A 25-ton (50,000-lb) truck coasts down a steep 7% mountain grade without brakes, as show...

A 25-ton (50,000-lb) truck coasts down a steep 7% mountain grade without brakes, as shown in Fig. P9.49. The truck’s ultimate steady-state speed, V, is determined by a balance among weight, rolling resistance, and aerodynamic drag. Assume that the rolling resistance for a truck on concrete is 1.2% of the weight and the drag coefficient is 0.96 for a truck without an air deflector but 0.70 if it has an air deflector (see Video V9.13). Determine V for these two situations.