Physics, a helicopter and cameras

First watch this (and be amazed… well, if you’re anything like I am.)

So, when the students can get past the idea that there is some foul play involved, then it becomes a wonderful opportunities to discuss the idea of frequency.

Frequency is an odd discussion because it’s got a strange unit. The “per time” can be a little challenging for students to wrap their heads around.

And the opportunity that this video provides is that here, we don’t need to immediately concern ourselves with the quantitative value of the frequency (maybe 300 RPM for the helicopter rotor, for example, or 5 frames per second on the camera), but we can begin with the qualitative value of the frequency (that the frequencies, whatever they are, are the same.)

And then it opens the door for them discussing some quantitative issues. For example, the fact that the standard unit of frequency (the “per unit time”), obviously isn’t constant. So, the helicopter rotor is RPM and the camera shudder is typically in frames per second (at least, I think. Not a photographer…) So, you’ve got some nice dimensional analysis opportunities.

Where could you take this next?

One thing’s for sure, I’d hate to waste a video like this. Fully captivating, and it only costs your 30 seconds of class time.

Source: I owe TwistedSifter credit for blogging about this video first.

Seeing through the eyes of 5th and 6th graders

The assignment was simple enough. Take a photo that reflects energy changing from one form to another. It could be a photo that you find funny or interesting. Or it could be something that you’re curious about or have questions about. That part was up to them. The “why” behind the photo was their business.

Here’s a few of the highlights. Enjoy. It’s not very often you get to see physics through the eyes of 10-12-year-olds.

 

Which one is your favorite?

Morning reading – The Loudest Sound in the World

From the physics department, I started my morning with a fascinating bit of reading from FiveThirtyEight.

They hooked me with the intro line:

The questions kids ask about science aren’t always easy to answer. Sometimes, their little brains can lead to big places adults forget to explore. With that in mind, we’ve started a series called Science Question From a Toddler, which will use kids’ curiosity as a jumping-off point to investigate the scientific wonders that adults don’t even think to ask about.

You want to capture my attention? That’s a pretty good way to do it.

What follows is a really approachable discussion of sound energy that is designed to be understandable but doesn’t skimp on all the science-y goodies to do it. It also doesn’t shirk on the drama.

A sound is a shove — just a little one, a tap on the tightly stretched membrane of your ear drum. The louder the sound, the heavier the knock. If a sound is loud enough, it can rip a hole in your ear drum. If a sound is loud enough, it can plow into you like a linebacker and knock you flat on your butt. When the shock wave from a bomb levels a house, that’s sound tearing apart bricks and splintering glass. Sound can kill you.

Go ahead and give it a read. I’d consider using it in a high school physics course. Although, full disclosure: I can’t universally recommend FiveThirtyEight since I know they also write about a lot of other topics and not all of their writers stick to basic school-appropriate rules, like no swears.

It also mixes in a bit of history (some nice story-telling on the eruption of Krakatoa) and some nice unit discussions (hertz, decibels, some prefixes get in the mix, too.)

All in all, definitely an article worth checking out.

Sky Dive Trampoline: Real or Fake?

It has been a while since I’ve posted an additional installment to my “Real or Fake” Collection, but when I see videos like this, I just wonder what everyone else sees when they watch it.

So, a man jumps out of a plane at several thousand feet with no parachute and slips through a 3 x 5 hole in the roof of a warehouse to land on a trampoline where a crowd of perhaps 100 wait to celebrate his victorious descent.

If this is a hoax, the sell job is pretty elaborate: the tech team on the in the control room, the steering device, the slow-motion replay… It sells well. I suppose that is why the video went viral.

But I’m not sold.

First, this stunt is awfully high-risk. Like, it either works, or the stunt man isn’t getting up.

Second, no rehearsal for this technology that is probably seriously tricky to get right. I suspect this guy would have wanted to see a trial drop with a test dummy at least once before he jumps.

I envision that first test drop going sort of like this:

Third, can some of my physics friends verify my skepticism over the meager bounce the man shows once he lands? One minute at free fall? That’s a lot of kinetic energy. A lot. That’s all I’m saying.

 

All right, your turn.

 

What do you think? Real or fake?

 

If you are curious, here are my other posts in the “Real or Fake” collection.

Life-Saving Baseball Catch

Ski Jump Luge