You might think physics is so useful, actually it’s not in real life situation. It is heavily researched but not as much as before, because lots of the findings just can’t be applied in real.
Theory #1 Force = Mass X Acceleration
It’s one of the most famous physics formula. Though it actually doesn’t mean anything. Friction just shatters this formula and makes it completely useless. It’s just impossible to calculate friction. If there was a variable for it, it would never be constant and nearly impossible to calculate. That’s why this formula is inaccurate and not used much in physics. Physicists do research on very small objects, such as atoms, in that scale friction doesn’t exist or is very small.
Theory #2 Light Speed
The speed of light is calculated to be 186,284 miles per second. Though this formula/ calculation has another variable to it. But normally there is something called air on it’s path. Einstein said that we should look at this theory assuming it’s in a vacuum. So basically the light that is traveling around you right now is not moving, exactly at the speed of light, probably a few miles slower.