Friction is the force resisting the relative lateral (tangential) motion of solid surfaces, fluid layers, or material elements in contact. It is usually subdivided into several varieties.

Already I’m like, WHOAH, what does THAT mean? I have no idea! That’s why sometimes I feel stupid, ’cause I read stuff on the internet when I just wanna find out a simple answer to a simple question like, “Why is ice slippery” and I get this sentence about relatives and ladders and tangerines. I don’t get it! But I really wanted to know, ’cause I been tryin’ to look things up like Mr. W says, so I tried the next link down at fearofphysics.com and that definition made WAY more sense:

Friction is the “evil” of all motion. No matter which direction something moves in, friction pulls it the other way. Move something left, friction pulls right. Move something up, friction pulls down.

Already I can tell a little more about Friction! It’s some kinda force that keeps you from moving one way ’cause it’s pushing the other way. That’s not so hard to understand. And when I read the rest of the definition, I could already kind of guess what the answer to my question was! Look, I made a practice question out of it:

Friction is the “evil” of all motion. No matter which direction something moves in, friction pulls it the other way. Move something left, friction pulls right. Move something up, friction pulls down. It appears as if nature has given us friction to stop us from moving anything. Friction is actually a force that appears whenever two things rub against each other. Although two objects might look smooth, microscopically, they’re very rough and jagged… As they slide against each other, their contact is anything BUT smooth. They both kind of grind and drag against each other. This is where friction comes from. — fearofphysics.com

Why can you slide on ice more easily than on concrete?

1. Concrete is evil.

2. Ice has more friction than concrete.

3. Concrete has more friction than ice.

4. Ice has no friction at all.

5. It’s impossible to know from this passage.

Since this is my practice question, I’ll let you guys figure it out! But I wanted to also say that, well, if at first you don’t succeed, try, try again! I mean, when I first tried to look up friction, I just didn’t get it. I think that if I was lookin’ this stuff up before I started studying for the GED, I woulda given up after the first try. I woulda thought I was an idiot! But I’m not! Even if I have to go to a site that’s meant for kids in middle school or something, I’d rather understand something that was explained really simplistically than not get it at all!

So everyone out there, keep trying and searching for answers to your questions! Eventually, you’ll find something that makes sense to you!

For more information about the GED test and GED test preparation, visit the GED Academy at http://www.passGED.com.

Check out this practice question I found about the GRAVITRON!

A man stands on a ride at an amusement park that spins around. As the ride spins faster, the man is pushed back against the outer wall and finds it very difficult to pull himself away from it.

Which statement best explains this event?

1. There is glue on the wall holding him on.

2. The ride is creating a magnetic force that pulls the man toward the metal in the walls.

3. The ride is creating a new center of gravity inside the walls.

4. The spinning of the ride creates a centrifugal force that pushes the man outward from the center.

5. The ride creates an optical illusion the makes the man think he is falling backward into the wall.

Haha, well unless he’s a metal man, I don’t think 2 is right! Magnetics only work on metal, and only some kinds of metal. Maybe if he had a lot of metal in his pockets? But the question doesn’t say he does, so I’m gonna guess not. Especially ’cause I don’t think spinning around creates magnetic forces, that has something to do with the north and south pole I think?

Anyway, 1 is always wrong, there’s no glue in theme park rides unless some kind puts it there. That leaves me with 3, which says it’s gravity; 4, which says it’s centrifugal force; and 5, which says it’s all an optical illusion. Well, I guess there are some optical illusions that make you think you might be moving when you’re not. They got this other ride at Universal Studios that has a long tunnel that spins, and when you get out of the tunnel, you realize that everyone on the ride is leaning to their left ’cause of the spinning! I don’t know how that works, but I don’t think it’s true here. When you spin something around, like if you had a cup filled with water and spun it really fast, the water would stick to the sides too! So that’s not it.

I don’t think it’s 3 either, ’cause gravity is something that big things do. The sun, the Earth, the moon, they all have gravity, but they’re big masses… I mean HUGE masses of rock and stuff, and they only create a little bit of gravity. I mean, we can still jump and fly in planes. But when you’re on the Gravitron, you couldn’t jump. It says that in the question too. “The man finds it very difficult to pull himself away.” So if the Earth creates a little bit of gravity, I really doubt the Gravitron could creation even MORE gravity (as much as its name wants it to).

