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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Name: ____________________ Date: ____________

1.Easy

The sound intensity level at a point is 65 dB. Find the sound intensity I.

β = 65 dBI₀ = 10⁻¹² W/m²

I = µW/m²

2.Easy

The sound intensity level at a point is 80 dB. Find the sound intensity I.

β = 80 dBI₀ = 10⁻¹² W/m²

I = µW/m²

3.Medium

A source of 800 Hz moving at 30 m/s and an observer moving at 15 m/s approach each other. The speed of sound is 343 m/s. Find the frequency f′ that the observer hears.

f = 800 Hzv = 343 m/sv_s = 30 m/sv_o = 15 m/s

f′ = Hz

4.Medium

An object 4 cm tall stands 60 cm in front of a thin converging lens with a focal length of 5 cm. Find the image height h_i (negative for an inverted image).

h_o = 4 cmd_o = 60 cmf = 5 cm

h_i = cm

5.Hard

An object is 25 cm in front of a convex mirror with a radius of curvature of 40 cm. Find the image distance d_i, positive for an image in front of the mirror (real) and negative for one behind it (virtual).

d_o = 25 cmR = 40 cm

d_i = cm

6.Hard

Two thin lenses share an axis, 50 cm apart: lens 1 with f₁ = 10 cm and lens 2 with f₂ = 12 cm. An object stands 15 cm in front of lens 1. Find the position d_i2 of the final image measured from lens 2 (positive beyond lens 2, real-is-positive convention).

f₁ = 10 cmf₂ = 12 cms = 50 cmd_o = 15 cm

d_i2 = cm

Answer key

1. I = 3.162 µW/m²
2. I = 100 µW/m²
3. f′ = 915 Hz
4. h_i = −0.3636 cm
5. d_i = −11.11 cm
6. d_i2 = 30 cm

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