# Unreal physics gravity question

Okay I have a altitude dependent temperature system which works fine but when I was doing some testing to see if it is correctly working I found some unusual data. I am on the first person template and made one of the boxes z*500 on the scale to make a box 500 meters tall. I jumped off for some laughs and it took forever to hit the ground, 14.46s because I did it again to test my hypothesis that ue4 doesn’t have -9.81 m/s^2 gravity. So at the top of my box I was at 500.4m, at the bottom I was at 2.68m which took me 14.46s. Finding velocity with delta d/delta t I got -34.4m/s, then I took acceleration with delta v/delta t and got -2.38 m/s^2. Then to backwards calculate to find how high I should have been for 14.46s I got just over 2,000m.

Is there anyway to change the engines gravity so that it is correct? Is there something I am missing? I would really like to know since I am creating a game that for some key parts of the mechanics depend on gravity being 9.81 m/s^2. Thank you

@RaZeXzZz

This might help you. I don’t know exactly, how the global override is measured in terms of gravity or if the global override is only depending on an arbitrary value, but you might find some kind of math to work with it. The only downside with this option is that you can’t change it in runtime. The upside is that it applies to the current map/level, so you can have different gravity implementations across several maps. Just tick the box “override world gravity” and set the “Global gravity Z” to some value you choose in the World Settings.

Awesome! Thank you. I will have to change this when I get some free time today.