I think the answer’s number 4. I’m not even entirely sure what centrifugal force is, but it sounds about right. Like isn’t a centrifuge something the put blood in and spin REALLY fast? Even if you don’t know about that, all the other answers just don’t make as much sense. Like 3 says it’s making gravity IN the walls, which doesn’t work, but 4 says that it’s creating a force that just pushes the man out from the center. That makes more sense.

Hope everyone has a good new year! 2010!! Keep studying for the GED! Make a resolution to pass! You can totally do it!

For more information about the GED test and GED test preparation, visit the GED Academy at http://www.passGED.com.

However, if it weren’t for the greenhouse effect, we’d all be ice statues! Check it out!!

Much of the Sun’s energy is absorbed by the Earth’s surface. When the ground heats up, it sends energy back into the atmosphere. The atmosphere absorbs the energy as well and some of it escapes up into space while some falls back down to Earth. This is called the greenhouse effect. This system of rising and falling energy is what keeps Earth warm enough for human life to exist.

Which of the following gives the best reason for calling this system “the greenhouse effect?”

1. Greenhouses have an atmosphere that is similar to Earth.

2. Both greenhouses and Earth have many plants.

3. There are tiny particles of glass in Earth’s atmosphere that trap the warm air.

4. There is no relation to the greenhouse effect and actual greenhouses.

5. The glass in greenhouses behave similarly to that of the Earth’s atmosphere.

The greenhouse effect is pretty kewl! I wish I lived in a greenhouse. Then I could lay out and get a sweet tan in January.

So, number one is totally bogus. Greenhouses are tiny little houses made out of glass. They don’t have an atmosphere!

Number two is totally true because Earth DOES have a lot of plants. And so do greenhouses. I mean, that’s what greenhouses exist for, right? But since the passage doesn’t say anything about plants, then that’s probably not the best answer. And it doesn’t say anything about there being glass in the atmosphere either. It just says that the atmosphere lets some of the sun’s energy escape, and bounces the rest back. Maybe it acts like glass, but there isn’t any actual glass in the air! Otherwise we’d all have some serious breathing problems!

Number four is bogus too. Come on, it’s called the GREENHOUSE effect. I mean, it COULD be just a coincidence that the two have the same name, but it’s unlikely. And check it out, number four doesn’t even ANSWER the question! “What is the reason they call it the greenhouse effect?” “There’s no relation between greenhouses and the greenhouse effect.” That doesn’t make sense! So, there’s no way that’s right.

Five is the best answer. Even if I’d never seen or been to a greenhouse before, everyone knows what it’s like to get in a car on a really hot day. The air inside is like 100 degrees hotter, dude! All because of the windows, right? That sounds a lot like how the atmosphere bounces back warm energy, so the glass in a greenhouse has got to do the same thing!

Stay warm while you’re studying, everyone. Maybe you should try to find a greenhouse to study in! Sweet!!

For more information about the GED test and GED test preparation, visit the GED Academy at http://www.passGED.com.

So, today’s GED Science problem has to do with creepy clones! Ok, so maybe not clones, but families that look alike.

Which of the following would provide the best evidence of a blood relation?

1.) The two people look alike.

2.) Matching fingerprints

3.) Similar interests

4.) Legal documentation stating a blood relation

5.) DNA analysis

If we were thinkin’ about that clone family, then I think all of these would match! They all liked pizza and dressed the same! But wait, wait, we’ve got to figure out the best answer here. You always gotta look out for that word “best” or “most” so you don’t find an answer that kinda fits, then forget to read the rest. So, let’s check ‘em all out!

Number one looks like it might fool you. At first, I thought it was right, I mean, families look alike, right? Then I thought of this dude, Randy, I grew up with who totally coulda been my long lost twin brother! Hm… I wonder if he was? So that’s no good for an answer. Matching fingerprints sounds right too, right? But think about it. Fingerprints is used to detect criminals… and to get into secret secure government buildings… where they do alien autopsies! If families had the same fingerprints, that wouldn’t work. So number two’s out. Number three… similar interests… no way dude!!! Like, my dad’s interests is nothin’ like mine. It’s my friends that are into all the same stuff I am. Legal documents and DNA are both good answers, but sometimes documents can be wrong! Like if a dudette lied and said that Joe Somebody was Betty Somebody’s father, when her dad was actually Bob Anybody! Get it? DNA tests are solid! I’d go with answer 5. The “best evidence” is somethin’ pretty good to know, and something the GED wants you to think about… so you can tell for sure what’s going on. You know, make good decisions about what’s true. Legal documents might be pretty good evidence, but DNA evidence is totally proof. Can’t fake your DNA, right? Unless you’re part of a secret government lab faking alien DNA… but that’s another story…

Do you think any of these answers could help me figure out if that crazy family really was a quad of clones? Good luck with your GED studyin’!

