What is Physics?
Physics is often described as the "fundamental science" because it explains the core principles that govern the universe. Whether it’s understanding how the planets move or why your phone screen works, physics provides answers to how and why things happen.
The Definition of Physics
Physics is the study of matter, energy, and the forces that shape the universe. It helps us understand how things move, interact, and change under different conditions. Here are some core ideas:
Newton's Laws of Motion Made Simple
The three laws of motion, formulated by Sir Isaac Newton in 1687, lay the groundwork for classical mechanics, a branch of physics that explains the behavior of physical objects. Newton’s Philosophiæ Naturalis Principia Mathematica introduced these laws, which continue to be fundamental to our understanding of motion.
First Law (Law of Inertia): “An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.” In other words, objects stay at rest or in motion unless acted on by an outside force. Example: A soccer ball won’t move until you kick it.
Second Law (Law of Acceleration): “The acceleration of an object depends on the mass of the object and the amount of force applied.” Formula: F = ma (force equals mass times acceleration). This law explains that heavier objects (greater mass) require more force to achieve the same acceleration as lighter objects. It’s why pushing a heavy cart takes more effort than pushing a light one.
Third Law (Action and Reaction): "For every action, there is an equal and opposite reaction". This means that whenever one object exerts a force on another, the second object exerts an equal but opposite force back on the first. For instance, when you jump off a boat, you push down on the boat with your legs, and the boat pushes you upward and forward with an equal force in the opposite direction, causing you to jump out of the boat.
These three laws form the cornerstone of classical mechanics, explaining motion and the interactions between objects. Newton's contributions are used every day in engineering, aerospace, and everyday mechanics.
Key Physics Concepts to Know
Energy and Conservation Laws: Energy can’t be created or destroyed, only transformed (like turning electricity into light in a bulb).
Gravity: The force that keeps us grounded and governs planetary orbits.
Electromagnetism: How electricity and magnetism work together, powering everything from phones to lights.
Waves and Oscillations: The study of sound, light, and other waves that transfer energy.
Thermodynamics and Heat: Explains how heat and energy interact, essential for understanding engines and climate science.
Quantum Mechanics: Investigates how particles behave on a microscopic scale, leading to advancements in computing and nanotechnology.
Exploring Different Areas of Physics
Physics has various branches, each focusing on different aspects of the physical world. Here are some of the main branches of physics:
Classical Mechanics studies how objects move and interact with forces.
Thermodynamics studies heat, energy, and the transformations they undergo, governed by the principles called the Laws of Thermodynamics. This branch explains how energy flows, transfers, and changes, affecting everything from engines and power plants to the weather.
Electromagnetism studies electric and magnetic fields and how they interact with charged particles.
Optics explores how light behaves. For example, it researches reflections, refractions, and how light is used in cameras, fiber optics, and lasers.
Quantum Mechanics investigates the behavior of particles at the atomic and subatomic levels. Unlike classical mechanics, quantum mechanics reveals a world where particles can exist in multiple states simultaneously.
Relativity is two related theories developed by world-famous physicist Albert Einstein. His theories fundamentally reshaped our understanding of space, time and gravity.
Special relativity explains the relationship between space, time, mass, and energy for objects moving at constant speed– you may have heard of the classic equation E = mc^2, which ultimately explains that mass and energy are interchangeable.
General Relativity builds on this by explaining how gravity works: instead of a force, gravity is a curvature of spacetime caused by massive objects, altering the paths that objects travel through space. Relativity is essential for fields like astrophysics, allowing scientists to predict the movement of stars, understand black holes, and explore the structure of the universe.
Real-World Applications of Physics
Physics plays a role in nearly every aspect of our lives, from powering our homes to advancing medical technology. Here are just a few ways it shapes our world:
Space Exploration: From launching satellites to studying black holes, physics fuels our curiosity about the cosmos.
Transportation: Helps design safer, more efficient cars, planes, and trains.
Medicine: Physics led to tools like X-rays, MRIs, and radiation treatments that save lives.
Technology: Smartphones, laptops, and drones all rely on principles of physics.
Energy: Physics drives renewable energy solutions like solar panels and wind turbines.
