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
v = 2 × 10⁸ m/s

Light travels at 2 × 10⁸ m/s in a transparent material. Find its refractive index n.

v = 2 × 10⁸ m/sc = 3.00 × 10⁸ m/s
n =
2.Easy
λ = 1 mv = ?f = 2 Hz

A water wave has a frequency of 2 Hz and a wavelength of 1 m. Find its speed v.

f = 2 Hzλ = 1 m
v = m/s
3.Medium
S15 m/sOf = 1200 Hz

A source of 1200 Hz moves at 15 m/s towards a stationary observer. The speed of sound is 343 m/s. Find the frequency f′ that the observer hears.

f = 1200 Hzv = 343 m/svs = 15 m/s
f′ = Hz
4.Medium
θc = ?90°flint glass, n1​ = 1.62ethanol, n2​ = 1.36

Light travels in flint glass (n = 1.62) towards a flat boundary with ethanol (n = 1.36). Find the critical angle θc beyond which it is totally reflected.

n1 = 1.62n2 = 1.36
θc = °
5.Hard
Fdo​ = 30 cmR = 24 cm

An object is 30 cm in front of a concave mirror with a radius of curvature of 24 cm. Find the image distance di, positive for an image in front of the mirror (real) and negative for one behind it (virtual).

do = 30 cmR = 24 cm
di = cm
6.Hard
λ = 500 nma = 0.12 mm

Light of wavelength 500 nm passes through a single slit 0.12 mm wide. Find the angle θ2 of dark fringe number 2 from the straight-through direction.

λ = 500 nma = 0.12 mmm = 2
θ2 = °

Answer key

  1. 1. n = 1.5
  2. 2. v = 2 m/s
  3. 3. f′ = 1255 Hz
  4. 4. θc = 57.09 °
  5. 5. di = 20 cm
  6. 6. θ2 = 0.4775 °

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