ACTIVITY SHEET SCIENCE BEHIND SINK OR FLOAT When objects are placed in water, they will either sink, or they will float. If something sinks, that means it goes down beneath the surface of the water, and when something floats, that means it rests on or near the surface of the water. Whether an object sinks or floats, doesn’t have as much to do with its weight as it does with its density. Everything around us is made up of tiny molecules. How closely these molecules are packed together determines its density. Objects with molecules packed very close together are always going to be more dense than those with the molecules packed loosely.
KEY TERMS Buoyancy - the ability or tendency to float. Density - the degree of compactness of a substance. Molecules - a group of atoms bonded together. Object - a material thing that can be seen and touched. Pressure - continuous physical force exerted on an object by something in contact with it. • Surface - the outside or uppermost layer of something.
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401 SW Second Street • Fort Lauderdale, FL 33312 • 954.467.6637
ACTIVITY SHEET SINK OR FLOAT KEY TERMS • Buoyancy - the ability of an object to float. • Sink - to go beneath the surface of a liquid. • Float - to rest on or near the surface of a liquid.
SUPPLIES
STEPS
• Bathtub or sink full of water. • Other items to test such as toys, soap, spoon, rock, leaf and anything that your family says is okay to test.
1. Fill your bathtub full of water deep enough for some items to sink. 2. Collect items around house to test if they sink or float. 3. Make a guess if the item will sink or float. 4. Drop your item into the tub. What happened? 5. Repeat with the other items.
EXPLORATION I wonder how I could take something that sinks and make it float. 401 SW Second Street • Fort Lauderdale, FL 33312 • 954.467.6637
ACTIVITY SHEET MAKE YOUR OWN LIFE JACKET DESIGN PROCESS • • • • •
SUPPLIES
A problem to solve Imagine a solution Design the solution Test the idea Improve idea
STEPS
• Action figure or toy that sinks in water • Choice of materials that float including packing peanuts, bubble wrap, sponges or corks • Tape • Rubber bands • Bathtub full of water
1. Fill your bathtub full of water deep enough to sink your figure. 2. Collect items around you house to help your figure float. 3. Experiment with adding or removing items to make the toy float. Use the tape and rubber bands to attach the items to the figure. 4. Continue to test different designs to make the figure float in different ways. 5. Can you make your toy float with the body below the water and the head above?
EXPLORATION I wonder where I would wear a life jacket. I wonder how a life jacket works. 401 SW Second Street • Fort Lauderdale, FL 33312 • 954.467.6637