# Chapter 4. Step examples

Step package contains several instructive examples to help you understand the principles of the application work. To open an example from the default set choose FileExamplesOpen Example... from the main window menu.

You can find the descriptions of the default example files below.

brownian.step

Plots trajectory of the rigid disk interacting with 40 particles that randomly drifting in a box. This example simulates Brownian motion of ideal gas particles.

doublependulum.step

This example simulates double pendulum motion using 2 massive particles and two sticks.

eightpendulum.step

This example is a simple demonstration of the famous Newton's cradle. It is done in Step using sticks, 8 discs and a box. The six balls in the middle are not moving because they just transfer momentum and energy, not a motion.

first.step: First example

This example has two parts. The first part contains two particles connected by a spring and the second part contains two charged particles.

Two particles connected by a spring

In this example two particles are added to the scene and spring is connected between them. The properties of both the particles such as velocity, momentum, position etc. has been set in the properties browser. The properties of the spring such as stiffness, restLength, damping etc. also has been set in the properties browser.

Explanation of the simulation:

This is good example of a simple harmonic motion. Here the acceleration of the one particle is set in direction of positive x-axis and the acceleration of the other particle is set along negative x-axis. As a result both the particles pulls the spring in opposite directions, where as spring tries to bring the two particles back to their original positions. Thus the system executes simple harmonic motion. The simulation of the particles and spring under these conditions can be seen on the scene.

Two charged particles

Velocity of the each charged particle is set in some direction so, the charged particles moves in respective direction of their velocity but each particle has been given a equal and opposite charge so the particles try to attract each other. As a result the simulation of the charged particles under these conditions can be seen on the scene.

fourpendula.step

This example is a correct demonstration of the Newton's cradle. As the system is imperfect two disks in the middle get visual movement with time.

gas.step

This example simulates ideal gas pressure caused by Brownian motion.

graph.step

Plots velocity vs. position graph for particle1 in the system of two particles connected with a spring.

liquid.step

This example simulates monoatomic liquid.

lissajous.step

This example simulates Lissajous curve using two-particle model. The parameters on the model can be changed using the controller at the center of the world.

motor1.step

Simulates triangular rigid body under the loading of the three linear motors.

motor.step

Simulates interaction of the linear motor with a rigid rectangular body on a spring.

note.step

Example with LaTeX formula (divergence theorem) and embedded image.

resonance.step

This example simulates resonance in the system with angular motor.

softbody.step

This example simulates interaction of two rigid bodies with a soft body between them.

solar.step

This example simulates the motion of Solar system major bodies (Sun and the planets).

springs.step

This example simulates the motion of the planar system of five particles connected with four springs.

wave.step

The graph on the scene shows oscillations of the green particle. When you start simulation the wave starts to travel from the red particle. The blue particle will reflect the wave and it will travel in reverse direction until the red particle reflects in again. After some time the wave will vanish because springs have damping.