Intensity and Distance Calculator
〰 Oscillations & waves. Use the Intensity and distance formula to find intensity at r₂, intensity at r₁, distance r₁, distance r₂: pick the value you want, type the others, and the answer updates as you go.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Intensity at r₂ | W/m² |
| Intensity at r₁ | W/m² |
| Distance r₁ | m |
| Distance r₂ | m |
Worked example
Find the intensity at r₂ when Intensity at r₁ = 1 W/m², Distance r₁ = 1 m, Distance r₂ = 2 m.
Using I1 r1² = I2 r2²: Intensity at r₂ = 0.25 W/m².
Frequently asked questions
What is the formula for Intensity and distance?
I1 r1² = I2 r2².
What do the letters stand for, and what units are used?
Intensity at r₂ in W/m², Intensity at r₁ in W/m², Distance r₁ in m, Distance r₂ in m.
How do you calculate intensity at r₂?
Put the values into I1 r1² = I2 r2². For example, with Intensity at r₁ = 1 W/m², Distance r₁ = 1 m, Distance r₂ = 2 m, intensity at r₂ = 0.25 W/m².
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (intensity at r₂, intensity at r₁, distance r₁, distance r₂) and fill in the others: it rearranges the formula for you.
