Average Acceleration?

Physics! Average Acceleration!?

• I know the answer, but not sure how to get it. Question: At an air show, a jet plane has velocity components : Vx= 695 km/h Vy= 430 km/h Time= 4.85s And.. Vx= 888 km/h Vy= 425 km/h Time= 7.32 s For this time interval, find the x component of the plane's average acceleration... When I calculated it I computed average acceleration as (delta X/ Delta T)= (888-695)/(7.32-4.85)=78.14 The answer is actually 2.81E^5 km/h^2...How did they get that??? (P.S. no need to change km/h to m/s) Please help! Thanks =)

• Answer:

  velocity=(888km/h-695km/h)=193km/h then you have to change this velocity(193m/h) into m/s by multiplying it by 1000m/3600sec to get 694.8m/s time=(7.32-4.85)=2.47 seconds then avg. acceleration=velocity/time=(694.8m/s)/(2… then you convert it back into km/h^2 by multiplying 281.2955 by 1000 to = 2.81^5 km/h^2 I hope that makes sense. For the equation of average acceleration you do have to have the units m/s for it to work.