A skier goes from the foot of a ski slope up to the summit and gains $10000\ \text{J}$ of gravitational potential energy. She then skis back down the slope. When she reaches the bottom, her kinetic energy is $2000\ \text{J}$. How much energy is dissipated in overcoming friction and air resistance as the skier moves down the slope?
- A$2000\ \text{J}$
- B$8000\ \text{J}$
- C$10000\ \text{J}$
- D$12000\ \text{J}$