For more information about the GED test and GED test preparation, visit the GED Academy at http://www.passGED.com.

Here’s how it works… the kids ate a little bit of peanuts every day, and their bodies sort of got used to dealing with them. They built up a tolerance for peanuts. Man, I wish I’d done that when I was little! But be careful, this article says that it’s just a study for now… and no one should do it without a doctor. You don’t want to set off your peanut allergies. No kidding! The article’s called “Children Can Complete Treatment For Peanut Allergies And Achieve Long-term Tolerance, Studies Suggest”

Here’s a GED Practice question from the article… First, read this paragraph from the article:

Duke and Arkansas Children’s Hospital began enrolling patients in studies five years ago to determine if incremental doses of peanut protein could change how the body’s immune system responds to its presence. The doses start as small as 1/1000 of a peanut. Eight to 10 months later, the children are ingesting the equivalent of up to 15 peanuts per day. The children stay on that daily therapy for several years and are monitored closely.

So, based on this study, what might a scientist hypothesize would be an effective treatment for an allergy to milk?

1) a regular daily dose of 1/1000 oz. of milk

2) a daily dose of milk, beginning at a very small quantity and slowly increasing

3) a daily dose of milk, beginning at the maximum tolerable quantity and slowly decreasing

4) a daily dose of 10 oz. of milk for 8 to 10 months

5) a small dose of milk administered at random intervals

So, what’d'ya think? Read more to find the answer…

The answer’s #2. Why? Cuz you’re applying what the scientists did for the peanut allergy to a milk allergy, that’s why! Dudes! Think about it. The peanut scientist guys started out givin’ kids really tiny amounts of peanut, like 1/1000 of a peanut… that’s, like, so small, you couldn’t even see it… like itty, bitty, tiny peanut crumbs on the head of a pin… Then, by 8 or 10 months later, they’re eattin’ like, 15 peanuts a day. The amount starts out tiny, and it gets bigger! That’s what answer 2 is sayin’, except about milk: a daily dose, startin’ small and gettin’ big. There ya’ go!

Good luck with that GED studyin’!

For more information about the GED test and GED test preparation, visit The GED Academy at http://www.passGED.com.

It’s like this… they put something on your head, like a sweet sci-fi swimming cap, with thingies all over it in different colors. Only it reads your thoughts. It’s connected to a computer… and when you think of what you want the computer to do, it does it! Totally sweet, man, like they say if you hooked somethin’ like that up to a TV, you could use it instead of a remote control. And jus’ sit on your couch and not even press a button… jus’ think about what you want your TV to do. Oh, yeah, an’ it helps people with disabilities and stuff do things, cuz you can control stuff with your THOUGHTS, like Magneto!

Kay… here’s an excerpt from the article, and a GED practice question, to help you rock your GED science…

Light switches, TV remote controls and even house keys could become a thing of the past thanks to brain-computer interface (BCI) technology being developed in Europe that lets users perform everyday tasks with thoughts alone. …

“The BCI lets people turn on lights, change channels on the TV or open doors just by thinking about it,” explains Christoph Guger, the CEO of Austrian medical engineering company g.tec that developed the application.

Read more…

Which of these computer devices does a brain-computer interface perform a similar function to?

1) printer

2) scanner

3) mouse

4) monitor

5) headphones

So…. what’s your answer? Seriously, doodz, think through it… the question is what’s called APPLICATION… you got to apply what you know about this brain-computer interface (kewl!) to something else. It’s askin’ you what the function of the BCI is. What’s the function? That means, what’s it DO? Like, it turns on lights, changes channels… so, it’s like a light switch or remote control, all in one. It tells the machines what to do. So, which of the five choices tells the machine what you want it to do?

