1.When a submarine dives to a depth of 500 m, how much pressure, in Pa, must it hull be able to withstand? How many times larger is this pressure than the pressure at the surface?

2. A 2 m tall barrel is closed on top except for a thin pipe extending 8 m up from the top. When the barrel is filled with water up to the base of the pipe (2 m deep), the water pressure on the bottom of the barrel is 20 KPa. What is the pressure on the bottom when water is added to fill the pipe to its top?

3. A dike in Holland springs a leak through a hole of area 1cm squared at a depth of 2m below the water surface. How much force must a boy apply to the hole with his thumb to stop the leak? (Hint: convert the area from squared cm to squared meters before solving the problem).

4.In lab you find that a 1kg rock suspended above water weights 1ON .when the rock is suspended beneath the surface of the water, the scale reads 8N.

(a) what is the buoyant force on the rock ? (b) if the container of water weights 10N on the weighing scale , what is the scale reading when the rock is suspended beneath the surface of the water? (c) what is the scale reading when the rock is released and rest at the bottom of the container ?

5. A merchant in Katmandu sells you a solid gold 1-kg statue for a very reasonable price. When you arrive home, you wonder whether or not you got a bargain, so you lower the statue into a container of water and measure the volume of displaced water. Show that, for pure gold, the volume of water diplaced will be 51.8 cm³

6. Water at a pressure of 400 KPa flows through a horizontal pipe at a speed of 2 m/s. The pipe narrows to one-fourth its original diameter. What is the speed of the flow in the narrow section?

7. A sedimentary rock weighs 202 N in air and 120 N when submerged in an alcohol solution with a density of 700 Kg/m³. What is the density of the rock?

8. A boat is built of wood having a density of of 590 Kg/m³. The surface area of the bottom of the boat is 6 m² and the total volume of its wood is 0.7 m³. When the boat is placed in fresh water (density : 1000 Kg/m³) , how deep is the bottom of the boat below water level?