Answer:

Explanation:
Take at look to the picture I attached you, using Kirchhoff's current law we get:

This is a separable first order differential equation, let's solve it step by step:
Express the equation this way:

integrate both sides, the left side will be integrated from an initial voltage v to a final voltage V, and the right side from an initial time 0 to a final time t:

Evaluating the integrals:

natural logarithm to both sides in order to isolate V:

Where the term RC is called time constant and is given by:

Voltage (V)= Current (I) * Resistance (R)
I=V/R=140/2=70A
Hope this helps!
Answer:
Relativistic velocity is of the order of 1/10th of the velocity of light
Explanation:
We define relativistic speed (or velocity) as a speed that is a significant fraction of the speed of light: c = 3*10^8 m/s
Such that for these speeds, the special relativity theory starts to apply (the relativity effects starts to apply).
Usually, we define relativistic speeds as those that are of the order (or larger) of c/10, which is one-tenth of the speed of light.
Then the correct option is C:
Relativistic velocity is of the order of 1/10th of the velocity of light