Answer:
I answered Number 4 (Solids and Elasticity)
Explanation:
solids and elasticity
Answer:

Explanation:
Angular acceleration is defined by 
Angular velocity is related to the period by 
Putting all together:

Taking our initial (i) point now and our final (f) point one year later, we would have:



So for our values we have:

Where the minus sign indicates it is decelerating.
Answer:
the work done by the motor is 531,45 Joules
Explanation:
Using a sketch of the possible conditions, we need to find the distance that the block was moved, in order to find the work done by the electrical motor.
The sketch could be seen in the attached image.