Aforce acting on an object does no work if
a machine is used to move the object.
the force is not in the direction of the object’s motion.
the force is greater than the friction of motion.
the object accelerates

If the force is not in the direction of the object’s motion then a  force acting on an object does no work
work is done if force is applied on a body and body covers some distance in the direction of the force
W=FS
hope it helps

Wind or electric energy force force of friction

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.