Pressure & Pressure Differences in Fluids (Edexcel GCSE Physics)

Figure 1 shows an object under the surface of the sea.

[1]

Figure 1

Figure 2

What is the pressure due to the water on the top surface of block Y?

[1]

Figure 3

[2]

depth = ............................... unit = ...............................

[1]

[1]

An aeroplane takes off from the ground.

State two factors that affect the pressure of the atmosphere on the aeroplane as the aeroplane goes higher in the atmosphere.

Figure 3

The pressure on the diver is due to both the water above him and the Earth’s atmosphere.

The pressure of air on the surface of the water is one atmosphere. 10m of water is equivalent to one atmosphere.

How many atmospheres of pressure will be on the diver at a depth 20m?

A balloon is filled with helium when it is on the ground.

The balloon is released and it rises through the atmosphere.

Explain what happens to the size of the balloon as it rises through the atmosphere.

The weight of the container is 15 000 N.

Figure 4

Calculate the pressure that the container exerts on the floor.

   
Use the equation

pressure of the container on the floor = ................................ Pa

Figure 1 shows a fish tank holding water.

Figure 1

The pressure in the bottom of the tank is 37 kPa.

Calculate the weight of water in the tank.

On Figure 1, sketch the direction of the forces from the water on the inside of the tank.

Higher Only

A fish in the tank in Figure 1 swims from a depth of 3.7 cm to a deeper depth. The increase in pressure on the fish is 3.1 kPa. 

The density of the water is 1000 kg/m³ and the gravitational field strength is 10 N/kg.

Calculate the depth the fish swims to.

Water is removed from the tank.

Explain how the pressure at the bottom of the tank changes when water is removed from the tank.

Figure 8

The force on the bottom of the tank, due to the water, is 2400 N.

Calculate the pressure, due to the water, on the bottom of the tank.

[3]

pressure = .............................................................. Pa

[2]

Figure 9

Draw an arrow on Figure 9 to show the direction of the force exerted by the water on the surface of the object at point X.

[1]

Figure 10

[2]

change in pressure = .............................................................. kPa

[1]

Figure 11

Explain why the person exerts a different pressure on the bed when standing up than when lying down.

Higher Only

Figure 1

A student investigates the water depth in the barrel.

She measures the depth and then opens the tap.

To investigate the water depth in the barrel, a researcher measures the initial depth and then opens the tap. They measure the depth every minute.

Figure 2 shows their results. 

Figure 2

State two measuring instruments the student could use in her investigation.

Describe the relationship between depth and time as shown by the graph.

The researcher notices that the water flows out less quickly as time passes.

Suggest a reason for the decrease in flow rate of the water.

Higher Only

Figure 25 shows four identical metal cans, each filled with water to the same level.
Each can has three tubes.
Water comes out of each tube.
Which of these shows the correct pattern of water coming out of the tubes?

Figure 25

Higher Only

Figure 26 shows a glass U-tube containing water of density 1000 kg/m³.

The water levels are the same on both sides of the U-tube.

Both ends of the U-tube are open to the atmosphere.

Atmospheric pressure is 101 000 N/m²

Figure 26

Figure 27 shows the U-tube with one side connected to a gas supply.
The difference in the levels of water, h, is 0.200 m.

Figure 27

Use an equation selected from the list of equations at the end of the paper.

[3]

pressure of gas supply = .............................................................. N/m²

[2]

Higher Only

Figure 28

The boat floats lower in the water when there is a load inside the boat.
Explain why the boat floats in water and why the boat floats lower in the water when there is a load inside the boat.
You may add to the diagram to help with your answer.

Figure 17 shows a crane lifting a concrete block from the bottom of a deep pool of water.
The top of the block is a distance, h, below the surface of the water.

Figure 17

The force on the top of the block due to the water above it is 41 000 N.
The pressure due to the water on the top surface of the block is 66 000Pa.

[2]

area of the top surface of the block = ............................................... m²

Calculate the distance, h, between the top of the block and the surface of the water.

Gravitational field strength, g, is 10 N/kg.

Use an equation selected from the list of equations at the end of this paper.

[2]

h = ............................................... m

[2]

Figure 18

Explain why the lifting force changes as shown on the graph in Figure 18.

Include calculation(s) in your answer.

[6]

atmospheric pressure = ............................................... kPa

atmospheric pressure = ............................................... kPa

Explain why the water runs out of the tap of container A faster than out of the tap of container B.

10 m of sea water exerts the same pressure as the atmosphere.

A submarine is at a depth of 50 m below the surface of the sea.

Calculate how many times greater the pressure is on the submarine than atmospheric pressure.

pressure = ........................... times greater

Explain why the tip of the drawing pin goes into the wood but the head of the drawing pin does not go into the thumb.