Explain how an event in one area could affect another area

The 'economic impact' of a major event refers to the total amount of additional expenditure generated within a defined area, as a direct consequence of staging the event. For most events, spending by visitors in the local area (and in particular on accommodation) is the biggest factor in generating economic impact; however, spending by event organisers is another important consideration. Economic Impact studies typically seek to establish the net change in a host economy - in other words, cash inflows and outflows are measured to establish the net outcome. Not sure if this is the answer your looking for but it might help!

Velocity is the speed of an object in a certain direction so you'd need to know speed and direction