what should i wear today in · polymita mollusk flamingos . museum of the revolution (where the...

Warm – up

How much water vapor is in the air at 20˚ C?

15 g/m3

MYP Unit Question: What should I wear today?

Area of Interaction: Environment

Learner Profile: Communicator

Standard: Understand how the distribution of land and oceans affect climate and weather

Learning Standard: Today I’m learning about relative humidity because it tells me if it might rain.

Opening:

What would you wear in _____?

Bad Hair Day

Work Session:

Humidity Lab

Closing: Relative Humidity Video

• Largest island in the Caribbean

• Part of a chain of islands formed by convergent boundaries.

• Invaded by Spain

What type of government did

Cuba have?

Led by President Fidel Castro until February 2006.

His brother, Raul Castro took over. • Chief of State • Head of Government, • Prime Minister • First Secretary of the

Communist Party of Cuba (PCC)

• Commander in Chief of the armed forces.

Cuba’s Government

Communist

Raul Castro Fidel Castro

Rocks and coral help prevent the waves from eroding the city.

Smallest frog in the world. 7mm long (3/4 inch)

The refuge has more of these endangered crocodiles nesting on its beaches than anywhere else in the world.

Snowy Egret

Screech Owls

Polymita mollusk

Flamingos

Museum of the Revolution (Where the past presidents have lived.

Havana Cathedral Square

Cuba is famous for its cigars.

The only place in the world that you can purchase NEW, old cars.

The U.S. USED to have a factory in Havana that would make NEW cars (1950’s). When the trade embargo was started, the Cubans had no way to purchase newer cars. Since the car factories were still there (abandoned) they continued to make the “new” older model cars.

Temp:

Wind Chill: (feels like)

Wind Speed:

Humidity:

Dew point:

Visibility:

Ever had a bad hair day?

Maybe it was caused by the condition of

the atmosphere!

The humidity of the atmosphere affects human hair. Hair is a very delicate part of the human body and is susceptible to the slightest changes in the atmosphere.

• Hair gets frizzy when it's humid because the strands absorb the moisture and expand.

• As the strands of hair expand, they lose their shape and become twisted, which leads to frizzy hair.

How does water get into the air to make your hair frizz?

17

Solar energy causes air molecules to heat up which makes them move faster and farther apart.

18

There is more space between air molecules so the air’s volume has increased.

That means there is more room for water vapor molecules.

Expanding warm air – more spaces to hold

water vapor

19

Shrinking cold air – less space to hold water

vapor

20

Luck of the Draw Student

seating in

seat #11,

please answer the question.

It is a beautiful, hot, sunny day outside. The temperature is close to 90 and you decide to wash your car. Afterwards you put the wet towels on a nearby fence to dry. You come back in about 30 minutes to clean up. You find the towels already dry! Why??? Where did the water go?

The water in the towels evaporated

into the atmosphere.

Humidity is the amount of

water vapor present in the

atmosphere.

The more water vapor

in the air, the more

humid the weather

becomes and the

greater the chances of

rain.

If relative humidity is 50%, then it contains 1/2 the amount of water vapor it could hold at a given temperature.

It’s a hot day and the humidity is close to 90%. Do you think it will rain?

Student seating in

seat #23,

please answer the question.

Probably not. The warm air can hold more

water vapor so it may just be very humid outside.

Student seating in

seat #30,

please answer the question.

It’s a cool day and the humidity is close to 95%. Do you think it will rain?

Probably, cooler air is denser and can’t hold

as much water vapor as hot air can. The air becomes saturated

(can’t hold any more).

The amount of humidity in the atmosphere can help meteorologists predict the possibility of precipitation such as rain, snow, sleet or hail as well as fog and dew.

Anything close to 90% indicates that there is lots of water in the air.

(Remember, air temperature determines if it will rain.)

Humidity is measured with a hydrometer

or a sling psychrometer.

Using the key for relative humidity, where would do think there might be precipitation?

Were you correct?

What happens to the amount of water vapor in the atmosphere when the difference between the wet bulb and dry-bulb changes?

The greater the difference, the less humidity is in the air.

Lab Safety Rules

1. Follow all directions given by the teacher.

2. Clean up water spills immediately.

3. Stand up and away from the table when using the psychrometer.

4. If a thermometer is broken, notify the teacher immediately.

Relative Humidity Lab Data Table Relative Humidity

Trial 1 Trial 2 Trial 3

Dry-bulb temperature

Wet-bulb temperature

Subtract (dry – wet = ?)

Relative Humidity