Final answer:
P(10)=N means that at 10 a.m. on a given day, there are N people at Copacabana beach, as per the function P(t) that models the number of people at the beach based on the hour past midnight.
Step-by-step explanation:
The statement P(10)=N signifies that the function P(t), which models the number of people at Copacabana beach, has a value of N when t, the number of hours past midnight, is 10. In simpler terms, there are N people on the beach at 10 a.m. on that specific day. This type of function is useful for understanding patterns in the number of beachgoers throughout the day and is an application of mathematical modeling in real-world situations.