9709 P41 - Nov 2021 - Q5 - 11 marks
3501
A car of mass 1600 kg travels at constant speed \(20\mathrm{\ m\,s^{-1}}\) up a straight road inclined at an angle of \(\sin^{-1}(0.12)\) to the horizontal.
Use \(g=10\mathrm{\ m\,s^{-2}}\).
(a) Find the change in potential energy of the car in 30 s. [3]
(b) 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. [3]
(c) Calculate, in kW, the power developed by the engine of the car. [2]
(d) Given that this power is suddenly decreased by 15%, find the instantaneous deceleration of the car. [3]
