A light pulse travels through 0.60 m of glass at 2.0 × 108 m/s. A second pulse travels the same distance through air at 3.0 × 108 m/s.
The pulses enter their paths at the same time. Use t=d/vt=d/vt=d/v.
How much later does the pulse travelling through glass reach the end of its path?
1.0×10−9 s1.0\times10^{-9}\ \mathrm{s}1.0×10−9 s
2.0×10−9 s2.0\times10^{-9}\ \mathrm{s}2.0×10−9 s
3.0×10−9 s3.0\times10^{-9}\ \mathrm{s}3.0×10−9 s
5.0×10−9 s5.0\times10^{-9}\ \mathrm{s}5.0×10−9 s
84 exam-style questions on Edexcel GCSE Physics 5.2 The electromagnetic spectrum, covering 5.2.1 Electromagnetic waves and refraction in glass (core practical), 5.2.2 Groups of the electromagnetic spectrum, 5.2.3 Wavelength-dependent behaviour of EM waves, and 5.2.4 Velocities of EM waves in different substances. Each one has a worked solution and a mark scheme showing where the marks go.