physics- density of materials
All matter contains particles. The difference between the different states of matter is how the particles are arranged:
volume
states
in a solid - particles are tightly packed in a regular structure
in a liquid - particles are tightly packed but free to move past each other
in a gas - particles are spread out and move randomly
Density also depends on the material. A piece of iron with the same dimensions as a piece of aluminium will be heavier because the atoms are more closely packed.
If the object has an irregular shape, the volume can be measured using a displacement can.
If the object is a regular shape, the volume can be found by using a ruler
density= mass/volume
cube
length x width x height
sphere
4/3 x pi x(diameter/2)cubed
cylinder
pi x(diameter/2)squared x length
cone
pi x(diameter/2)squared x length/3
practical
regular shapes
Use a ruler to measure the length (l), width (w) and height (h) of a steel cube.
Place the steel cube on the top pan balance and measure its mass.
Calculate the volume of the cube using (l × w × h).
Use the measurements to calculate the density of the metal.
Use vernier callipers to measure the diameter of the sphere.
Place the metal sphere on the top pan balance and measure its mass.
Calculate the volume of the sphere
Use the measurements to calculate the density of the metal.
irregular shapes
Place the stone on the top pan balance and measure its mass.
Fill the displacement can until the water is level with the bottom of the pipe.
Place a measuring cylinder under the pipe ready to collect the displaced water.
Carefully drop the stone into the can and wait until no more water runs into the cylinder.
Measure the volume of the displaced water.
Use the measurements to calculate the density of the stone.