Acceleration due to Gravity on Mars is about 2.57 times less then that on earth.. So if we plug it in there (i.e., g/2.57 instead of just g).... Whoa... We get 25,700m....thats pretty close to about 26km....
One question, the mountain looks like a cone rather than a cylinder. And we can easily calculator the maximum height of a mountain by assuming that mountain has cone shape, and it gives that the maximum height can be 30,000m. Then why we still assume the shape as a cylinder?
It wouldn't matter because we are just doing an order of magnitude calculation. What we got in the video is 10 km. This doesn't mean mountains cannot be literally more than 10 km. The way to read this is, 'mountains can only be few tens of km long'. Your answer also fits the 'few tens of km' order of magnitude!
Maybe because the value of g must be different, value of elastic limit could be different cuz matirial on mars which from mountain is made of, could be different.. ( every matirial has different elastic limits) thats why value of h would be different..
Why not estimate the shape as a cone instead? It should be more accurate to reality but since it instantly decreases volume by a factor of 3, it gives a much more inaccurate bound