# Homework Help: Did I do this right?

1. May 28, 2007

### TAN6

Did I do this right??

How much chemical energy would be consumed to travel 100km?
* Assuming 100% efficency *
Mass of car = 1953 kg
velocity = 22.2m/s

Here is what I did
E = 1/2 m v^2
E = 1/2 * 1953 * 22.2^2
E = 481258.26 J

Now I plugged the Energy I got into this formula
W = F * D
481258.26 = f * 100,000
Divide both sides by 100,000
F = 4.8 N

Ok so thats the work that I have done. I don't think I was supposed to find the force. What is chemical energy. I thought I did it wrong becasue I thought I was supposed to use E = 1/2mv^2 and add the answer to the W =Fd answer.
So Im kinda lost... Any help is appreciated!!

2. May 28, 2007

### dontdisturbmycircles

Are you traveling on gravel/asphalt/sand/water? Are you repeating the question exactly as it appears in the assignment? It doesn't make sense.

Last edited: May 28, 2007
3. May 28, 2007

### TAN6

Asphalt, The assignment was to get the car up to 80km/h then shift it into neutral and see how far you coast.

here is someother info you might need
mu = 0.0251