Intro to Physics
About this free Intro to Physics course
Intro to Physics is a free introductory physics course that starts where every physics class begins: motion. Physics explains everything from the tiniest particles to the vastness of space, and kinematics, the study of how objects move, is the foundation for all of it. Through 22 short video lessons, you'll learn how physicists describe where an object is, how fast it's going, and how its motion changes over time.
The course focuses on the language and graphs of physics and on why things fall the way they do. Once you can read a position-time graph and understand what its slope and the area under the curve mean, you're ready to think like a physicist: ask big questions and solve real problems with the tools of science.
Who this course is for
This course is for high school students in grades 9 through 11 taking their first physics class, including AP Physics 1, and for curious middle schoolers with strong math skills. You should be comfortable with Algebra 1, especially slope and linear equations.
Course outline
- Scalars and vectors. The difference between scalar and vector quantities and why direction matters.
- Measuring change. How physicists measure change, rates of change, and average vs. instantaneous rates.
- Physics notation. How symbols, subscripts, and the delta notation are used in equations.
- Kinematic quantities. Position, displacement, distance, velocity, speed, and acceleration.
- Position-time graphs. Linear and parabolic position-time graphs and what their shapes tell you.
- Kinematic graphs. Velocity-time and acceleration-time graphs, slopes of linear graphs, and why the area under the curve matters.
- Gravity and free fall. How gravity accelerates falling objects, and using slope and area to solve motion problems.
What you'll learn
- Distinguish scalar and vector quantities
- Define and calculate displacement, velocity, and acceleration
- Read and sketch position-, velocity-, and acceleration-time graphs
- Use slope and area under a curve to move between kinematic graphs
- Solve basic free-fall problems
How long it takes
The 22 videos add up to about 40 minutes, but you'll learn the most by pausing to sketch graphs and work examples. Plan on about 8 hours in total, including practice problems.
Frequently asked questions about Intro to Physics
Is Intro to Physics really free?
Yes. Intro to Physics is completely free, with no fees, subscriptions, or account required. STEM for Others is a 501(c)(3) nonprofit, and every course in our curriculum library is free for students, families, and teachers.
Does this course help with AP Physics 1?
Yes. Kinematics is the first unit of AP Physics 1, and graph interpretation shows up throughout the exam. These lessons are a strong foundation or a quick review.
How do I start the course?
Start with the first lesson in the video series on this page, then pause to work through each example yourself. Every lesson is short, so you can fit one into a study break.
Do I get a certificate?
The self-paced Intro to Physics materials don't include an official certificate. If you're taking the course through a STEM for Others chapter program, ask your chapter leader about recognizing your completion.
Can teachers and clubs use this curriculum?
Yes. Teachers, homeschool families, libraries, and after-school clubs are welcome to use the Intro to Physics materials with their students at no cost. STEM for Others volunteers also teach our curriculum in partner schools and libraries. You can find a chapter near you or start one at your school.
Related free courses
Related free webinar
Watch NASA Exoplanets, a free STEM for Others webinar, to explore how scientists find planets around other stars. Browse all free STEM webinars.
