Do USB controllers work in parallel or serial?

Many USB controllers have more than one USB port. If, for example, 4 USB devices are connected to a controller (USB stick, mouse, keyboard and card reader), can the USB controller process the signals (data) of these 4 devices simultaneously (parallel operation) or does it switch sequentially from one input to the other and then…

Exercises Distance parallels in a plane?

Hello, unfortunately, the internet doesn't offer many exercises for calculating the distance between two parallel lines. I'm not interested in vector functions, but rather in f(x)=mx+n functions. Does anyone have any exercises for this in their textbooks, perhaps even with solutions? Or do they know of a website where I can calculate something like this…

[Physics] Parallel connection of resistors?

Good evening, I would like to understand why the following two points (1️⃣ and 2️⃣) apply: For resistors connected in parallel, you can also calculate a total resistance, but here the following applies: 1️⃣ The reciprocal values ​​of the individual resistors add up to the reciprocal value of the total resistance 2️⃣ The total resistance…