Question 50ae6

As $T = 2 \pi \sqrt{\frac{l}{g}}$ the change in period will be an increase of sqrt2% or 1.41%#
The equations they use will almost always be exponential not linear (I.e $y = {x}^{n}$ where $n \ne 1$.) Good examples are kinetic energy and velocity, the frequency of a pendulum (the inverse of period, so requires two mental operations/calculations) and orbital motion, whether gravitational or magnetic forces are involved.