The Language of Measurement
Rearranging Equations
12 min · 2 worked examples · 3 questionsFree
One equation, three questions. How to solve for whichever quantity you actually need.
After this lesson you can
- Rearrange any two-term formula for the quantity you actually want
- Check a rearrangement is right before you trust the number
- Get resistance out of V = I x R without guessing which way up it goes
Why this is the most useful skill in engineering
Ohm's law is usually written V = I × R. But you will rarely be handed the current and resistance and asked politely for the voltage. Far more often you know the supply voltage and the current you want, and you need the resistance. Or you know the voltage and resistance and want to check the current is safe.
One relationship, three different questions. Rather than memorise three separate formulas, learn to rearrange one. Then you can handle any equation you meet, including ones you have never seen.
In the full lesson
- Why this is the most useful skill in engineering
- The golden rule
- Working through a real one
- Check your answer is sensible
Free with an account. Read it, work the examples, answer the questions, then build it in the simulator.