New
New
Year 9
Pressure
I can describe and calculate pressure, the effect of a force acting over an area.
New
New
Year 9
Pressure
I can describe and calculate pressure, the effect of a force acting over an area.
Lesson details
Key learning points
- Pressure is a measure of how concentrated a force is.
- Pressure = force ÷ area.
- Pressure is measured in newtons per square metre or per square centimetre.
- Another name for newtons per square metre is the pascal (Pa).
Common misconception
Pressure and force are terms that are often used interchangeably.
Explore examples with pupils in which similar sized forces are used to create different pressures that the pupils can experience first hand.
Keywords
Pressure - The effect of a force acting over an area.
Concentrated - When a force is concentrated on a small area the pressure is higher.
Newton per square centimetre - A unit for pressure.
Newton per square metre - The standard unit for pressure, and this is also known as the pascal (Pa).
Show the pupils the effect of high pressures on surfaces by demonstrating cutting, this should be linked to prior learning on increasing forces with levers.
Teacher tip
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Video
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Starter quiz
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6 Questions
Q1.
Complete the sentence: The unit of force is the , which has the symbol N.
Correct Answer: newton, newtons
newton, newtons
Q2.
The figure shows a force acting on a balloon resting on a table with a hand pushing downwards on it. Which statements are correct?
The force causes the balloon to speed up.
Correct answer: The force causes the balloon to change shape.
The force causes the balloon to change shape.
Correct answer: The balloon will put an upwards force on the hand.
The balloon will put an upwards force on the hand.
Correct answer: The balloon will put a downwards force on the table.
The balloon will put a downwards force on the table.
Correct answer: The table will put an upwards force on the balloon.
The table will put an upwards force on the balloon.
Q3.
Which force on objects like springs or rubber bands will cause them to stretch?
gravitational force
Correct answer: tension
tension
magnetic
upthrust
electrostatic
Q4.
A set of bathroom scales shows a reading of 110 kg. What is the weight of the object on the scales? The gravitational field strength on Earth is 10 N/kg
110 N
11.0 N
Correct answer: 1100 N
1100 N
11 000 N
1.1 N
Q5.
A spring is used in a newton meter. The total length of the spring increases by 2 cm when a force of 4 N acts on it. Which of the following statements is correct?
The total length of the spring will double when 8 N is placed on it.
Correct answer: The extension of the spring will double when 8 N is placed on it.
The extension of the spring will double when 8 N is placed on it.
The total length of the spring will stay constant when 8 N is placed on it.
The total length of the spring doubles every time 4 N is added to it.
Q6.
This boat is floating on the surface of the water. The boat has a mass of 120 kg and passengers have a total mass of 80 kg. What is the size of the upthrust acting on the boat?
120 N
200 N
1200 N
Correct answer: 2000 N
2000 N
400 N
Q5 UYSEG
Exit quiz
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6 Questions
Q1.
Which of these will increase the pressure acting on a surface?
Correct answer: Increasing the size of the force.
Increasing the size of the force.
Decreasing the size of the force.
Increasing the area the force acts over.
Correct answer: Decreasing the area the force acts over.
Decreasing the area the force acts over.
Q2.
Which of these are units of pressure?
newtons
newtons per centimetre
Correct answer: pascals
pascals
Correct answer: newtons per square metre
newtons per square metre
Correct answer: newtons per square centimetre
newtons per square centimetre
Q3.
A force of 300 N acts over an area of 20 cm$$^2$$. What pressure does the force cause?
0.07 N/cm$$^2$$.
Correct answer: 15 N/cm$$^2$$.
15 N/cm$$^2$$.
6000 N/cm$$^2$$.
280 N/cm$$^2$$.
320 N/cm$$^2$$.
Q4.
Which of these is the same pressure as 100 000 Pa?
100 000 N/cm$$^2$$.
1000 N/cm$$^2$$.
Correct answer: 10 N/m$$^2$$.
10 N/m$$^2$$.
1 N/m$$^2$$.
0.000 1 N/cm$$^2$$.
Q5.
A bench of weight 800 N makes contact with the floor over an area of 400 cm$$^2$$. What pressure does it put on the floor in pascals?
0.5 Pa
2.0 Pa
5000 Pa
Correct answer: 20 000 Pa
20 000 Pa
200 000 Pa
Q6.
Starting with the largest, sort the following into order of pressure.
1 - A force of 5000 N acting over an area of 1 square metres.
1
- A force of 5000 N acting over an area of 1 square metres.
2 - A force of 5000 N acting over an area of 2 square metres.
2
- A force of 5000 N acting over an area of 2 square metres.
3 - A force of 6000 N acting over an area of 3 square metres.
3
- A force of 6000 N acting over an area of 3 square metres.
4 - A force of 2000 N acting over an area of 50 square metres.
4
- A force of 2000 N acting over an area of 50 square metres.
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