A cyclist and her bicycle have a total mass of 70 kg . She cycles along a straight horizontal road with constant speed \(3.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). She is working at a constant rate of 490 W .
Find the magnitude of the resistance to motion.
The cyclist now cycles down a straight road which is inclined at an angle \(\theta\) to the horizontal, where \(\sin \theta = \frac { 1 } { 14 }\), at a constant speed \(U \mathrm {~m} \mathrm {~s} ^ { - 1 }\). The magnitude of the nongravitational resistance to motion is modelled as \(40 U\) newtons. She is now working at a constant rate of 24 W .