A narrow light beam from a surveying instrument strikes a flat reflective panel. The smaller angle between the incident beam and the reflected beam is 116∘116^\circ116∘.
The panel is then rotated so that the angle of incidence decreases by 9∘9^\circ9∘.
Calculate the new angle between the reflected beam and the surface of the panel.
93 exam-style questions on Edexcel GCSE Physics 5.1 Reflection, refraction and lenses, covering 5.1.1 Reflection, refraction and total internal reflection, 5.1.2 Specular and diffuse reflection, 5.1.3 Colour of light: absorption and filters, 5.1.4 Lenses: power, focal length and shape, 5.1.5 Ray diagrams for converging and diverging lenses, and 5.1.6 Real and virtual images. Each one has a worked solution and a mark scheme showing where the marks go.