Power calculation from energy and time: What is the power if 200 J of energy are used in 10 s?

Introduction / Context:
Many practical problems present energy consumed over a time interval, from which you must compute average power. This is a direct application of the definition of power in the time domain.

Given Data / Assumptions:

• Energy E = 200 J.
• Time t = 10 s.
• Average power P = E / t.

Concept / Approach:
Use the basic relation: power equals energy divided by time. Ensure units are SI to avoid conversion errors. The arithmetic should be straightforward as the numbers are chosen to divide cleanly.

Step-by-Step Solution:

Verification / Alternative check:
If the same 200 J were used in 20 s, power would halve to 10 W; if used in 5 s, it would double to 40 W. This proportionality confirms the calculation.

Why Other Options Are Wrong:

Common Pitfalls:
Forgetting that “per second” means divide by time; confusing power (W) with energy (J).

Final Answer:
20 W