A point traversed half a circle of radius \(R=160 \mathrm{~cm}\) during time interval \(\tau=10.0\) s. Calculate the following quantities averaged over that time: (a) the mean velocity \(\langle v\rangle\); (b) the modulus of the mean velocity vector \(|\langle\mathbf{v}\rangle|\) (c) the modulus of the mean vector of the total acceleration \(|\langle\mathbf{w}\rangle|\) if the point moved with constant tangent acceleration.