A skier travels from the foot of a ski slope to the top, increasing her gravitational potential energy by $10000\ \text{J}$. She then skis back down the slope. When she reaches the bottom, her kinetic energy is $2000\ \text{J}$. What amount of energy is dissipated in work done against friction and air resistance as the skier descends the slope?
- A$2000\ \text{J}$
- B$8000\ \text{J}$
- C$10000\ \text{J}$
- D$12000\ \text{J}$