A certain aircraft has a liftoff speed of 124 kmh What minim
     A certain aircraft has a liftoff speed of 124 km/h  What minimum constant acceleration does the aircraft does the aircraft require if it is to be airborne after a takeoff run of 206 m?  m/s^2  How long does it takes the aircraft to become airborne?  s 
  
  Solution
equaltion of ;inear motion: v^2 = u^2 -2as
wher v ----final vel ; u ---intial vel; a --- constant acc. s ---distance
124 km/hr ---- 124*5/18 = 34.33 m/se
a) a = ( v^2 - u^2)/2s = ( 34.44^2 -0)/(2*206)
= 2.86 mt/sec^2
b) Using v = u +at
t = ( v-u)/a = ( 34.44 -0)/2.86 = 12.04 sec

