A person runs 21.0 km west then turns around and runs 10.0 km east. (L2) a) What is the person's distance? (31.0 km)
b) What is person's displacement? (11.0 km west)

330 wpu is be the right temperature

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.

Answer a, i don't feel like going into detail on this one because of how long that read was. water goes whoosh moving through the turbines to turn them and convert the energy of these mechanisms into electrical energy :