Answer
The slope of the secant line: m$=2$
represents the average velocity of the object over the time interval $[0,0.5]$.
Work Step by Step
Graph s(t) by building a table of function values.
Plot the points and draw a smooth curve through them.
See image.
The slope of the secant line:
m= $\displaystyle \frac{s(0.5)-s(0)}{0.5-0}= \displaystyle \frac{1}{0.5}=2$.
This represents the average velocity of the object over the time interval $[0,0.5]$.