How far does the probe travel in 7.00 s ?

Question

In outer space, a constant net force of magnitude 142 N is exerted on a 31.6 kg probe initially at rest.

Answer 1

Constant force means constant acceleration, so you can work with

d(t) = at²/2 + v₀t + d₀

v₀ = 0 [started from rest]
d₀ = 0 [set origin at 0]

a = F/m = (142 N)/(31.6 kg) ≅ 4.494 m/s²

 

a/2 = 4.494/2 = 2.247 m/s²

 

d(t) = 2.247t² 

 

Now plug in

 

t = 7.00 s

 

and get d in meters.  You can finish from here.