Physics 10-17-19 Newton’s Law of Inertia

PHYSICS: Remind me again why didn’t that pen go flying across the room instead of dropping into the bottle? Hmmm…..

So what do you reckon is the inertia of this car? Great start today relating mass to inertia! Now go forth and apply what you know to find the mass of your unknown!


Unsplash.com photo by Rodolfo Mari

Physics 10-3-19 2D Motion Problems Review & Help Session

PHYSICS: Wow! You have grown so much in understanding these problems! Here’s yesterday’s discussion of one of the relative motion problems (#44) and the torpedo problem – #7 from the 2D worksheet. Add #37 from the end of the chapter review to your homework for this weekend.

Below the vodcast from today’s class is the help session from this morning – #5 and #6 from the 2D worksheet – a stone is thrown and a bird in the wind.

Have a great homecoming tomorrow!!


Photo by Andrew Palmer on Unsplash

Help Session from Thursday morning:

Photo by Brina Blum on Unsplash

Physics 10-1-19 Kid on a Slide with a Water Gun & a Rocket

PHYSICS: From Monday, here’s our work on the kid on a slide with a Water Gun and an almost to the end look at the accelerating rocket.

So it wasn’t very pretty today, BUT I think you made tons of progress in how you think. Can you go back now and polish them up and make them beautiful?

Need some extra practice? Help session Thursday morning, 7:20ish A.M.


Photo by Markus Spiske on Unsplash

Physics 9-27-19 Relative Motion Revisited & a HW Baseball Problem

PHYSICS – Wow, we finally made it to the official end of chapter 3! Do you realize how much you’ve accomplished? Awesome!

How’d you do with relative motion “revisited”? You know, you’ve done this already. The only new part is the motion of objects in the same direction and opposite directions, relative to each other. Don’t forget, you’ll use what you learned about vector addition to work those “boat goes across a river” and “plane experiences a head wind” types of problems.

Also included at the end – a look at one of the angular projectile homework problems – a baseball hit over a fence.


Photo by Fernanda Caetano on Unsplash

Physics 9-26-19 More Angular Projectiles & the Monkey-Hunter Problem

PHYSICS – Great job today working through the monkey-hunter problem!

Do the problems make more sense now? Don’t give up on the next set! They are tough, but you can do it!

If you need some inspiration – here are links to the Monkey-Hunter videos from class today:

MIT Physics Demo – Monkey and a Gun
The (Human) Monkey and the Hunter


flickr photo by Johnson Cameraface

Physics 9-25-19 Angular Projectile Motion

PHYSICS – So we are finally putting it all together – angular projectile motion! Here’s the lesson – some homework discussion and then angular projectile motion. Mic battery died in the middle of recording, so here’s a recording from a looooooooong time ago. I think you will find it helpful. Ahem.

The number one thing to remember – Never use the resultant velocity to do more than find the vertical and horizontal components! And vertical is vertical, horizontal is horizontal and don’t ever mix the two!

PHYSICS 9-30-14 Angular Projectile Motion from Tammy Skinner on Vimeo.

flickr photo by gpwarlow

Physics 9-24-19 Horizontal Projectile Motion

PHYSICS: Great job today – and applying stuff from the last chapter no less!

Just go slow and easy, talk yourself through what you are doing and ask if the formulas you are using are legit. You’ll master it in no time flat. Watch out for squirrels throwing nuts!


Photo by Toimetaja tõlkebüroo on Unsplash

Physics 9/19/19 Graphical Vector Addition

PHYSICS – Hey guys, great job today drawing motion with vectors – graphical vector addition, resultants, and the like. Have you done anything like this before?

A couple of super important things – GRAPH PAPER(!) and sketch it out before you start so you’ll know where to place the first vector with out running off the page. Also, graphical addition is adding vectors head to tail – then the resultant is found from the tail of the first vector to the head of the last vector. Get the direction by measuring from the tail of the resultant.


flickr photo by diegoluis