# Mass of a rod

1. Apr 8, 2010

### juggalomike

1. The problem statement, all variables and given/known data
A long thin rod lies along the x-axis from the origin to x=L, with L= 0.750 m. The mass per unit length, l (in kg/m) varies according to the equation l = l0 (1+1.110x2). The value of l0 is 0.500 kg/m and x is in meters.

2. Relevant equations
stated in equation

3. The attempt at a solution
I am lost on this question, i tried plugging the given numbers into the above equation, but my answer is not right(and tbh that seemed entirely to easy)

so i know .50*(1+1.110*.750^2) is not right, but other then that i am stuck, any help is greatly appreciated

2. Apr 8, 2010

### rock.freak667

You need to integrate over the entire length of the rod.

3. Apr 8, 2010

### juggalomike

alright i solved for the mass and got .453 kg, which is correct.

Now i need to figure out

Calculate the x-coordinate of the center of mass of the rod.
A=

I tried integrating x*m then dividing by m, but that didnt work