Physics · Grades 7–11
Wave speed from frequency and wavelength
Use wavelength in metres and frequency in hertz.
Rule and assumptions
Use wavelength in metres and frequency in hertz.
v = fλ
Worked examples
A wave has frequency 63 Hz and wavelength 1.9 m. Find its speed. Round to 3 decimal places if needed. Answer in m/s.
v = fλ 63 × 1.9 = 119.7
119.7 m/s
A wave has frequency 38 Hz and wavelength 4.3 m. Find its speed. Round to 3 decimal places if needed. Answer in m/s.
v = fλ 38 × 4.3 = 163.4
163.4 m/s
Try two questions
A wave has frequency 30 Hz and wavelength 1 m. Find its speed. Round to 3 decimal places if needed. Answer in m/s.
A wave has frequency 110 Hz and wavelength 3.1 m. Find its speed. Round to 3 decimal places if needed. Answer in m/s.
Answers and reasoning
Answers and marking notes
- 30 m/s
v = fλ 30 × 1 = 30
- 341 m/s
v = fλ 110 × 3.1 = 341
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.