For Cambridge IGCSE, GCSE, AP Physics 1, NGSS and more

Physics you can run.
Exams you can pass.

Physics taught with three of the best-proven methods in learning science. Free to begin for every student, teacher and curious mind.

Orbital motion
One of 216 lessons across 10 modules. In every lesson you set the variables yourself and watch the physics respond.
How Physiworld Works

See it before the formula

Every lesson starts with a question: what happens if you double the mass? You predict, run the simulation and see if you were right. By the time F = ma appears, it describes something you have already watched happen — so in the exam you can picture the problem, not just remember a line.

Five minutes is enough

Most lessons take about five minutes, so one fits between homework, on the bus or before bed. Your progress is saved to your account, on your phone and your laptop, and Learn always has your next lesson ready.

Every answer explained

Quiz questions are written like the ones on your exam, and every answer, right or wrong, comes back with the full worked solution set out the way an examiner expects. You find out why, not just whether, you were wrong.

Free, without a catch

Every lesson, simulation and unit quiz is free with an account: no card, no time limit and no ads. Physi+ adds extra exam practice for when your exam gets close, but you never need it to learn the course.

What people say about physiworld

Physics that finally makes sense

For anyone curious about physics, students and teachers included

“The interactive explanations make things much easier to visualise.”

Student, Year 11

“Physics started making a lot more sense when I stopped just memorising equations…”

AP Physics 1 Student

“I find the explanations easier to follow than some of the resources I’ve used before.”

IGCSE Physics Student

“Some physics topics are difficult to imagine, but seeing them visually helps everything click.”

Year 10 Student

“The visual elements make learning more enjoyable.”

IGCSE Student

“Visual learning is incredibly important in physics.”

Secondary School Physics Teacher

“It’s encouraging to see my child engaging with physics outside school.”

Parent of a GCSE Student

“Being able to change variables and immediately see what happens makes physics feel much less abstract.”

IGCSE Physics Student

“Really useful for revising difficult topics.”

GCSE Student

“It makes studying feel more engaging and less repetitive.”

AP Physics Student

“A great supplementary resource for physics.”

AP Physics C Student

“Sometimes seeing the same concept presented differently is all it takes.”

GCSE Student

“I like the emphasis on making abstract concepts more accessible.”

Physics Educator

“I like the idea of a platform that combines clear explanations with interactive ways to explore science.”

Parent of an IGCSE Student
Pick your course

Walk into your exam genuinely ready

Your syllabus the way your exam board writes it: every point, the lesson that teaches it, the quiz that proves it, and your mastery on each. The maps are public, so open yours before you sign up.

Kelvin, your AI tutor

A tutor that makes you think, not copy

Ask anything in physics. Every answer follows the same three moves, and the last one is always yours.

If gravity pulls everything at the same rate, why does a feather fall slower than a hammer?

You askAnything, in your own words.

Gravity gives both the same acceleration. The difference is air resistance: the feather has a lot of surface for very little weight, so drag soon balances it. On the Moon, with no air, they land together.

1 · The idea firstPlain words before any formula.

Try this: a 2 kg ball falls and feels 5 N of drag. What is its acceleration?

2 · A question back to youReal numbers, real units, your turn.

Weight is 2 × 9.8 = 19.6 N. 19.6 − 5 = 14.6 N, so a = 14.6 ÷ 2 = 7.3 m/s².

You work it outNot Kelvin.

That’s it: resultant force first, then F = ma. As the ball speeds up the drag grows, so what happens to its acceleration?

3 · Checked, one step furtherYour answer confirmed, the next idea opened.
An example written to show how Kelvin answers. Not a real student’s chat.
Physiworld Challenges

Put your physics to the test

Exam-style problems that make you use a whole topic, not one formula. Each one has a worked solution, and most come in more versions to practise: the same problem with new numbers.

10modules
350+practice versions
Featured challengeEasy

Free Fall from a Cliff

Dynamics · Kinematics · equations of motion

A ball is dropped from rest from a 20 m cliff. How long does it take to reach the ground, and how fast is it moving when it does?

10 versions of this one: solve it, then try it again with new numbers.
Pricing

Learn for free. Pass with Physi+.

Every lesson, simulation and unit quiz is free. Physi+ adds the exam practice: mock exams, theory papers, and Kelvin marking your written answers.

Free

Learn the whole course
0EURforever
  • Every lesson and simulation
  • Every unit quiz and a sample mock
  • Ask Kelvin every day
Start learning free
Best for your exam

Exam pass

For this exam season
29EURone-time
  • All of Physi+ until 31 July
  • Covers the May/June exams
  • One payment, nothing renews
Get the exam pass

Monthly

Try it first, stop anytime
5.99EUR/ month
  • All of Physi+, month by month
  • 14 days free
  • Cancel anytime
Start 14 days free

Lifetime

No exam, or several ahead
59EURone-time
  • All of Physi+, with no end date
  • One payment
  • Every future exam covered
Get Physi+ Lifetime

Secure checkout with Stripe 14-day refund policy on every plan No lock-in

The Physiworld Calculator

Solve any physics equation, instantly

Type a calculation and press enter — the free calculator solves it with full step-by-step working. No sign-up required.

39 physics formulas
Kinematics, energy, waves, electricity and more — ready to drop in.
Step-by-step working
Every answer shows the full method, not just the final number.
No sign-up needed
Type any expression and get an instant answer.
Open the calculator

What do you want to calculate?

Your calculation

Press Enter to solve on the full calculator

Physiworld For Educators

The teacher console in 6 steps

How students join

Every class has its own six-character code. Students use it once; from then on their lessons and quizzes count for your class.

  1. You create a class

    Name it on your Profile or in the teacher console. You get the class code and a join link.

