Ki has the potential to be of energy of a small nuke, as with the resource of ki doing such things is not plausible at all. One is able to melt things at above 100 celsius and make shape take form with such and so forth. However the latter of the attack could not even destroy the islandary structures on namek.
Wikipedia on Thermonuclear Explosions said:
A thermonuclear weapon weighing little more than 2,400 pounds (1,100 kg) can produce an explosive force comparable to the detonation of more than 1.2 million tons (1.1 million tonnes) of TNT. Thus, even a small nuclear device no larger than traditional bombs can devastate an entire city by blast, fire, and radiation. Nuclear weapons are considered weapons of mass destruction, and their use and control have been a major focus of international relations policy since their debut.
The attack clearly had at least that amount of weight behind it, but while it is evident as you pointed out that the attack IS indeed powered by both the velocity and the speed of where goku kicked, however frieza was kicked across one, if not several islands before landing. Frieza flying through that structure at mach 93 is just furthermore adding on to this. The point of this?
Well, read. One weighing 2,400 can produce an explosion of approximately 1.2 million tons, which can devastate an entire city by the blast, fire and radiation. Meaning if the attack had the power of a small nuke, which is around 2,000-2,400 pounds, the islandary structure would have vanished from the energy scale of the attack. The only thing where applying physics here works is the weight and speed.
What I am trying to say..? Does it have the weight? Yes, easily. DBZ had this type of weight in Piccolo Daimao. However, does it have the energy, scale, radiation, width or anything of the sort? Not even remotely close.