Учитель физики рассказал ученикам о вечном двигателе на самоделке с колесами разного диаметра

Back in high school, probably in a physics class although I can’t be certain, Howard Elrod told us the story about the time his brother built a motorless go-cart with bicycle tires for back wheels and toy wagon tires, probably Radio Flyer, for front wheels. Mr. Elrod (tell me there’s a person out there who didn’t have one or two teachers who, no matter how old you became, would always be mister) taught math and physics and chemistry, and in his spare time he was high school principal. He could be a fierce guy if you tested him, but most of us learned a lot from him, sometimes from the quirky tales he would tell as part of a lesson. The story of his brother and the home-made go-cart was one of those times. ADVERTISEMENT “My brother figured that with small front wheels and big back wheels, the cart would always be going downhill,’’ Elrod said, holding his hand out in front of him with his fingertips pointing 45 degrees toward the floor. “He was convinced he had invented perpetual motion.’’ At that point, he stopped talking, kept holding his hand at an angle and looked around the room as, one by one, we saw the light. We were a relatively intelligent bunch of kids, I always thought. Thinking back, it’s kind of amazing how long it took for the realization to set in that the wheels would always be flat, no matter how steeply the chassis leaned toward the front. That was in 1960 or 1961, I guess. Out on the California coast, car enthusiasts had been doing a version of the dropped nose for quite a while, I read somewhere. The style originated on the drag strips, where big rear tires provided traction and small front tires cut weight. A car with that forward rake just plain looks fast, and that’s part of why some of the vehicles cruising the Strip in the movie “American Graphitte’’ were styled that way, even if they weren’t ready to race. Mr. Elrod didn’t explain that part. I picked it up from some street rod magazine some years after high school. I still remember him telling the story of his brother and the drop-front go-cart. Was it true? You know, I really don’t know. I know it took me longer than I care to admit to see the flaw in the design. Even when I did figure it out, I spent some time later that day, probably in study hall, picturing the contraption Mr. Elrod described and wondering if there was any way a person could make a cart that continued to roll without a motor and on flat ground. That’s probably part of why Mr. Elrod told the story in the first place, to get us thinking about something not in the text books. It worked on me, and I still remember the concept of perpetual motion, even if it wasn’t on the test. I also remember how my older cousin solved the problem of crafting a home-make go-cart that would run on flat ground. He didn’t mess around with different sized wheels or a special suspension or some other gizmo or gadget. He swiped a small motor, from one of our old, no-longer-used, combines, I think it was. He fitted that into his go-cart design, figured out a to turn the engine’s rotations into rotations of the rear axle and had himself a nifty little hot rod. Read more columns from Terry Woster here... At least I think he did. I have this memory of him building the thing, but I can’t recall ever watching him drive it anywhere. And if I had seen it, I’m pretty sure I would remember. For one thing, the engine would have been loud and unmuffled. For another, their family boxer, Duke, would have been running alongside the cart, yapping and snapping at the wheels the way he did to the pickup tires every time someone pulled out of their yard and halfway down the lane. ADVERTISEMENT In college, I had a ’57 Chevy. It was a six-cylinder, four-door model. During one journalism class, a friend who read car magazines said I should rake the front end so it would look fast. I told him that wouldn’t work. I learned that back in high school. By Terry Woster Listen to this article Conversation