Showing that N(t)=Ne^(-kt) describes the amount of a radioactive substance we have at time T. For students with background in Calculus. Not necessary for intro chemistry class. Created by Sal Khan.
Introduction to Exponential Decay. Using the exponential decay formula to calculate k, calculating the mass of carbon-14 remaining after a given time, and calculating the time it takes to have a specific mass remaining . Created by Sal Khan.
Join Tarissa and Sabrina as they measure and compare the volume of different sounds across New York City in this video from DragonflyTV.
In this video segment adapted from Interactive NOVA, astronaut John Young experiences extreme temperatures on the Moon that are a result of the Moon's low gravity and lack of atmosphere.
How a current can be induced in a loop of wire by a change in magnetic flux.
Example calculating induced current based on change in flux.
How Faraday's Law is used to generate electricity in turbines.
Sal solves a Bernoulli's equation example problem where fluid is moving through a pipe of varying diameter. Created by Sal Khan.
Sal finishes the example problem where liquid exits a hole in a container. Created by Sal Khan.
Using our understanding of fluid pressure to figure out the height of a column of mercury. Created by Sal Khan.
Overview of the first law of thermodynamics.
Worked example of the first law of thermodynamics.
In this activity, students critically analyze prior conceptions and textbook visuals of the relative sizes and orbiting distance of the Earth-moon system (and other bodies in our solar system), search out sources for this data, and construct scale models by using balls of various sizes. There are tips for helping learners understand the large scales (i.e., millions rather than thousands) that characterize our solar system, and examples are provided of scaling using different sizes of athletic balls.
In this activity, students investigate how pressure affects the temperature of air and how this relates to the formation of clouds in the troposphere. They will form a cloud in a bottle, find the dew point and relative humidity of air at different places in the school and use a chart to estimate how high that air would have to rise to form a cloud.
In this video segment adapted from NOVA, scientists investigate how farming along the Mississippi River impacts floods and what can be done about it.
In this activity, students use a National Weather Service flood forecast, USGS gauging data, and other reports to estimate the maximum storm discharge from the New River and Wolf Creek, two streams in the Southeast U.S. which experienced flooding in November 2003. Topographic and urban maps are used to predict where flooding would occur and to evaluate strategies for reducing flood risk for the residents of the region.
Introduction and intuition for flux and magnetic flux.
Explore the forces at work in a tug of war or pushing a refrigerator, crate, or person. Create an applied force and see how it makes objects move. Change friction and see how it affects the motion of objects.
In this lesson designed to enhance literacy skills, students learn how the forces of gravity and air resistance affect the motion of falling objects.
This media-rich essay from NOVA Online describes the challenges of forecasting volcanic eruptions and includes information about specific cases.