Why are heavier skiers faster?

Question

I always experienced that heavier skiers are faster than me. Why is that? All the physical rules I know lead to the solution that they aren't faster, but that can't be :-(

Thanks in advance for your help

Andi

okay, that was a quick answer kutekymmee :-)

How can I calculate it then?

Answer 1

more mass means they have more momentum, which overcomes the friction of the skis against the snow more efficiently.

think about it this way: if you roll a bowling ball and a soccer ball at the same speed, which is harder to stop? the bowling ball has more mass, so it takes more energy to stop it.
For a skier, the friction of the skis against the snow and the air resistance is the only thing trying to stop you. These forces are pretty much equal for everyone. But it takes more energy to stop a heavier skier, so he wont lose as much speed on the flats, and carries more speed into the next downhill.

Answer 2

Well, I mever thought about this, but it makes sense to me. Let's assume the ground is frictionless (because it's near frictionless enough to neglect.) Now, gravity pulls things straight down. If the thing is on a slope, it's still pulling down, but the thing will move along the incline (slower than freefalling, depending on the angle). Heavy objects fall the same speed as light objects, but with air resistance, this isn't the case. The heavier object will fall faster. Heavy objects also have more momentum becuase of mass, so it's harder to stop. Therefore, the heavier object can overcome the little friction that exists better than the lighter object.

Answer 3

It called potential energy.

To get a heavier object up a mountain requires more energy to get up the mountain. Formula is (mgh (mass x grafitational acceleration x height))

So a 100 kg person has twice the ammount of potential energy a 50 kg person has.

Convert this energy into speed on the way down and the heavier person has the advantage. (But he will also be suffering from more friction and air resistance).

Answer 4

when 2 bodies are suspended from an incline, the heavier mass will have more gravitational force going downhill than the lighter one....
you think because the heavier object exerts more friction on the ground, it should be slower ....

so, its harder to move the heavier object from a dead stop... but once moving downhill, the heavier object has more weight pointed downhill then the lighter and should be faster

Answer 5

To the first response:

A bowling ball does not fall faster than a feather because of its greater mass. In a vacuum they would fall at the same rate. The feather falls slower because of air resistance (or buoyancy of the air) slowing the feather down as it travels.

Answer 6

in a simple way -

think of F=ma

gravity has constant acceleration for everything, it is not different for the same location.

bigger mass = bigger force.

more force allows you to go 'faster'

Answer 7

they push down faster & fall faster, like a boulder falls from a buiding faster than a feather.