Answer
The average forward force on the airplane is $4800~N$
Work Step by Step
We can find the acceleration:
$v_f = v_0+at$
$a = \frac{v_f-v_0}{t}$
$a = \frac{35~m/s-0}{8.0~s}$
$a = 4.375~m/s^2$
We can find the average forward force on the airplane:
$F = ma = (1100~kg)(4.375~m/s^2) = 4800~N$
The average forward force on the airplane is $4800~N$
