# Moment of Inertia Constant

1. Jun 5, 2010

### stalebrownie

1. The problem statement, all variables and given/known data
For a little background, this lab was on energy of a rolling object. We rolled a hollow cylinder from the top of a ramp on a table and onto the floor. We are trying to experimentally derive the constant (k) found in the equation for moment of inertia.

Variables: h = height from top of ramp to table, H = height from table to floor, x = distance ball travels from end of ramp to its landing on floor

Make a graph of x^2 vs h. Add a trendline. Calculate k from the slope of the trendline as it corresponds to x^2 = (4Hh)/(k+1)

My trendline equation is x^2 = 1.98h - .086

2. Relevant equations

I = kmr^2
x^2 = (4Hh)/(k+1)
We know theoretically that k=1 for a hollow cylinder

3. The attempt at a solution
At first I thought the slope was k but that doesn't make sense because my expected k is 1.
I could just calculate k given my experimental measurements, but that's not what they're asking. I'm trying to relate the given equation to mx+b form but I'm drawing a blank. I don't know how to start.

Thanks!

2. Jun 5, 2010

### rock.freak667

You have x2 = (4Hh)/(k+1) ⇒ x2 = (4H/(k+1)) h

this is in the form Y=MX+C, Y=x2 and X=h. What is M?