What do you need?
Three pieces of cardboard, candle, needle.
What do you do?
1. Make a hole through the centre of each of three pieces
of the cardboard using a needle.
2. Place the three pieces of the cardboard upright and 30
cm apart from each other.
3. Place a lighted candle in front of the cardboard
furthermost from where you stand.
4. Arrange the three pieces of the cardboard s0 that the
candle flame can be seen through the holes.
5. The shift one the pieces of the cardboard to one side.
6. Try to observe the flame of candle again. Can you see
it now?
What do you find?
1. We are able to see the candle flame through the hole
when they are in a straight line.
2. When any one of them is not in the line with others,
the candle flame will be blocked by the cardboard. Therefore the light is not
visible to eye.
What do you conclude?
Light travels in straight lines.
