-- If velocity is constant, then there is no net force
on the chair.
-- If there is no net force on the chair, then friction
must exactly balance out your push.
-- The force of friction is exactly equal in magnitude
to your push, and in exactly the opposite direction.
Answer:
(a) 
(b) 
(c) 
Explanation:
First change the units of the velocity, using these equivalents
and 

The angular acceleration
the time rate of change of the angular speed
according to:


Where
is the original velocity, in the case the velocity before starting the deceleration, and
is the final velocity, equal to zero because it has stopped.

b) To find the distance traveled in radians use the formula:


To change this result to inches, solve the angular displacement
for the distance traveled
(
is the radius).


c) The displacement is the difference between the original position and the final. But in every complete rotation of the rim, the point returns to its original position. so is needed to know how many rotations did the point in the 890.16 rad of distant traveled:

The real difference is in the 0.6667 (or 2/3) of the rotation. To find the distance between these positions imagine a triangle formed with the center of the blade (point C), the initial position (point A) and the final position (point B). The angle
is between the two sides known. Using the theorem of the cosine we can find the missing side of the the triangle(which is also the net displacement):


I think it is A) but someone might need to double check that.
Mamie Phipps Clark is a noted woman psychologist, best known for her research on race, self-esteem, and child development. Her work alongside her husband, Kenneth Clark, was critical in the 1954 Brown vs Board of Education case and she was the first black woman to earn a degree from Columbia University.