The position of a body moving on a coordinate line
is given by for ,
with in meters and in seconds.

(a) Find the body's displacement and average velocity
for the given time interval.
Displacement =
Average velocity =

(b) Find the body's velocity at the endpoints of the interval.
Velocity at is
Velocity at is

(c) Find the body's acceleration at the endpoints of the interval.
Acceleration at is
Acceleration at is

(d) When, if ever, during the interval does the body change direction?
If there is more than one answer, enter a comma separated list. If the
body never changes direction during the interval, enter NONE.