Answer:
3.63 s
Explanation:
We can solve the problem by using the equivalent SUVAT equations for the angular motion.
To find the angular acceleration, we can use the following equation:

where
is the final angular speed
is the initial angular speed
is the angular distance covered
is the angular acceleration
Re-arranging the formula, we can find
:

Now we want to know the time the bit takes starting from rest to reach a speed of
. So, we can use the following equation:

where:
is the angular acceleration
is the final speed
is the initial speed
t is the time
Re-arranging the equation, we can find the time:

As mass increases, the potential energy also increases, I hope that helped :)
Answer:
I like to memorize excerpt from articles to solve and answer questions like these. I hope this can help, it's from study.com: "The relationship between voltage, current, and resistance is described by Ohm's law. This equation, i = v/r, tells us that the current, i, flowing through a circuit is directly proportional to the voltage, v, and inversely proportional to the resistance, r."