Physics: riding a bike uphill: horsepower

Tutoring physics, you notice it in everyday situations. The tutor mentions horsepower riding a bike uphill.

Let’s imagine a kid on a bike – perhaps 40kg total – riding uphill, perhaps a 5% grade (5m up for every 100m up the slope). Further, imagine they must pedal at least 0.50m/s to keep the bike upright. How much horsepower is required?

Solution: Power=force*velocity = 40*9.8*sin(5.0deg)*0.5 = 17W

hp=17W*1hp/746W = 0.023hp

So it takes about 2% of a horsepower to accomplish the above ride.