Work, Energy and Power

Work, energy, and power are essential physics concepts. Work happens when a force moves an object. Energy is the ability to do work, and power is how fast work is done. Let’s explore these in detail.

What is Work?

Work is done when a force causes an object to move. The work done depends on the force applied and the distance moved in the direction of the force. Work is a scalar quantity, meaning it only has magnitude, not direction.

Formula for Work:

Where:

• W is work
• F is force
• d is displacement
• θ is the angle between the force and displacement

When is No Work Done?

• If there is no displacement
• If no force is applied
• If the force is perpendicular to the displacement

Unit of Work:

• The SI unit of work is the Joule (J).
• Example: If a force of 100 N moves an object 8 m, the work done is 800 J.

What is Energy?

Energy is the ability to do work. It can’t be created or destroyed, only transformed from one form to another. Energy is measured in Joules (J).

Types of Energy:

• Kinetic Energy (energy of motion)
• Potential Energy (stored energy)
• Mechanical, chemical, electric, magnetic, radiant, nuclear, and thermal energy

What is Power?

Power is the rate of doing work. It shows how quickly energy is used.

Formula for Power:

Where:

P is power

W is work done

t is time taken

Unit of Power:

• The SI unit of power is the Watt (W), which equals one Joule per second (J/s).

Overview of Work, Energy, and Power:

Work:

• Definition: Work is the product of the force and the displacement in the direction of the force.
• Formula:
• Unit: Joule (J)

Energy:

• Definition: Energy is the capacity to do work.
• Formula: Potential Energy (P.E.) is given by
• Unit: Joule (J)

Power:

• Definition: Power is the rate of doing work.
• Formula:
• ​Unit: Watt (W)

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