4 A car of mass 1400 kg is moving on a straight road against a constant force of 1250 N resisting the motion.
- The car moves along a horizontal section of the road at a constant speed of \(36 \mathrm {~m} \mathrm {~s} ^ { - 1 }\).
- Calculate the work done against the resisting force during the first 8 seconds.
- Calculate, in kW , the power developed by the engine of the car.
- Given that this power is suddenly increased by 12 kW , find the instantaneous acceleration of the car.
- The car now travels at a constant speed of \(32 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) up a section of the road inclined at \(\theta ^ { \circ }\) to the horizontal, with the engine working at 64 kW .
Find the value of \(\theta\).