The strength of the gravitational field is dependent upon the mass of the planet you are standing on. If you are on the moon, which is 1.2% the mass of Earth, the value of the gravitational field is only 17% of that you would feel here on Earth.
You are on an alien planet. You drop a small rock so that air-resistance can be ignored. It hits the ground with a speed of 16.8m/s after a time of 2.5s. What is the value of the gravitational field in N/kgon this planet using the flat-earth approximation?