A light ray in acrylic (n = 1.49) strikes a flat boundary with crown glass (n = 1.50) at 70° to the normal. Find the angle of refraction θ2, measured from the normal.
Waves, sound & optics worksheet with answers
A string of length 1 m and mass 4 g is stretched with a tension of 20 N. Find the speed v of transverse waves on it.
A source of 500 Hz moving at 34 m/s and an observer moving at 10 m/s move away from each other. The speed of sound is 343 m/s. Find the frequency f′ that the observer hears.
An object stands 8 cm in front of a thin converging lens with a focal length of 12 cm. Find the image distance di. Use the sign convention 1/f = 1/do + 1/di (f < 0 for a diverging lens, di < 0 for a virtual image).
An object is 5 cm in front of a concave mirror with a radius of curvature of 60 cm. Find the magnification m (negative for an inverted image).
Light of wavelength 450 nm falls on two slits 0.5 mm apart. The screen is 1.2 m away. Find the spacing Δy between neighbouring bright fringes.
Answer key
- 1. θ2 = 68.98 °
- 2. v = 70.71 m/s
- 3. f′ = 441.6 Hz
- 4. di = −24 cm
- 5. m = 1.2
- 6. Δy = 1.08 mm
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