Answer:
Newton's second law of motion
Explanation:
Newton's second law of motion can be stated
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
in another form,
Force = mass * acceleration
Answer:
r = 0m is the Minimum distance from the axis at which the block can remain in place wothout skidding.
Explanation:
From a sum of forces:
where Ff = μ * N and 
N - m*g = 0 So, N = m*g. Replacing everything on the original equation:
(eq2)
Solving for r:

If we analyze eq2 you can conclude that as r grows, the friction has to grow (assuming that ω is constant), so the smallest distance would be 0 and the greatest 1.41m. Beyond that distance, μ has to be greater than 0.83.
To the picture the answer is A. I can’t answer the typed question because I need the picture for the box
Answer: idk that is a tough one!
Explanation: that is a hard question IDK
B. By vibrations in wires or strings