The one formula to know for motion is:
speed*time=distance
Take the red bullet as and example. You know the time (1 second) and the distance (90 degrees). so the equation is:
speed*1 = 90
You want to know the speed of the rotation so isolate speed on one side and we get:
speed = 90/1
or
speed =90
then you can do the motion with an event like:
every tick:
--- rotate red 90*dt degrees counter-clockwise
--- rotate green 40*dt degrees counter-clockwise
--- rotate blue 70/2*dt degrees counter-clockwise
My next question is do you want the bullets to continue turning after that of just continue straight?
If continue staight use "rotate toward angle" instead.