# Emilie du Chatelet and Energy

1. May 7, 2004

### physics_illiterate

We are learning about Emilie in physics right now and we are trying to determine if the equation for energy is e=mv or e=mv^2. Obviously we know the answer but I need to prove it using a block of clay a metal ball and a measuring device such as a ruler. I know how to do the experiment but I want to know if anyone knows where I can find information on the original experiment done by Emilie. I have tried google and I get one result if that. Any ideas or suggestions would be great.

2. May 7, 2004

### Yian The Craft

I thought kinetic energy was 0.5(mv^2)

3. May 7, 2004

### arildno

If I am not altogether wrong, the concept "vis vitae" (life force), preceded the concept of kinetic energy , and the
"vis vitae" concept was probably the one current at du Chatelet's time.
(I think it was originally crafted by Leibniz)
"vis vitae"=m*v^(2)

4. May 7, 2004

### Yian The Craft

Is that not the equation for KE but without the 0.5 at the front?

5. May 7, 2004

### arildno

I never said you were wrong!!!
Just wanted to note that du Chatelet probably wanted to find out whether it was
mv or mv^(2) which was the important quantity in the problem, i.e. whether momentum or "vis vitae" was the significant parameter in determining the fall length of the ball through the clay.
Sorry if you took offense; none was intended.

6. May 7, 2004

### Yian The Craft

"Sorry if you took offense; none was intended."
Strange,I was about to write that same line.In any case,no offense taken.To return to the topic at hand,was Leibnitz not Newton's rival?I think he was,and they often made similar discoveries via different routes,but at about the same time...

7. May 7, 2004

### arildno

Yes, unfortunately they became embittered rivals.
The origin is probably that Newton as a person was rather insecure and suspicious of nature.
There is no doubt that Newton developed calculus or "fluxion arithemetics" as he called it earlier than Leibniz.
However, Newton had the bad habit of "never" publishing, and only circulated his results among a few, select friends (Leibniz was not one of them!).
Hence, when Leibniz on the Continent developed and published his ideas on calculus, Newton immediately suspected him of plagiary,
which no one today thinks Leibniz did.
The net result of the quarrel was that British mathematics developed in isolation from Continental trends, to the detriment of the British..