Hi there!
We can begin by calculating the acceleration using the kinematic equation:
d = vit + 1/2at²
Since the rocket starts from rest, we can rewrite this as:
d = 1/2at²
Plug in given values:
4.2 = 1/2a(0.137²) ⇒ a = 447.55 m/s²
Now, we can use Newton's Second Law to find the appropriate force:
∑F = m · a
∑F = 50,000 · 447.55 = 22,377,500 N