Classic Gizmos are venerable Gizmos that have been retired and are no longer officially supported by ExploreLearning.

• #### 2D Collisions (Classic)

Adjust the mass and initial velocity of two pucks on a frictionless table and observe the motion in two dimensions. The initial velocity and mass of the pucks can be changed, along with the angle of the table. Collisions can be elastic, inelastic, or magnetic. Velocity of the pucks is determined by measurement of spark tracks, and the center of mass of the collision can be observed.

Control red, green, and blue spotlights (primary colors or RGB). Observe the additive colors as the spotlights overlap.

• #### Basic Prism (Classic)

Explore Snell's Law by shining white light, or light of a specific frequency, through a prism. The angle of incidence and refraction can be measured.

• #### Black Hole

A game where you try to get small masses to hit a target. This is challenging since several "black holes" exert a gravitational force on the moving objects.

• #### Center of Mass (Classic)

Add, remove, or shift blocks of mass on a two-dimensional grid while determining the center of mass. The center of mass can be hidden or visible while moving the blocks.

• #### Coulomb Force

Place fixed charges on a two‑dimensional grid before firing a moving charge (velocity can be adjusted). The velocity of the charge will be acted on and altered by the Coulomb forces.

• #### Density Lab

With a scale to measure mass, a graduated cylinder to measure volume, and a large beaker of liquid to observe floatation, the relationship between mass, volume, density, and floatation can be investigated. The density of the liquid in the beaker can be adjusted, and many different objects can be studied during the investigation.

• #### Doppler Effect (1 source)

Visually observe sound waves produced by a moving source. Gain an understanding of the Doppler shift and recognize why the pitch of a train whistle changes as it passes and why a sonic boom occurs as planes travel at high speeds.

• #### Doppler Effect (2 sources)

Control the velocity of two sound sources in which the wave crests are visually represented. As the sound sources move, interference patterns and evidence of the Doppler effect can be observed and measured.

• #### Driven Harmonic Motion (1 mass)

A traditional lab where a sinusoidal driving force can be applied to a system consisting of a mass between two springs. Many variables can be adjusted, including oscillation frequency, the drag coefficient, and each spring constant, in an effort to find resonant frequencies.

• #### Driven Harmonic Motion (2 masses)

A traditional lab where a sinusoidal driving force can be applied to a system consisting of two masses between three springs. Many variables can be adjusted, including oscillation frequency, the drag coefficient, and each spring constant, in an effort to find resonant frequencies.

• #### Fermat's Principle

A "person" travels across the screen from one side to the other. The maximum velocity can be adjusted in each half of the screen, and the direction of motion can be controlled as the person walk or runs. Explore Fermat's principle in this real‑world application as a person tries to minimize the time required for a trip.

• #### Floating Log

Manipulate the length, radius and mass of a log floating in a pond (where the density of pond can be adjusted). Add additional blocks of mass to the log, and study the log as it sinks and floats under different conditions.

• #### Force on a Wing

Using an airplane wing placed in a wind tunnel, observe the magnitude of both the lift and drag forces acting on the wing as the angle of attack is adjusted.

• #### Freefall Lab - Terminal Velocity

Investigate the motion of a ball, including terminal velocity, as it is dropped to the ground. The mass, radius, and initial height of the ball can be changed (along with the air density and vertical wind speed) as the position, velocity, and acceleration are measured.

• #### Interference Patterns

The wave crests of two sound sources are visually represented by concentric circles. The position of one sound source can be adjusted so that patterns of constructive and destructive interference can be observed.

• #### Intro to E & M

This introduction to the principles of electricity and magnetism provides an overview of static and moving charges, magnetism, creating electricity with magnets, magnetic fields produced by electrical currents, and a brief introduction to circuits.

• #### Intro to Plasma

An introduction to plasma and the states of matter. Topics presented include atoms, elements, molecules, states of matter, density, and units (conversion and scientific notation).

• #### Lissajous Figures

A simulated oscilloscope where you can study Lissajous figures. Adjust the frequency, amplitude, and phase shift of the voltage on the x‑ and y‑ inputs to the oscilloscope while trying to create specific patterns such as a figure eight.

• #### Longitudinal Wave (Classic)

Speaking (or screaming!) compresses a region of air in the throat that subsequently travels through the atmosphere. Compress air and observe how the wave (displaced air) travels through the atmosphere, the decay of amplitude over time, the cause of an echo, and how a standing wave can be created.

