Since ancient times people needed to be able to tell time. These days, we use digital wrist watches or electric clocks to accurately tell the time, but in the old days telling time was not such a convenient task. They used hourglasses, candle clocks and a device called a water clock. Do the following science experiment to learn how water can be used to tell time:
Materials:
MARKING PEN
STOP WATCH
SMALL NAIL
BOOKS
TAP WATER
2x TRANSPARENT PLASTIC CONTAINERS
STICKY TAPE
How To Proceed:
1. Make two plastic containers by asking an adult helper to cut in half two 1L plastic water bottles, so that you have two large transparent plastic 'cups'
2. Use a thin nail to make a small hole in the centre of the bottom of one of these containers. Place a piece of sticky tape over the hole and fill this container with some water.
3. Build a 'stand' out of books or similar objects so that the empty container fits in below the container with the water and the hole.
4. With the configuration as above, quickly remove the piece of tape and ask a friend to start the stop watch at the same time to start timing the water dripping from the hole in the top container to the bottom container.
5. After 1 minute, use the magic marker to mark the '1 minute' water level on the bottom container. Keep on marking the water levels at one minute intervals until all the water has dripped into the bottom container.
6. Tape the hole, and refill the top container with the water from the bottom container. Set up as before and remove the tape. This time you do not need the stop watch, as you now have a 'water clock' that tells the time in minutes!
