Final answer:
In Physics, we calculate the work done by forces on a sled moving at constant velocity by considering the applied force and friction. The work of the applied force is equal and opposite to the work of friction, resulting in zero net work, due to the constant velocity.
Step-by-step explanation:
The subject of this question is Physics, more specifically related to the topic of work and energy as applied in the context of friction and forces on objects in motion. We'll calculate the work of the applied force, the work of friction, and the total work done using the given information of mass, distance, and coefficient of kinetic friction.
(a) To find the work of the applied force (Wa), we use the formula W = F * d * cos(θ), where F is the force applied, d is the distance, and θ is the angle of the applied force with respect to the horizontal. However, since the problem states that the sled moves across the snow at a constant velocity and doesn't provide an angle, we can assume that the applied force equals the force of friction and acts horizontally. The work can then be given by Wa = μk * m * g * d, where μk is the coefficient of kinetic friction, m is the mass of the sled, and g is the acceleration due to gravity (9.81 m/s2).
(b) The work of friction (Wf) is calculated using the same formula as Wa, but since friction always opposes the motion, the work done by friction is negative, so Wf = - μk * m * g * d.
(c) The total work (Wtotal) done on the sled is the sum of the work of the applied force and the work of friction. Since the sled is moving at constant velocity, the net work done on the sled is zero, so Wtotal = Wa + Wf = 0 J.