As far as your current problem is concerned, the reason why objects fall from the sky and hurt people is because the momentum of the objects increases after falling. If you hit someone in an instant, it will take a short time and be strong, and it is not a matter of increasing quality. (mv 2)/2 = mgh，mv = ft。 You can calculate the product of the mass and the landing speed, and then divide it by the instantaneous action time with the ground (of course, it is very short), and you will get the magnitude of the force.

The increase in quality you said can tell you that the quality will not increase, so you can understand that the quality is unchanged now. If you are interested, or have studied the theory of relativity, you will understand that with the increase of the speed of an object, the mass of the object will decrease under other conditions unchanged, and there is a quantitative formula. Of course, within the scope of our reality, the decrease of quality is very small and can be considered as constant, but when the speed reaches a considerable level, the change of quality will be obvious. Therefore, you should understand why the mass of photons is zero, because the speed of light is the limit of the speed of an object.