- A cyclist is travelling on a straight horizontal road and working at a constant rate of 500 W .
The total mass of the cyclist and her cycle is 80 kg .
The total resistance to the motion of the cyclist is modelled as a constant force of magnitude 60 N .
- Using this model, find the acceleration of the cyclist at the instant when her speed is \(6 \mathrm {~m} \mathrm {~s} ^ { - 1 }\)
On the following day, the cyclist travels up a straight road from a point \(A\) to a point \(B\).
The distance from \(A\) to \(B\) is 20 km .
Point \(A\) is 500 m above sea level and point \(B\) is 800 m above sea level.
The cyclist starts from rest at \(A\).
At the instant she reaches \(B\) her speed is \(8 \mathrm {~ms} ^ { - 1 }\)
The total resistance to the motion of the cyclist from non-gravitational forces is modelled as a constant force of magnitude 60 N . - Using this model, find the total work done by the cyclist in the journey from \(A\) to \(B\).
Later on, the cyclist is travelling up a straight road which is inclined at an angle \(\alpha\) to the horizontal, where \(\sin \alpha = \frac { 1 } { 20 }\)
The cyclist is now working at a constant rate of \(P\) watts and has a constant speed of \(7 \mathrm {~m} \mathrm {~s} ^ { - 1 }\)
The total resistance to the motion of the cyclist from non-gravitational forces is again modelled as a constant force of magnitude 60 N .
- Using this model, find the value of \(P\)