Graph This!
Imagine you are an officer on an Ohio-class, Trident nuclear submarine. In order to make a dive, you must know the density of your submarine compared to seawater. If there is a miscalculation, the submarine could dive to the wrong depth and endanger the lives of the crew. Make a line graph from the data in the chart and then see if you can answer these questions. On your graph, put density of seawater on the vertical (Y) axis and put depth on the horizontal (X) axis.

Density of Seawater
Depth (m)	Density (kg/m3)
0	1028
1,000	1,033
2,000	1,038
6,000	1,046
8,000	1,063
10,000	1,071

1. In percentage terms, how much denser is seawater at 10,000 meters than it is at the surface?
2. Why do you think seawater is denser at 10,000 meters than at the surface?
3. Your submarine has a density of 775 kg/ m3. Will it float? Why?
4. How much will you have to add to change the density to take the sub down to 2,000 meters? (Hint: Compare the density of your submarine to the density of seawater at that level.)
5. If each cubic meter (m3) of seawater adds 0.048 kg/ m3 in density to your submarine, how many cubic meters of seawater must be added to the ballast tanks to submerge to a level of 2,000 meters?
6. One cubic meter of water equals 264 gallons. How many gallons of water must be added to reach a depth of 2,000 meters? (Hint: Take your answer from No. 5 and convert it into gallons).
7. Using data from your line graph, approximately how many cubic meters of seawater must be added to the ballast tanks to submerge from 2,000 to 4,000 meters?