A space vehicle deploys its re-entry parachute when it's traveling at a vertical velocity of - 150 meters/second (negative because the parachute is going down.) It comes to rest at 0 meters/second after 30 seconds. What's the average acceleration of the shuttle during this time span?

Acceleration, in physics, is the rate of change of velocity of an object with respect to time. An object's acceleration is the net result of any and all forces acting on the object, as described by Newton's Second Law.

a = change in velocity / change in timea = 0 - (-150) / 30 - 0a = 5 m/s2