Question

What is normal force acting on a 3kg object on mars (g=3..37 m/s/s)

Answer 1

In rest, the normal force acting on an object is equal to:

$$N = mg$$

where $m = 3kg$ and $g = 3.37m/s^2$ is the gravitational acceleration on Mars. Thus:

$$N = mg = 3kg\cdot 3.37m/s^2 = 11.1\space N$$

Answer. 11.1 N.