6. A vehicle of mass 3500 kg is moving up a slope inclined at an angle \(\alpha\) to the horizontal. When the vehicle is travelling at a velocity of \(v \mathrm {~ms} ^ { - 1 }\), the resistance to motion can be modelled by a variable force of magnitude \(40 \nu \mathrm {~N}\).

1. Given that \(\sin \alpha = \frac { 3 } { 49 }\), calculate the power developed by the engine at the instant when the speed of the vehicle is \(25 \mathrm {~ms} ^ { - 1 }\) and its deceleration is \(0.2 \mathrm {~ms} ^ { - 2 }\).
2. When the vehicle's engine is working at a constant rate of 40 kW , the maximum speed that can be maintained up the slope is \(20 \mathrm {~ms} ^ { - 1 }\). Find the value of \(\alpha\). Give your answer in degrees, correct to one significant figure.