An aircraft is at a standstill. It accelerates to 140kts in 28 seconds. The aircraft weighs 28,000 lbs. How many feet of runway was used?

runway use is 3307.8 feet

Explanation:

given data

velocity = 140 kts = 140 * 0.5144 m/s = 72.016 m/s

time = 28 seconds

weight = 28000 lbs

to find out

How many feet of runway was used

solution

we will use here first equation of motion for find acceleration

v = u + at ... 1

here v is velocity given and u is initial velocity that is 0 and a is acceleration and t is time

put here value in equation 1

72.016 = 0 + a (28)

a = 2.572 m/s²

and

now apply third equation of motion

s = ut + 0.5*a*t² ... 2

here s is distance and u is initial speed and t is time and a is acceleration

put here all value in equation 2

s = 0 + 0.5*2.572*28²

s = 1008.24 m = 3307.8 ft

so runway use is 3307.8 feet