Water Experiments

Wednesday, 19th December. Some easy water experiments to try at home:

Make a Diver
We made a diver out of marla, and connected him to a pen cap with a paper clip and an elastic band.
We can get the diver to sink by squeezing the bottle, and we can make him surface again by letting go.
This is because the diver floats when the pen cap is full of air but he sinks when the air in the cap is compressed (from the squeezing) and the cap fills with water. Water in the lid is too heavy to keep the diver floating.

Bath Tricks
Water will spill out of a bottle if you fill it with water, put your hand on top, turn it
upside down and then take your hand away.
Water will not spill out of the bottle if you fill it with water, put your hand on top, turn it upside down under the water and then take your hand away.
This is because the air pressure pushing down on the water in the basin is as strong as the water pressure in the bottle trying to get out, so the water in the bottle stays put.
We can get a card to stick on our bottle of water. When we turned the bottle with the card on it upside down and let go, the card didn’t fall off. Why not? Because the pressure of air
pushing up on the card was as strong as the water pressure in the bottle so the water couldn't get out and the card stays put. Water Walks Along a String

You can get water to spill sideways by pouring the water down along a string. The water holds tightly on to the string by surface tension and travels along the string instead of spilling straight down. Detergent Power

Our speed boat is floating on the water.
We can break the surface tension of the water by squirting in some wash up liquid. When we do this the boat will shoot forward. Water Races
Does water flow faster if you shake or squeeze the bottle?........
….No, it doesn’t, but if flows faster if you make a tornado in the bottle by swirling the bottle of water. Making a tornado is fun. You can make one by joining two bottles together with plumbers tape. Start the tornado by swirling the water in the top bottle.

Making Boats
Does marla float or sink? Both. If it is in a ball it will sink but you can make it into a boat shape and it will float.We made boats and then when they could float we filled them with peas (passengers)
Flat thin shapes with high sides seem to make the best boats.