Physics

We found 50 articles

Annual revenue at a Starbucks: the power of Fermi approximations
What is a Fermi approximation?  The only thing that physicists like more than dimensional analysis is a good order of magnitude estimation, also known as a Fermi problem or Fermi approximation. A classic is the piano tuner problem: “How many piano tuners are in the city of Chicago?” 
Working with lenses and mirrors - how to draw a ray diagram
Ray diagrams can look intimidating, but they don’t have to be! In this blog post, we will tackle five examples of ray diagrams.
Checking your answers in physics
Having worked through a long physics problem, you finally have an answer. How do you know if it’s right and all that work wasn’t for naught? In this post, I will cover a few quick strategies that can help rule out wrong answers.
What physics equation sheets can do for you and what they really, really can’t
In your time taking physics courses, you will likely run into one that deals with equation sheets. These can be note cards or an entire sheet of paper, and anything that can fit on it is fair game and can be brought into a test. The natural reaction might be to try to cram and squeeze an entire textbook on those sheets using really, really tiny ...
The Physics of Martial Arts: Using Physics to Understand the World
As a practicing biomedical engineer and martial artist, I belong to two communities that, at a glance, seem to conflict with one another; engineering requires rigorous thought and thorough validation of proposed innovations, while martial arts focuses on sensing subtle body motions and quickly reacting to one’s environment. When I first became ...
Introduction to Physics: The Language of the Universe
  In elementary and middle school, we learn mathematic for the sake of mathematic, we are never told what mathematics can ultimately be used for or why mathematics is useful other than the fact that its can help us make change and do our taxes one day. What they should be telling you is that the laws of the universe are written in a language that ...
How to Solve Kinematics Problems: Using Vectors
This article is the third chapter in a series on how to understand and approach kinematics problems. The first chapter covered position, velocity, and acceleration. The second chapter covered solving kinematics in one dimension Now we are going to take a quick detour into vectorland so that we’re ready to approach kinematics in two (and even ...
What is moment and how do you calculate it?
When I tutor my physics students, I want them to understand the fundamentals of the concept, not just how to plug in numbers into an equation. I wished when I was learning physics, my teachers drew upon real life applications more, things we already understand about the world to help us really get it.
How to solve kinematics problems, part 2
This article is the second chapter in a series on how to understand and approach kinematics problems. The first chapter covered position, velocity, and acceleration. Now that we understand these quantities, we are going to use them to solve problems in one dimension. 
What is Kinematics? Physics Answers Made Simple
How to use this guide This blog post is the first in a series on how to understand and approach kinematics problems. It is meant to supplement your class and textbook. I will focus on practical applications, how to solve problems, and common mistakes that students make. If you want to learn the basics of kinematics, I recommend a textbook, but if ...
4 tricks for solving any physics problem
Physics can be intimidating—all those pulleys and protons and projectile motion. If you approach it with the right mindset, however, even the hardest problems are usually easier than you think. When you come up against a tough question, don’t panic. Instead, start with these short, easy tricks to help you work through the problem. 
Learn, Don’t Memorize!
Intro to Physics Blues    As a high school student, I took physics my junior year and struggled to stay afloat in the class. While I was interested in understanding and applying the theories I learned, it was difficult to make sense of them in my head. As a result, I began my first collegiate physics course with a lot of excitement, yet some ...
Why logarithms are actually useful: Simplifying Arrhenius temperature dependence using log tricks
Learning about logarithms is one of those times in math class where you wonder if this will ever be useful in any way. I see lots of students struggle with topics like logs, since they can seem abstract and they aren’t obviously useful. But I’m here to explain why they are actually incredibly important and describe so much of the world we live in! ...
Astronomy vs. Physics: Cultural Differences
  Many people, often family members, ask me how astronomy and physics differ. Since I am studying solar physics, I usually give the “short answer”-- that astronomy is just a specific branch of physics. However, there are widespread cultural differences that make the “long answer” rather more involved.
