The first controlled, sustained flight in a heavier-than-air craft was made by Orville Wright on 17 December 1903. The plane took off at the end of a rail that was 60 ft long, and landed 12 s later, 180 ft away from the beginning of the rail. Assume the rail was essentially at the equal height as the ground.
(a) Find the average velocity of the plane in feet per second while it was in the air.
(b) Determine the average velocity in kilometers per hour?