Billy is driving a bumper car for 5 minutes. In this time, Billy crashes into three other cars. The first car is carrying another small child, the second is carrying a large adult, and the third is empty. Each car is sitting still when Billy hits it at full speed. Place the crashes in order of how much force Billy feels, from smallest to largest.

empty car
large adult
small child
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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.