Dimensional Reasoning Math Example 2
Follow the full solution, then compare it with the other examples linked below.
Example 2
mediumA formula for the period of a pendulum is proposed as where is length (m) and is gravitational acceleration (m/s²). Verify dimensional consistency.
Solution
- 1 Compute : .
- 2 Compute : .
- 3 Compute : is dimensionless, so the result has units of seconds.
- 4 The period should be in seconds. The formula is dimensionally consistent.
Answer
Dimensional consistency is a necessary (though not sufficient) condition for a formula to be correct. A formula that fails dimensional analysis is definitely wrong; one that passes may still be wrong by a numerical factor.
About Dimensional Reasoning
Using the units and dimensions of physical quantities to check formulas, guide derivations, and eliminate impossible answers.
Learn more about Dimensional Reasoning →