Step 1 :The problem is asking for the time $t$ when the height $h$ of the rocket is 35 meters. This is a quadratic equation problem.
Step 2 :We can solve it by setting the equation $70t - 5t^2 = 35$ and solving for $t$.
Step 3 :We can use the quadratic formula to solve for $t$, which is $t = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$, where $a = -5$, $b = 70$, and $c = -35$.
Step 4 :Substituting the values of $a$, $b$, and $c$ into the quadratic formula, we get two solutions for $t$, $t1 = 0.52$ and $t2 = 13.48$.
Step 5 :Final Answer: The values of $t$ for which the rocket's height is 35 meters are \(\boxed{0.52}\) seconds or \(\boxed{13.48}\) seconds.