| A | B |
|---|
| absolute zero | the temperature at which a substance has no kinetic energy per particle (thermal) to give up |
| friction | the force that acts to resist the relative motion (or attempted motion) of objects or materials that are in contact |
| Archimedes' Priciple | the relationship between buoyancy and displaced fluid; an immersed object is buoyed up by a force equal to the weight of the fluid it disperses |
| fluid | anything that flows; particularly gas and liquids |
| atom` | the smallest particle of an element that can be identified with that element |
| molecule | two or more atomsof the same or different elements bonded to form a larger particle |
| atomic number | number of protons in the nucleus of an atom |
| nucleus | the positively charged center of an atom which contains protons and neutrons and has almost all the mass but a fraction of the volume |
| calorie | unit of heat |
| centripetal force | a center directed force that causes an object to move in a curved, sometimes circular pattern |
| efficiency | In a machine, the ration of useful energy output to total energy input of the percentage of the work input that is converted to work output |
| element | a substance made of only one kind of atom |
| entropy | a measure of the amount of disorder in a system |
| first law of thermodynamics | heat added to a system is transformed to an equal amount of some other form of energy |
| impulse | product of force and time interval during which the force acts |
| insulator | a material that is a poor conductor of heat and that delays the transfer of heat |
| law of conservation of energy | energy cannot be created or destroyed; it may be transformed from one form to another but the total energy never changes |
