HARAKU vs Motion Physics Gallery

HARAKU is an interactive educational app that visualizes the physics of waves in real time. Designed for students, teachers and anyone curious about science, it lets you control how waves behave just by moving sliders, so you can intuitively connect the equations with what you see. Developer: Fuji Bit Inc. HARAKU is the waves edition of the "-raku" physics simulation series. It helps you understand the wave concepts taught in middle school, high school and university physics as moving pictures, not just formulas. 12 simulations in 3 categories: - Wave basics - Superposition: Combine two sine waves and watch them reinforce or cancel. Change the amplitude, frequency and phase of each wave independently to see the principle of superposition. - Reflection: See the moment a traveling wave reflects at a boundary. Switch between a fixed end (phase inverts) and a free end (phase is kept), with the incident, reflected and total waves shown in three layers. - Standing waves: Watch standing waves on a string fixed at both ends while changing the harmonic. Check the positions of nodes and antinodes and the effect of tension and damping. - Fourier synthesis: See how square, triangle and sawtooth waves are made of sine waves (harmonics). The more terms you add, the closer the sum gets to the target waveform. - Sound waves - Beats: Overlap two waves with slightly different frequencies and feel the beats. The envelope clearly shows how the amplitude changes. - Doppler effect: Drag the source and see the wavefronts bunch up in front and spread out behind. Go past Mach 1 to create a shock wave. - Air column resonance (new): Switch between closed and open pipes and change the length, air temperature and resonance number to see the resonant frequency and wavelength. The motion of air particles (a longitudinal wave) is shown next to a graph that draws the displacement as a transverse wave, so you can find the nodes and antinodes. - Waves in a plane & light - 2D ripples: Tap the screen to place sources; a numerical solution of the wave equation draws the interference pattern in real time. - Interference: See the lines of reinforcement and cancellation made by two point sources. The fringe spacing changes with the source separation, frequency and speed. - Diffraction: See waves spread through a slit according to Huygens' principle. The ratio of slit width to wavelength changes how strongly they diffract. - Refraction: Visualize Snell's law, including how waves bend at a boundary and total internal reflection at large angles. - Thin-film interference (new): See why soap films and oil slicks shine in color by changing the film thickness, refractive index, angle and what lies below (air or glass). The phase shift on reflection, the color seen under white light, a color-vs-thickness strip and a reflectance-vs-wavelength graph are shown together. Features: - Clean, easy-to-read design (dark and light themes) - Home screen organized by category - Intuitive parameter sliders: touch, try and understand - An explanation sheet with formulas for every simulation - On iPad in landscape, the canvas and control panel are shown side by side - 16 languages (Japanese, English, Chinese Simplified/Traditional, Korean, Spanish, Portuguese (Brazil), German, French, Hindi, Indonesian, Russian, Italian, Turkish, Thai, Vietnamese), following your device language - No sign-in: start exploring right away Price: - Free - In-app purchases: none - Subscriptions: none - Ads: a banner ad by Pangle at the bottom of the screen

Motion Physics Gallery is a collection of interactive physics simulations. The app interface and learning explanations are in Japanese. Change height, gravity, mass, speed, angle, wavelength, focal length or voltage, then tap GO. Run A and B together to observe how changing one condition affects the result while keeping the other conditions shared. 11 INTERACTIVE EXHIBITS - Motion under gravity: falling, upward throws, horizontal and angled launches, and air resistance. - Pendulum: length, gravity, amplitude and period. - Collisions: mass, velocity and motion before and after a collision. - Levers: the fulcrum, lever arms and balance of forces. - Buoyancy: object and liquid density, floating and sinking. - Wave superposition: two waves and their combined wave. - Standing waves: string length, frequency, nodes and antinodes. - Doppler effect: a moving sound source and changes in observed pitch. - Reflection and refraction: angle of incidence, refractive index and total internal reflection. - Lenses: converging and diverging lenses, focus, images and two-lens setups. - Electric circuits: voltage, resistance, current and bulb brightness. CHANGE, RUN AND COMPARE - Compare A and B with one selected condition changed. - Start synchronized animations with GO. - Adjust sliders. Selected experiments also let you drag objects or controls directly in the experiment area. - Observe motion using time-spaced images, vectors and scales. - In Motion under Gravity, switch between 2D and a 3D view that you can rotate and zoom. - In Doppler Effect, compare the source tone with the observed tone. - Animated tutorials demonstrate how to use the experiments. Each exhibit uses a simplified educational model, with its assumptions explained in the app. The models do not reproduce every real-world effect of friction, shape or the environment. The experiments run on your device and can be used offline. No account registration or ads. LANGUAGE The app interface and learning explanations are in Japanese. This store listing is provided in English.