Question

Do uphills and downhills cancel out?

For a given level of power output, a cyclist will obviously go more slowly up a slope than down the same slope; and on a level road he'll have a speed somewhere between these two cases. Let's see whether one does any better on a flat road, as opposed to going up and down a hill.

On a day without wind,Andrew Talansky(m= 69.8 kg, including bike) put out 250 W of power on his racing bike

a) How long would it take him to ride 100km on a level road at constant speed?

b) How long would it take him to ride 50 km up a hill with a 4% grade constant speed?

c)How long would it take him to ride 50 km down a hill with a 4% grade at constant speed?

d) Does the shorter time achieved on the downhill cancel the longer time required for the uphill, or is Talansky's time better on a level road?

Answer 1