Exercises 1–6 give the positions s = f(t) of a body moving on a coordinate line, with s...

Exercises 1–6 give the positions s = f(t) of a body moving on a coordinate line, with s in meters and t in seconds.

a. Find the body’s displacement and average velocity for the given time interval.

b. Find the body’s speed and acceleration at the endpoints of the interval.

c. When, if ever, during the interval does the body change direction?