Lesson: Pressure

Science

Differentiation

in action Which side would you prefer to press with your finger?

Pointed side?

Why?

Flat side?

Science

Differentiation

in action Which puts more pressure on the ground?

OR Why?

Science

Differentiation

in action PRESSURE is a measure of the amount of

force

being put on a certain

area

.

Force Pressure = ------------ Area

Pressure is measured in Pacals (Pa).

Science

Differentiation

in action REMEMBER Mass is the amount of matter in an object. It is measured in Kilograms (Kg).

It is not a force.

MASS = 120 Kg WEIGHT = 1200 N

Weight is the force of gravity acting on the mass of an object. Weight is measured in Newtons .

Science

Differentiation

in action If a block weighs 1200 N and the area under the block is 12m 2 , calculate the pressure it puts on the ground.

FORCE Pressure = ------------ AREA 1200 N Pressure = ------------ 12 m 2 Pressure = 100 Pa

Science

Differentiation

in action Some important examples of pressure!

Where else is pressure important?

Science

Differentiation

in action Teton Dam (USA) Failure in 1976 Why is it important to understand pressure?

Science

Differentiation

in action Carry out an investigation to show the relationship between pressure and depth in a liquid.

METHOD 1. Set up the apparatus as shown.

2. Remove the pins.

3. Remove the cap.

4. Measure how far the water spurts out from each hole.

5. Record results in a table.

Plastic bottle cap pins Ruler

Science

Differentiation

in action Review Questions Force

1

. Pressure = ------------ ?

2

. What unit is Pressure measured in?

3

. How does pressure vary with depth in a liquid?

Science

Differentiation

in action Question to think about!

Why is pressure important in a space station?