Question

Lance Armstrong bikes at a constant speed up the Col d’Izoard, a famous mountain pass. Assume his teammates do such a good job riding ahead of him that he can draft behind them and encounter no air resistance. This climb is described as "beyond classification" in terms of its difficulty. The climb is 14.1 km long at a 7.3º average grade. Assume that the combined mass of Lance and his bicycle is 83 kilograms. What is the magnitude of the work he does against the force of gravity? show work

Answer 1

Work done against gravity to climb upwards is always stored in the form of gravitational potential energy

so we can say

`W = mgh`

here h = vertical height raised

so here we know that

`h = 14.1 sin7.3 km`

here we have

`h = 1.79 km`

now from above equation

`W = (83 kg)(9.81 m/s^2)(1.79 * 10^3 m)`

`W = 1.46 * 10^6 J`

so work done will be given by above value