## Saturday, October 26, 2019

If you're not following Frank Noschese (@fnoschese) on Twitter, why even be a physics teacher with a Twitter account?

And if you get useful mileage out of constant velocity buggies (such as these from Arbor Scientific) but wish you had a convenient, reliable way to curb their enthusiasm, Frank tweets this:

## Monday, October 07, 2019

### Doggies on a waxed floor

Where will you use it: inertia, friction, centripetal force? I don't think students will mind if you use it for all of those.

Can you stretch it into conservation laws? Of course you can! Low stopping force requires longer stopping time. Impulse/momentum: check. That wee force will need to act across a large distance to change the kinetic energy of those goggies! Work-energy: check.

Want to take it a step further? How did those doggos get up to speed to begin with? Hmmm...

And fear not: it all ends well.

Hat tip to Wendy A. (Rio Phyz ’88). Old physics teacher flex? Why, yes!

## Thursday, October 03, 2019

### Whiplash Model

As I'm starting Forces and Newton's Laws of Motion in my Conceptual Physics class I am bringing out every demo I've got on inertia. I've got viral videos like the Target Shopping Cart Fail, stuffed animals on toy cars to run into walls, etc. As I was going through my list I realized that I didn't have a whiplash demo. I have plenty of images from physics textbooks and medical journals (Wikipedia version below) but I didn't have a physical representation of one to have in my classroom. And you know what happens when I decide I need a physical model ...

By BruceBlaus - Own work, CC BY-SA 4.0, Link

Trying to start with what I had I found the biggest stiffest spring in my cabinet, something that I picked up at the hardware store because, why not? I usually can't get this thing to move much when I hang weights from it unless I'm adding over 2 kg so its a very stiff spring. It is similar to this one from Home Depot, about an inch diameter and almost a foot long.