1. 1
   A car maintenance garage uses a hydraulic lift to raise vehicles for servicing. The lift's platform has a large surface area supporting the car, while a small piston is used to apply force from a compressor.

   (a)

   Which equation is used to calculate the pressure produced by a force acting on an area?

   [1 mark]

   • Ap = F + A
   • Bp = F × A
   • Cp = A/F
   • Dp = F/A

   (b)

   What is the SI unit for pressure?

   [1 mark]

   • Anewton
   • Bjoule
   • Cpascal
   • Dwatt

   (c)

   A technician applies a force of 300 N to the small piston, which has an area of 0.02 m². Calculate the pressure produced. Show your working and give the correct unit.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A marine biologist dives to study coral reefs and monitors the pressure exerted by the seawater on her equipment as she descends to different depths.

   (a)

   As the diver descends deeper into the sea, the pressure due to the water:

   [1 mark]

   • Adecreases
   • Bstays the same
   • Cbecomes zero
   • Dincreases

   (b)

   Besides gravitational field strength, which two factors determine the pressure due to a column of liquid?

   [1 mark]

   • Adensity of the liquid and its colour
   • Bheight of the liquid column and its temperature
   • Cheight of the liquid column and its density
   • Dvolume of the liquid and its temperature

   (c)

   The density of seawater is 1030 kg/m³. Calculate the pressure due to the water at a depth of 10 m, taking g = 9.8 N/kg. Give your answer to 3 significant figures.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A wooden rowing boat floats on a calm lake. Part of the boat is submerged below the waterline, and the rest is above the water, supporting the weight of a passenger sitting inside.

   (a)

   Explain, in terms of forces, why the boat floats and does not sink.

   [3 marks]

   (b)

   Explain why a swimmer finds it easier to float in the sea (salt water) than in a freshwater lake, and explain how atmospheric pressure above the lake's surface would change if the lake were located high in the mountains rather than at sea level.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Hospital equipment engineers design a hydraulic patient hoist that uses a small hand-pump piston to lift heavy patients safely, and a blood pressure cuff (sphygmomanometer) that relies on the same underlying pressure principles to measure a patient's blood pressure.

   (a)

   Explain how such a hydraulic lifting system can use a small force applied to a small piston to lift a much larger patient load, referring to pressure transmission through the fluid and the relationship between force and area at each piston.

   [6 marks]

   (b)

   A blood pressure cuff is inflated around a patient's arm until it stops blood flow, then slowly released while a doctor listens for pulses. Explain, using ideas about pressure, why this method allows the doctor to measure the patient's blood pressure, and evaluate why using the correct cuff size matters for obtaining a reliable reading.

   [6 marks]

   Total for question 4: 12 marks

End of questions