Physics · Grades 7–11
Waves & sound · Formula reference
Formula reference
Rule and assumptions
Wave speed from frequency and wavelength
Use wavelength in metres and frequency in hertz.
v = fλ
Period from many oscillations
A period is the duration of one complete oscillation, not its frequency.
T = total time / number of cycles
Distance from an echo
The recorded time includes travel to the reflector and back.
d = vt/2
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · independent educational and translation review required. Suggested grades are not official curriculum alignment.