5 A car of mass 1600 kg travels at constant speed \(20 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) up a straight road inclined at an angle of \(\sin ^ { - 1 } 0.12\) to the horizontal.
- Find the change in potential energy of the car in 30 s .
- Given that the total work done by the engine of the car in this time is 1960 kJ , find the constant force resisting the motion.
- Calculate, in kW , the power developed by the engine of the car.
- Given that this power is suddenly decreased by \(15 \%\), find the instantaneous deceleration of the car.