Final answer:
The potential energy of a sled at 20 m is double compared to its potential energy at 10 m because gravitational potential energy is directly proportional to the height above the ground.
Step-by-step explanation:
When comparing a sled's potential energy at different heights, the principle of gravitational potential energy (GPE) must be taken into account. The potential energy of an object due to its height above ground is given by the formula GPE = mgh, where 'm' is mass, 'g' is the acceleration due to gravity, and 'h' is the height of the object.
Doubling the height of the sled from 10 m to 20 m, while keeping the mass of the sled and acceleration due to gravity constant, will result in the potential energy being doubled as well. This is because the formula for potential energy is directly proportional to height. If height 'h' is doubled, the potential energy 'GPE' is also doubled.
Therefore, the correct answer to how does doubling height affect potential energy is: a. The potential energy is doubled.