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danhosey.bsky.social
Dan Hosey
@danhosey.bsky.social
410 followers 210 following 210 posts
HS Physics Teacher. Desmos simulation fan. Spreadsheets too. Always tinkering. www.mrhosey.com/desmos
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 1d
In calculus based (AP Physics C) Electricity and magnetism, students learn about Gauss's Law,which we use here for radially symmetric charge where charge density varies with radius.I wanted a way to create a visual of charge density in a sphere varying with radius.The sim above matches the expected
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 1d
#iTeachPhysics Playing with @desmos.com 3d, exploring spherically symmetric charge distributions where p(r)=r^n. Vary n and watch the charge distribution change in 3d. p(r),Q_enc(r),E(r) graphed on XY plane. Toggle each octant on and off by clicking large corner Pts. www.desmos.com/3d/wmp7fkjdyh
[DH-125] 3d Spherical Charge Distribution
www.desmos.com
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 2d
For high school physics? incline,pulley,meterstick,stop watch,tiny bowling ball pendulum,ferris wheel,2 cars colliding, 2 vectors and their resultant,tiny mass on a tiny spring, a gyroscope,balancing bird,lens, a diffraction grating,small light bulb and battery,2 magnets,double rainbow,f=ma card
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 4d
Just playing around some more with Desmos 3d. Specifically Spherical Coordinates and octants. Points generated randomly. Click single dots to hide Octants. Change Vector in Spherical Coordinates. Just for fun ... www.desmos.com/3d/bkcwfvungl
Spherical Coordinate and Octant Play
www.desmos.com
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 4d
I gelt the same way. It is especially nice that changung N does randomize the masses, so you can toggle back and forth. They don't retandomize until you click a mass.
danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 5d
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 5d
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 5d
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 5d
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 5d
A few more minutes of messing around so a line is drawn automatically for 2 masses, triangle for 3 masses, up to 4 masses. www.desmos.com/3d/0or8l2m0mj
Center of Mass
www.desmos.com
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 5d
This is great. I've missed this kind of inspiration. I played around to make the number of masses variable and scaled the size of the masses to their mass. www.desmos.com/3d/4zniktcj6g Click on a mass to randomize. I completely ripped your segment idea. Toggle on and off "ConnectDots".
Center of Mass
www.desmos.com
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 5d
What would your graph for "How Old I Feel" vs "How Old I am" look like?
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 7d
youtu.be/FV_msKBkoDI
Desmos 124 Vector Addition D Hosey
YouTube video by PrerequisiteName
youtu.be
danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 7d
Speaking of, I just put this together this week to teach vector addition.

www.desmos.com/geometry/ont...
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 9d
Typically I would write that in green or black since it represents a time, even though expressed with an X/v_x. I also like to draw an arrow showing that I am substituting. This isn't a standard technique or anything, just how I choose to emphasize.
danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 9d
When there are enough numbers, I would normally have students solve for the time and plug in the numerical value of time. If you have to plug deltaX/Vx things are getting hairy. If say deriving y(x) for a projectile, I sidestep subscripts, use t=X/[v0*cos()] and sub into y=v0*sin()t-1/2gt^2 for t.
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 9d
I also use the Red and Green Vectors in this Desmos simulation of the components of velocity in projectile motion. www.desmos.com/calculator/q... [5/5]
[DH 85] Drawing Vectors in Bulk
www.desmos.com
danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 9d
Time is neither color. It doesn't belong to X or Y. It is ususually the one thing that links them. Here are some early notes. It leads to somewhat less mistakes, but gives us a languate to talk about the kind of conceptual mixup. "Oh, I made purple". [4/n]
Projectile Motion calculations. All X-component are drawn in Red, All Y-components are in blue, time is in green
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 9d
First Draw a picture clearly labeling initial and final position.
Then write your knowns and unknowns (It could be a table, but what works for you." I ask students to write "X" or "Y", and importanly I write all X calculations in Red, and all Y calculations in Blue. [3/n]
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 9d
Kinematics equations don't soley belong to the X or Y (and certainly not just the magnitude). Just because you have a hammer doesn't mean every nail needs to be hammered. Sometimes you need to use that hammer differently (for example to pull a nail out). [2/n]
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · 9d
I find that students struggle with subscripts in general. For projectiles I tell a story about a Sleep Away camp from childhood where the boys wore blue shirts and the girls red. There was a "No Purple" Rule. I have a no purple rule for projectile problems. [1/n]
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · Apr 9
Bree is an eternal fountain of physics teaching energy and ideas.
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · Apr 8
Upside: Path of totality went through my driveway. Downside: It was completely cloudy. Upside: Still got great brightness data, and learned a lot about the logness of our perception of brightness and made a simulation to demonstrate. #iTeachPhysics www.desmos.com/calculator/8...
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · Mar 29
This is one of those interesting phenomena that looks new, but is actually quite an old problem. There is not and exact solution, the math often blows up, and it is still solved by hand.
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danhosey.bsky.social
Dan Hosey @danhosey.bsky.social · Mar 27
What a lovely and succinct way to compare and contrast horizontal and vertical springs by slowly transitioning the angle. I love the side by side pairing of the physical spring and the corresponding graphs, both force and energy. Really well done. (As always).
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