Board Thread:Questions and Answers/@comment-34954086-20120922085545/@comment-34954086-20120923120446

thankyou for metric conversions. t=4 hr-15 min-19 min, =12360 sec

ok KE=1/2 mv^2, v=d/t, 4.8E6/12360, v=388m/s.

speed of sound 340 m/s, well i'll be, he was being modest when he said a few mph shy of the speed of sound, he was going Faster.

KE= 4742136 Joules/1133 Kcal.

Energy is Force*metres, frictional force is what we want here. frictional force is coefficient of friction*Normal Force, Normal Force effectively balances gravitational force.

Normal Force=mg, 63*9.8, 617.4 N. coefficient for wet snow is 0.03, dry snow is higher value, up of 1.2 at low enough temperature, we'll go with that to give highest Energy expenditure. gives Frictional Force of 740.88, From that F*m, 3556224000 J, 849958 Kcal. a lot more energy loss is due to fricion as you can see, even though we maximised the value.

Now im not sure how to determine energy expenditure during the fight, but i'll do from heat losses as well. Give about -20C, convective losses, assume heat transfer coefficient of 2.6 which is a semi-typical value, though i dont think we'll get a value for a kid going faster then speed of sound through a blizzard wearing some unknown material costume. Q=kA(T2-T1)=2.6*2*(37+20)=296 W, 12360 sex, E=296*12360=3663504 J/876 Kcal.

ignoring radiation and conductive losses, the vandal point and movement of arms and legs about body axis, all of which would rise enery use, we have 851967 KCal, daily requirement is about 3000 KCal for a 16 yr old, in other words, he needs all the ice cream he can get his hands on dayum.