Final answer:
The exact work done by the pulling force cannot be calculated without the force applied or distance moved. The gravitational force on a 50.0 kg sled is 490.5 N, calculated using the mass of the sled and the standard gravitational acceleration.
Step-by-step explanation:
To address part C of the question, since the student didn't provide the distance over which the sled was pulled or the force applied, we cannot calculate the exact work done by the pulling force. Work is defined in physics as the product of the force applied in the direction of the displacement and the magnitude of the displacement itself (Work = Force x Distance x cos(θ), where θ is the angle between the force and the direction of displacement). Without one of these values, an exact number cannot be provided.
For part D, the gravitational force on the sled can be calculated using the formula Fgrav = mass x gravitational acceleration (Fgrav = m x g). On Earth, the gravitational acceleration (g) is approximately 9.81 m/s2, so for a sled with a mass of 50.0 kg, the gravitational force would be 50.0 kg x 9.81 m/s2 = 490.5 N.