Prior to touching the bar magnet, the magnetic domains in the nail were pointing in random directions. When Taylor touched the nail to the bar magnet the magnetic fields of the magnetic domains aligned and it became a temporary magnet.
Answer:
A. 79.3 keV
Explanation:
Because the procedure involves many steps for its resolution and it works faster on paper and pencil, the detailed solution of this exercise is attached as a scanned image of the procedure for review.
In the procedure, the initial values of the problem and the replacement of these values with the correct formulas for this process are taken into account.
To solve this problem it is necessary to apply the concepts related to the relationship between tangential velocity and centripetal velocity, as well as the kinematic equations of angular motion. By definition we know that the direction of centripetal acceleration is perpendicular to the direction of tangential velocity, therefore:

Where,
V = the linear speed
r = Radius
Angular speed
The angular speed is given by


Replacing at our first equation we have that the centripetal acceleration would be



To transform it into multiples of the earth's gravity which is given as
the equivalent of 1g.


PART B) Now the linear speed would be subject to:



Therefore the linear speed of a point on its edge is 51.05m/s
mass of one liter of water= 1kg
Archimedes says:
F= m g = 1 kg* 9.81 m/s^2 = 9.81 newtons