Physics 01
How to Convert Wavelength to Frequency (With Examples)
Convert wavelength to frequency with f = v/λ: worked examples for a red laser, FM radio, Wi-Fi and a 440 Hz note, plus photon energy and the unit traps.
waves
Physics 02
Why Does an Ambulance Siren Change Pitch as It Passes?
At 90 km/h a 700 Hz siren is heard at 755 Hz coming and 652 Hz going, 2.5 semitones apart. Here is the Doppler math, and how to read speed from the pitch.
Physics 03
Why Does Sound Travel Faster in Water and Steel?
Sound is 4 times faster in water and 17 times faster in steel than in air, because stiffness matters more than density. The numbers, worked through.