Find out how the gravitational field strength is directly related to the mass of the object and indirectly related to the square of the distance from the center of mass. [5:38]

Paul Andersen explains how an object with mass placed in a gravitational field experiences a gravitational force. [5:01]

Award-winning science teacher Paul Andersen helps make physics understandable as he explains how gravitational forces differ from the other three fundamental forces: electromagnetic, and strong and weak nuclear forces. [5:05]

Paul Andersen explains how the gravitational mass is a measure of the force on an object in a gravitational field. [6:02]

In the following video Paul Andersen explains how a radioactive nuclei can decay by releasing an alpha, beta, or gamma particle. The exact moment of decay for each nuclei can not be determined but probability is useful in predicting the half-life. [7:42]

In the following video Paul Andersen explains how heat is the movement of energy from an object with a higher temperature to an object with lower temperature. Heat transfer can occur through conduction, convection, and radiation. [4:10]

In the following video Paul Andersen explains how energy can be transferred from warmer objects to colder objects through heat. Temperature is a measure of the average kinetic energy of the particles in a substance. When two objects are in contact collisions between the particles will transfer energy from the warmer object in the form of heat. [5:05]

In the following video Paul Andersen explains how heating is the transfer of energy (heat) from a warmer object to a cooler object. Heat can be transferred through conduction, convection and radiation. At the microscopic level conduction results from the collision of particles and therefore the transfer of kinetic energy. [3:32]

Paul Andersen explains how hugs between tissues can help maintain homeostasis. Countercurrent heat exchange allows heat to stay within the core of the body. Close contacts between the capillaries and alveoli allow our body to maintain the correct concentration of oxygen. Capillaries also hug the tubules in the nephron to maintain osmolarity and filter the blood. [8:34]

Paul Andersen explores population dynamics of the human population. The population has show exponential growth since the industrial revolution and all countries will eventually move through the demographic transition. [11:14]

Paul Andersen talks about the impacts of human growth on the environment and on themselves. The population, affluence, and destructive technology of a population impact the environment according to the IPAT equation. An analogous model is the ecological footprint which increases with the development of a nation. Be sure to check out the additional resources provided. [8:47]

Paul Andersen explains how the world population has undergone exponential growth since the industrial revolution. Predicting the future world population is difficult because each country will grow at different rates. Age-structure diagrams and the demographic transition model can allow countries to plan for future growth. [10:18]

In the following video Paul Andersen explains how the pressure, volume, amount, and temperature of an ideal gas are related. Absolute zero of a gas can be determined by varying the temperature and measuring the corresponding volume of a gas sample. Several examples including Boyle's and Charle's Law are included. [5:35]

Paul Andersen explains how your body protects itself from invading viruses and bacteria. He starts by describing the nonspecific immune responses of skin and inflammation. He then explains how we use antibodies to disrupt the function of antigens and mark them for destruction. [13:46]

In the following video Paul Andersen defines impulse as the product of the force applied and the time over which the force is applied. The impulse of an object is equivalent to the change in momentum of the object. [9:11]

Paul Andersen explains how inertial mass is defined and measured in context of Newton's second law of motion. [4:30]

In this video, Paul Andersen explains how society influences the natural world through increasing science, engineering, and technology. As the world population increases, it will require more natural resources and it will impact the global conditions. Society can control some of these changes through regulations. A K-12 teaching progression is also included. [5:22]

Mr. Anderson illustrates the concept that forces on an object always require another object, and that an object cannot exert a force on itself. If net forces on an object are balanced the object will remain at rest or move with a constant velocity. [6:28]

How and why do organisms interact with their environment and what are the effects of these interactions? [8:13]

In the following video Paul Andersen explains how the kinetic energy of an object if due to the motion of an object. Objects can have kinetic energy but they cannot have potential energy unless they are part of a system. [4:47]