Physics
Physics
Problem
A cyclist maintains a constant power output of while riding at a steady speed of along a horizontal road. (a) Calculate the magnitude of the total resistive force (mainly air resistance and rolling friction) acting on the cyclist. (b) How much work is done against these resistive forces in of such motion?Intuitive explanation
The key insight here is that constant power means the cyclist is doing work at a steady rate, and at steady speed, all that power goes into fighting resistance—not accelerating. Power relates force and velocity through , so you can find the resistive force directly. Once you know the force, work is just force times distance (or equivalently, power times time).
Intuitive explanation
The key insight here is that constant power means the cyclist is doing work at a steady rate, and at steady speed, all that power goes into fighting resistance—not accelerating. Power relates force and velocity through , so you can find the resistive force directly. Once you know the force, work is just force times distance (or equivalently, power times time).