The velocity in a certain two-dimensional flow field is given by the equation \mathbf{V}=7 x t \hat{i}-8 y t \hat{j} where the velocity is in ft/s when x, y, and

t are in feet and seconds, respectively. What is the magnitude of (a) the velocity and (b) the acceleration at the point x = y= 3 at the time t= 0? (a) |V| =________ft/s (b) |a| = ______ft/s^2.