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zanick
zanick is offline
#67
Apr2-09, 07:30 PM
P: 49
Thanks Chris,

But if acceleration = power/(mass x velocity or a=P/p , the rate of change of momentium would be proportionally higher from 50-60mph as it would from 60 to 80mph and so would the force for the two speed ranges. However, the power would be much higher at the higher speed range. Thats why I seemed to remember power equaling rate of change of kinetic energy, not momentium. I agree that the rate of change of momentium would get you to "Force".

so I guess what I'm saying is that the rate of change of kinetic energy gets you power and thus acceleration at any given velocity, and from power you could get force. (working backward )right?
mk

Quote Quote by xxChrisxx View Post
Your thinking is correct but you have the wording wrong zanick.

Rate of change of kinetic energy wont tell you the force nor acceleration. K.E = .5mv^2

The thing you want is rate of change of momentum. momentum = mv
Dy differentiating this you get the magic formula of F = ma.