23 Draw a cuboid and square pyramid. Count the
of faces, vertices, edges and verify Fulers formula
Answers
The speed-indicating mechanism of the speedometer is actuated by a circular permanent magnet that is rotated 1,000 revolutions per mile of vehicle travel by a flexible shaft driven by gears at the rear of the transmission. The magnet turns within a movable metal cup made of a light nonmagnetic metal that is attached to the shaft carrying the indicating pointer; the magnetic circuit is completed by a circular stationary field plate surrounding the movable cup. As the magnet rotates it exerts a magnetic drag on the movable cup that tends to turn it against the restraint of a spiral spring. The faster the magnet rotates, the greater is the pull on the cup and the pointer. The speed-indicating dial is graduated in either miles per hour or kilometres per hour or, in certain models, both.