A skate boarder with mass 66 kg is skating back and for in a giant hemispherical bowl. The motion is simple harmonic. The skater starts off from rest 20 meters high in the bowl. It is timed that it takes the skater 25 seconds to get to the other side of the bowl. Which is Horizontally 313 meters from where the skater starts on the other side. (I know that is ridiculous... just pretend) assuming no energy is lost...

The best answer i can think of is b

Distance covered = speed x timethe distance traveled going against the stream = distance traveled with the stream.therefore it is the speed and the time that are the variables.as he travels the same distance both ways, speed x time is the same for each way.going upstream his speed is 4 kph; going downstream his speed is 6 kph.therefore we have two simultaneous equations: time upstream x 4 = time downstream x 6time upstream + time downstream = 60 minutestherefore we have the equation: time upstream = 6/10 hour, time downstream therefore = 4/10 hour.distance traveled at 4km/hr in 6/10 hour = 24/10 = 2.4km.check: distance traveled at 6km/hr in 4/10 hour = 24/10 = 2.4km.