Meriam, Kraige & Bolton — Plane Kinetics of Rigid Bodies: Problem 6_117

6/117 A small experimental vehicle has a total weight \(W\) of \(1100\text{ lb}\) including wheels and driver. Each of the four wheels has a weight of \(88\text{ lb}\) and a centroidal radius of gyration of \(16\text{ in.}\) Total frictional resistance \(R\) to motion is \(90\text{ lb}\) and is measured by towing the vehicle at a constant speed on a level road with engine disengaged. Determine the power output of the engine for a speed of \(45\text{ mi/hr}\) up the \(10\text{-percent}\) grade (a) with zero acceleration and (b) with an acceleration of \(9\text{ ft/sec}^2\). (Hint: Power equals the time rate of increase of the total energy of the vehicle plus the rate at which frictional work is overcome.)