Inertia Experiments and Rolling Motion Part II
Last time on our physics tutoring blog, we conducted an experiment to investigate the influence of the moment of inertia on rolling motion. We started with two objects that had the same shape, but very different size and mass. Starting from rest, we then set them both rolling down a ramp, to see which one would reach the bottom first. The objects ...
Inertia Experiments & Rolling Motion Part I
Not that kind of inertia. Sometimes, when you are sitting in a physics class staring at an intimidating wall of math, it can be easy to lose sight of the fact that the laws of physics originated as hypotheses to explain observations in the real world. Whether it was Newton getting bopped on the head by an apple, Galileo dropping stuff off the ...
Physics Tutor: 3 Tricks for Physics Standardized Tests
Learning to take standardized physics exams, like the AP Physics exam or the SAT Physics Subject Test, is not unlike trying to become fluent in a foreign language. Both follow highly idiosyncratic logic and are best learned through practice. (And believe it or not, standardized physics exams have less to do with physics than physics aficionados ...
Physics Tutor: Analogies V--What makes Quantum Mechanics Quantum?
Conceptual picture of a photon, from physicsworld.com
Physics Tutor: Quantum Strangeness – Heisenberg Uncertainty Principle
This week, let’s push a bit beyond the boundaries of standard high school academics and introductory college physics curriculum.  Let’s dive into a topic that demonstrates the beauty and occasional counter-intuitive strangeness of modern physics: quantum mechanics! As a physics tutor and enthusiast, I came across this article recently, and thought ...
Tips from a Physics Tutor: Geometric Intuition, Part II - Symmetry
Welcome back to our series of posts of using our physical intuition in E+M!  We’re focusing today on how you can easily intuit the direction of an electric or magnetic field created by some arrangement of charges or magnetic fields.  This skill, of looking at a problem and using logic and physical reasoning to figure out with a good deal of ...
Tips from a Physics Tutor: Geometric Intuition, Part I - Vectors
Welcome back to our series of posts on building your physical intuition for E+M!  In this series, we’ve looked at some physical reasoning behind Coulomb’s law, imagining point charges as radiating electric field, and saw that the Biot-Savart law gives an analogous result for magnetic fields.  We then took the intuition that we’d developed for ...
The Intuitive Approach: A Personal Story from a Physics Tutor
In these blog posts, I aim to present techniques that will help you generally excel in your physics courses and exams, regardless whether you are taking your first high school physics class or your second semester of graduate-level quantum mechanics.  With that goal in mind, we’ve explored ways you can breeze through the math on your homework ...
Physics Tutor: Doing the Experiment - 3 Simple Rules for Uncertainty
Welcome to the last post in our series on experimental error! As a physics tutor, I walk you through the experiental process and explore the traps that might lead you down the wrong path. Over the last several posts, we’ve explored the concepts of accuracy and precision of a measurement, averaging out the noise inherent in your measurement, and ...
Physics Tutor: Doing the Experiment, Part 2 - Dealing with Noise
Every measurement in your physics experiment will have some noise.  How can we measure it, and what can we do to deal with it? Welcome back to the series of posts on experimental error!  In the first post, we began to explore some of the ways even a fairly simple experiment is prone to unavoidable experimental error.  In this post, we will outline ...
Putting Your Physical Intuition to Work
As an overarching theme, I’ve tried to stress that there is more to studying physics than slogging through the math.  Instead of treating a problem as a series of dry mathematical manipulations, a sequence of numbers that, when punched into the calculator in the correct order, will yield your answer, we should always try to think about the ...
Tips from a Biology Tutor in Cambridge: Taking science tests
We all know that science tests can be challenging. Not only is the content broad and sometimes difficult to master, but the tests themselves can be tricky and confusing. How many of you have run out of time because you got stuck on one confusing question that was probably low yield? Science tests are also notorious for having poorly articulated ...