It must have a medium. It must travel in empty space. Mechanical waves are waves which needs medium of propogation.
12.8 rad
Explanation:
The angular displacement
through which the wheel turned can be determined from the equation below:
(1)
where



Using these values, we can solve for
from Eqn(1) as follows:

or



Mechanical advantage is the ratio of output force to input force of a machine.
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