In this video David explains what constructive and destructive interference means as well as how path length differences and pi shifts affect the interference. Created by David SantoPietro.
In this activity, students construct three-dimensional models from terrain information provided by two-dimensional topographic maps. This will allow them to visualize how changes in elevation over a certain distance can be represented on a flat piece of paper that can be folded up and tucked away. Each group is responsible for constructing a model of Mount St. Helens 'before' and 'after', a depression, a stream, and a hill. Discussion questions related to the different representations are also included.
This video segment adapted from the Atmospheric Radiation Program explains the differences in the formation of tropical convective cloud systems over islands and over the ocean.
An introduction to Convex Lenses. Created by Sal Khan.
Some Convex Lens Examples. Created by Sal Khan.
In introduction to Convex Parabolic Mirrors. Created by Sal Khan.
In this video segment adapted from ZOOM, two solar cookers are tested against a control to see which can cook a "s'more" faster.
In this video segment, ZOOM guest Cassie takes us on a tour of the coral reef near her home in Key Largo, Florida, and points out some of its unique features.
This video from NASA features the Cosmic Origin Spectrograph (COS), which allows scientists to use spectrographic analysis to assess the composition of intergalactic material.
This interactive activity from ChemThink takes a closer look at a covalent bond--how it is formed and how the sharing of two electrons can keep atoms together.
In this activity, learners use crayons to draw conclusions about rocks and the rock cycle. Learners form crayons ((which can be "weathered"--heated, compressed and cooled--like rocks) into models of sedimentary, metamorphic, and igneous rocks.
Introduction to the cross product. Created by Sal Khan.
A little more intuition on the cross product. Created by Sal Khan.
Find the current due to closing a switch using equivalent resistance and Ohm's law.
How to calculate the current through a resistor in parallel using equivalent resistance and Ohm's law.
In this interactive activity from the Building Big Web site, investigate dams in distress and decide if they should be repaired, removed, or left alone.
In this video segment adapted from NOVA, scientists search for carbonized remains of plants preserved in lava flows to find out how long it has taken rain forests on Hawaii to regenerate after a volcanic eruption.
In this video, David explains how Louis De Broglie got his Nobel Prize for the idea of matter having a wavelength.
In this video segment adapted from ZOOM, cast members use a hair dryer to balance a ball in a stream of air, seemingly defying gravity.
In this video segment, the ZOOM cast is challenged to keep a ping pong ball in a funnel while the funnel is held upside down, seemingly defying gravity.