anyone know the benifits of lightweight wheels?

[Biggie™]

Originally Posted by fu_im_from_texas

Biggie, This is false. When the car is going 0mph the energy is 0. When the car is going 60mph the energy is about 4xxx kW. The difference, or amount of energy it takes to accellerate the mass is 4xxx-0 = 4xxx kW

Wrong again buddy... In your equitation you are attempting to calculate the actual energy the Yaris possesses at 60 mph. Not the energy it took to get the car to 60mph. But thank you for letting us know what the ballistic energy of an object that is close to the mass of yaris being flung out at 60 mph.

What you need to do is calculate "force", mass multiplied by acceleration. And of course it will take less energy to accelerate a lighter object. The formula to calculate rotational acceleration is a bit more complex, but this is actually what you are looking for here. Try google...

[fu_im_from_texas]

Originally Posted by Biggie™

...What you need to do is calculate "force", mass multiplied...

Biggie,
I am approaching the problem from an energy stand point. I base this approach on the first law of thermodynamics - a law that states there is a conservation of energy.

You are approching the problem from the standpoint of Force. You are useing Newtons second law of motion. F=ma...

Both are valid. There is 300+ years of emperical evidence that shows that conservation of energy, and F=ma will ultimately get you to the same answer. I am using conservation of energy because, in this case, it is the simpler approach...

Originally Posted by Biggie™

... Try google...

I have a degree in mechanical engineering from the university of texas @ austin. I have taken several classes in physics, dynamics, and dynamic system controlls. My approach to the problem is correct. Google will give you a ton of information. Information is dangerous when it is applied incorrectly...

I am not trying to give you a hard time here, because we are all trying to figure out the same answer to the same tough problem ...