Answer:
P = W / t = m g s / t = m g v where work by auto = m g s
30 kw = 30000 watts = 30000 J / s
Work wasted = F v as shown above relating work and power
Work done against incline = m g s sin 8.75 and power against incline
= m g v sin 8.75 = 1222 v Joules / sec
power in moving auto = power available - power lost to friction
power in moving auto = 30000 - resistance = 30000 - 910 v
1222 v = 30000 - 910 v
v = 30000 / 2132 = 14 m/s
Note: constant resistance to motion must mean P = W / t = F s / t = F v