why are cranshafts so heavy?
458407
Because they are made of solid metal.  This is necessary to withstand the various stresses it must endure transmitting the chemical energy created in the combustion chambers to the rotational energy of the drive train.
938764
you need harder wheels and a higher ABEC bearing for them.:)
108792
They are made of wood, which floats because it has a lower density than water.  If you made a ship out of solid gold, it would sink, for example.
465216
Well if you had been paying attention, Mythbusters proved that there is not such thing as quick sand. They tried their best but it just doesn't exist.\n\nSeems like the principle of a body being lifted up by a force equal to the weight of the material displaced keeps getting in the way. Sand and water on a cubic foot basis weights much more than either the donkey's or mule's average weight per cubic foot.
373950
definitely because of the sweating thing. Having a sag of skin that weighs a .5lbs to the inside of your leg isn't fun.\n\nAlso, it could be to readjust the Big Guy. He decides to grow @ completely random times, and if he's facing down (towards his feet) or straight out or to either side, he doesn't have much room to grow too! So you need to get down there and straighten out the situation before it starts to hurt too much. And after you do, well you're hand is in your lap already, do you have to move it? No. Then why move it? Leave it there.\nIt's not too complicated really.
1175073
Shafts are subjected to Fatigue Loads and Torsional forces.This requires good Tensile strength combined with High elongation and Impact strength.Therefore shafts are manufactured from forged steel materials instead of castings because castings have low elongation properties although the tensile strength is more.Where damping properties are required,Castings are used.Also castings are prone to have internal defects and this may cause a catastropic failure.I hope it is clear.D.P.SARMA
314529
Because they are less heavily built.  On average men are taller, burlier, more muscular and hav thicker bones.  Women do not need huge manly feet as they are smaller and thus do not need to balance as much weight.
1139376
It has something to do with being top heavy.  Each arm alternates front and back individually, however there are certain parts of the anatomy that bounce up and down simultaneously, causing interference on the forward arm side... This causes the duck waddle run,,,    They cant escape it!  Even if they put both hands up palms forward and run the carwash motion.  That causes certain anatomy to bounce side to side causing an uneven oscillation.  -- Dancing in a consistant slow bounce = graceful.  Figure skating is on skates (no bouncing) = graceful
904917
It is an extremity and requires blood to maintain the proper body temperature. Extra blood  going there to increase the temperature makes them hard
694966
Because its atomic weight is huge.
436928
If the Earth's radius were bigger, and the mass of it stayed the same, then you would weigh lighter.  That's because with a bigger radius, you're farther away from the centre of gravity, therefore less pull.  If the mass change, then the situation would be different.
799766
well, depending on what wheels you have any trucks could seem heavy. ricta wheels are pretty light... wait, lost focus... trucks...tensors are real light, not all that cheap(around $40[zumiez.com]), but also not the most expensive, and they have a slider peice in the baseplate that helps with nose and tail slides.
1003427
heavier than a small sized bag of heavy things
983948
The thing that weighs people down is they reach for their toes. NO! Bring your toes and legs to your hands, keep your back upright and straight as possible. \n\nAnd of course, practice every day.\n\nGood luck!
1019994
People actually swell when they die. So it would be heavier to lift them. Also, there weight is not being regulated, so it makes them APPEAR heavier, when there not, there weight is just dispersed unevenly.
257433
They usually are overweight.
722743
A person with increased muscle mass will tend sink.Those with a higher body fat percentage will tend to float.