Final answer:
The work done by the horse on a round trip around the park is zero, as the force is perpendicular to the direction of displacement. Consequently, the power, which is the rate of work done over time, is also zero in this idealized scenario.
Step-by-step explanation:
Work and Power in Physics
A horse pulling a carriage around a circular park road exerts an average force of 800 N. To calculate the work done by the horse during a round trip, we must consider the distance traveled. Since work is defined as the product of force and displacement in the direction of the force, and the displacement in this case is circular and perpendicular to the force exerted by the horse, the work done is zero. The horse is applying force to the carriage in a direction that does not result in any displacement (in the direction of force), as the carriage merely goes in a circle and ends up at the starting point.
For power, which is the rate at which work is done, the horse travels around the park in 12 minutes (720 seconds). As the work done is zero, the power delivered by the horse is also zero. However, in practical scenarios, horses do expend energy to overcome friction and air resistance; but because these factors are not given, we can't calculate them. We're only considering the idealized physics concept of work.