What does Big-O notation represent? How does it relate to program performance?

Most of the run-time for a given program results from an O(n³) algorithm, where n represents the number of inputs. The program takes 10 seconds to process 1000 inputs. About how long will it take to process 5000 inputs?

What is the order of operations for a linear search?

What is the order of operations for a binary search?

What is the order of operations for a matrix addition (n x n matrix).