8.1 and 8.2 Pressure and its applications

• Science
• Middelbare school
• vwo
• Leerjaar 2

Examples of pressure on daily life

What is pressure?

Pressure is defined as the physical force exerted on an object over a certain area.

Formula of pressure

pressure= force/area​

  p = F/A

p is the pressure

F is the force

A is the area 

Pascal is defined as a force of 1N that is exerted on a unit area.

1 Pascal = 1 N/m2

Tekst

units of Pressure

Force is measured in Newtons (N). 

Area can be cm² or m² and so pressure is measured in N/cm² or N/m² (Pascals).

Rearranging the formula

P= F/A   3=6/2

F=p×A

A=F/p

​

Difference between pressure and force

A force can be a push or a pull. When a force is exerted on an object it can change the object's speed, direction of movement or shape. Force Is applied to faces, vertices and edges.

Pressure is a measure of how much force is acting upon an area. Pressure is applied to faces.

Assignment

A force of 150 N is being applied over an area measuring 

0.5 m^2.  Calculate the pressure on the object ensuring you give the correct units.

Answer

Given: F=150 N

A=0,50 m^2

Asked: P=?

F: P=F/A

150÷0.5=300 N/m^2 or Pascals

Assignment

A woman is applying 300  Pascals

  of pressure onto a door with her hand. Her hand has area 0.02 m^2.  Work out the force being applied

Answer

G:      P=300 pascals

             A=0.02 m^2

A:             F= ?

F:           F=P.A

C:      P=300×0.02=6 N

Assignment

Pressure of 150 Pascals is experienced when a force of 20 kN is applied. Calculate the area over which the force is applied to obtain the pressure stated.

Answer

G:     P = 150

             F= 20000

Asked: A=?

F: A=F/p

C:   20000÷150=133.3 m^2

1 N/m2 = 0.0001 N/cm2