Maths Paper 1, November 2024, question 10.2

A runner travels from checkpoint A and stops at checkpoint B. Her speed (in km/h) after $t$ hours is given by $s\text{’}(t)=-6t^2+24t$, where $s(t)$ is the distance travelled from A. Note: speed is the rate of change of distance with respect to time, and she starts at A when $t=0$. Calculate the distance between checkpoint A and checkpoint B.