Question

calculate the slope of the red portion of the line.
two points on the line are: (7,10) and (9,30).
position vs. time
what is the velocity of the object, as represented by the slope of the red portion of the line?
options: +20 m/s, +10 m/s, -10 m/s

Explanation:

Step1: Recall slope formula

Slope = $\frac{\Delta y}{\Delta x} = \frac{y_2 - y_1}{x_2 - x_1}$

Step2: Define the two points

Let $(x_1, y_1)=(7, 10)$ and $(x_2, y_2)=(9, 30)$

Step3: Substitute values into formula

Slope = $\frac{30 - 10}{9 - 7} = \frac{20}{2} = 10$

Step4: Interpret sign from graph

The red line slopes downward, so slope is negative.
Slope = $-10$ m/s

Answer:

• 10 m/s