Lesson 3. Engage Do a demonstration to show that the wax is heavier than the clay but that the wax floats and the clay sinks. Materials for the demonstration 1 tea light candle Clay Clear plastic container Water Large balance Teacher preparation Use a small enough piece of clay so that you are sure that the candle weighs more than the clay. Procedure Place a piece of clay that weighs less than a tea light candle on one end of a balance. Remove the candle from its metal container and place the candle on the other end of the balance.
Expected results Even though the candle weighs more than the clay, the candle floats and the clay sinks. Explore Have students compare the density of water, wax, and clay.
Question to investigate Why does a heavier candle float and a lighter piece of clay sink? Materials for each group 2 tea light candles in their metal containers Clay Water in cup Small balance Tape Dropper Procedure Compare the density of wax and water Roll two pieces of tape and stick them to the center of the pan at each end of the balance.
Attach each tea light candle to the tape so that each candle is in the center of the pan. Use the wick to pull one candle out of its container. Expected results The water has a greater mass than an equal volume of wax. Ask students: Which weighs more, wax or an equal volume of water? Water weighs more than an equal volume of wax. Which is more dense, wax or water? Water is more dense.
Compare the density of clay and water Make sure you have one piece of tape in the center of each pan on the balance.
Fill one container with clay and place it on the tape so that it is in the center of the pan. Place an empty container on the tape at the opposite end of the balance. Slowly and carefully add water to the empty container until it is full. Expected results The clay has a greater mass than an equal volume of water.
Ask students: Which weighs more, the clay or an equal volume of water? The clay weighs more than an equal volume of water. Which is more dense, clay or water? Scientists are curious and students can model being a scientist by exploring things that can affect whether an object floats such as its shape, weight or the amount or type of liquid used to float it.
This investigations are a perfect opportunity for students to develop experimenting and reporting skills. This story could provide opportunities for students to raise further questions about floating and sinking. Our website uses a free tool to translate into other languages. This tool is a guide and may not be accurate.
For more, see: Information in your language. You may be trying to access this site from a secured browser on the server. Please enable scripts and reload this page.
Skip to content. Water pushes back up against objects so the more surface area an object has the more water pushes back against it helping it to float. When an object floats, it pushes water out of the way displacement. Have you ever noticed that when you climb into a bath the water level rises? This easy activity demonstrates how reducing the density of a heavy object allows it to float.
Place the bubble wrapped ball on the surface of the water, you should find it now floats. Although the bubble wrap makes the ball weigh a little more, it also displaces extra water making the ball more buoyant. The pockets of air in the bubble wrap mean that the ball and bubble wrap together are less dense than the water, which means the ball floats! Can you think of a different way to make the ball float?
What if you made it a boat with plasticine? Babble Dabble Do has a fabulous ship building activity to demonstrate how displacement helps objects float. Do you know what density means? Well everything around us is made up of tiny molecules. In some objects these molecules are jam packed together, and in others they are loosely packed together. This is actually what density means. How does this sink and float work?
Some boats are massive, and would seem very dense, so how do they stay afloat? Now comes buoyancy, which is the opposite of gravity. But what is buoyancy? Think about what happens when you put an ice cube into a glass of water. As the ice cube displaces moves some of the water to make way for itself, the water level rises and the ice floats partially in and out of the water.
0コメント