Here is the tutorial we used in class today to help you plot data in LoggerPro.

Why I like the Metric System.

It’s much easier to say “18.4 cm minus 14.3 cm.”

While watching a recent episode of White Collar, I began to question what I saw.

Agent Jones carrying $2 million in gold

Could Agent Jones carry a case of Krugerrand with the weak grip shown in the exchange scene?

This questions leads us to some initial questions:

• What is Krugerrand?
• How big is the case?
• How many coins are in the case?
• How much does the case weigh?

Below are some more pictures from the episode to help your investigation.

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So, a couple weeks ago when we were all learning about magnets and their many uses we discussed that they are used on some roller coasters.  I was aware of this but never fully understood how it worked.  Now that I understand how it works it is intriguing to watch.  While on the senior trip to Six Flags I noticed at least one coaster that was driven with electromagnets.  The one I noticed was V2.  Those have to be some pretty strong magnets to launch that whole train of people that far up a vertical track!  Did anyone notice any other coasters powered by magnets?

Noah’s Ark Water Park, in Wisconsin Dells, will open the only looping waterslide in the U.S. this summer.

Popular Science explains how it works:

If you don’t have enough momentum to reach the top of the loop, and slip back to its start instead, an opening lets you exit (one in 100 riders might do this). more…

With our recent, but brief, look and nuclear energy and weapons, I thought about the concept that humanity has enough weapons to destroy itself.  I wanted to learn more about this so I did a little research.

The total global nuclear arsenal is about 30,000 nuclear warheads with a destructive capacity of 5,000 megatons (5,000 million tons of TNT).

A single 100 megaton explosion would be enough to cause a nuclear winter and pollute the Earth for many years.  Theoretically, a 100 megaton bomb detonated below ground could produce a massive earthquake and the constant explosions of a full blown nuclear war may also cause numerous earthquakes around the globe.  But this would not destroy the world or all human life.

Globally there are enough nuclear bombs to completely kill every human 50-60 times.  It would only take the detonation of 500-600 bombs to kill every person.

Although both America and Russia account for most of these nukes, I think they will never be used.  The fact that countries know how unsurvivable a nuclear war would be deters all countries from using them.  The reason the United States used them to bomb Japan was that it was conservatively estimated that over a million American soldiers could have died in an amphibious assault, and the fact that no one else had nuclear weapons.  Today, with so many nukes, it is more of a way for a country to flex its might, but I doubt they will ever be used, especially against another nuclear country. 

I believe that the largest nuclear threat now comes from terrorist organizations that could get their hands on nuclear weapons.  They have no second thoughts about killing innocent civilian on a massive scale, and accept death as glorious.  Also, rouge countries like Iran and North Korea also bring new threats of nuclear war, which is why the international community must do everything it can to limit nuclear weapons around the world, and stop the movement of nuclear material and technology. 

Although unlikely to happen, just the thought of killing every person in the world with just a fraction of the available bombs should make anyone shudder.

After watching October Skies, the subject of renewable and non-renewable energy came up in class. I got a sense that some of you think that we are using far more renewable energy sources than we actually are. I suppose this has to do with the amount of publicity things like solar panels and wind farms receive.

Unfortunately, we have a long way to go with renewable energy.  Consider the graphic from the Department of Energy that was shared in class on Friday.

U.S. Primary Energy Consumption by Source and Sector, 2008

Let’s look at this another way. A few weeks ago the U.S. approved the Cape Wind Energy Project on the Outer Continental Shelf off Massachusetts.

An article about the first U.S. off-shore wind farm makes the following production estimates:

Cape Wind Associates will harness energy from the wind to add an hourly average of 182 electric megawatts to the power distribution grid. All energy must be converted to BTUs (British Thermal Units) to properly assess its positive contribution to the national energy deficit. Multiplied out, Cape Wind will add 5.5 quadrillion BTUs to America’s reliable energy resources. Put another way, it replaces about one billion barrels of imported oil over the course of a year, every year once in operation.

First off, they got the math wrong here. A quick trip to Wolfram|Alpha shows that it will only replace 939,000 barrels of oil not the one billion originally claimed. (The story has now been corrected after some physics teacher pointed out the mistake in the comments )

Corrections aside, let’s compare the power the off-shore wind farm may someday produce to another off-shore energy story that broke the same week as the Cape Wind announcement. That story was the explosion at the Deepwater Horizon drilling rig in the Gulf of Mexico. Shortly after the explosion, it was estimated that the disaster was spilling 5,000 barrels of oil per day. Unfortunately, more recent assessments of the situation have projected this number to be much higher.

However, for the sake of argument, let’s stick with the 5,000 barrels per day figure. If we were to convert all that wasted oil to power we’d get 350 megawatts! It’s safe to say that the oil spill is easily wasting twice as much energy per day than the future off-shore wind farm could produce per day.

We see that wind has a long way to go but more importantly, our understanding of energy has a long way to go too. The news often uses terms like: megawatts, BTU’s and barrels of oil but I don’t think their audience knows what these terms mean.

I hope that you will leave physics with a better understanding of some of these terms. For starters, our ‘Energy at Home’ project should have given you an understanding of kWh and Watts but you shouldn’t stop here. Your future will be filled with local, national and global discussions on energy. You will need to keep a mindful eye on the topic of energy. Unfortunately, some of those discussions will misrepresent the physics. They may cater to your emotions and dazzle you with meaningless numbers. The good news is that you have tools (like Wolfram|Alpha) to refute or verify the energy claims that will come your way.

Use physics to make informed decisions. Do the math. Have an honest and realistic understanding of our energy needs as you push forward in life.

On Tuesday Fermilab announced that matter beats antimatter in the battle of existence. As we know when particles of matter and antimatter collide they destroy each other. Well that is not completely true, after a particle collision the antimatter is completely destroyed, but 1 percent of the matter from the collision still remains.

Let the physics rap battle begin…

Rhett Allain at the dotphysics blog recently reviewed some iPhone acceleration apps.

I’m curious to hear what physics-related apps you’ve found useful, interesting or just plain fun.