What Objects Convert Mechanical Energy to Heat Energy?
I have a science fair project and I feel like doing something that involves using exercise to achieve warming up a type of food.
exp. Lifting weights to warm up bread
Problem is, I don’t know what could convert mechanical energy to heat energy. Also, where can you buy a motor that can convert mechanical energy to electrical energy?
Mechanical energy is converted to heat energy by friction. However the amount of energy for cooking is relatively high, possibly more than a human can produce. Maybe it could be warmed, as you suggest.
Something that generates heat this way is a brake, just like car brakes. Don’t ask me how you would get that heat into the food. I suppose warm up a lump of something and drop it in a saucepan.
You could go down through three energy conversions, one from mechanical to electricity, one to microwaves, one to heat. They are all reasonably efficient. It would be easy to design, and also to get an idea what is needed. My microwave is 1400W. The person driving the peadals or windlass would have to produce 1400W for the minute or two it takes. That would be very hard work. The link below says that 200 – 400W or so is what can be done, 150 watts for 30 minutes. That is your target. Driving a microwave is a task more like what a horse would do. However you could use the generator to charge a large battery over a longer period of time) and run such a thing.
It would be a good show at a science fair to use a car alternator as the generator (needs no battery once it is going) and a toaster or electric jug that runs on 12V, and uses a power around 200W. This would be possible, and someone trying it would really appreciate the energy involved. The only problem is you have to spin the alternator at about 5000 RPM or even more, so it is not ideal. If you get 100 RPM on the pedals, that needs a 1:50 step up.
I think just having it drive a car headlamp bulb or two (50W each) would be a reasonable goal. Later you could use the bulbs to heat water. You could run a competition, how many bulbs, and do some research at the same time, what is the capability.
I think that would be hard. There was one classical experiment wherein a closed vessel was filled with water. Inside it were paddles that were turned by a dropping weight. After dropping the weights, the water temperature was observed to be higher than the initial temperature.
It’s simple, make an experiment for friction like rubbing 2 stones together and there is fire or rubbing 2 belts and will create heat.
Any generators can be used for converting mechanical energy into electrical energy when combined with a dynamo.
Motors convert electrical energy to mechanical energy.
Generators convert mechanical energy to electrical energy .
The Motor you are looking for, do not exist.