Question

calculate the average acceleration from a period of 2 s to 10 s.

Explanation:

Step1: Identify initial and final velocity

From the graph, at $t_1 = 2\ s$, $v_1=5\ m/s$; at $t_2 = 10\ s$, $v_2=- 10\ m/s$.

Step2: Use average - acceleration formula

The formula for average acceleration $a_{avg}=\frac{v_2 - v_1}{t_2 - t_1}$.
Substitute $v_1 = 5\ m/s$, $v_2=-10\ m/s$, $t_1 = 2\ s$, and $t_2 = 10\ s$ into the formula:
$a_{avg}=\frac{-10 - 5}{10 - 2}=\frac{-15}{8}=-1.875\ m/s^{2}$.

Answer:

$-1.875\ m/s^{2}$