Answer:
The acceleration of a point on the wheel is 11.43 m/s² acting radially inward.
Explanation:
The centripetal acceleration acts on a body when it is performing a circular motion.
Here, a point on the bicycle is performing circular motion as the rotation of the wheel produces a circular motion.
The centripetal acceleration of a point moving with a velocity 
and at a distance of 
from the axis of rotation is given as:
Here, 
∴ 
Therefore, the acceleration of a point on the wheel is 11.43 m/s² acting radially inward.
(a) 1200 rad/s
The angular acceleration of the rotor is given by:
where we have
is the angular acceleration (negative since the rotor is slowing down)
is the final angular speed
is the initial angular speed
t = 10.0 s is the time interval
Solving for 
, we find the final angular speed after 10.0 s:
(b) 25 s
We can calculate the time needed for the rotor to come to rest, by using again the same formula:
If we re-arrange it for t, we get:
where here we have
is the initial angular speed
is the final angular speed
is the angular acceleration
Solving the equation,
Answer:
Isolated or Closed system, both are correct