  2. Students enter the code

    Write it on the board: they tap Join with code on their Profile and type it in. Or send the link, which joins them on its own.

  3. They’re in the class

    A new student first makes a free account, with Google or an email. You only ever see the username they chose.

See what every student understood

How the teacher console works, step by step. Students join your class once with a code; after that, the lessons and quizzes they already do fill the console in. Built for IGCSE, GCSE, AP Physics and NGSS.

Free for every teacher: creating classes, the join code and teacher view on the projector. Class mastery, assignment results, live lessons and reports come with a school licence: one per school and school year, priced per school, with a 14-day trial.

Rolling out class codes across a department or want a walkthrough? Email us — we’ll help you set it up.

Right now on Physiworld

Physics is better together

Physiworld is a place to learn physics with people you know: your class, your friends, and everyone else working through the same problems. No public rankings, just a goal you reach together.

Weekly goal · resets every Monday
—to orbit

Orbit is this week’s goal. Every lesson, quiz and challenge anyone finishes lifts the rocket.

Resets Monday
All-time activity
500lessons finished
1,250quizzes taken
640 New!challenges solved
Frequently Asked Questions

Common questions

Find your part: for your exam, or for your class.

Physiworld

What it is and what it costs

What is Physiworld? +
Physiworld is an interactive way to master physics, for anyone who has ever wondered how the world works, whether or not there is an exam at the end of it. Ten modules, from Dynamics and Gravity to Optics, Electromagnetism, Nuclear Physics and Astrophysics, are built as units of short lessons, each around a simulation you run and change yourself. Units close with a quiz, every mistake comes back for review, and your mastery is tracked point by point against your syllabus.
Is Physiworld free to use? +
Yes, to learn. Every lesson, every simulation and every unit quiz is free with an account, and no card is asked for at any point. Review of your latest topic and asking Kelvin, the AI tutor, every day are free too.

Physi+ is the optional exam layer: 21 mock exams, 9 theory papers and 6 mixed sets, Kelvin marking your written answers against the mark scheme, review of every mistake in every topic, 300 questions a day to Kelvin, and the practice versions of every challenge.
What does Physi+ cost? +
The Physi+ exam pass is one payment of 29 EUR (29 USD, 25 GBP or 299 SEK) and is valid until 31 July, through the May/June exams. There is also a monthly plan and a lifetime option. Every price is on the public pricing page, so you can see it before you make an account.

If you're just starting

No background needed, whatever your course

Do I need to be good at physics or maths to start? +
No. You need to be curious, and that is the whole entry requirement. Every topic opens with a question you can answer from everyday life, such as why ships float or why the Moon does not fall down, and the maths arrives only once you already know what it is for. People start here having never passed a physics test in their life.
I'm not studying for an exam — is Physiworld still for me? +
Yes, and you are not an edge case. Adults who dropped physics at school, people who got curious after a documentary, students years away from an exam and teachers borrowing the simulations all learn here. Nothing is locked behind picking a syllabus: choose General physics when you start, open a lesson, and stop when you have had enough. Your progress is kept either way.

If you have an exam

IGCSE, GCSE, AP Physics 1, NGSS — or any other course

Does Physiworld cover IGCSE, GCSE, AP Physics 1 and NGSS? +
Each one has a public syllabus map that shows every point against the lesson that teaches it and, once you are signed in, your mastery on it. Cambridge IGCSE (0625) is mapped section by section, with questions tagged Core or Supplement. GCSE has one map for AQA, Edexcel and OCR, with each board's references, and it names what is not taught yet. AP Physics 1 is mapped unit by unit. NGSS is mapped too, but not every performance expectation is covered yet, and the map shows which ones are.
Physiworld is an independent study resource and is not affiliated with, endorsed by, or involved with Cambridge Assessment, AQA, Pearson Edexcel, OCR, the College Board or Achieve, Inc. AP® is a trademark of the College Board; NGSS® of Achieve, Inc.
My syllabus is none of those — can I still use Physiworld? +
Yes. Physiworld teaches physics, not one exam board’s version of it. Forces, energy, waves, circuits and the atom are the same physics in A-level, IB, a national curriculum or a first-year university course; what changes between syllabuses is the order, the depth and the section numbers.

Pick General physics when you start, open the topics your course covers, and every simulation, quiz and worked solution works exactly as it does for anyone else. What you will not get for an unlisted syllabus is a section-by-section map or questions tagged with its codes.

If you teach

Classes, codes and what you can see

Can teachers use Physiworld in the classroom? +
Yes, from the first year of high school to introductory college. Make a class and share one code: no approval step and nothing to install, and you only ever see the username each student picks. Open any lesson in teacher view and it unfolds fully unlocked on the projector.

A school licence adds the teacher console: a mastery grid, assignments with question-by-question results, live lessons with class votes, and reports. One licence covers every physics teacher at a school for the school year, priced per school, with a 14-day trial.

Open the walkthrough to try it with a sample class (nothing real, no card), or write to physiworld.team@gmail.com for a quote.
Where is the data, and who can see it? +
In the EU (AWS Frankfurt). A class is readable by the teacher who created it and nobody else. You see usernames, activity and answers for your own classes; email addresses, real names, passwords and device data are never shown to a teacher at all. Students can leave a class from their profile whenever they want. A data-processing agreement, and deletion on request, are both available from physiworld.team@gmail.com.

Your physics journey
starts in 10 seconds.

Start with one simulation. Stick around because it actually makes sense.

No credit card required  ·  Fast and easy account creation

Welcome back

Sign in to continue your journey

or
New here? Create account

By registering with Physiworld you agree to our Terms and Privacy Policy.

Signing in with Google…