2 A car of mass 1400 kg , travels along a straight horizontal road AB , after which it descends a hill BC inclined at a constant angle of \(7 ^ { \circ }\) to the horizontal (see diagram). \(\mathrm { A } , \mathrm { B }\) and C all lie in the same vertical plane. Throughout the entire journey, the total resistance to the car's motion is constant.
\includegraphics[max width=\textwidth, alt={}, center]{cad8805d-59f6-4ed2-81f4-9e8c749461f5-3_232_1227_392_251} Between A and B, the car moves at a constant speed of \(12 \mathrm {~m} \mathrm {~s} ^ { - 1 }\), and the power developed by the car is a constant \(P \mathrm {~W}\). When the car reaches B , the engine is switched off and the car travels down a line of greatest slope from \(B\) to \(C\) with an acceleration of \(0.8 \mathrm {~m} \mathrm {~s} ^ { - 2 }\). The resistance to motion is unchanged.

1. Determine the value of \(P\). When the car reaches C it turns round and travels back up the hill towards B at a constant speed of \(v \mathrm {~m} \mathrm {~s} ^ { - 1 }\). The power developed by the car between C and B is a constant 16 kW . The resistance to motion is unchanged.
2. Determine the value of \(v\).