1. The problem statement, all variables and given/known data Starting from rest an airplane lifts off the ground after 40s and 1.8km. What is its speed at takeoff and its average acceleration during the takeoff run? 2. Relevant equations V= distance/time Acceleration= (Vf-Vi)/time 3. The attempt at a solution The airplane travels 1.8km in 40 seconds. This would mean that when substituting in to the formula V=d/t the velocity at takeoff is .045km/s or 45m/s. I then plugged in this value into the acceleration formula a= (45-0)/40s and got an answer of 1.125 m/s^2. The answer key says that that answer should be 90m/s and then 2.25 m/s^s and I'm not sure why they are getting that answer?