Free PDFGrade 6 · Science · 35 min
Refraction flip trick
Move a drawing behind a glass of water and watch the arrow flip.
I can explain how a round glass of water bends light like a lens and flips a picture.
A science experiment video with a free worksheet and answer key for teachers
About the video
In the video an arrow drawn behind a glass of water suddenly flips direction. At home your child draws two 6 cm arrows, fills a round glass so only the bottom arrow is behind water, and moves the paper back 0, 2, 10 and 20 cm to see when the arrow flips.
A round glass of water bends light like a lens and focuses it at a focal point about 3 or 4 cm behind a 7 cm glass. When the drawing is further away than that, the light rays cross, so left and right swap, but up and down stay the same because the glass is straight from top to bottom.
What your child learns
- Explain refraction as light bending between air and water
- Find the distance where a lens flips a picture
- Draw light rays crossing inside a round glass
What's on the worksheet
- 1Predict first
- 2Record the arrow
- 3What did you see?
- 4The science behind it
- 5Match the words
- 6True or false
- 7Same after a flip?
- 8Lens maths
- 9Draw the light rays
You need
1 round clear glass with straight sides (about 7 cm wide), 250 ml water, 1 sheet of white paper, 1 thick black marker, 1 ruler and a box or book to lean the paper on.
Safety
Put the glass on a steady table and wipe up spilled water.
Tip for the adult
Keep your child's eyes level with the arrows at 50 cm, because looking from above or below makes the flip hard to see.
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