Recent content by crador

On the scale of molecules the kinetic energy of individual motion constitutes heat. The internal energy of a closed system reacting chemically will remain constant. You are exchanging some chemical potential energy for thermal energy.

I'd think it is the bonding atoms that initially gain a kinetic energy boost from bond formation. This makes them hotter than their surroundings. The heat then flows into the surroundings in the standard way - intermolecular collisions and such.

Perhaps you should just review a unicycle before trying the bicycle. Say you have the pedals attached directly to the wheel. How would changing the length of the pedals change the force and torque on the wheel?

This is basically all wrong. The force transmitted to any tooth of any gear is not 1000N. That is the force you are exerting on the pedal with some speed. Force is not a fundamental thing that you are supplying. Fundamentally you are supplying power, and the levers you use determine how that...

The wheel doesn't slip normally. You need more force to combat gravity. More torque on the wheel of fixed radius means more output force, by definition. You are trying to spin the wheel harder.

T=IA doesn't apply here, you have no idea about the wheel's moment of inertia and it isn't free to rotate (it has to move the bicycle forward to rotate. Some force in the form of tension in the chain will be supplied from the front gear to the back gear. If the back gear is small it will...

If you are in the USA it would be a good idea to add a major in one of the engineering disciplines if you plan to work for someone else. Also: look into internships with engineering firms. Despite what your professors may tell you, many see a physics degree as not very practical / not preparing...

No, nothing is heating up the fluid. If a molecule bounces off of the paddle to move it forward, then that molecule will get a backward impulse. If a molecule bounces the paddle backward, then it will get a forward impulse. If the paddle has no net movement, then the molecules have net impulses...

Fundamental contradiction to the laws of thermodynamics. Only free energy can be used to do work (hence the term free energy). Consider this: what if you could use the random thermal energy at a single temperature to generate electricity? Then do some work with that electricity and everything...

If you look at the speed of light for what it is -- the speed of fluctuations in the electromagnetic field, and notice that most things we encounter are due to electromagnetic forces, such as touching, then it is pretty obvious: If I could move faster then the speed of light, then I could...

I suppose I am not being eloquent enough for you. My apologies. I am trying to make you get it, namely that Faraday's Law is a rule of thumb for predicting the net result of the Lorentz forces on the charged particles in a closed loop of conducting material. This is not much beyond what jtbell...

What this means is that the physics is simply about moving charges in magnetic fields. Yes, apparently Faraday's Law is a rule of thumb, since it only describes conveniently closed paths. Do you think the physics breaks down if I only look at each half of the path independantly?

No, it is due to charges moving in a magnetic field. Change in flux is a rule of thumb. Notice that if the charges all move in one direction (i.e. down, not clockwise) then the emfs of each half of the loop will cancel. You'll just have some charges collecting at the top/bottom of the loop.

I'd bet that the 90 degree air is quite hot compared to the soil 15 feet below your home. That seems like a temperature differential to me. Good luck getting much work out of it though, if anything you'd be better off lining your inside walls with a nice heat conductor, say iron, which continues...

And the question is then whether paraffin oil can expand significantly up that column you drew, without going into gas phase. No (at least I doubt it, given the definition of a liquid). Basically the oil will sit in the tank, giving off fumes that you vacuum away. It will continue to do so since...