FYKOS Year 35 Series 2 Problem 1 — chasing the light · FYKOS 35 #35.2.1

Physics · optics

Problem

Jindra walks down a long, lit corridor. His eyes are at a height of

1.7\,\mathrm{m}

above the floor, the light on the ceiling is at a height of

3.4\,\mathrm{m}

. Jindra is now at a distance of

10\,\mathrm{m}

(horizontally) from the nearest light and is approaching it at a speed of

3\,\mathrm{km\cdot h^{-1}}

. He sees a reflection of the light on the polished floor. How fast is the reflection approaching Jindra at this point?