Structural constraint is the answer :)
In the process of peppering the question with those forty (40 !) un-necessary quotation marks, you neglected to actually show us the illustration. So we have no information to describe the adjacent positions, and we're not able to come up with any answer to the question.
When the heat source is removed from a fluid, convection currents in the fluid will eventually distribute heat uniformly throughout the fluid. When all of the fluid is at the same temperature, convection currents will stop.
Hi there!
We can begin by finding the acceleration of the block.
Use the kinematic equation:
The block starts from rest, so:
Now, we can do a summation of forces of the block using Newton's Second Law:
mb = mass of the block
T = tension of string
Solve for tension:
Now, we can do a summation of torques for the wheel:
Rewrite:
We solved that the linear acceleration is 1.5 m/s², so we can solve for the angular acceleration using the following:
Now, plug in the values into the equation: