls off the hill.

**Problem 3:** What is the potential energy of a 500 gm fruit hanging from a tree branch that is about to fall from the height of 2 m? (Take the value of gravitational acceleration, g = 9.8 m/s^{2})

Solution:

Given data:

Potential energy of a fruit, PE = ?

Mass of a fruit, m = 500 gm = 0.5 kg

Height of a fruit, h = 2 m

Gravitational acceleration, g = 9.81 m/s^{2}

Using the formula of potential energy,

PE = m g h

PE = 0.5 × 9.81 × 2

PE = 9.81 J

Therefore, a fruit hanging from a tree branch has the potential energy of **9.81 J**.

**Problem 4:** One monkey of mass 10 kg sitting on the edge of a wall is about to jump from the height of 4 m. Calculate the potential energy of a monkey. (Take the value of gravitational acceleration, g = 9.8 m/s^{2})

Solution:

Given data:

Mass of a monkey, m = 10 kg

Height of a monkey, h = 4 m

Potential energy of a monkey, PE = ?

Gravitational acceleration, g = 9.81 m/s^{2}

Using the formula of potential energy,

PE = m g h

PE = 10 × 9.81 × 4

PE = 392.4 J

Therefore, a monkey sitting on the edge of a wall has the potential energy of **392.4 J**.

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**Related:**

- Thermal Energy Equation
- Gravitational Potential Energy Formula
- Electric Potential Energy Formula
- Elastic Potential Energy Formula
- Kinetic Energy Formula
- Rotational Kinetic Energy Formula
- Electrical Energy Equation
- Mechanical Energy Formula
- Photon Energy Equation
- Conservation of Energy Formula

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