Explore the forces at work when you try to push a filing cabinet. Create an applied force and see the resulting friction force and total force acting on the cabinet. Charts show the forces, position, velocity, and acceleration vs. time. View a Free Body Diagram of all the forces (including gravitational and normal forces).

This lesson unit is intended to help teachers assess how well students are able to understand what the different algebraic forms of a quadratic function reveal about the properties of its graphical representation. In particular, the lesson will help teachers identify and help students who have the following difficulties: understanding how the factored form of the function can identify a graphŐs roots; understanding how the completed square form of the function can identify a graphŐs maximum or minimum point; and understanding how the standard form of the function can identify a graphŐs intercept.

Learn how to make waves of all different shapes by adding up sines or cosines. Make waves in space and time and measure their wavelengths and periods. See how changing the amplitudes of different harmonics changes the waves. Compare different mathematical expressions for your waves.

Learn how to make waves of all different shapes by adding up sines or cosines. Make waves in space and time and measure their wavelengths and periods. See how changing the amplitudes of different harmonics changes the waves. Compare different mathematical expressions for your waves.

Match shapes and numbers to earn stars in this fractions game. Challenge yourself on any level you like. Try to collect lots of stars! The main topics of this interactive simulation include fractions, equivalent fractions, and mixed numbers.

Match shapes and numbers to earn stars in this fractions game. Challenge yourself on any level you like. Try to collect lots of stars! The main topics of this interactive simulation include fractions, equivalent fractions, and mixed numbers.

Explore fractions while you help yourself to 1/3 of a chocolate cake and wash it down with 1/2 a glass of orange juice! Create your own fractions using fun interactive objects. Match shapes and numbers to earn stars in the fractions games. Challenge yourself on any level you like. Try to collect lots of stars!

Explore fractions while you help yourself to 1/3 of a chocolate cake and wash it down with 1/2 a glass of orange juice! Create your own fractions using fun interactive objects. Match shapes and numbers to earn stars in the fractions games. Challenge yourself on any level you like. Try to collect lots of stars!

Explore fractions while you help yourself to 1 and 1/2 chocolate cakes and wash it down with 1/3 a glass of water! Create your own fractions using fun interactive objects. Match shapes and numbers to earn stars in the mixed number game. Challenge yourself on any level you like. Try to collect lots of stars!

In 1845, the Narrative of the Life of Frederick Douglass, an American Slave, and Written by Himself was published. In it, Douglass criticizes directly often with withering irony those who defend slavery and those who prefer a romanticized version of it.

In this lesson, students will use a primary source—an NBC news report from 1961—to investigate the Freedom Rides. The lesson will also explore segregation in the South and the tenets of nonviolent protest.

The American civil rights movement incorporated a variety of cultural elements in their pursuit of political and legal equality under law. This lesson will highlight the role of music as a major influence through the use of audio recordings, photographs, and primary documents. Students will participate in their own oral history, examine lyrics, and work with case studies such as the Freedom Rides to gain an appreciation of how music influenced the early 1960s.

Learn how friction causes a material to heat up and melt. Rub two objects together and they heat up. When one reaches the melting temperature, particles break free as the material melts away.

Learn how friction causes a material to heat up and melt. Rub two objects together and they heat up. When one reaches the melting temperature, particles break free as the material melts away. Arabic Language.

In 1845 Frederick Douglass published what was to be the first of his three autobiographies: the Narrative of the Life of Frederick Douglass, an American Slave, Written by Himself.  As the title suggests, Douglass wished not only to highlight the irony that a land founded on freedom would permit slavery to exist within its midst, but also to establish that he, an American slave with no formal education, was the sole author of the work.

In the years after World War I Americans quickly reached the conclusion that their country's participation in that war had been a disastrous mistake, one which should never be repeated again. During the 1920s and 1930s"”recognized as the Interwar Period (1921-1939)"”U.S. officials pursued a number of strategies aimed at preventing war.

This lesson unit is intended to help teachers assess how well students are able to: articulate verbally the relationships between variables arising in everyday contexts; translate between everyday situations and sketch graphs of relationships between variables; interpret algebraic functions in terms of the contexts in which they arise; and reflect on the domains of everyday functions and in particular whether they should be discrete or continuous.

Pump gas molecules to a box and see what happens as you change the volume, add or remove heat, change gravity, and more. Measure the temperature and pressure, and discover how the properties of the gas vary in relation to each other.

Express yourself through your genes! See if you can generate and collect three types of protein, then move on to explore the factors that affect protein synthesis in a cell.

Build a gene network! The lac operon is a set of genes which are responsible for the metabolism of lactose in some bacterial cells. Explore the effects of mutations within the lac operon by adding or removing genes from the DNA.