Support Videos: AIR, AIR PRESSURE & TEMPERATURE

Video # 9: Cheetah Can

(Sep 20)  Matter (stuff) that flows easily is called a fluid.  Water is a fluid.  Duh!  But so is air.  Gases are fluids, too.  Here's something you learned about fluids.  They move from areas of higher density to areas of lower density until things even out.  When talking about air, we say that air moves from areas of higher pressure to lower pressure.  That's what wind really is.  Yep. it is air moving from areas of high pressure to low pressure.  Wind is air looking to even things out.

Now, the inside of your can was supported by water vapor right before you tapped into a dish of cold water.  Once the water vapor rapidly condensed back into drops, the can had REALLY low air pressure inside of it.  Air will back inside the can in a fraction of second if we let it.  Do you remember the high-to-low pressure thing?  But if we make the opening really small, it is harder for air to rush back in and balance things out.  

Cheating?  I don't know.  We simply used scientific understanding to improve our chances of a can collapse.

Video # 7: Answering Page 2 

(Sep 18)  Teach people through your answers.   

Few people at home would understand why the can is not really empty.  Educate them!  Grandma is going to say, "Child, that can is empty!"  Be ready to answer her (respectfully).

Your teacher used five sentences to answer this.  They did NOT have to be in the exact order that he chose.  But, when looking down at the paragraph we put together, most of you will see that you just might need to do a bit more writing.  We will get you there!!

Video # 8:  Be Proud That You Allowed

(Sep 20)  Handout #5, Pages 11-12

Air pressure is slamming into the outside of the aluminum can with a force of 14.7 pounds per square inch.  But there is air on the inside slamming into the walls

• Then you put 10 drops of water in the can and heated it up.

• The liquid water soon turned into a water gas (water vapor).  So, the water evaporated into a gas.

• The water vapor eventually moved out most of the air that had been supporting the inside of the can.

• So, we just changed the gas supporting the inside of the can.  It went from air to water vapor.

• The can did not collapse even when it got really hot.  Why?  Water vapor was now supporting the inside of the can.  So, the drum beats kept on going.

• But water vapor is not like the air we breathe.  When the can was turned over and tapped in cold water, much of the water vapor cooled down really quickly.  It condensed back into a few drops of water and could no longer support the inside of the can.  This is why you dropped drumsticks and clapped!  By dropping the drumsticks, you were showing that there was no longer any support inside the can.

• The air outside never stopped slamming into the can from all directions.

• With nothing supporting the can from the inside, the air pressure outside the can crushed your can inwards.  CLAP!

Explicación en español

Video # 5:  Brass Ball & Hoop

(Sep 13)  Each student did this in class.  Is an explanation needed as to why the brass ball increased in size?   How about the water in the beaker?  It started at about 7.5C (46 F) and rose to 22C (72 F) after the brass ball plunged into it.  

We will spend much more time later on the different types of energy, but here is a big one --  Thermal energy moves from warmer objects (brass ball) to cooler objects (water).  This movement or transfer of thermal energy is called heat.

And no, your teacher is not trying to be cool.  He thought waiting in silence for 60 seconds for the ball to expand would be dumb.  So, let's introduce the band, Led Zeppelin, and the greatest rock-n-roll drum intro of all time.  All hail Jason Bonham!

Video # 6:  Brass Ball & Hoop #2

(Sep 13)  This is getting ahead of ourselves, but this short video reinforces one of the more important concepts in the physical sciences.  It's called the conservation of energy.  Follow along and see if this makes sense.

Video #3:  Thermal Expansion (1 of 2)

(Sep 11-12)  Recording of the 1st half of the PowerPoint presentation shown in class (Handout #4).  

Video #4:  Thermal Expansion (2 of 2)

(Sep 11-12) Recording of the 2nd half of the PowerPoint presentation shown in class (Handout #4).

Video # 1:  What Temperature Measures

(Sep 10) Temperature measures the average kinetic energy of the particles within a substance.  Kinetic = motion.  Particles = atoms or molecules.  So, temperature measures how fast an object's atoms/molecules are moving or vibrating.   

This is an 8-minute video of you pretty much staring at water.  It's was used by students in Sep 2020 when all learning and labs were done remotely.  It is a great visual for temperature.   The left beaker clearly shows less mixing of the red and blue food coloring.  Less mixing means slower moving water molecules.  Slower movement = lower kinetic energy = colder temperature.   Obviously you can fast-forward through this.  You don't have to stare at water for 8 minutes.

Funny thing is that it was filmed on Blue's (our dog) 2nd birthday.  The background squeaking is that of a happy, happy dog with at least three new things to chew on.  

Video # 2:  Temperature Paragraph

(Sep 10) Which beaker has the colder water in it?  

A year-long goal is to have 8th graders turn correct answers into intelligent, well-supported answers.  This is our first attempt at teaching students to educate others within their answers.  Write your answer to someone that doesn't know what temperature measures.  Educate them, and yes, you will probably be writing more than you'd like to.