As regards Superman SupermemeWe spoke last week, Francisco Ríos comments: “The greater the force required to stop a mobile phone, the shorter the braking distance, so if you stop a lady who falls a few inches off the ground, your powerful steel arms will be almost worse than if you let them hit the ground. It doesn’t even make sense to stop a bus that throws itself at a child. No matter how strong you are, the maximum force you can do is rubbing your shoes on the ground, so if you get between a poor boy and a bus, it will happen that you will be the one to hit the child. Again, it is better to let the bus pass than to hit it with strong legs; at the very least, if the wheels do not pass any essential point, they may be rescued. ‘
Another factor to consider is the pressure exerted by the superhero’s hands when lifting a large weight or stopping a moving vehicle. Even if Superman had enough power to lift a 100-ton whale with one hand, the pressure on the pivot point, assuming the surface of the hand is one 200 square centimeters, would be about 500 kilograms per square centimeter: a man’s fingers would sink into the body of an unhappy whale like butter.
And when Superman arrives at high speed to stop, he has to neutralize the kinetic energy in his body, he has to “brake” in some way, and when he stops, the kinetic energy will be converted into a lot of heat. It can’t just sit gently, cold as a rose …
And when we talked about Superman, some readers were reminded of his home planet, Krypton, and its intense gravitational field, which led to some doubts about gravity and its hypothetical variants (see last week’s comments). Along these lines, it is worth wondering what would happen if the attraction between two masses was inversely proportional to the distance, not their squares. I urge my clever readers to speculate on this simplistic law of universal gravity.
What if the attraction between two masses was inversely proportional to the distance, instead of its square?
Returning to our universe and continuing on the subject of gravitational attraction and falls is a typical “Fermian” problem in which the lack of data should not discourage us:
Two people jumped windows from different floors of a burning building at the same time, and one of them hit fire rescue pillows two seconds in front of the other. Fortunately, both people are unharmed. What can we deduce from this data?
Carlo Frabetti is a writer and mathematician, a member of the New York Academy of titleonlys. He has published more than 50 popular science works for adults, children and young people, such as “Damn Physics”, “Damn Mathematics” or “Great Game”. He was the screenwriter of “La bola de cristal”.