Careers in Physics
A foundation in physics can lead to diverse and exciting career paths. Whether you’re interested in engineering, healthcare, or environmental science, a physics degree opens doors to numerous opportunities. Here are a few career possibilities:
Engineer: Applies physics to design and build everything from electronics to infrastructure.
Physicist: Studies the fundamental laws of nature, often specializing in research.
Medical Physicist: Uses physics principles to improve medical imaging and treatments.
Astrophysicist: Investigates the properties and behaviors of celestial objects.
The Top 5 Most Famous Physicists
Physics owes much of its progress to some truly brilliant minds—people whose discoveries have completely transformed how we see and understand the universe. Here’s a look at five legendary physicists and the groundbreaking work that made them famous:
Albert Einstein (1879–1955): Einstein is best known for his theory of relativity, which includes the famous equation E=mc². His ideas reshaped our understanding of space, time, and energy, and paved the way for modern physics. He also won the Nobel Prize in Physics in 1921 for his work on the photoelectric effect, which was a key step in developing quantum theory.
Isaac Newton (1643–1727): Newton’s three laws of motion are the foundation of classical mechanics, and his work on gravity (including the story of the apple falling from the tree) remains iconic. He also invented calculus and made groundbreaking contributions to optics and mathematics. Newton’s work is still taught in physics and math classes worldwide.
Marie Curie (1867–1934): Marie Curie was the first woman to win a Nobel Prize and the only person to win Nobel Prizes in two different sciences (Physics in 1903 and Chemistry in 1911). She discovered the radioactive elements polonium and radium, and her research on radioactivity laid the groundwork for medical treatments like X-rays.
Galileo Galilei (1564–1642): Known as the "Father of Modern Science," Galileo used telescopes to observe celestial bodies and supported the idea that the Earth orbits the Sun—a controversial view at the time. His work in astronomy, kinematics, and physics helped kickstart the scientific revolution.
Nikola Tesla (1856–1943): Tesla is celebrated for his pioneering work with electricity, particularly alternating current (AC), which powers most of the world today. His inventions and ideas contributed to technologies like radio, wireless communication, and electric motors. Tesla’s visionary thinking made him a legend in both physics and engineering.
These physicists proved that with curiosity and determination, there’s no limit to what you can discover through physics. While you might not be calculating relativity or inventing groundbreaking technologies just yet, building a strong foundational knowledge of physics can help you at least ace your test.
Get Started on Studying Physics with UPchieve
Struggling with forces, motion, and all those tricky equations? Close your physics textbook or homework app, log on to UPchieve, and connect with a Physics tutor in minutes.
Our expert online tutors are available 24/7 to help you understand assignments and boost your grades. Get the personalized help you need to master physics concepts and excel!
Physics FAQs
Can UPchieve’s tutors help with my physics homework?
Yes! UPchieve’s tutors can guide you through physics topics, whether it’s for homework, quizzes, or exams.
What topics can my physics tutor cover?
UPchieve’s physics tutors can help you with any basic physics, Physics 1, or AP Physics problems you’re stuck on. If you don’t see the subject you need help with, you can request help and see if your coach can support you (for example, if we offer Physics I, but you need help with Physics 2).
Can I find a physics tutor near me?
Absolutely! UPchieve’s tutors are fully online, so you can connect with an expert from anywhere in the U.S. No need to search for “chemistry tutors near me”—we’re always available, 24/7.
Is physics tutoring really free?
100% free! UPchieve makes free online physics tutoring available to low-income middle and high school students, thanks to contributions from individuals and organizations who support our mission to democratize academic support.
When are UPchieve’s physics tutors available?
With our physics tutor service, you can connect with an experienced tutor 24/7. We know that students often need help outside of school hours, so our physics tutors are available around the clock.
Can I get help with physics homework?
Absolutely! Doing homework is the best way to retain the information you’ve been taught because you’re putting that knowledge into motion. Our homework helpers can help you get started and finish strong, completely free for students in 6th-12th grades.
How do I find a private physics tutor online?
Step 1: Create an UPchieve account. Step 2: Choose a physics study topic and connect with a private physics tutor in under 5-10 minutes. Step 3: Use the virtual chat and document editor to communicate with your physics instructor. Head over to our Student FAQs for more info!