Question 1071394
I do not think anyone, on Earth, jumps of an airplane and starts to accelerate at a rate of 6m/s^2. The initial downwards acceleration rate should be 9.7 - 9.8 m/s^2, no matter how high your airplane is flying, and it should take several seconds of increasing downwards speed and increasing air drag force to reach an acceleration of 6m/s^2.
At that point the acceleration has little to do with the force of gravity.
The net force acting upon a 70kg body accelerating at 6m/s^2 is 4200 Newtons:
{{{(70kg)(60m/s^2)=4200N}}} .
However, that is not the "force of gravity." It is the sum of the downwards force of gravity, and a substantial upwards air resistance force.