When the bikers are starting at the blocks and then the starting gun goes off, the speed at which they are going at at that time is slower than at any part, like during the middle of the race.
Why is this? The question says that you must relate air resistance to this. What I know about air resistance is that it builds up as something increases speed.
So how come it is more difficult to start a biking race (at the starting block) than it is to just ride during the middle of the race? Wouldn't there be more air resistance as you start moving?