Moderate# Speed with Vectors and Parametric Equations

APCALC-TZFEOL

The position vector of a particle moving in the xy-plane for $t\geq0$ is $\vec{p}=\left(t^2+5t\right)\vec{i}+\left(4t^2-3t\right)\vec{j}$.

What is the speed of the particle at $t=3.5$?