Science Smarts: Float or Sink

By PATTY ROOKS on March 4, 2022.

I was rearranging things in my office the other day, and I ran across a box of materials that made me a bit nostalgic.

Sometimes teachers invite me into the classroom to do presentations and I wanted to share with you one of my favorite games I play with students – Float or Sink. You will be amazed and the results. Let’s get started!

Remember to ask an adult before doing this experiment

Materials

• Old empty aquarium or large clear plastic container

• Water

• Sturdy table

• Area you can make a mess in

• Can of cola

• Can of diet cola

• Orange

• Peeled orange

• Paper clips

• Plasticine balls

• Tennis ball

• Ping pong ball

• Other various materials you want to see if they will float or sink

• Science notebook

• Pencil

Procedure

• Make a chart in your notebook with all of the materials you are going to test on one side and on the other side of the chart make your prediction. Will the object float or sink? Make a third column to write the correct answer down once you have tested the material.

• Fill the aquarium (or plastic container) about 2/3 full of tap water and place on a sturdy table.

• One by one, place the material gently in the water.

• Wait a couple of seconds.

• Does it float or sink?

• Record your results in your science notebook.

• Pay particular attention to the special articles I listed – are you as amazed by the results as I am?

• Why do you think similar objects have different results?

What is going on?

In this experiment you are exploring buoyancy. A buoyant force is a force that acts on an object causing it to float. An object will sink when its weight is greater than the buoyant force. On the other hand, an object will float when the buoyant force is greater than its weight.

What may be surprising in this experiment is that one of the cans of soda will float and one will sink. Although they look identical, they are not. Diet soda actually weighs less than the regular soda due to the artificial sweetener in it. It takes a great deal less artificial sweetener to make a diet soda than a regular soda as a result it weighs much less.

What were your results of the other items? Were you surprised?

Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. Address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca.

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