When you look at it that way, it’s not so hard, right? It’s the mouse that tells the computer what you want it to do… and it works just fine, until the computers start thinkin’ for themselves……. but that’s another story. Good GED studyin’ guys!!! Go read about more science!

For more information about the GED test and GED test preparation, visit The GED Academy at http://www.passGED.com.

Well, I jus’ read about how our brains are like, totally active when we’re daydreaming. So I guess I’m all solvin’ problems without knowin’ it… just not the one’s I’m s’posed to be thinkin’ bout. Here’s the link to read all ’bout it… Daydream Brainy-Science

So, here’s a practice question on that article… an’ don’t daydream till after you’re done answerin’ it!

Read this excerpt from the article:

The quantity and quality of brain activity [while daydreaming] suggests that people struggling to solve complicated problems might be better off switching to a simpler task and letting their mind wander.

“When you daydream, you may not be achieving your immediate goal – say reading a book or paying attention in class – but your mind may be taking that time to address more important questions in your life, such as advancing your career or personal relationships,” says Christoff.

Based on this passage, brain activity when you’re daydreaming:

1) is limited and slow but more focused on important activities.

2) is highly active but probably leads to no results.

3) is focused on simple, everyday tasks.

4) is high and centered on complex problem-solving.

5) is likely to make you pay better attention in class.

Dudes! Get the answer? Come on, if you can’t solve it, sit and daydream for a bit!!! It answer 4. See, the beginning of the quote says “quantity and quality” of brain activity. That means there’s a LOT of brain activity, plus it’s good quality for problem solving. That nixes answers 1 and 2, they’re no good. Answer 3’s no good, too, cuz what you AREN’T doin’ when daydreaming is focusing on boring, simple stuff like your classwork. And, same goes for answer 5. So, answer 4’s right… a “high” amount of brain activity (that means LOTS!), that helps you solve complicated problems. Never knew I was doin’ so much kewl stuff while daydreamin’.

Okay, dudes, totally get goin’ on your science GED. Let me know what’s stumpin’ you!!!

Here’s the deal. Think about it. What makes people, you know, people? Like, how different are we from chimps, or other animals? Well, it’s one of the things that scientists study. They look at how animals act an’ how animals think, and see how different humans are from animals.

An’ what the chimp’s actions show–is that he plans things in advance. That’s somethin’ a lot of people have thought animals couldn’t do… think far enough in advance to make plans for what they’d do.

Here’s the story:

http://www.sciencedaily.com/releases/2009/03/090309121931.htm

So, how ’bout a GED practice question?

Here’s a quote from the article:

“I think that wild chimpanzees might be even better at planning as they probably rely on it for their daily survival,” Osvath said. “The environment in a zoo is far less complex than in a forest. Zoo chimps never have to encounter the dangers in the forest or live through periods of scarce food. Planning would prove its value in ‘real life’ much more than in a zoo.”

Now, answer this GED question ’bout it:

Osvath’s idea that chimpanzees in the wild use planning even more than zoo chimpanzees is:

A) A hypothesis that he might want to test in the future.

B) A scientific theory based on the evidence in his study.

C) The variable in his study of the chimpanzee’s behavior.

D) New data that he can use to test his conclusions.

So, how’d you answer? See, I’m testin’ to see what you know about science and science terms. Tha answer’s A… a hypothesis is somethin’ that you think is true and can make an experiment to test. Cuz he didn’t study chimps in the wild, his idea’s not a scientific theory based on his evidence. He has a reason why he thinks it’s true, but it’s based on what he knows about chimps’ life in the jungle, Dude, not about the evidence he’s collected. To make a scientific theory, he’d have to do a lot of testing. Answer C isn’t true… a variable is something that a scientist changes in an experiment to see what different results he gets. That’s not right at all. Answer D isn’t true, cuz the idea isn’t evidence or data… data comes from testing, and this idea hasn’t been tested.

See y’all soon! Good luck with the GED, an’ read your science news!

For more information about the GED test and GED test preparation, visit the GED Academy at http://www.passGED.com.

Seriously, Darwin’s a famous old dude. And, you should know about him if you’re gonna have a good science background for the GED. So who is he? Charles Darwin wrote a book called The Origin of Species. What’s it about? Evolution! You can actually totally read the whole book online, dudes: http://www.literature.org/authors/darwin-charles/the-origin-of-species/

Now, this book basically says that animals evolve over time… that they change. Totally new species get made! How’s it work?

