u/ImpatientProf

Your teacher is almost as confused as you are. The stuff about moving the origin is a red herring.

The only question is what does it mean for a direction to be "from the front of the robot". If it means "from the forward direction", then it's 162.8°. If it means from the front surface, that's in the x-direction, so the angle is only 72.8°.

You can get your vectors graphed if you assemble them into coordinates with parentheses and comma. To draw the line, give a second Desmos line with the point times t. https://www.desmos.com/calculator/ifbvuf1xwm

As a bonus, you can simply add the vectors c=a+b without having to add x and y components yourself. Then to extract components use something like c.x and c.y.

It's usual to take the arctan of y/x, or to explain why you're doing c/d. So I would take arctan(d,c) in your case, getting an angle from the x-axis. Then to get the angle CCW from a different reference, simply subtract that reference and maybe add 360. Is the front up? Subtract 90 and maybe add 360.

Points? Bah. These points are insignificant compared to the future mistakes that come from confusion.

Go to understand what's going on.

Whether one velocity is "faster" than the other depends only on its magnitude. Maximum velocity refers to the maximum speed.

Intuitively, temperature is a system's willingness to give up heat (thermal energy). Inversely, it's a system's greediness to suck up heat.

• Cold systems want to gather more heat, if possible.
• Hot systems want to shed heat, if possible.

We live in a universe with (mostly) positive temperatures. The substances we encounter tend to increase in temperature when they gather more heat. This leads to equilibrium, where a system has gathered "enough" heat, compared to its environment. Place a cold drink on the table, and it will gather heat until it reaches room temperature.

The connection that says, "more energy leads to higher temperature" is because of the stuff. It's not a fundamental law of thermodynamics. It just turns out that almost all stuff behaves that way.

Most drones compensate for varying wind conditions. The drone will try to stay stationary with respect to the (outside) ground.

federal authorities will make the arrest,

The CNN article says Maryland Transportation Authority arrested him on state charges. https://www.cnn.com/2026/09/04/us/disruptive-passenger-duct-tape So are they just holding him until they can convince the feds to come get him? Will he get off on the state charges because they can't prove he actually committed a crime in Maryland?

Ultimately, the intermolecular forces causing the energy differences are electromagnetic, as others have said. But that's behind so much in our world that it doesn't really explain surface tension.

The molecules in a liquid stick together. That's what makes the liquid exist in the first place. Normally, they're surrounded by friends, maybe 5 or 10 of them. This is a stable, low-energy configuration.

How do we know liquid molecules stick together? Evaporating a liquid requires energy (heat of fusion). In the gas, each molecule has basically no neighbors. This is a high-energy configuration (compared to the liquid molecules).

In between those extremes are the molecules at the surface of the liquid. They don't have as many neighbors, so their energy is higher than the ones in the middle of the liquid. This is high-energy for a liquid molecule, though not as high as an evaporated gas molecule.

For every surface molecule, the liquid has more energy than it would if that molecule was in the bulk. To summarize this, we can say that the surface has extra energy. This means reducing the surface area reduces the energy. That's surface tension. Collectively, the liquid changes its shape to eliminate as much surface energy as possible, achieving the lowest-energy state with a surface area as small as possible.

You may have git misconfigured on your machine. Even if it authenticates with your github credentials to push to github, git locally puts whatever author name and email you have configured (in git) onto the commit header.

What exactly are you trying to explain? This is described well in textbooks.

One thing I point out is that in the discharging capacitor, the current is decreasing Q, i.e. I = -dQ/dt. The current is positive while the slope of Q is negative.

In the charging capacitor, the current is increasing Q, i.e. I = dQ/dt. The slope of Q is positive, and so is the current.

Another thing is that each quantity has an initial value, and quickly starts moving toward its equilibrium value. The slope becomes more gentle as time goes on. The equilibrium DC current in a capacitor is zero, so I goes to zero. The equilibrium charge depends on the circuit.

Overall, yes, energy is conserved.

But if you're using Newton's Laws to track energy transfer between "objects", then W = ΔK (work is the change in kinetic energy) is the rule. Calculating the work done on the two objects will yield an imbalance. We know this is due to thermal energy which is randomly-distributed microscopic kinetic (and potential) energy, but Newton didn't know this.

The amount of energy given must match the amount of energy received

Not always. One example is a box sliding on the ground, with friction. The force of friction on the two objects is the same, but their displacements are different during the process.

https://docs.astral.sh/uv/getting-started/installation/#upgrading-uv

Your problem is described on that page.

You could just download the binaries from github (also linked on the above page) and replace the 3 files in the zip release.

You say they're not emergency hires, but it probably feels like an emergency to each hiring committee.

Highlight if not your book.

You mean highlight if it IS your book?

If the road banks, so does the contact force.

For a motorcycle on a solid road, you're right, you need friction + normal to form a net contact force. But the "contact force" behaves exactly like the banked or tilted normal force.

https://www.w3schools.com/sql/

https://en.wikipedia.org/wiki/Garbage_collection_(computer_science)

At a US university, we called it a qualifying exam or qualifiers. Those that passed got their Master's and entered the PhD program. Those that failed got their Master's and moved on.

venv isn't a project, it's a core Python library: https://docs.python.org/3/library/venv.html

The more modern place to list dependencies is pyproject.toml, instead of requirements.txt.

There's a few projects, like Astral uv (https://docs.astral.sh/uv/), which are amazingly good at helping to manage a .venv, installing dependencies in there where they won't disturb your other projects.

For installing within a .venv, it comes down to:

• pip: the standard package installer. If your venv is active, stuff gets installed in there.
• uv: new, fast, and versatile.
• conda: doesn't technically use venv, but does have multiple "environments" for installing different sets of packages.

There are other systems like poetry and hatch, but I'm not familiar with them (yet).

Upload them to YouTube and set them to Unlisted. Then only people who have the link can access them, but you can post links on your LMS.

https://www.av8n.com/physics/uncertainty.htm

Tomy Digital Derby

https://www.ebay.com/sch/i.html?_nkw=tomy+digital+derby

OK, I understand what you're saying, and what Griffiths is saying.

A material is a complicated thing. The energy in a material isn't just due to the macroscopic electric field. There's a baseline energy of electrons bound to atoms and molecules. This includes the microscopic electric fields. Even though the microscopic electric fields in a neutral material average out to zero, they still carry an energy density. There are microscopic magnetic fields as well, which also carry energy. Additionally, the electrons are whizzing about carrying kinetic energy. (Technically, they're not masses with (1/2) mv² energy, but the wavefunctions have a kinetic energy.)

The capacitor energy (1/2) C V² is the energy input into the capacitor. This is a real, practical energy input. But merely looking at change of the integral of the macroscopic E² does not equal this. Some of the input energy goes into the electric field, but some of it changes the other energy of the material. This could be summarized by talking about the spring energy of the bonds, which must be supplied to polarize the material.

The integral of (1/2) D·E does equal this, though. So this energy density accounts for both the electric field and the material properties. Where is the additional energy stored? As I mentioned, in microscopic electric and magnetic fields, and kinetic energy.

It's worthwhile to note that Griffiths made no attempt to calculate the microscopic energy density. On Page 179, he called the microscopic electric field "fantastically complicated". It's amazing that even though we don't know the VALUE of the energy density of the material, we do know the CHANGE of the energy density due to the external electric field or free charges. In this sense, it's a potential energy.

Please reference the textbook version and pages you are looking at. I can help you understand, but I don't want to have to search and search for what I think you're looking at.