Step 1: Understand the behavior of an inductor.
In an RL circuit, the voltage across the inductor for \( t>0 \) is governed by the natural response of the inductor, given by the equation:
\[
v_L(t) = V_0 e^{-\gamma t}
\]
where \( \gamma = \frac{R}{L} \) is the time constant.
Step 2: Apply the given values.
Here, \( V_0 = 25 \, \text{V} \), and we find that the voltage across the inductor for \( t>0 \) is:
\[
v = 25e^{-\gamma t} \, \text{V}
\]
Final Answer:
\[
\boxed{(2) \, v = 25e^{-\gamma t} \, \text{V}}
\]