For fully developed laminar pipe flow in a circular pipe, the velocity profile is given by \(u(r)=2\left(1-r^{2} / R^{2}\right)\) in \(\mathrm{m} / \mathrm{s}\), where \(R\) is the inner radius of the pipe. Assuming that the pipe diameter is \(4 \mathrm{~cm}\), find the maximum and average velocities in the pipe as well as the volume flow rate.