A resistor by itself has no time constant. For a circuit to have a time constant it must contain either capacitors or inductors.

The time constant of an RL series circuit is calculated using the formular:

time constant=L/R

In theory ... on paper where you have ideal components ... a capacitor all by itself doesn't have

a time constant. It charges instantly. It only charges exponentially according to a time constant

when it's in series with a resistor, and the time constant is (RC). Keeping the same capacitor,

you change the time constant by changing the value of the resistor.

No the ozone hole is not constant over the time

Acceleration with respect to time = a , where 'a' is a constant.