5 Physics Equations Everyone Should Know

All the technology we rely on, from cars to smartphones, was engineered using physics. You don’t need to know science to use these things. But a well-rounded person should understand at least some basic concepts – including some music, art, history and economics. Robert Heinlein says it all Time enough for love:

“To change a man’s diaper, to plan an attack, to butcher a hog, to rig a ship, to design a building, to write a sonnet, to balance an account, to build a wall, to set a bone, to comfort death, Must be able to take orders, give orders, cooperate, work alone, solve equations, analyze a new problem, pitch, program a computer, cook a delicious meal, fight skillfully, kill bravely Go. Specialization for insects.”

So, in the interest of not being a bug, here are my top five physics equations you should know.

1. Newton’s second law

I’m sure you’ve seen it before—it’s over 300 years old, and it’s popular for science memes and t-shirts. It states that the net force on an object is equal to its mass (Mr) times the acceleration (A) But what does that really mean? It’s all about interaction—like when you kick a soccer ball or drop a water bottle on the floor.

Newton’s second law states that we can describe this interaction with the concept of “force”. And what does the force do? A net force on an object changes the object’s motion. But wait! There’s a bunch more cool stuff in this simple-looking equation.

Look at those arrows f And A? This indicates variables that are vectors, meaning they contain multiple pieces of information. For example, if someone told you to “socially distance” 1 meter, where would you go? Who knows? You can go 1 meter east or west or 39 degrees north. Distance itself is not the whole story; You need to point a direction. This is true for both force and acceleration. Other quantities (such as mass or temperature) do not have direction. We call those scalar values.

Newton’s second law is extremely useful, but strangely, people don’t believe it. A common misconception is that a constant force causes an object to move at a constant speed. What this equation says, rather, is that if you push on an object with a constant force, it will continue to accelerate.