All the technologies we are counting on, from smartphones, have been designed use physics. You don’t need to know science to use these things. But a complete human being should understand at least some of the key concepts, as well as a little music, art, history and economy. Robert Heinlein said everything Enough time for love::
“A human being should be able to change a layer, to plan an invasion, to massacre a pork, to pilot a ship, to design a building, to write a sonnet, to balance accounts, to build a wall, of Return a bone, to comfort the dying, to take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, throw manure, program a computer, cook a tasty meal, fight effectively, die valiant.
So, in the interest of not being insects, here are my five main physical equations that you should know.
1. Newton’s second law
I am sure you have already seen this one: he is over 300 years old and he is popular for scientific memes and t-shirts. He says that the net force exerted on an object is equal to its mass (M) times acceleration (A). But what does that really mean? It’s all about interactions, such as when you hit a football ball or drop a bottle of water on the ground.
Newton’s second law says we can describe these interactions with the concept of “strength”. And what do the strengths do? The net force exerted on an object modifies the movement of the object. But wait! There are many other nice things in this simple equation.
See these arrows above F And A? This indicates variables that are vectors, which means that they contain more information. For example, if someone asks you to “ward off socially” by a meter, where would you find you? Who knows? You can go 1 meter to the east or west or 39 degrees from the north. The distance in itself does not constitute a complete explanation; You must also specify a direction. This is true for both forces and for acceleration. Other quantities (such as mass or temperature) have no steering. We call these scalar values.
Newton’s second law is very useful, but oddly, people do not seem to believe it. The most widespread false idea is that a constant force moves an object at a constant speed. What this equation says is rather is that if you push on an object with a constant force, it will continue to accelerate.
