Force= mass*acceleartion.
Look at the velocity/time graph here (red line).
http://www.aerospaceweb.org/question/aerodynamics/q0025.shtml
max acceleration (slope) occurs from 1min to 2 min, I see the slope as
4000-2500)/(2:01-1:26)= 1500ft/sec/35sec
1500ft/35sec^2=49ft/s^2 or 12.5m/s^2
Force=78*12.5 Newtons
How many g's is that? 12.5/9.8=?
The acceleration varies with launch profile, payload, so this is probably atypical. The max g forces is about 3g, but they are not typical. The graph above is a typical launch profile.
What is the maximum total force exerted on a 78 kg astronaut by her seat during the launch of the Space Shuttle?
2 answers
and in the above, you have to add the force of gravity, so the max force is
force= mass(g+a)=78(9.8+12.5)
which is about g equivalentof ((12.5+9.8)/9.8)g
force= mass(g+a)=78(9.8+12.5)
which is about g equivalentof ((12.5+9.8)/9.8)g