Describe motion that would represent constant acceleration due only to a change in direction.

-- the motion of a point on the tire of a bicycle that's moving
at a constant speed on a straight road;

-- the motion of a point on the tire of a car that's moving at
a constant speed on a straight road;

-- the motion of a planet in a perfectly circular orbit;

-- the motion of any point anywhere on any of the hands on an 'analog'
clock ... a clock that has hands ... except right at the center of the clock.