# Interactive Physics Simulations

## (HTML and Java)

### Does the above simulation run? If it does, sure you can open the following Html5 simulations too.

 Vector Addition 矢量加法 One would learn how vector addition be done within seconds.

 Newton's first law of motion (inertia) 牛頓運動第一定律(慣性) A thought experiment is performed under Newton's apple tree.

 Analyzing uniformly accelerated motion 分析勻加速運動 By exploiting the scenario of a car race, the uniformly accelerated motion is brought into discussion.

 Projectile Motion 拋物體運動 The horizontal and vertical motions in a projectile are, respectively, a motion of constant velocity and a motion exactly the same as a free fall.

 Spring-mass Oscillator 彈簧-質量諧振 It underlines the connection between shm and circular motion. The three kinematic graphs (x-t, v-t and a-t) of shm are plotted.

 Two-body Motion 二體運動 Besides the real gravitational force, some hypothetical ones (force proportional to r, proportional to 1/r) are taken as possible options in the two-body interaction.

 Types of Waves 橫波與縱波，行波與駐波 It gives a visual comparison between transverse and longitudinal waves, traveling and standing waves.

 Longitudinal Traveling Wave 縱 行 波 Features are: (i) Color is lightened in rarefactions (ii) Displacement-time graphs at some selected points along the wave are plotted.

 Interference of Water Waves 水波干涉 A noteworthy feature is a probe (the red dot) placed on the water surface. The probe responses to the amplitude of surface oscillation at its location. If it situates at a position of constructive (destructive) interference, the light bulb will flash at full brightness (go off).

 Diffraction of Water Waves (Opening) 水波衍射(縫隙) By adjusting the wavelength and the size of the slit, one realizes how these changes affect the diffraction pattern.

 Generating Standing Waves on String (Resonance) 弦線上產生駐波(共振過程) Resonance occurs (a standing wave is formed) when the driving frequency matches with one of the natural frequencies of the system, i.e., the condition of forming a standing wave is satisfied.

 Generalized Lissajous Figures 廣義利薩如圖形 The conventional Lissajous figures are those with x and y coordinates varying according to two sinusoidal waveforms of different frequencies and phases. We introduce a little more complexity by raising the two numbers to some positive integral powers.

 Electromagnetic Induction (Motional emf) 電磁感應(動生電動勢) Whenever a metal rod cuts across a magnetic field, an emf will be induced. When this rod is a part of a complete circuit, an induced current will flow. This induced current, together with the magnetic field, will next produce a magnetic force on the moving rod. This magnetic force, according to Lenz's law, must be .........

 RLC Series AC circuit RLC 串聯交流電路 The very core relevant concepts are incorporated in this simulation. It has been found helpful for teachers to explain and students to understand.

#### Java Simulations

 Author and Copyright: Chiu-king Ng Feedback/Contact: feedbackXY@phy.hk, where XY is the prime number following 23 Mirror Site: http://phy.hk Last Update: 14-9-2017