--- title: "Simulations you run yourself | DuckyHelper" url: "https://duckyhelper.com/features/simulations/" description: "Ask DuckyHelper to show you how a pendulum, a projectile or a circuit works and get a small sandbox to run yourself: drag, change a slider, read the numbers." updated: "2026-10-09" --- Mac app # Simulations you run yourself Some things you have to see move. Ask DuckyHelper to show you how a pendulum works and you get a small sandbox, not a video: pull the ball, let it go, drag the length slider and watch the period change. Pendulums, projectiles, circuits, sound waves and more, in the Mac pill or on Eddy's desk, with the numbers right there. [Download for Mac](https://duckyhelper.com/download/)[Get the Mac app](https://duckyhelper.com/download/) Pull it, let go ## Change one thing. Watch what happens. Say show me how a pendulum works. A sandbox opens with the pendulum, its sliders and its numbers: length, gravity, damping, start angle, the period it swings with. Drag the ball and let go. Make the string longer and it swings slower. Ask for a change, like now try it on the Moon, and Ducky sets it up and explains what you see. [Guide: Try it: simulations](https://docs.duckyhelper.com/study/simulations/) Ask what if What if the string were four times longer? Try it, then ask why it happened. The numbers are live Every number on the sandbox updates as you drag, so you can test a rule yourself. In Eddy ## On Eddy's desk, in the Eddy tab. Eddy opens the same kind of sandbox on its desk. Ask how sound travels and you get the air particles bunching up and spreading out between a speaker and an ear, with sliders for pitch and loudness and buttons for air, water and steel. What you can try ## Throw it. Swing it. Wire it. Each sandbox is small on purpose: one idea, a few things to change, and the numbers that show you the rule. ### Projectiles Change how it is thrown and see where it lands. ### Pendulums Length, gravity and start angle against the period. ### Circuits A battery and a resistor, with the current worked out as you change them. ### Waves and sound Pitch, loudness and what the sound travels through. Wire it ## I = V / R, while you drag. In a circuit sandbox, change the resistance and watch the current change with it, worked out with I = V / R. A rule you watched happen is easier to remember than one you copied. ## Ask to see it. Then run it. How a simulation lesson goes. 1. 1. Ask show me Show me how a pendulum works, on a Mac or in Eddy. 2. 2. A sandbox opens With the thing itself, its sliders and its numbers. 3. 3. Play with it Drag, slide, let go. Ask what if. 4. 4. Ask why Ducky explains what you saw, and you try the next change. ## Learn it by doing it. Trying something and seeing the result teaches more than reading about it, because you are the one making the prediction. Every simulation in DuckyHelper is a small experiment you run. The learning science behind it: [Keep the learner doing, not watching](https://duckyhelper.com/research/principles/active-learning/). Physics Chemistry Math [Physics with DuckyHelper](https://duckyhelper.com/subjects/physics/) ## How to use it ## Frequently asked questions ### Can I get an interactive physics simulation explained to me? Yes. Ask DuckyHelper to show you how a pendulum, a projectile or a circuit works and a small sandbox opens: drag the ball, move the sliders, read the numbers, while Ducky or Eddy explains what you see and asks what you think will happen next. ### How does a pendulum simulation help me understand the period? In the pendulum sandbox, drag the length slider and watch the period: a longer string swings slower. Change gravity, try the Moon, and see it slow down again. You find out what the period depends on, and what it does not, by changing one thing at a time. ### Which simulations are there? Pendulums, projectiles, circuits and sound waves, and more as you ask: Ducky picks a sandbox that fits your question. Each one is small, one idea with a few things to change and the numbers that show the rule. ### Do simulations work on a Chromebook? Not right now: DuckyHelper is a Mac app (macOS 14 or later, Apple silicon). There is no Chromebook or web version. On a Mac, Eddy opens simulations on its desk in the Eddy tab, and they also open in the pill over whatever you are working on. ### Are the simulations accurate? They are small models built to show one rule clearly, like how the length of a string sets a pendulum's period. They are for building your understanding: for a lab, use one to make a prediction, then check it against your own measurements. ## More features ### Ask out loud and hear the answer: press fn on a Mac, or talk to Eddy in the app's Eddy tab Ask DuckyHelper out loud and it answers out loud while it shows you the steps. On your Mac, press fn in any app, or talk to Eddy in its tab. ### Write your working and get it checked line by line, or answer a quick check on Eddy's whiteboard Write your working and DuckyHelper checks it: the first wrong line marked with why on a Mac, and Eddy's whiteboard for a quick drawing or check. ### Say quiz me: tap, type math or answer true or false, and every miss comes with why Say quiz me and DuckyHelper writes a quick quiz on what you are learning: tap, type math or answer true or false, and every miss comes with why. ### Worked steps, one move each, that you can keep, and graphs you can hover, zoom and slide Ask DuckyHelper to work it out and get worked steps, one move each, plus graphs you can hover, zoom and change with sliders. Keep the steps as a note. ### It asks back and gives the next hint before an answer, so you do the thinking DuckyHelper asks back and gives the next hint before it gives an answer, so you do the thinking. Why that matters, and how it works on a Mac and in Eddy. ### Run your code against tests, then watch it step by step with every variable as it changes DuckyHelper runs your code against tests and plays it back step by step, every variable as it changes, so you see why it gives the wrong answer. ## Keep reading ### Physics: simulations you can play with and every step worked through An AI physics tutor that shows the why: simulations you can play with, forces drawn out, worked steps with real numbers. In the DuckyHelper Mac app. ### Chemistry: see the atoms, then work the equations step by step An AI chemistry tutor that shows what atoms are doing: labelled pictures of bonds, steps for every equation, quizzes and flashcards. In the DuckyHelper Mac app. ### Every DuckyHelper feature: what it does, where it runs, and a short film of each What DuckyHelper for Mac does: Eddy teaches out loud on a blackboard, and Ducky sees your screen, draws on it and walks you through your own apps. ## Run your first experiment Press fn on your Mac, or open the Eddy tab, and say show me how a pendulum works. [Download for Mac](https://duckyhelper.com/download/) [See what it does](https://duckyhelper.com/features/) The Mac app needs Apple silicon and macOS 14 Sonoma or later. There is no Chromebook, Windows or web version right now.