Worksheet Chapter 2: Pressure

1. A freshwater swimming pool has a depth of 2.5 m. (a) Calculate the water pressure at the bottom of the pool. (b) Calculate the total (absolute) pressure at the bottom of the pool, given Patm = 101.3 kPa.

2. True or False: According to Pascal's Principle, pressure applied to an enclosed fluid is transmitted equally in all directions throughout the fluid.

3. An open U-tube manometer containing mercury (density = 13,600 kg m⁻³) is connected to a container of trapped gas. The mercury level in the open arm is 15 cm LOWER than the level in the arm connected to the gas container. (a) State whether the gas pressure is higher or lower than atmospheric pressure. (b) Calculate the gas pressure in Pascals, given Patm = 101,300 Pa.

4. Air flows horizontally past an aircraft wing with an upper surface area of 20 m². The air speed above the wing is 60 m s⁻¹ creating a pressure of 99.5 kPa, while the air speed below the wing is 45 m s⁻¹ creating a pressure of 101.0 kPa. (a) Calculate the pressure difference (ΔP) between the bottom and top of the wing. (b) Calculate the total upward lift force exerted on the aircraft wing.

5. A wooden wooden rod of uniform cross-sectional area 0.002 m² and total length 0.80 m has a mass of 1.12 kg. (a) Calculate the density of the wood. (b) When placed vertically in water (density = 1000 kg m⁻³), determine the submerged length (h_sub) of the wooden rod when it floats in equilibrium.

6. Fill in the blank: The upward force exerted by a fluid on an object fully or partially immersed in it is called the ________ force.

7. Which principle explains why an aircraft wing experiences an upward lift force during high-speed takeoff along a runway?

8. True or False: A hot air balloon ascends when the total weight of the balloon and its heated air becomes greater than the buoyant force of the surrounding cool air.

9. A concrete block of dimensions 0.4 m × 0.2 m × 0.1 m and mass 19.2 kg is completely submerged in sea water (density = 1025 kg m⁻³). (a) Calculate the volume of the concrete block. (b) Calculate the buoyant force acting on the submerged block. (c) Calculate the apparent weight of the block while submerged in sea water.

10. A hydraulic press has a small input piston with a radius of 0.05 m and a large output piston with a radius of 0.25 m. (a) Calculate the ratio of the area of the output piston to the input piston (A2 / A1). (b) If an input force of 150 N is applied to the small piston, calculate the output force produced on the large piston.