Answer:
(Example Person) has to push hard to get the skateboard started, but once it begins moving, it takes much less effort to keep it rolling over the smooth, flat pavement. In fact, if (Example Person) tries to stop the rolling skateboard, it may take as much effort to stop it as it did to start it rolling in the first place.
Explanation:
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Answer:
The distance traveled by the skier is 5.309 km
Solution:
As per the question:
Mass of the skier, m = 64 kg
Coefficient of friction between the ski and the snow, 
Mass of snow, M = 5.0 kg
Now,
To calculate the distance, 's' traveled by the skier, in order to melt 5.0 kg of snow:
We know that:

where
= coefficient of friction
N = Normal Reaction
N = mg
Thus
(1)
Also,
(2)
where
= Latent Heat of fusion
Thus from eqn (1) and (2):


s = 5.309 km