Energy should be transferred to an object to move it. Transferring energy can be in the form of force. This amount of energy transferred by the force to move an object is called work or work done. Thus, the relation between work and energy is direct i.e., the difference in the kinetic energy of an object is work done by an object.
What is the Relation between Work and Energy?
Work and energy are directly proportional to each other. Work done by an object can be mathematically expressed as:
\(\begin{array}{l}W=\frac{1}{2}mv_f^{2}-\frac{1}{2}mv_i^{2}\end{array} \) |
Where,
- W is the work done by the object measured using Joules.
- m is the mass of the object measured using kilograms.
- vi is the initial velocity of the object measured using m/s.
- vf is the final velocity of the object measured using m/s.
Thus, the work-energy theorem states that:
The net work done by the force on an object is equal to the change in its kinetic energy.
Work and Energy – Formula and Unit
| Formula | Terms | SI Unit | |
| Work to Energy | \(\begin{array}{l}W=K_{i}-K_{f}\end{array} \)
Or \(\begin{array}{l}W=\Delta K\end{array} \) |
W is the work done.
Ki is the initial Kinetic Energy. Kf is the Final Kinetic Energy. ΔK is the difference in Kinetic Energy. |
Joules |
Note:
Please note that work and energy formula is applicable for the net force acting on a body, and not for the single force acting on a body.
You may also want to check out these topics given below!
- Equivalence Principle
- Nuclear Binding Energy
- Mass Energy Equivalence
- Derivation of Work-Energy Theorem
Watch the video and learn more about circular motion, work, power & energy
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Can you give few examples of the relationship between energy and work done ?
A speeding bullet has some amount of energy associated with it which we call kinetic energy. The bullet gained this energy by the work done on it by a charge of gunpowder which lost some chemical potential energy in the process.