Pressure

Pressure
1 / 14
suivant
Slide 1: Diapositive
NatuurkundeMiddelbare schoolhavo, vwoLeerjaar 2,3

Cette leçon contient 14 diapositives, avec quiz interactif et diapositives de texte.

time-iconLa durée de la leçon est: 50 min

Éléments de cette leçon

Pressure

Slide 1 - Diapositive

You can convert metric units for distance, area and volume
You can use the formula for pressure in different situations

Slide 3 - Diapositive

Slide 4 - Diapositive

Pressure
To sit on a nail is painful...
for obvious reasons.

But when you sit down on 1000 nails,
you hardly feel anything anymore.

This is because the gravitational force is
equally shared over a large surface.

Slide 5 - Diapositive

Pressure
Pressure=on a surfaceForce
P=AF
(m2)(N)

Slide 6 - Diapositive

Calculation skills
Watch these videos if you are having trouble with

  • converting units

  • cinvert areas and volumes

  • forgot how to use formula's

Slide 7 - Diapositive

Pressure example
When you dive a force of a larger surface, it will hurt less because of a smaller pressure. 

In this example you can put a block on side A or B. The surface for side B is 4 times as big as the surface of side A. This means that the experienced pressure for side B will be 4 times less as well.

It helps when you make a little drawing when you need to convert areas from cm2 to m2. It will give you a quick insight by how much you need to multiply or devide to convert the unit.

Slide 8 - Diapositive

Falling through ice
This often ends fatal..
But there is something you can do.
Cette vidéo n'est plus disponible
Therefore prepare and spread your weight as much as possible when moving over the ice.

Slide 9 - Diapositive

Example question
Shufling over the ice on your stomach will make a big difference as you will found with this example.

In this question the trick is not to forget that you have two feet instead of one.





5 Steps
GIVEN
ASKED
FORMULA
CONVERT UNITS
CHECK 1 UNKNOWN & CALCULATE

Slide 10 - Diapositive

Pressure in a liquid
The pressure in a liquid is equal everywhere.

Because of the constant relationship between force and surface in the equation, the pressure of the liquid will cause a bigger force near the larger cilinder (B).


Although there is more force on cilinder B, it will travel more slowly

Slide 11 - Diapositive

Slide 12 - Diapositive

Assignment: Thumbtack
A force of F = 1,5 N is exerted on the topside of a thumbtack.
The topsurface is A = 0,65 cm2
The surface of the needle is A = 2,1 mm2
To push the thumbtack into a bulletin board you need a pressure of 106 Pascal

a) Calculate if you can push the thumbtack into the board.
b) Calculate the minimal force needed for this

Slide 13 - Diapositive

The thumbtack

upload your solution

Slide 14 - Question ouverte