1) A sailboat with a bottom surface area of 10 m^2 has 40 cm high gunwales(sides). it has a mass of 40 kg. (Use the density of water as 1000 kg/m^3 or 1 g/cm^3)

a) Does it float?

b) if it floats how much additional mass can it hold without water coming over the gunwales of the boat? if it sinks how much higher would the gunwales need to be so it would float?

2) A standard AL80 aluminum (the density of aluminum is 2.70 g/cm^3) SCUBA tank can hold about 80 cubic feet of air (under pressure) (density of air is 1.29 kg/m^3), enough for about 90 mins. of typical dive time. it measures 21 inches high and 6.25 inches in diameter, and weighs about 35 pounds empty.

a) What is the total mass in kg when full? Hint: air + tank!

b) What is its apparent mass under water when empty? (the volume of the cylinder is pi*r^2*h)

c) what is its apparent mass under water when full?

d) what does this mean to a SCUBA diver?

3) A giant squid want to drift upward with a net force of 100N, It currently has a mass of 50 Kg and a volume of 250 liters, and is neutrally buoyant. how much should he increase the size of his air bladder?

4) A boat with a bottom surface area of 30m^2 is floating in a lake. 380 pound Perry steps in.

a) How much lower does the boat sink?

b) How much would it sink if its surface area was only 15 m^2?

c) How much lower would the original boat sink if both Perry and is identical sized girlfriend Mary both got in?

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