Lesson 5

Pressure in liquids
1 / 16
next
Slide 1: Slide
NaskMiddelbare schoolhavo, vwoLeerjaar 2

This lesson contains 16 slides, with text slides.

Items in this lesson

Pressure in liquids

Slide 1 - Slide

This lesson
  • Recap + exercise
  • Fluid pressure
  • Working on exercises


Slide 2 - Slide

Learning goals
  • Name the formulas for pressure and weight and be able to apply them.

  • Explain what is meant by liquid pressure.

  • Explain why there is greater pressure at the bottom of the sea than at the surface.

Slide 3 - Slide

Recap

Slide 4 - Slide

P3 — Pressure & density
  • Pressure is the result of force being applied to a surface.
  • Force is measured in newtons (N)
  • area is measured in square meters (m2)

  •  The formula for pressure is: 

  • The unit of pressure is pascal (Pa). One pascal is 1 N/m2
Pressure=areaforce

Slide 5 - Slide

P3 — Pressure & density
Weight:
  • With how much force an object is pulled down

Weight=massgravitationalfieldstrength
W=mg

Slide 6 - Slide

Pressure
ρ=AF
pressure=AreaForce
Pressure (ρ): Pascal (Pa – N/m2), N/cm2
Force (V): N
Area (m): m2, cm2

Slide 7 - Slide

Pressure
w=mg
Weight=massgravitationalfieldstrength
Weight (W): Newton (N)
Mass (m): kilogram (kg)
Gravitational field strength (g): N/kg

Slide 8 - Slide

Exercise
Two scenario's:
  • 1) A man is standing on 7,60 cm thick ice. He has a mass of 88 kg and one of his feet has an area of 0.0047 m2

  • 2) A man is laying flat on his back on 7,60 cm thick ice. He has a mass of 88 kg. His body touching the ice has an area of 0.0915 m2

Ice of this thickness breaks at about 18.000 Pascal (N/m2). 
The gravitational field strength on Earth is 9.8 N/kg

a) Calculate the pressure for each scenario.
b) Explain wether the ice will break or not.

Slide 9 - Slide

Liquid pressure

Slide 10 - Slide

Slide 11 - Slide

Upthrust
What is upthrust?

Slide 12 - Slide

Upthrust

Slide 13 - Slide

Liquid pressure 

And upthrust

Slide 14 - Slide

To-do for the coming week
Read: 
  • 8.3
  • 8.4

Do:
  • 8.3 yellow block + workbook exercises
  • 8.3 yellow block + workbook exercises

Due for the seconds lesson of next week

Slide 15 - Slide

Learning goals
  • Name the formulas for pressure and weight and be able to apply them.

  • Explain what is meant by liquid pressure.

  • Explain why there is greater pressure at the bottom of the sea than at the surface.

Slide 16 - Slide