A thin, horizontal copper rod is 1.26425 m long and has a mass of 26.7791 g. The acceleration of gravity is 9.8 m/s 2 . What is the minimum current in the rod that will cause it to float in a horizontal magnetic field of 2.06172 T

Iwould think it is temperature, silica, oxides (gases)

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.