I remember, in the Omsk school in the first year, a physics teacher painted a task on a board about the dam and the bobra. At the same time, he was catastrophically unable to draw, the bobber in him turned out to be similar to the xxx and the entire audience kept his breath behind and watched the development of events.

Prepod noted that he completely captured the attention of the audience and took the method to arm. And it went: the elastic collision of two chariots with the bobras, the centrifugal force of the bobra, the sum of the vectors of the forces of the bobra hanging behind the tail...

In the second course, we followed the bobrome-electric, and in the third, when the bobrome looked at the sunlight through the prisma and calculated the fracturing coefficient of the light beam passing through the glass, we and my family moved to Peter and I never learned what happened to the bobrome-atomic.