A small body of mass m is located on a horizontal plane at the point O. The body acquires a horizontal velocity vo. Find:
(a) The mean power developed by the friction force during the whole time of motion, if the friction coefficient k = 0.27, m = 1.0 kg, and vo = 1.5 m/s;
(b) The maximum instantaneous power developed by the friction force, if the friction coefficient varies as k = ax, where a is a constant, and x is the distance from the point O.