Reflecting a ray of light and a rubber ball
Practical Activity for 14-16
Comparing the paths of a reflected ray of light and a rubber ball.
Apparatus and Materials
- Light source, compact (100 W 12 V)
- L.T. variable voltage supply (12 V 8 A)
- White screen (500 mm x 300 mm approx)
- Card with slit (5 mm wide approx)
- Retort stand and boss
- Plane mirror
- Rubber ball
Health & Safety and Technical Notes
Be aware that compact light sources using tungsten-halogen lamps without filters are significant sources of UV. Ensure that no-one can look directly at the lamp.
- Set up the compact light source with the card and slit in front of it, so that a thick
rayof light splashes across the vertical white screen.
- Catch the ray with a piece of plane mirror held in the hand and reflect it across the screen.
- Bounce the rubber ball against a hard wall or floor to show its reflection.
- This demonstration introduces the idea of reflection. It is not intended for careful measurements, but students should see some connection between the angles.
- Make sure that students observe the similarity between the path of the ray of light, and the path of the ball.
- You could ask the question 'What is light made of... bullets?'. If students have seen waves being reflected in a ripple tank, they might also give waves as an answer.
This experiment was safety-tested in August 2006