Question

Not a test. Not counted. Just want to know how ot do it.

Answer 1

The rule of the average is

$A=\frac{f(b)-f(a)}{b-a}$

Since we need to find the average speed in the interval 1 to 3 seconds, then

f(1) = 10.5 ------- a = 1

f(3) = 94.5 ------ b = 3

Substitute them in the rule above

$\begin{gathered} A=\frac{94.5-10.5}{3-1} \\ A=\frac{84}{2} \\ A=42 \end{gathered}$

The average speed is 42 m/s

The correct option is D