Sal explains how to draw free body diagrams when forces are applied at an angle. How to find horizontal and vertical components of an angled force using trigonometry.
In this demonstration of chemical change, the presenter blows breath into a methylene blue solution releasing carbon dioxide which acidifies the water and changes it from a bright blue color to green.
In this interactive activity from the Building Big Web site, use your knowledge of bridge design to match the right bridge to the right location in a fictitious city.
Students work in groups to create soap bubbles on a smooth surface, recording their observations from which they formulate theories to explain what they see (color swirls on the bubble surfaces caused by refraction). Then they apply this theory to thin films in general, including porous films used in biosensors, listing factors that could change the color(s) that become visible to the naked eye, and learn how those factors can be manipulated to give information on gene detection. Finally (by experimentation or video), students see what happens when water is dropped onto the surface of a Bragg mirror.
Whether you want to light up a front step or a bathroom, it helps to have a light come on automatically when darkness falls. For this maker challenge, students create their own night-lights using Arduino microcontrollers, photocells and (supplied) code to sense light levels and turn on/off LEDs as they specify. As they build, test, and control these night-lights, they learn about voltage divider circuits and then experience the fundamental power of microcontrollers—controlling outputs (LEDs) based on sensor (photocell) input readings and if/then/else commands. Then they are challenged to personalize (and complicate) their night-lights—such as by using delays to change the LED blinking rate to reflect the amount of ambient light, or use many LEDs and several if/else statements with ranges to create a light meter. The possibilities are unlimited!
In this hands-on activity, students explore the electrical force that takes place between two objects. Each student builds an electroscope and uses the device to draw conclusions about objects' charge intensity. Students also determine what factors influence electric force.
Students are challenged to design their own small-sized prototype light sculptures to light up a hypothetical courtyard. To accomplish this, they use Arduino microcontrollers as the “brains” of the projects and control light displays composed of numerous (3+) light-emitting diodes (LEDs). With this challenge, students further their learning of Arduino fundamentals by exploring one important microcontroller capability—the control of external circuits. The Arduino microcontroller is a powerful yet easy-to-learn platform for learning computer programing and electronics. LEDs provide immediate visual success/failure feedback, and the unlimited variety of possible results are dazzling!
Students build their own small-scale model roller coasters using pipe insulation and marbles, and then analyze them using physics principles learned in the associated lesson. They examine conversions between kinetic and potential energy and frictional effects to design roller coasters that are completely driven by gravity. A class competition using different marbles types to represent different passenger loads determines the most innovative and successful roller coasters.
In this video segment adapted from ZOOM, the cast shows how the 34 steps in their Rube Goldberg invention use everything from gravity to carbon dioxide gas in order to accomplish one simple task: pouring a glass of milk.
In this video segment from ZOOM, Jillian explains how her simple machine uses marbles, levers, flowing sand, and a spinning wheel to water a plant.
Students create and decorate their own spectrographs using simple materials and holographic diffraction gratings. A holographic diffraction grating acts like a prism, showing the visual components of light. After building the spectrographs, students observe the spectra of different light sources as homework.
Students design and construct electromagnets that must pick up 10 staples. They begin with only minimal guidance, and after the basic concept is understood, are informed of the properties that affect the strength of that magnet. They conclude by designing their own electromagnets to complete the challenge of separating scrap steel from scrap aluminum for recycling, and share it with the class.
How do you build a tunnel 32 miles long -- under water? This video segment adapted from Building Big, follows the construction of the Channel Tunnel (nicknamed "Chunnel"), the engineering wonder that connects England to France.
In this video we show you how to build a simple motor. Created by Karl Wendt.
We are surrounded everyday by circuits that utilize "in parallel" and "in series" circuitry. Complicated circuits designed by engineers are made of many simpler parallel and series circuits. In this hands-on activity, students build parallel circuits, exploring how they function and their unique features.
When will objects float and when will they sink? Learn how buoyancy works with blocks. Arrows show the applied forces, and you can modify the properties of the blocks and the fluid.
When will objects float and when will they sink? Learn how buoyancy works with blocks. Arrows show the applied forces, and you can modify the properties of the blocks and the fluid.
This illustrated demonstration from the NOVA Web site explains the concepts of buoyancy and density by showing what happens when different kinds of wood blocks are dropped in water.
This interactive brainteaser from the NOVA Web site challenges you to explain the behavior of a helium-filled balloon in a moving car.
This interactive brainteaser from the NOVA Web site challenges you to figure out what happens to the water level when a rock is resting in a boat and when it is submerged in water.