Question

Imagine that you enter in a 10 km running race that consists of an out and back flat course.

i. Estimate your time for running 10 km (10,000 m) and your average running speed (there is no wrong answer here, but be realistic… no one likes a humble bragger!) (0.5 pt)

ii. Determine what the drag force would be acting against your motion if the drag coefficient is 0.8, your frontal area is 1.0 m2 , and your density is 1 kg/m3 (1 pt)

iii. Now consider what would happen with a constant wind of 1 m/s blowing as a headwind (into your face) in the first half and a tailwind (behind you) in the last half of the race. What would the drag forces be in the two halves of the race? (2 pt

) iv. How much more work (the units will be kJ) would you have to do against the drag force under the wind condition versus if there were no wind blowing?

Answer 1