Science

1. Work (Definition)

Work is said to be done when a force is applied to an object and the object moves in the direction of the force.

📌 Formula:

Work=Force×Displacement×cos⁡(θ)\text{Work} = \text{Force} \times \text{Displacement} \times \cos(\theta)Work=Force×Displacement×cos(θ)

  • SI Unit: Joule (J)

  • If no movement happens, work = 0!

2. One Joule of Work

One Joule (1J) is the work done when a force of 1 Newton (N) moves an object 1 meter (m) in the direction of the force.

📌 1 Joule = 1 Newton × 1 meter

1J=1N×1m1J = 1N \times 1m1J=1N×1m

3. Power (Definition)

Power is the rate of doing work or how fast work is done.

📌 Formula:

Power=Work DoneTime Taken\text{Power} = \frac{\text{Work Done}}{\text{Time Taken}}Power=Time TakenWork Done​

  • SI Unit: Watt (W)

4. One Watt of Power

One Watt (1W) is the power when 1 Joule of work is done in 1 second.

📌 1 Watt = 1 Joule / 1 second

1W=1J/1s1W = 1J / 1s1W=1J/1s

5. Relation Between Watt & Its Multiples

Since Watt is a small unit, we use its multiples:

  • Kilowatt (kW) → 1 kW = 1000 W

  • Megawatt (MW) → 1 MW = 10⁶ W

  • Gigawatt (GW) → 1 GW = 10⁹ W

6. What Does "60W" Marked on a Bulb Mean?

  • "60W" means the bulb consumes 60 Joules of energy per second.

  • It tells us the power rating of the bulb.

  • Higher wattage = brighter light & more energy consumption.