If 550 J of work is done to pull a box horizontally across the floor 4.6m, what is the force of friction between the box and floor?

The answer is 119.57.. W=(force)(displacement) so you would do 550J=Ff(4.6m) then to get Ff on its own you divid 4.6 on both sides:)

None. nothing. zero. zilch.

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.