1. What is the Energy Equation?

The energy equation E = P × t calculates the amount of energy consumed or produced by an electrical device, where E is energy in joules, P is power in watts, and t is time in seconds.

2. How Does the Calculator Work?

The calculator uses the energy equation:

Where:

• \( E \) — Energy (joules)
• \( P \) — Power (watts)
• \( t \) — Time (seconds)

Explanation: This equation shows the direct relationship between energy, power, and time. The longer a device operates or the more powerful it is, the more energy it consumes.

3. Importance of Energy Calculation

Details: Calculating energy consumption is essential for understanding electricity usage, estimating costs, and designing efficient electrical systems in GCSE physics.

4. Using the Calculator

Tips: Enter power in watts and time in seconds. Both values must be positive numbers. The calculator will compute the energy in joules.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between power and energy?
A: Power is the rate at which energy is transferred or converted (watts), while energy is the total amount of work done or heat transferred (joules).

Q2: How do I convert joules to kilowatt-hours?
A: To convert joules to kilowatt-hours, divide the energy in joules by 3,600,000 (since 1 kWh = 3,600,000 J).

Q3: Can this equation be used for any type of energy?
A: This specific equation (E = P × t) is primarily used for electrical energy calculations, but the concept applies to other forms of energy where power and time are factors.

Q4: What are typical power values for household appliances?
A: Typical values range from 5-10W for LED bulbs, 60-100W for incandescent bulbs, 800-1500W for microwaves, and 2000-5000W for electric heaters.

Q5: Why is energy measured in joules?
A: The joule is the SI unit of energy, named after physicist James Prescott Joule, and provides a standard measurement for energy across all scientific disciplines.