物楽

BUTURAKU is a simulation app that lets you enjoy physical phenomena with real-time animations.

You can intuitively understand the laws of physics with beautiful visuals. Freely change parameters with sliders and observe the changes in physical phenomena in real time.

12 types of simulations:

【Translational Motion】

- Free Fall: Observe the effects of gravity and air resistance. Tap to add a ball, swipe to throw it.

- Projectile Motion: Adjust the launch angle, initial velocity, and air resistance to observe parabolic motion.

- Inclined Plane: Motion on an inclined plane with friction. Experience the conditions for sliding by adjusting the angle and coefficient of friction.

- Brachistochrone: A simultaneous descent race using three orbits: a straight line, a circular arc, and a cycloid. Experience Bernoulli's classical problem from 1696; the cycloid is the fastest.

- Conservation of Mechanical Energy: Observe the exchange of kinetic and potential energy with a ball rolling on a coaster. Adding friction visualizes the dissipation into thermal energy. - Elastic Collision: 2D collision based on conservation of momentum and kinetic energy. Supports momentum vector display.

[Oscillation/Periodic]

- Pendulum: High-precision reproduction of a nonlinear pendulum using the RK4 method. Set the angle by dragging.

- Double Pendulum: A coupled pendulum that generates chaotic motion. Lagrangian mechanics + RK4 method.

- Coupled Pendulum: Two pendulums connected by a spring. Observe the "beat" phenomenon where energy is transferred from side to side.

- Spring: Simple harmonic motion according to Hooke's Law. Adjustable spring constant, damping, and mass.

- Circular Motion: Uniform circular motion. Visualize the velocity vector and centripetal force (F=mω²r) by changing the radius, angular velocity, and mass.

[Waves]

- Waves: Place wave sources by tapping and observe interference patterns. Numerical analysis of 2D wave equations using the finite difference method.

【Features】

- Real-time physics simulation
- Intuitive touch controls
- Freely adjust parameters with sliders
- Includes physics explanations for each simulation
- Supports dark/light themes
- Supports Japanese and English