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Author:
Trevor Blondin

Density and Buoyancy- Grade 8

All objects experience a buoyant force when immersed in a fluid. As a basis for understanding this concept:

Students know density is mass per unit volume.

Students know how to calculate the density of substances (regular and irregular solids and liquids) from measurements of mass and volume.

Students know the buoyant force on an object in a fluid is an upward force equal to the weight of the fluid the object has displaced.

Students know how to predict whether an object will float or sink.

Tutorial

What makes an object float? How can we determine which objects will float and which will not?

This formula for determining buoyancy was created by Greek mathematician and physicist, Archimedes.

If water has a density of 1g/cm cubed, will an object with a mass of 30 grams and a volume of 470 milliliters float? Give its density in g/cm.

Answer here:

Grade Eight Science standards: Density and Buoyancy

All objects experience a buoyant force when immersed in a fluid. As a basis for

understanding this concept:

a. Students know density is mass per unit volume.

b. Students know how to calculate the density of substances (regular and irregular

solids and liquids) from measurements of mass and volume.

c. Students know the buoyant force on an object in a fluid is an upward force equal

to the weight of the fluid the object has displaced.

d. Students know how to predict whether an object will float or sink.