A carpenter uses nails to make a hole in the wood.

The hammer hits the nail on its flat head. The nail's

sharp point pushes into the wood.

Why does the nail have a sharp point? The force of

the hammer is concentrated on a small area so that

the nail will be able to penetrate the wood.

If a nail is blunt, the force of the hammer is spread over a bigger area and the nail will not go into the wood.

Today we will understand why nails work this way, so let's get familiar with the concept of pressure:

After this short presentation, the class will be divided into groups and you will explain the following cases in your notebooks using the concepts of pressure, area and force:

1) Most people in Alaska has

snowshoes, why do they work?

2) Vaccines are applied using

a sharp needle

3)A truck used in the desert

must have wide tyres

4) A shovel has a sharp end

5) A soft mattress is more comfortable

than the floor

6) A sharp knife works better

Finished already? practice the concept of forces and friction with the GIZMO:

1) Enter the explorelearning website

2) Enroll to your class using the right class code:

7A : ELKF8TLM

7B : ELQDZ5MV

7C : EL3MRLW2

3) Play with the Gizmo called "FORCE AND FAN CARTS"

4) Try to solve the questions below the gizmo

Class 2: Let's measure pressure

Today you will be using the formulas to calculate pressure:

Solve the following classwork in your notebook:

1) An elephant weighs 60000 N. It stands on four feet. Each foot has an area of 0.1m2

a) Calculate the total area of the elephant's feet

b) Calculate the pressure the elephant exerts on

the ground

c) The elephant lifts one foot off the ground.

Calculate the pressure it now exerts on the ground

2) When the wind blows, it creates a big pressure on any surface it blows against. A large window has these measurements: 1.6 m X 2 m. If the wind causes a pressure of 2000 Pa on the window, what force acts on it?

3) A foot bridge has been designed to withstand a pressure of 15000 Pa or 15000N/m2. The area of the bridge is 15 m2.

a) What is the greatest force the

bridge can withstand (resist)?

b) If the average weight a person has

is 600 N, what is the maximum amount

of people that the bridge can resist?

4) A hammer hits a nail with a force of 200 N. The point of the nail has an area of 0.5 mm2 touching a piece of wood. Calculate the pressure on the wood in N/mm2. Then give the pressure in pascals (1m2 = 1000000mm2)

5) A large fish tank is filled with water. The pressure on the base of the tank is 4000 N/m2. The base of the tank is rectangle measuring 2.0 m by 4.5 m

A carpenter uses nails to make a hole in the wood.

The hammer hits the nail on its flat head. The nail's

sharp point pushes into the wood.

​

Why does the nail have a sharp point? The force of

the hammer is concentrated on a small area so that

the nail will be able to penetrate the wood.

​

If a nail is blunt, the force of the hammer is spread over a bigger area and the nail will not go into the wood.

​

Today we will understand why nails work this way, so let's get familiar with the concept of pressure:

​

​

​

​

​

​

​

​

​

​

After this short presentation, the class will be divided into groups and you will explain the following cases in your notebooks using the concepts of pressure, area and force:

​

​

​

​​

​

​

1) Most people in Alaska has

snowshoes, why do they work?

​

​

​

2) Vaccines are applied using

a sharp needle

​

​

​

​

3)A truck used in the desert

must have wide tyres

​

​

​

​

​

​

4) A shovel has a sharp end

​

​

​

​

5) A soft mattress is more comfortable

than the floor

​

​

​

​

​

6) A sharp knife works better

​

​

​

​

​

Finished already? practice the concept of forces and friction with the GIZMO:

​

1) Enter the explorelearning website

​

2) Enroll to your class using the right class code:

​

7A : ELKF8TLM

7B : ELQDZ5MV

Solve the following classwork in your notebook:

​

​

​

​

​

1) An elephant weighs 60000 N. It stands on four feet. Each foot has an area of 0.1m2