potential energy
It's because of kinetic energy
before they go down the incline.
At the top of the hill, the skier possesses potential energy. As he travels down the hill, his potential energy is converted into his kinetic energy. Conservation of energy says that the skiers potential energy equals his kinetic energy further downslope (plus a little lost to heat from friction).
because the skis are on the snow it causes friction which turns in to heat causing the skier to stop
because the skis are on the snow it causes friction which turns in to heat causing the skier to stop
Just standing there, a skier on the top of the mountain has potential energy. If she uses her poles to push-pull before taking off, she's building up a small amount of kinetic energy. If a skier is then moving down the mountain, his movement downward is kinetic energy which increases as his speed increases. If he or she collides with an immovable object while skiing, kinetic energy abruptly ends. If he or she takes off from the top of the mountain and an avalanche happens to hit at the same time, the kinetic energy of the avalanche engulfs the skier and overpowers the lower kinetic energy of the skier. The skier and avalanche become as if one in the kinetic force of the avalanche--until the skier collides with something or is buried, and thus is separated from the avalanche's kinetic energy which continues until the avalanche stops.
In Washington State, a skier-down flag must be displayed when a skier is in the water.
Gravity is the answer for this question. If you need other help with questions, there are other questions that are answered for this. I've used Wiki Answer the whole Science Study Island.....
chemical energy to mechanical energy
Potential energy to kinetic energy
When skier is at the top of mountain he had kinetic energy which is further converted in to potential energy from the time when he start skiing from the top of the mountain.
Half way down the slope, the skier has kinetic energy and potential energy. At the top of the slope, before he starts moving, he only has potential energy. At the bottom of the slope, he has only kinetic energy. This is an extremely simplified explanation, but it's probably the answer that your teacher is looking for. Hope that helps.