9L PRESSURE AND MOMENTS

PRESSURE

What is the equation for calculating pressure?

Name 2 ways that pressure can be increased.

What are the units of pressure?

ONE OF THE SHARPEST KNIVES IN THE WORLD

http://youtu.be/8PQiaurIiDM

CALCULATING PRESSURE

Pressure (N/cm2) = Force (N)

Area (cm2)

AIM: TO INVESTIGATE HOW THE PRESSURE I EXERT ON THE GROUND CHANGES.

Body part/shoe

Area (cm2) Force (N) Pressure (N/cm2)

1 foot

2 feet

1 hand

2 hands

CALCULATING PRESSURE

Pressure (N/cm2) = Force (N) b

Area (cm2)

e.g. Pressure = force ÷ area

= 700 ÷ 20

= 35 N/cm2

ALWAYS1. Formula2. Add numbers3. Answer4. Units

WATER PRESSURE

What is water pressure?

Which direction does it act in?

How does it change with depth?

SCUBA DIVING EXPERIMENTS

http://youtu.be/PavY_JmYyTs

http://youtu.be/HlZXDcSR-Z4

http://youtu.be/t8wFIMbMJvs

Polystyrene cup

http://www.sciencedump.com/content/what-happens-coffee-cup-2300-meters-depth-ocean

Mythbusters

http://youtu.be/YU2PSHeFSlA

AIR PRESSURE

What is air pressure?

How does it change with altitude?

How can you increase air pressure?

DEMOS

http://www.youtube.com/watch?v=_xB7q6bJ8k8

http://www.youtube.com/watch?v=QeAp3CuGjk8

MOMENTS

What is a moment?

Complete this formula:

Moment ( ) =

What unit is a moment measured in?

WHY DID THIS HAPPEN?

BALANCINGLeft Right

Distance from fulcrum (m)

Mass (g) Weight (N)

Moment (Nm)

Distance from fulcrum (m)

Mass (g) Weight (N)

Moment (Nm)

CONVERTING MASS TO WEIGHT

Mass (kg) = mass (g) ÷ 1000

Weight (N) = mass (kg) ÷ 10

CALCULATING THE MOMENT

Moment (Nm) = Force (N) x distance (m)ALWAYS1. Formula2. Add numbers3. Answer4. Units

LEVERS

What is a lever?

Name 5 examples of where we use levers.

LETS LOOK AT A BIKE AND SOME TOOLS

PLENARY

Find the lever and fulcrum

Capsizing

http://youtu.be/S-FlN97Y3ok

World speed sailing record

http://youtu.be/qzkulFGa4Mc

Moth boat

http://youtu.be/1SN1gSkqvy0

L´Hydroptere

http://youtu.be/MdUyLxVa6xQ

Sailrocket 2 2012 record (125km/h)

http://youtu.be/pipGWQmerEQ

Windsurf speed record

http://youtu.be/t15LZ1Er-a8