Do Lab Report Graphs Need to Include the Origin Point?

[chroncile]

Homework Statement

I have to do a lab report on centripetal force, frequency and radius. My question is, does a graph have to show the (0,0) points? Also, I got an equation out of the graphing software for one of the graphs and it was y = 1.51x^0.4233, is it okay to use this equation or y = ax^b?

Homework Equations

y = ax^b
y = 1.51x0.4233

The Attempt at a Solution

None

 

[rock.freak667]

What are you plotting on the graph? Once the axes are labeled, you don't necessarily have to point out (0,0).

 

[chroncile]

I'm plotting Frequency vs radius for a constant centripetal force. Also, the graph has an exponential relation; frequency is exponentially proportional to the radius. But, the graph is going downards, not upwards. So, how do I state the proportionality? Here is the equation:

y = 36.86 x^-0.7429

 

[rock.freak667]

I'm plotting Frequency vs radius for a constant centripetal force. Also, the graph has an exponential relation; frequency is exponentially proportional to the radius. But, the graph is going downards, not upwards. So, how do I state the proportionality? Here is the equation:

y = 36.86 x^-0.7429

36.86 is a constant so you can just say that y∝x^-0.7429

 

[chroncile]

Like this?

Table 2 shows that frequency decreases with radius. A plot of the frequency vs. radius from the data in Table 2 is drawn in Graph 2. The shape of this graph suggests that y ∝ x-0.7429. The software shows that the curve that best fits the data is given by y = 36.86 x-^0.7429.