HAMILTON, Mich. — Does an orange float or sink in water? It’s a question that you can never be wrong answering. Bentheim Elementary students learned about buoyancy and how the orange actually can do both! All you need for this experiment is two oranges, two glasses and water.
First you need to fill both glasses ¾ full of water. Then place one orange in one glass and after peeling the other orange place it in second glass. Watch what happens and compare the two oranges.
Which orange sinks? Which one floats? The orange with a peel is heavier than the orange without a peel but why and how does the heavier orange with a peel float??? The orange with a peel floats because the peel is porous and filled with tiny air pockets. Those air pockets make the orange less dense than water and causes it to float.
The other orange without a peel sinks when you place it in the glass of water. When you remove the peel you are making the orange lighter but you’re removing those tiny air pockets. This then makes the orange without a peel more dense than water so it sinks. This is how buoyancy works which is an objects ability and tendency to float in water or other fluids.
When the orange is placed in the water gravitational force pulls it down while buoyant force pushes it upward. The secret is all in the peel! When you make the orange heavier and less dense by keeping the peel on it helps the orange displace enough water to float. One the other hand though when you take the peel off and make the orange lighter and more dense it can’t displace enough water to overcome the gravitational force so it sinks.