Waves, sound & optics worksheet with answers

Free printable Waves, sound & optics worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
λ = ?v = 1.5 m/sf = 0.2 Hz

A water wave has a frequency of 0.2 Hz and travels at 1.5 m/s. Find its wavelength λ.

f = 0.2 Hzv = 1.5 m/s
λ = m
2.Easy
L = 0.6 m

A string of length 0.6 m and mass 8 g is stretched with a tension of 250 N. Find the speed v of transverse waves on it.

L = 0.6 mm = 8 gT = 250 N
v = m/s
3.Medium
S25 m/sOf = 300 Hz

A source of 300 Hz moves at 25 m/s away from a stationary observer. The speed of sound is 343 m/s. Find the frequency f′ that the observer hears.

f = 300 Hzv = 343 m/svs = 25 m/s
f′ = Hz
4.Medium
L = 0.8 mn = 7

A pipe closed at one end is 0.8 m long. The speed of sound is 343 m/s. Find the frequency f7 of its harmonic number 7.

v = 343 m/sn = 7L = 0.8 m
f7 = Hz
5.Hard
λ = 656 nmθ1​ = ?

Light of wavelength 656 nm falls at right angles on a grating with 100 lines per millimetre. Find the angle θ1 of the order-1 maximum.

N = 100 mm⁻¹λ = 656 nmm = 1
θ1 = °
6.Hard
λ = ?49.4°

A grating with 1200 lines per millimetre shows the order-1 maximum of a spectral line at 49.4° from the straight-through direction. Find the wavelength λ of the line.

N = 1200 mm⁻¹θ1 = 49.4°m = 1
λ = nm

Answer key

  1. 1. λ = 7.5 m
  2. 2. v = 136.9 m/s
  3. 3. f′ = 279.6 Hz
  4. 4. f7 = 750.3 Hz
  5. 5. θ1 = 3.761 °
  6. 6. λ = 632.7 nm

Full step-by-step solutions: practise this topic on examproblems.com.