Public Speaking [Tuesday, February 12, 2013, 1st period]

[professor-lyman.livejournal.com]

"Good morning, class," Josh said, coming in with a box of various gadgets and then signaling for Natalie and Lex if they were there to assist him with two more boxes. "If you've ever been up past your bedtimes, and you're teenagers living relatively unsupervised in a dorm, so of course you have, you've seen various products being shilled on television, aimed at the demographic apparently too stupid to boil water without help."

He waved at the boxes. "I've procured--" made Donna buy, "--a number of these products that will be handed out to you. You'll have ten minutes to examine whatever miraculous marvel you receive and then to come up with a three minute persuasive speech to tell the others in the class how it works and why they can't possibly live without one."

He also held up a bag of buzzers. "To make this more fun, the moment you've lost the audience's attention--even if it's not been three minutes--they will buzz you to sit down. Note how I don't give these out until I'm already done talking. That's called being smart, kids. You have to give back the telemarketing crap at the end of class but the buzzers are yours to keep."

The rest of the faculty will love him for that.

"Oh and...." he ran his finger down the class sheet, "Petra West, come on down. You're our next press secretary."

Industrial Arts, Tuesday

[not_a_whiner]

"Starting this week, we're going to be talking about cars," Kaidan said. As anyone could tell, going by the three cars sitting neatly in the center of the Danger Shop. "Just to make a compromise here, since we're kind of spread out time-wise, I'm going to be focusing primarily on early 21st century automotive engineering. If any of you are interested, I'm willing to extend this to vehicles from my time... later."

He cleared his throat. "20th and early 21st century engineering means one thing for cars: combustion engines. The first electric cars are only just inching their way onto the market. Most of 'em still have one of these."

He pulled open the hood of one of the cars and patted the engine. "Internal combustion means you use fuel to cause controlled explosions, generating energy. Most of the engines used in 21st century cars are four-cycle. That means they use a piston and a crankshaft." Stepping back, he called up an image of the inside of a car on his omni-tool, projected big so everyone could see it. "The pistons pass on their linear motion to the crankshaft, which turns it into circular motion, or rotational force. Push that through the axle via the transmission, and the wheels start to turn."

The image shifted to one focused on the engine in particular. "Of course, a lot has to happen to get there. Like those controlled explosions. Now like I said earlier, most combustion engines like this work on a four-cycle system. Those cycles are intake, compression, combustion and exhaust. Every cycle causes the crankshaft to spin - the amount of times one can spin in a minute is what we call RPM. Revolutions per minute." The image began to move. "During the intake, the cylinder the pistons are in pull in fuel from the tank and oxygen from outside. Then the piston moves up to compress the fuel. As the fuel gets compressed, the spark plug activates, causing the fuel to ignite and explode, forcing the piston back down. During the final cycle, what's left gets pumped out of the cylinder."

He shut off the image. "Just to throw a few more words out there, horsepower stands for the amount of force put out by the grand total of pistons in your engine. Torque is the force put out by the crankshaft. Finally, looking at cars, you're going to probably find someone talking about V's - V6s, V8s, and so on. That's a reference to the arrangement of the pistons. Pistons in a V-engine are arranged in - you got it - a V shape. So a V8 has eight pistons arranged in a V."

Kaidan patted the car'ss engine again. "One more thing before I let you take these apart and figure out what everything does," he said. "The displacement of an engine is also important in terms of how much power it puts out. It refers to the amount of volume a piston displaces in the cylinder. You can calculate that by multiplying the width of the cylinder with the length and the amount of pistons. Now, find a partner and crack these things open. Just take a look. Take the engine apart. Calculate the displacement. Write a short piece about what you know about engines."

He paused. "And if you already know a lot about engines," he said, "get cracking on your Battlebot."