Final answer:
The angle a in a relativistic context changes as the relative velocity approaches the speed of light, affecting how axes are transformed, while the existence of a zero electric field point between S and T can be reasoned out using principles of electric field representation.
Step-by-step explanation:
The student's question seems to relate to physics concepts, specifically concerning the behavior of points in a coordinate system affected by motion, and the properties of electric fields. When analyzing the angle a = tan (u/c), where u is the velocity and c is the speed of light, as v (the relative velocity between two frames of reference, S and S') approaches the speed of light, the angle would change implying a change in the orientation of the transformed axes in a reference frame diagram.
As the velocity approaches the speed of a light, relativistic effects become significant and can dramatically affect the perceived position and time, as depicted in space-time diagrams.
Regarding the electric field between points S and T, to determine whether there is a point where the electric field is zero, one needs to use principles of electric field representation such as equipotential lines or field lines. The student is guided to consider the problem by applying concepts they have learned to see if they can reason out whether the classmate's statement could be true.