# What would happen if you stand on a platform that can just support your weight and jump up?

I have played many video games and the title summarizes a scenario I have encountered many times, mainly platformers.

So in this scenario, the platform in question is structurally weak, be it ice, glass or weathered rock. The platform just happens to be strong enough to support your weight, your weight is its critical point, you can stand on it, walk on it or even run on it, but if you jump up while on the platform, when you fall down and touch the platform, the platform breaks...

So how realistic is this scenario? Can this scenario happen in reality?

Edit: let mass be m, let max height reached by jumping relative to platform be h, let gravity accelaration be g and ignore small differences caused by changes in altitude, the motion would be in two parts: first upward motion with decreasing speed, at height h your speed is 0, then downward accelarating motion, at height 0 your speed is sqrt(2gh), your kinetic energy is... well, mgh, so it would break... This seems plausible... This question specifically states the platform breaks when you fall down on it...

• Why couldn't it happen? For any platform strength, we can identify a load that's infinitesimally smaller, that would cause failure for a slight increase. Commented Dec 14, 2020 at 6:09
• Then wouldn't it break already when you push down with your feet in order to jump? :) Commented Dec 14, 2020 at 6:14
• A rocket ship can accelerate by shoving gas out its back end with nothing supporting the gas at all. Commented Dec 14, 2020 at 6:17

Assuming your mass is $$m$$, the force on the platform is $$mg$$ when you just stand on it, and given your problem the maximum force the platform can support vertically is $$mg$$. When you try to jump up, you are exerting an extra force $$F$$ on the platform, which will break the platform.