Physics - Intensity
See Also
- [[Physics - Waves]]A
- [[Physics - Diffraction]]A
- [[Physics - Polarisation]]A
- [[Physics - Reflection and Refraction]]A
Flashcards
What is the intensity of a wave?
The radiant power passing through a surface per unit area.
What is the SIMPLE formula for intensity?
\[I = \frac{P}{A}\]
What is the formula for intensity?
\[I = \frac{P}{4\pi r^2}\]
Why does the intensity of a wave decrease as you move further away?
Energy is conserved but spread over a larger area, so each piece of area gets less energy.
What’s the equation for the intensity of this wave as radiant energy spreads out from a point?
What’s the equation for the intensity of this wave as radiant energy spreads out from a point?
\[I = \frac{P}{4\pi r^2}\]
What’s the formula for the volume of a sphere?
\[\frac{4}{3} \pi r^3\]
What’s the formula for the surface area of a sphere?
\[4\pi r^2\]
What is intensity directly proportional to?
\[\text{intensity} \propto \text{amplitude}^2\]