Dynamic elements fall when the scene loads based on the angle and intensity of the scene gravity. 
Element Types
Inactive and Static Elements are anchored to their position.
By default, all elements are 'inactive' elements, which are not affected by Physics. Dynamic elements fall & accelerate based on the scene's gravity. Static elements form the boundaries through which dynamic elements will not pass. Inactive elements do not move with gravity nor form boundaries.  Dynamic Elements Follow the 'Scene Physics Gravity' intensity and angle.
Since dynamic elements react to boundaries, moving boundaries can create new movement in your document after the initial gravity simulation has run its course. Physics simulations continously run. Using Hype's standard animation tools you can bring physics elements to life.  Click Bounce to animate the position of the blue rectangle:
Loading a new scene starts the Main Timeline at 00:00.00, and also resets the physics simulation.
Reload Scene
Physics + Animation
In most cases, you’ll only set a single ‘Scene Physics Gravity’ value for your scene. For more advanced simulations, you can set multiple gravity forces in a single scene for different groups of elements by creating a symbol. All elements within that symbol will follow the defined force. 
Gravity Realms
This document demonstrates Physics concepts in Tumult Hype Professional so you can quickly get up to speed. Our goal: create real (convincing) physics simulations on the web with no code. 
For documentation, please visit: https://tumult.com/hype/documentation/3.0/#physics 
Physics Crash Course
Element Control: The white cue ball above is a ‘Draggable’ element because we have set a ‘Control Element Position’ action on the element within the Actions inspector.
Create a 'Top Down' physics world by setting the Gravity force to 0.
The cannonball is an animated dynamic element, briefly ‘launched’ by a position animation.  The castle consists of rectangles placed on top of each other. 
Projectiles & Collisions
Fire Cannon Again
Level One
Rebuild Castle
Dynamic elements can fall into the scene from outside of the scene’s area. 
Physics Bodies: Initiating Off Scene
Turn on ‘Control gravity with device tilt’ for direct gesture control over dynamic elements positions on mobile devices. 
Static Element Boundaries
The flask on the left is surrounded by 'static' elements which form a circular boundary for dynamic elements. 
Elements fill this bottle by transitioning from 'Inactive' Physics bodies to 'Dynamic' bodies. 
The right ball is a regular physics body, which will fall, bounce, and roll based on the Air drag, Bounce, and Friction values assigned to it. 
Faking Physics with Easing
The ‘Bounce’ easing transition is another way to simulate physics and allows for greater control. The left ball has a simple animation with the ‘bounce’ easing transition. 
Symbol Physics Gravity (Force = .5) 
Scene Physics Gravity
Symbol Physics Gravity (Force = 0)
Three Gravity Realms using Symbols
Reload Scene.
Inactive and Static Elements are anchored to their position
Dynamic Elements Follow the 'Scene Physics Gravity' intensity and angle.
Static Elements become boundaries & floors
Inactive Elements, like this rectangle, allow dynamic bodies to pass in front or behind them.  
Physics + Animations: The L and R buttons animate the blue paddles. 
Any property can be animated in Tumult Hype: even the physics properties of elements.  For example, you can make an element become ‘dynamic’ by pressing the record button, moving the playhead forward in time, and adjusting the body type of the element. This generates a keyframe to switch that element’s body type.  Add more Physics-related properties by selecting the Properties Dropdown and adding more (or recording changes). 
Animatable Physics Properties
Make Ball Dynamic
Programmatic Physics 
The bounding box of elements define the edges of the element in the phyiscs space. Rectangular images dragged onto your scene can be made rectangular by increasing the 'Border Radius' value of the element in the Element Inspector. 
Ellipses & Rectangles: Element Bounds
drop ball
Pausing a timeline to start Physics via MarkHunte