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 The speed at which an object with the ski will move down the slope is determined by the net acceleration . The net acceleration is quite complex to determine but it depends on the gravitational pull which is pulling an object down the slope , air resistance which is a function of body shape and friction. To get the net accelaration the net force must be divided by the mass of the object. Typically this operation ( of dividing by the mass ) results in exactly the same accelaration for a heavy or light object. Thus the difference in acceleration ( and hence speed which is integral of acceleration ) depends on air resistance. Typically (but not always) a lighter body has higher air resistance ( e.g. a feather versus a stone; please note that this is not always true). Also a heavier object will result in larger pressure at the contact of ski with ice in comparison with lighter body. When the pressure is higher the freezing point of snow will be depressed more producing larger amount of water at the contact . This water lubricates the ski and hence frictional force at the contact of ski with snow/ice is lowered for heavier objects. In short because both the retarding forces ( air resistance and friction) are typically lower for a heavier object , the heavier object will speed faster.
(Rated by 2 Council Members)
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