I have a pretty simple highschool physics question and hope anyone here can answer it. Question - A space shuttle is coming in for a landing and is approaching the runway with a speed of 450km/h and at an range of 40 degrees below the horizontal. It smoothly changes direction so that when it hits the runway it is traveling horizontally with a velocity of 180km/h. If it takes 45 seconds to make this change, what average acceleration is the shuttle experiencing? PS: I hope one on this forum can answer this question.