Hi everyone, i'm a mechanical engineer student from italy!
my physics professor during one of his lectures gave us the exact same demonstration about the different distribution of charges on smaller radius corners that walter lewin gave in the first 4 minutes of his online lecture "8.02x - lect 6 - high-voltage breakdown, lightning, sparks, st-elmo's fire" (you can find it on yt. he eventually told us at the end of the lecture, that the demonstration is fundamentally incorrect, and that there is a profound conceptual assumption (no wrong calculus) we made that is profoundly false.. but he then said that, despite that wrong assumption, that model works pretty well at explaining why that happens.
he then gave us the task to find the wrong assumption we (and you) what would you say about that?

Na food processing facility, a spherical container of inner radius r1 5 40 cm, outer radius r2 5 41 cm, and ther- mal conductivity k 5 1.5 w/m · k is used to store hot water and to keep it at 100°c at all times. to accomplish this, the outer surface of the container is wrapped with a 800-w electric strip heater and then insulated. the temperature of the inner surface of the container is observed to be nearly 120°c at all times. as- suming 10 percent of the heat generated in the heater is lost through the insulation, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the container, (b) obtain a relation for the variation of temperature in the container material by solving the differential equation, and (c) evaluate the outer surface tempera- ture of the container. also determine how much water at 100°c this tank can supply steadily if the cold water enters at 20°c.

Select all of the following that are equal to an impulse of 20 unitsa) force= 5, time= 5.5b) force= 25, time= 0.8c) force= 0.1, time= 200d) force= 10, time= 2(its b, c, and d)(also in order to find answer they have to add to get the unit)ex= 25x.8=20 or .1x200=20

If frequency goes up, what happens to wavelength? does it get shorter or longer?