The gravitational acceleration constant, which is approximately 9.8 m/s² on Earth, indeed remains constant regardless of an individual's weight. However, the difference in speed between a 250-pound skier and a 150-pound skier on the same slope can be attributed to several other factors:
Force of Gravity: While the gravitational force is the same for both skiers, the force experienced by each skier due to gravity is different. The force of gravity acting on an object is equal to its mass multiplied by the acceleration due to gravity. Since the 250-pound skier has a greater mass, they experience a greater force of gravity, which contributes to their overall speed.
Friction: As skiers move down a slope, they encounter friction between their skis and the snow. Friction opposes the motion and slows down the skier. The frictional force depends on various factors, including the skier's weight and the quality of the ski-snow interaction. A heavier skier can exert more pressure on the skis, increasing the force between the skis and the snow. This increased force can improve the grip and reduce the effect of friction, allowing the skier to maintain higher speeds.
Momentum: Momentum is the product of an object's mass and velocity and represents its motion. The greater mass of the 250-pound skier contributes to a higher momentum. When a skier has a higher momentum, they require a larger force to slow down or change their speed. This means that the 250-pound skier will be more resistant to changes in speed due to external factors such as friction or air resistance, enabling them to maintain a higher speed.
It's important to note that these factors are simplified explanations and other variables, such as technique, skill, equipment design, and aerodynamics, can also influence a skier's speed.