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
v = ?

Find the speed v of light in crown glass, which has a refractive index of 1.50.

n = 1.50c = 3.00 × 10⁸ m/s
v = m/s
2.Easy
v = ?

Find the speed v of light in diamond, which has a refractive index of 2.42.

n = 2.42c = 3.00 × 10⁸ m/s
v = m/s
3.Medium
L = ?n = 3

A pipe open at both ends must have its harmonic number 3 at 792 Hz. The speed of sound is 343 m/s. Find the length L of the pipe.

v = 343 m/sn = 3f3 = 792 Hz
L = m
4.Medium
SO10 m/sf = 300 Hz

An observer moves at 10 m/s towards a stationary source of 300 Hz. The speed of sound is 343 m/s. Find the frequency f′ that the observer hears.

f = 300 Hzv = 343 m/svo = 10 m/s
f′ = Hz
5.Hard
Fdo​ = 20 cmR = 50 cm

An object is 20 cm in front of a convex mirror with a radius of curvature of 50 cm. Find the image distance di, positive for an image in front of the mirror (real) and negative for one behind it (virtual).

do = 20 cmR = 50 cm
di = cm
6.Hard
θn1​ = 1.48n2​ = 1.4n0​ = 1.00

An optical fibre has a core with n₁ = 1.48 and a cladding with n₂ = 1.4. Find its numerical aperture NA.

n1 = 1.48n2 = 1.4
NA =

Answer key

  1. 1. v = 2 × 10⁸ m/s
  2. 2. v = 1.24 × 10⁸ m/s
  3. 3. L = 0.6496 m
  4. 4. f′ = 308.7 Hz
  5. 5. di = −11.11 cm
  6. 6. NA = 0.48

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