| A | B |
|---|
| conduction | The transfer of heat energy by direct contact between particles. Heat travels through metal by conduction. |
| convection | The transfer of heat energy through liquids and gases by moving particles. Heat is carried throughout water in a pot on the stove. |
| effort force | The force that must be applied to an object to move the object. To do work, the effort force must be greater than the resistance force. |
| electromagnetic energy | The only form of energy that can travel through empty space. Energy from the sun travels outward through space in the form of waves. (Light is electromagnetic energy you can see. X-rays, ultraviolet, and infrared waves you can't see. |
| energy | The ability to do work or cause change, for example, change position, speed, temperature, or direction. Energy from the sun warms the air. |
| force | Any push or pull. When you open a door, you apply a force. |
| friction | The force produced by the rubbing of one thing against another. A force that acts to oppose motion. |
| glucose | A sugar; plants store energy from the sun in this form. |
| joule | The basic unit of energy and of work. Scientists measure amounts of energy in joules. One Nm is the amount of energy that is needed to raise the temperature of 1 gram of water 4.18 celsius. |
| kinetic energy | The energy that something has because of its motion. As a boulder rolls down a steep hill, it gains this energy. |
| light | Electromagnetic energy that you can see. |
| lubricants | Fluids such as oil, grease, and wax that are used to reduce friction. |
| medium | Substances or agents through which anything act. A medium can be matter in any state; solid, liquid or gas. Air serves as this when sound waves travel through it. |
| newton | A unit used to measure force. |
| potential energy | The energy an object has because of its position or structure; stored energy. A coiled spring has this energy. |
| radiation | The transfer of energy by waves. Energy given off by the sun travels in this form through space. |
| resistance force | a force, such as friction or gravity, that resists, or opposes, motion. |
| W = F x D | Work equals force times distance. Force is measure in newtons. Distance is measure in meters. A newton-meter (Nm) is the same as a joule. |
| work | The movement of a force through a distance. Work is done if a force moves an object. W = F x D. |
| two ways to reduce friction | l. ball bearings or wheels, 2. lubricants |
