Bathtub Physics - Density, Buoyancy and Flotation
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Russell, Renee South Shore High School
Understand Archimedes' Principle, flotation and the reaction of
bouyant forces. Explain the relationship between density and
triple-beam balance 800ml beaker
hooked mass 50g water
spring scale bathtub (large container
string or pool small)
500-ml graduated cylinder gallon jug
salt solutions: Use Epson Salt
1. sea water 3.5g of salt per 100cm3
2. Great Salt Lake 20g of salt per 100cm3
3. Dead Sea 25g of salt per 100cm3
1. Record the weight of an hooked mass with a spring scale. Fill a
graduated cylinder half-full of water and record the level of water.
Hang the mass from the spring scale and lower the object until it is
submerged in the water in the graduated cylinder. Record the weight of
the object in the water and the amount of water displaced.
2. Use a bathtub to find a student's volume. Fill the tub half-full
and mark the level. Submerge a student and mark the level of the
water. Once the student is out of the tub, use a measuring device-
large graduated cylinder, gallon jug - to fill the tub to the higher
mark. The amount of water needed to do this will be equal to the
3. Place an uncooked egg in a 800cm3 beaker half filled with water.
Next place the uncooked egg in each of the containers of salt
solutions one at a time. Make careful observations of what happens in
each solution and record your data.
Floating - A Key To Survival Science and Children October 1980 33-35.
Conceptual Physics Paul Hewitt