• #### Min/Max Thermometer

A min/max thermometer is a common device for recording daily temperatures. While observing a thermometer, the current, minimum, and maximum daily temperatures are determined in a quiz type setting.

• #### Moment of Inertia (Classic)

Wrap a string around a bike tire, run the string across a pulley, and place some mass at the end of the string. You will learn about the moment of inertia and rotational motion as the string pulls on the edge of the wheel, causing it to spin. Varying masses can be placed on the spokes of the bike tire.

• #### Mouse Genetics

An introduction to mouse genetics where the basics of probability and statistics are presented before you choose which mice to breed for multiple generations. Determine the genetics that control the fur and eye color of the offspring.

• #### Orbit Simulator

Planets orbit around the sun and moons orbit around planets due to gravitational forces acting on the objects. Manipulate the mass, position, and initial velocity for a range of "planets" in an effort to build a stable solar system.

• #### Phased Array (Classic)

Using four closely spaced objects that produce waves, the spacing, frequency, and phase shift of each wave source can be adjusted. Wave crests from each source is visible, and with all four sources you can see regions of constructive interference that move over time. This is known as a phased array and has real-world applications such as radar and ultrasound.

• #### Quadratics in Polynomial Form - Activity B

Compare the graph of a quadratic to its equation in polynomial form. Vary the coefficients of the equation and explore how the graph changes in response.

• #### Ray Tracing

Rays traced from an object to an image are shown as an object is dragged around, and the height changed. The converging lens can be moved to different locations and the focal length of the lens can be adjusted.

• #### Real-time Histogram (Classic)

Test your time estimation skills as you gather data by trying to click your mouse every two seconds. A histogram is displayed as the data is collected, along with a visual representation of the mean and standard deviation. The bin size of the histogram can be adjusted.

• #### See-Saw Torque

A see‑saw lever is one type of a simple machine. Place up to four masses on a see‑saw at different locations and try to balance the lever (equal torque on both sides of the fulcrum). The position of the fulcrum can be shifted.

• #### Shoot the Monkey (Classic)

Learn about projectile motion by firing directly towards a falling target (in this case balloons are flung at a monkey). The velocity and position (both horizontal and vertical) of the projectile can be manipulated, and the target begins to fall at the same time the projectile is fired.

Fold paper and cut in a certain way to make symmetrical snowflakes with six sides, similar to what can be found in nature. This simulation allows you to cut virtual paper on the computer screen with round dot or square dot "scissors" of various sizes before using physical paper.

• #### Snow Flake Designer (8 sides)

Fold paper and cut in a certain way to make symmetrical snowflakes with eight sides. This eight‑sided technique of folding the paper is common even though real snowflakes in nature have six sides. This simulation allows you to cut virtual paper on the computer screen with round dot "scissors" of various sizes before using physical paper.

• #### Snowflake Designer (6 sided)

Fold paper and cut in a certain way to make symmetrical snowflakes with six sides, similar to what can be found in nature. This simulation allows you to cut virtual paper on the computer screen with round dot "scissors" of various sizes before using physical paper.

• #### Sound Beats

Listen to sounds that have a similar frequency and you will hear pulses (or beats) due to the interference of the sound waves. After listening to beats caused by several known frequencies, you will use your knowledge to determine the frequency of unknown sounds. The beats are a common real‑world application that is very useful when tuning musical instruments.

• #### Subtractive Colors (Classic)

Move spots of yellow, cyan, and magenta paint on a white surface. As the colors overlap, other colors can be seen due to color subtraction. The color of most things you see, such as cars, leaves, paintings, houses and clothes, are due to color subtraction. Observe what colors appear as different paint colors overlap.

• #### Two-Dimensional Harmonic Motion

A puck on a flat table is placed between four springs in the x/y plane. The mass, initial velocity, and position of the puck can be adjusted, as well as the spring constants. Explore the conditions needed to have linear, circular, or diagonal motion occur.

• #### Ultrasound: How Does it Work?

Learn about the real‑world principles behind an ultrasound scan, such as the phased array and reflection of waves. Perform a scan on a patient to get a clear visualization of the images produced during the ultrasound.

Drag two vectors around to see the sum of the vectors. The magnitude and direction of each vector can be manipulated. Components of all vectors are shown in equation form.

• #### X-ray Imaging

Use x‑ray imaging to peer inside a mystery patient. X‑ray images may be taken from two different directions and, when working in pairs, one person can arrange and hide the objects inside the patient and have the other student try to determine the arrangement of objects.