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.

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.

A couple of problems involving Archimedes' principle and buoyant forces. Created by Sal Khan.

In this activity, learners burn a peanut, which produces a flame that can be used to boil away water and count the calories contained in the peanut. Learners use a formula to calculate the calories in a peanut and then differentiate between food calories and physicist calories as well as calories and joules.

Advanced topics in general chemistry including chemical kinetics, equilibrium, acid-base, and electrochemistry. Chemical principles are presented at a level appropriate for science majors and pre-professional students.

CK-12 Physical Science Concepts covers the study of physical science for middle school students. The 5 chapters provide an introduction to physical science, matter, states of matter, chemical interactions and bonds, chemical reactions, motion and forces, and the types and characteristics of energy.

In this demonstration, cook a cake using the heat produced when the cake batter conducts an electric current. Because of safety concerns, this activity should be conducted as a demonstration only and learners should be kept at a safe distance.

Calculating the dot and cross products when vectors are presented in their x, y, and z (or i, j, and k) components. Created by Sal Khan.

Do you know how many calories are in a macadamia nut? This video segment highlighting a Calorimetry experiment will give you the answer.

The effect on voltage and current when capacitors are constructed in parallel in a circuit. By David Santo Pietro.

When capacitors are connected one after another, they are said to be in series. For capacitors in series, the total capacitance can be found by adding the reciprocals of the individual capacitances, and taking the reciprocal of the sum. Therefore, the total capacitance will be lower than the capacitance of any single capacitor in the circuit. Created by David SantoPietro.

This module provides an overview of the biogeochemical carbon cycle. Major sources and sinks of carbon are discussed as well as the impact of human activities on global carbon levels.

In this video segment adapted from NOVA, find out how cars made of a material stronger than steel and half the weight can help combat climate change.

This interactive resource adapted from the National Park Service presents the key concepts of cave and karst systems, including how and where they form, different types, and various cave environments.

In this interactive activity from NOVA, discover how centripetal force can affect you when riding in a car or flying at high speeds in a fighter jet.

This video segment explains centripetal force and illustrates how roller coasters rely on it to give you a thrilling ride.

This video segment adapted from NASA describes the basic characteristics of our star, the Sun.

In this video segment adapted from NOVA, scientists are on the hunt for tornadoes. Using Doppler radar, they gather data in the hopes of solving the mystery of how tornadoes form.