Atmospheric pressure at sea level has a value of 100 kPa. The density of sea water is 1020 kg m-3.

At what depth in the sea would the total pressure be 250 kPa?

A.?20 m? ? ? ? ? ? ? ?B.?9.5 m? ? ? ? ? ? ? ?C.?18 m? ? ? ? ??D.?15 m

Icebergs typically float with a large volume of ice beneath the water. Ice has a density of 917 kg m-3?and a volume of Vi.

The density of seawater is 1020 kg m-3.What fraction of the iceberg is above the water?

A.?0.10 Vi? ? ? ? ??B.?0.90 Vi? ? ? ? ??C.?0.97 Vi? ? ? ? ??D.?0.20 Vi

Don't get confused by the two step process to find upthrust.

• Step 1: You need the volume of the submerged object, but?only?because you want to know?how much fluid was displaced
• Step 2: What you?really?want to know is the?weight of the displaced fluid.

A couple of familiar equations will help;

• m = ρV?to get mass (and that's the V from step 1 out of the way),

then

• W = mg?to get weight

If you are feeling particularly mathematical, you can combine your equations, so that?W = ρVg