# Homework Help: Center Of Mass

1. Dec 8, 2008

### kaylanp01

1. The problem statement, all variables and given/known data
To determine the location of the center of mass of a car, the car is driven over a scale. When the front wheels are over the scale, the weight recorded by the scale is 5.05 x 103 N. When the rear wheels are over the scale, the scale reads 6.20 x 103 N. The distance between the front and rear wheels is 3.58 m. How far behind the front wheels is the center of mass located?

2. Relevant equations
Ahh I did it using that math that we used in lower level high school. haha. Thought I might get lucky.

I missed these classes in physics, so I'm trying to figure it out and have no idea where to start.

3. The attempt at a solution
I did:
x + y = 3.58
5050x + 6200y = 112500 (because the weight of the car is equal to the sum of the weight measured on the front wheel and the weight measured on the rear wheel).
Solved for x, subbed it in, got the wroong answer. aha.

2. Dec 8, 2008

### LowlyPion

Maybe if you had thought of the see-saw?

Won't it be more like 5*x = 6.2(3.58 - x) ?

3. Dec 8, 2008

### kaylanp01

Sorry...I'm not following. Where did the 5 come from?

4. Dec 8, 2008

### LowlyPion

OK. 5.05 if you prefer.

5. Dec 8, 2008

### kaylanp01

oooh. hahah sorry. its exam week, i'm feeling a bit slow. so your formulas are actually x + y = 3.58 and then 5x = 6y. I understand, thank you :).

6. Dec 8, 2008

### LowlyPion

Basically, yes.

Where did your 6 come from then?

JK.

Cheers.

7. Dec 8, 2008

### kaylanp01

hahah now now, be nice.