Slope of a Parametric Curve

A particle moves in the $xy$-plane so that its position for $t \geq 0$ is given by the parametric equations $x = \ln(t + 1)$ and $y = kt^2$, where $k$ is a positive constant. The line tangent to the particle’s path at the point where $t = 3$ has slope $8$. What is the value of $k$?