1 A car of mass 850 kg is being driven uphill along a straight road inclined at \(7 ^ { \circ }\) to the horizontal. The resistance to motion is modelled as a constant force of magnitude 140 N . At a certain instant the car's speed is \(12 \mathrm {~ms} ^ { - 1 }\) and its acceleration is \(0.4 \mathrm {~ms} ^ { - 2 }\).

1. Calculate the power of the car's engine at this instant.
2. Find the constant speed at which the car could travel up the hill with the engine generating this power.