The world's most positive way to learn physics and chemistry.

We built a curriculum of over 3000 questions and 300 instructional videos out of my classroom in a South Memphis high school. The site is designed to replace a traditional textbook and make learning engaging for students of all background. It also saves time for teachers so they can focus on their students. Checkout this 1-minute video to learn more.

Questions or feedback? Please reach out to me anytime at I always write back.

Physics Problems in Action

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Please contact Jack Replinger with questions or to request a quote.
District pricing available by request.
We're working with The Physics Classroom and Flipping Physics . Check out how we're aligned .

Our Platform & Strategy

Example Student Problem View

Immediate Feedback for Student

Students can check their answers at anytime to ensure that they are practicing correctly. Students love seeing their correct answers turn green and can quickly identify and correct their errors.

Efficient Tracking & Grading for Teachers

The student scores page on our teacher account saves teachers countless hours of grading. In addition, teachers can track each student''s progress in real-time and see if there are specific skills or problems where students need more guidance.
Example Teacher Dashboard
Free body diagrams, accelaration, movement, collisions, circuits, and sound.

3000 problems including covering:

AP Physics 1 fundamentals, NGSS inquiry activities, & Conceptual Physics
Positive Physics includes multiple units on forces and motion as well as units on torque, momentum, energy, springs & oscillations, universal gravitation, waves, light, electrostatics, magnetism and electricity. Each unit includes an NGSS-aligned inquiry activity for each unit.

Traditional Problems Broken Down into Accessible Modules

Within each unit, students master individual skills to gain confidence before applying them to traditional physics problems.
Breaking Down Problems Into Accessible Modeles: ensures all students master the material.
iPads showing different numbers for each student as each student gets their own numbers and cannot copy work from others.

Different Problems for Every Student

Our random number generator ensures that each student receives different numbers in their problems and our random assessment generator provides a different assessment for each student. Our random assessment generator also allows teachers to easily provide retakes.

Award-winning platform designed for physics learners of any background

Teacher Reviews

Our Team & Our Story

Jack Replinger picture
Jack Replinger
Co-Founder, CEO & Content Creator
2020 Oxford University Skoll Scholar
2020 TFA National Social Innovation Award Finalist
2018 TFA-Memphis Alumni Leadership Award Winner
2015 Tennessee Charter School Teacher of the Year
Anthony Fizer picture
Anthony Fizer
Co-Founder & CTO
2020 Rhodes College Featured Black Entrepreneur
2019 Shelby County Commissioners' Impact Award
Soulsville Students Working on Laptops
Soulsville Students
Chiefs of Inspiration & Quality Control
During my second year of teaching, I was watching my class struggle through their midterm exam. It was one of the lowest points of my teaching career, but it would turn out to be one of the most inspirational. DeMarcus, lacking a strong foundation in mathematics, had made an error manipulating an equation; Raven was stuck on the third step of a problem, the step which always seemed to give her trouble; and Josh was just staring at the wall, averting his eyes from the paper, completely intimidated by the words and numbers on the test. My students were frustrated because they desperately wanted to be successful and they could not succeed at solving the problems. And at that moment it hit me, the failure was really my own.
By relying so heavily on long example problems and algebraic formulas as is done in the traditional approach to teaching physics, I was making physics inaccessible to too many of my students who came to me grade levels behind in math and reading. Worst of all, even those students who scored well on the exam, had not understood the larger picture—namely, how the process of solving the problem was a demonstration of a conceptual principle of physics, and they had not experienced any of the wonder and joy of learning physics.
So I started over, because I was determined that any student who sat in my physics class could learn and love physics. Over the last decade, through many trials and with the help and patience of my amazing students and co-workers, I developed a curriculum, I call Positive Physics. After seeing how successful my students were, I decided that this needed to become a website, so students could interact with the curriculum and I could share it with others. At first, everyone I spoke to said that I could not make this happen without a large team and immense financial resources. However, after a pick-up basketball game, I happened to share my story with my friend and incredibly talented developer, Anthony Fizer, and he said he believed we could make this happen ourselves. Less than three months later, my students were testing the first version of
The website that you are using has been revised and edited countless times based on feedback from my students and the amazing teachers who have tested the site. We hope that it helps you have a positive experience learning and teaching physics.

- Jack

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