Inverse Quantity Math Example 2

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Example 2

medium
The pressure PP of a gas varies inversely with its volume VV at constant temperature (Boyle's Law). If P=200P = 200 kPa when V=3V = 3 L, find PP when V=5V = 5 L.

Solution

  1. 1
    Inverse proportionality: PV=kPV = k (constant).
  2. 2
    Find kk: k=200×3=600k = 200 \times 3 = 600 kPa·L.
  3. 3
    When V=5V = 5: P=6005=120P = \dfrac{600}{5} = 120 kPa.

Answer

P=120P = 120 kPa when V=5V = 5 L.
Boyle's Law is the classic physical example of inverse proportionality. The constant product PV=kPV = k reflects conservation of the total 'amount' of gas — compressing it raises pressure, expanding it lowers pressure proportionally.

About Inverse Quantity

The reciprocal or multiplicative inverse of a quantity, where multiplying a number by its inverse yields one. Inverse quantities appear whenever two measurements are inversely related, so that doubling one halves the other.

Learn more about Inverse Quantity →

More Inverse Quantity Examples

Example 1 easy

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Example 3 easy

At [formula] km/h a trip takes [formula] hours. How long does the same trip take at [formula] km/h?

Example 4 medium

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