A substance changes from liquid to gas
The stone's altitude at time
is given by

where
is the acceleration due to gravity. The stone reaches the ground when
:

To develop this problem it is necessary to apply the concepts related to a magnetic field in spheres.
By definition we know that the magnetic field in a sphere can be described as

Where,
a = Radius
z = Distance to the magnetic field
I = Current
Permeability constant in free space
Our values are given as
diameter of the sphere then,

Thus z = a



Re-arrange to find I,



Therefore the current at the pole of this sphere is 
Answer:
What was not required by the Massachusetts Education law of 1642 is;
Children were to be sent to designated schoolmaster for their learning
Explanation:
The Law of 1642 required that parents and master see to it that their children knew the principles of religion and the capital laws of the commonwealth.
The important aspects of the 1642 Law includes;
1) The responsibility for the basic education and literacy of a child are those of the parents and masters of child apprentices
2) Reading and writing competency of all children and servants are a requirement
3) It is the duty of the government, where a parent or master are unable to meet their tutoring responsibility, to see that a child is placed where the basic educational requirement will be met.
The role of a schoolmaster or the setting of a formal school were yet to be formed as at that time.