Gravity and light
Bending light and splitting white light
What does water do to a beam of light, and what is white light made of?
Watch first
Find out why weight is really a force, and mass is not.
What you need
Tick each one as you find it — 0 of 6 ready.
Plan the fair test
- Change: The angle light enters the water at
- Measure: How much the beam bends, and the colours you see
- Keep the same: Same torch, same depth of water, same room brightness
Objectives this evidences
- Understand the transmission of light through materials, reflection, refraction and the colours of the light spectrum
Do it, one step at a time
Step 1 of 4
- Step 1. Stand a pencil in the glass of water and look from the side. Sketch exactly what you see.
- Step 2. Shine the torch into the water at a slant and note where the beam changes direction.
- Step 3. Rest the mirror in the tray at an angle and shine the torch onto it, catching the reflection on white paper.
- Step 4. Tilt the mirror slowly until a band of colours appears on the paper, then record the order.
What should happen
Light bends as it changes speed entering water, and white light splits into a spectrum.
Think about: The pencil looks broken but is not. Which part of the light's journey explains that?
Write up your result
A sentence or two is enough to save it.
The lessons behind this practical
Each one opens with the same short film, and the film has a written transcript underneath if reading is easier than watching.
Now the quiz for this topic
Questions come from the lessons behind this practical, so nothing is asked that has not been taught.
Quiz
Gravity and light quiz
4 questions from the lessons in this stage. No timer, and you can try again as many times as you like.