Dan Hosey

@danhosey.bsky.social

422 Followers 210 Following

HS Physics Teacher. Desmos simulation fan. Spreadsheets too. Always tinkering. www.mrhosey.com/desmos

Projectile Motion calculations. All X-component are drawn in Red, All Y-components are in blue, time is in green
During the total solar eclipse, it was cloudy here in Rochester NY, but we were in the path of totality. Blue Line shows the ratio of the brightness (in lux) to the brightness at the start. The blue graph goes down, then up in a sort of bowl shape with some undulations due to the varying cloud cover. The orange graph is the natural log of that brightness ratio which decreases very slowly at first and dips down very dramatically during the 10 and especially 5 minutes on either side of totality,more closely matching the feel of the rate of change in darkness. The desmos simulation to the right shows a black circle overlapping the yellow sun over the course of the eclipse. The color of the blue "sky" on the left half of the screen darkens linearly with the percent of the sun covered. The right half of the screen darkens as the natural log of the blocked percentage and much more closely matches the feeling of darkness during the eclipse.
Reading glasses held in my hand, showing 2 sets of reflections of the 4 lightbulbs above my dining room table. The pendant style small chandelier has 4 white candelabra shaped bulbs. In the reflected image we see a set of 4 white bulbs and a second set of 4 green bulbs. What do you think is going on?
Graph of v^2/(2*g*d*sin(theta)) vs cot(theta). The slope of the line is 0.196,consistent with the value of u obtained for the horizontal stopping distance experiment using the same board of wood and tape roll sliding on its side through a photogate.
Graph of the Ratio after to before the collision vs the ratio of the inner radius to outer radius of the spool. The Purple line treats the interaction as perfectly elastic. The Orange line treats the interaction as slipping until a new rolling condition is established.
Graph of V to Vo vs R to r. Non linear. Starts at 0, rises curving down. When R to r equal 1, V to Vo equal 1.
Linear and Rotational KE before equal Linear and Rotational KE After
V=wr
v0=w0R
Image of Spool with outer radius R, and inner radius r.
A desmos simulation showing a disk broken in to N rings. The rotational inertia contribution of each ring is shown. As the number of rings increases, the rotational inertia coefficient approaches 0.5
Pot of relative velocitiy of carts before collisions.
Hand sketch of graph of Velocity vs Time, with 2 representative rectangles showing conceptually how to integrate V(t), each rectangle has a width of dx, V(t). Also shows the integration of V(t) to get X(t)
Postion vs Time and Velocity vs Time Graphs of a mass oscillating on a vertical spring. The Position function is a sin curve, the the velocity graph is a cosine curve.
Screen Shot of an Excel worksheet. 11 rows of raw time trials are shown. Each trial a ball is dropped and bounces 5 times. The most useful information is the formula in cell C2 which performs a linear regression on the 5 times for that data trial. This is much faster than manually creating a graph and adding a trend line for each trial.
Picture of a ball bouncing inside a large plastic graduated cylinder. Also a screen shot from the phyphox app showing the flight time after each bounce.