UNIT ANALYSIS: In the table provided, give the correct units in both the English and the Metric systems.

1. An airplane begins its takeoff run at a speed of 40 knots. If the runway is 6,000 ft long and it takes 20 seconds to reach liftoff speed, what acceleration must the pilot maintain for takeoff? (One Knot=1.69 ft/sec)
   6,000 ft = a(20 sec)2/2 + [(40 kts x 1.69 ft/sec/kts)(20 sec)] a = 23 ft/sec
   
   
2. An 8,200 kg airplane touched its runway at 65 m/s and came to a stop in 25 seconds.
   Find
   (A) negative acceleration
   0 = a(25 sec) + 65 m/s a = -2.6 m/ sq s

   (B) the length of the runway
   X - X₀ = (-2.6 m/sq s)(25 sec)/2 + 65 m/s (25 sec) = 1592.5 m
   
   

3. A 9,600 lb airplane takes off at 160 ft/sec. If it accelerates at a constant rate of 30 ft/sec²:
   1. How much time is needed to reach takeoff speed?
      160 m/s = (30 ft/sq sec)t + 0m/s t=5.3 sec
      
   2. What length airstrip is used?
      X - X₀ = (30 ft/sq sec)(5.3 sec) = 80 ft
      
   3. What force is needed to produce this acceleration?
      F = (9600 lbs/32.2 ft/sl)(30 ft/ sq sec) = 8944 lbs
      
      
4. A military airplane flying at a speed of 350 m/s must make a supply drop. The pilot releases the supply crate 2,400 m before the drop target. How long will it take for the crate to hit the ground? 
   0 = (9.8 m/sq s)t/2 + (350 m/s) + 2,400 m
   t = 6.22 sec (by the quadratic equation)