KaiserScience

Home » Uncategorized

Category Archives: Uncategorized

Advertisements

Tidal power

Content objective:

What are we learning? Why are we learning this?

content, procedures, skills

Vocabulary objective

Tier II: High frequency words used across content areas. Key to understanding directions, understanding relationships, and for making inferences.

Tier III: Low frequency, domain specific terms

Building on what we already know

What vocabulary & concepts were learned in earlier grades?
Make connections to prior lessons from this year.
This is where we start building from.

Ocean tides are caused by tidal forces.

What are “tides”?

Types of tidal power

Tidal barrages -most efficient.

A dam that utilizes the potential energy generated by the change in height between high and low tides. This energy turns a turbine or compresses air, which generates electricity.

Tidal power generation

image from technologystudent.com/images5/tidal1.gif

Tidal fences – turbines that operate like giant turnstiles

mechanical energy of tidal currents used to turn turbines. These are connected to a generator that produces electricity

tidal fences GIF

Tidal turbines – similar to wind turbines but these are under water.

mechanical energy of tidal currents used to turn turbines. These are connected to a generator that produces electricity

tidal turbines

Many other designs are possible, for instance:

Fluid Pumping Apparatuses Powered By Waves Or Flowing Currents

 

Great animations

We have identified six main types of Tidal Energy Convertors (TEC):

 

Advantages of tidal power

Environmentally friendly

Relatively small amount of space

Ocean currents generate relatively more energy than air currents because ocean water is 832 times more dense than air and therefore applies greater force on the turbines.

Disadvantages of tidal power

high construction costs

Amount of energy is not constant per hour, or even per week

requires a suitable site, where tidal streams are consistently strong.

Must be capable of withstanding strong tides and storms, and can be expensive to maintain and repair

Related topics

Why Is There a Tidal Bulge Opposite the Moon?

Advertisements

Natural gas power

Content objective:

What are we learning? Why are we learning this?

content, procedures, skills

Vocabulary objective

Tier II: High frequency words used across content areas. Key to understanding directions, understanding relationships, and for making inferences.

Tier III: Low frequency, domain specific terms

Building on what we already know

What vocabulary & concepts were learned in earlier grades?
Make connections to prior lessons from this year.
This is where we start building from.

We can burn natural to release heat, and use that heat to create heat (e.g. cooking) or electrical power.

Burning natural gas is a chemical reaction called combustion.

Combustion of methane

In physics, power has a very specific meaning. It is the rate that energy is transformed from one form into another form.

How was natural formed?

oil Natural Gas Formation_Primary-L

Molecules

It is a mixture of hydrocarbon molecules

Mostly methane (CH4)

methane gas

And some other higher alkanes (acyclic saturated hydrocarbons)

alkanes methane ethane propane butane

And some small percent of CO2, N2, H2S (hydrogen sulfide,) or He

..

 

Stars are powered by nuclear fusion

Stars are powered by nuclear fusion

Before reading this section, you will first need to know

  • Atoms are the smallest stable building blocks of matter in the universe

  • Atoms are not solid. They are made of protons, neutrons, and electrons.

  • All solids, liquids, gases and plasma in our universe are made of these particles.

  • All matter is attracted to other matter through gravity. If you have enough mass floating around in space, over time, large amounts of matter will be attracted together to form giant gas clouds – nebulas.

  • Nebulas themselves can contract, due to gravity. This leads to the development of stars

  • Generally speaking, all matter in our universe is conserved (conservation of matter)

  • Generally speaking, all energy in our universe is conserved (conservation of energy)

  • Here’s the wacky bit: scientists discovered fascinating and unexpected violations of those supposedly inviolable laws, but instead of that being magic, it pointed towards an even greater discovery: the law of conservation of matter and  energy.  This was discovered by Albert Einstein, and is known as mass–energy equivalence.

As such, first read our lesson on the discovery of nuclear physics and radioactivity.

At this point you now have the background for what comes next.

Inside a star, gravity pulls billions of tons of matter towards the center. Atoms are pushed very close together. So close that sometimes two atoms will fuse into one, heavier atom. The mass of this new atom is slightly less than the mass of the pieces that it was made of in the first place? Where the did missing go? It effectively becomes energy – which we see as photons, or as the heat/motion energy of other particles.

As an example, here we see deuterium fusing with tritium. The resulting product has less mass than the parts going in to the collision. That missing mass we see becomes 3.5 mega electron-volts of energy,

Here we some typical nuclear fusion reactions that go on inside yellow dwarf stars like our sun.

fusion-sun

Here is a step-by-step cascade showing how hydrogen atoms can fuse to create Helium, giving off gamma rays and neutrinos in the process.

Solar nucleosynthesis

In a different form we see the same process here.issue3_fusion1_large

(More text TBA)

 

Catapult and Trebuchet build project

catapult is any one of a number of non-handheld mechanical devices used to throw a projectile a great distance without the aid of an explosive substance—particularly various types of ancient and medieval siege engines.

Catapult and Trebuchet.png

The name is the Latinized form of the Ancient Greek καταπέλτης – katapeltes, from κατά – kata (downwards, into, against) and πάλλω – pallo (to poise or sway a missile before it is thrown.) [from Wikipedia]

Ideas on how to build them at home

KnightForHire: How to build simple catapults

Quotes

Today’s Latin lesson:

“Cum catapultae proscriptae erunt tum soli proscripti catapultas habebunt.”
( “When catapults are outlawed, only outlaws will have catapults.” )

“Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam”
( “I have a catapult. Give me all your money, or I will fling an enormous rock at your head.” )

If you lived in the Dark Ages, and you were a catapult operator, I bet the most common question people would ask is, ‘Can’t you make it shoot farther?’ No. I’m sorry. That’s as far as it shoots.”
– Jack Handy, Deep Thoughts, Saturday Night Live

Build an onager, ballista or trebuchet.

Grading rubric. The project is worth 100 points.

Timeliness: Late projects lose 5 points per day.

A. Catapults use torsion (energy stored in a twisted rope or other material.) Do not merely use a stretched elastic (e.g. rubber band.)

If you build a trebuchet then you will need to use a pivoting beam and a counterweight.

B. It will have some kind of trigger or switch. (Without such a trigger, you would merely have a large slingshot.)

C. The payload range will be nearly constant (each payload lands within 15% of the other payloads.)

D. It will have adjustable firing: One setting will yield a shorter range (at least 4 feet.), while another setting yields a longer range (at least 8 feet.)

E. The weight limit is 10 pounds.

F. The longest allowable dimensions of height, length and width are 50 centimeters for each.

Scoring

100 points Machine built according to the above characteristics

– 20 points Minimum range is not met.

– 20 points Too large or too heavy.

– 10 points Firing range is not adjustable.

– 10 points Uses a stretched elastic material (e.g. rubber band) as the only source of power. (Not applicable for trebuchets, of course.)

– 10 points No trigger.

– 5 points Payload range is not constant

Catapult animations

Redstone projects.com: Catapult animations

trebuchet gif

.