1) Genetic variation…. Like, there’s short dogs and tall dogs, black dogs and white dogs. There’s blue-eyed people and brown-eyed people. There’s gray moths and brown moths. So there’s lots of different types of dogs and people and moths… and everything else!

2) Natural selection.. When something helps an animal or plant to survive and make babies… well, that is inherited by the babies. So more and more animals or plants have that trait. So, if being a black moth helps you hide from birds, and more light colored moths get eatten, there’ll be more black moths. Eventually, all the moths might be black… Maybe down the road in the next valley, there’s light colored trees, so the light moths survive. Now there’s light moths and black moths in two different places… if they keep getting different from each other… they’ll be two species.

Okay, that’s totally short and sweet, but there’s a lot to know! So, here’s some great evolution resources…

http://evolution.berkeley.edu/

http://www.pbs.org/wgbh/evolution/

And, learn some more ’bout Darwin:

http://www.sciencenews.org/view/feature/id/39754/title/Darwin_Special__Darwin_turns_200

How ’bout a GED evolution question?

On two sides of a river, scientists find two kinds of grasshoppers. The grasshoppers north of the river, where the ground is covered in green moss, are green, and the grasshoppers south of the river, where the ground is bare, are brown. What is the most likely explanation of the two types of grasshoppers?

1) Two different types of grasshoppers were brought to the area down the river.

2) Green grasshopers go north while brown grasshoppers go south.

3) Green grasshoppers are more likely to survive on the green moss, and brown grasshoppers are more likely to survive on the bare ground.

4) Green and brown grasshoppers got separated by the river many years ago.

What’s your answer? Well, if you got what I was sayin’ about natural selection, you gotta answer 3! It’s jus’ like I was sayin’ ’bout moths on different color trees. If a grasshopper is green, maybe it’s harder for a bird to see against green moss, so it survives better. That means more green grasshoppers! Same with brown grasshoppers on bare ground. So, now you know another good topic for the GED. And you got a reason to go party!

For more information about the GED test and GED test preparation, visit the GED Academy at http://www.passGED.com.

You really will run across questions on the GED science test that expect you to know all about the scientific method. It’s one of those things that gives you a science background! So, what’s this scientific method anyhow? It’s a process used in science to find out information about the world. The scientific method has five steps:

1) Observe

The first step is to notice what’s happening around you. Science begins with curiosity about the world. That means looking around you, asking questions, and wondering about what’s going on.

Example: I love the lava lamp on my desk, and I wonder what makes the ‘lava’ inside the lamp float up to the top and come down again.

2)  Hypothesize

Hypothesis is one of the important words that you should understand for the GED test. A hypothesis is an idea that explains what you’ve observed or answers a question that you’ve wondered about. A hypothesis is what you suggest or think might be the answer.

Example: I hypothesize that, since the lava sinks to the bottom when the lamp is off, the light from the lamp makes the lava rise, and when the lava is in the darker, top of the lamp, it falls.

3) Predict

After you have a hypothesis, predict something else that would be true if your hypothesis is true.

Prediction: If the bottom of the lamp only is exposed to any bright light, the lava lamp will work.

4) Experiment

Conduct an experiment to test your prediction.

Example: I put two lava lamps on two light sources. One is the original light source, and the other is a light source that’s equally bright but does not give off heat. I watch the lava lamps to see when they start working. The lava lamp on the original light source is the only one that works. The other lava lamp does not move.

5) Evaluate

Look at the results of the experiment. Is it what you would expect based on your prediction? If not, you need to go back and form a new hypothesis. If so, you can begin to develop your hypothesis (an idea that’s not proven) into a theory (an idea that has evidence behind it. That will require more testing and expanding your idea.

Example: The lava lamp does not work with a light source that only gives off light, not heat. That means that it’s not the light that makes the lava move. I think about what the light in the lava lamp has that was not present in my alternate light source, and I make a new hypothesis that applying heat to the bottom of the lava lamp is what makes the lava move. I’ll need to test my new hypothesis.

There ya’ go! A whole scientific method in five parts. Look for it on the GED science test!

For more information about the GED test and GED test preparation, visit the GED Academy at http://www.passGED.com.