Density

We measured the density of a bolt and a lego.

First, we figured out the mass of each using a triple beam balance. The bolt's mass was 96.85 grams; the lego's mass was 2.1 grams.

Next, we found the volume of each by submerging in a graduated cylinder of water. The bolt displaced 15ml of water; the lego displaced 3ml of water.

To get density, divide mass by volume, or D=m/v.

The bolt's density is 96.85/15 = 6.456 g/cc.
The lego's density is 2.1/3 = 0.7 g/cc.

The bolt is a lot more dense than the lego. This makes sense because the bolt is solid metal, but the lego is hollow plastic.

We tried to measure a packing peanut, but discovered it was biodegradable when it disintegrated in the water! It also floated. If we were quicker, we could attach a heavy washer to it to get the peanut under water, but then we'd also have to measure the mass and density of the washer too.

Energy Resources

Energy may be created by using fossil fuels. The fossil fuels are coal, oil, and natural gas. These are nonrenewable resources.

There is also nuclear energy which is created by either splitting atoms (fission) or joining them together (fusion). The downside to nuclear energy is that it's chemicals are harmful.

Solar energy is energy from the sun which is collected by solar collectors such as solar panels.

Hydroelectricity is energy created from water. Geothermal energy is energy from heat deep inside the earth. Wind energy is created through the use of windmills.

Biomass or wastes are animal waste, wood, or garbage that is burned to create energy. Bioconversion is when biomass is changed into a liquid or gaseous fuel.