Question

the graph shows the electrical resistance of a wire as a function of its length. determine the slope of the line and indicate the units on the slope.
resistance (milliohm)
length (m)
slope:
units:

Explanation:

Step1: Select two points

Let's take two points from the graph: (2, 25) and (6, 75) where the first - coordinate is the length in meters and the second - coordinate is the resistance in milliohms.

Step2: Apply slope formula

The slope formula is $m=\frac{y_2 - y_1}{x_2 - x_1}$. Here, $x_1 = 2$, $y_1=25$, $x_2 = 6$, $y_2 = 75$. So $m=\frac{75 - 25}{6 - 2}=\frac{50}{4}=12.5$.

Answer:

Slope: 12.5
Units: milliohm/m