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.

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1.Easy
λ = 0.0686 mv = 343 m/sf = ?

A sound wave in air travels at 343 m/s with a wavelength of 0.0686 m. Find its frequency f.

λ = 0.0686 mv = 343 m/s
f = kHz
2.Easy
λ = 0.34 mv = 340 m/sf = ?

A sound wave in air travels at 340 m/s with a wavelength of 0.34 m. Find its frequency f.

λ = 0.34 mv = 340 m/s
f = kHz
3.Medium
L = 1.2 mn = 1

A pipe closed at one end is 1.2 m long. The speed of sound is 343 m/s. Find the frequency f1 of its fundamental (first harmonic).

v = 343 m/sn = 1L = 1.2 m
f1 = Hz
4.Medium
65 dB?5 m10 m

A small source sends sound equally in all directions. The level is 65 dB at 5 m from it. Find the level β2 at 10 m, ignoring absorption and reflections.

β1 = 65 dBr1 = 5 mr2 = 10 m
β2 = dB
5.Hard
λ = 532 nmθ1​ = ?

Light of wavelength 532 nm falls at right angles on a grating with 800 lines per millimetre. Find the angle θ1 of the order-1 maximum.

N = 800 mm⁻¹λ = 532 nmm = 1
θ1 = °
6.Hard
λ = 600 nmθ2​ = ?

Light of wavelength 600 nm falls at right angles on a grating with 600 lines per millimetre. Find the angle θ2 of the order-2 maximum.

N = 600 mm⁻¹λ = 600 nmm = 2
θ2 = °

Answer key

  1. 1. f = 5 kHz
  2. 2. f = 1 kHz
  3. 3. f1 = 71.46 Hz
  4. 4. β2 = 58.98 dB
  5. 5. θ1 = 25.19 °
  6. 6. θ2 = 46.05 °

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