# How to predict future position of an object(bullet sync)?

There is a multiplayer game and server sends to all clients a message when a shot happens, containing bullet position, bullet velocity and timestamp. By having timestamp, we can calculate the lag, let's say it's 100ms.

My game uses Box2D. How can I predict the real and current bullet position by having such data? I guess velocity might also change a little bit too.

current_position = starting_position + ((lag_delay + time_elapsed ) * velocity)