| A | B |
|---|
| acceleration | The rate at which velocity changes. |
| velocity | Speed in a given direction. |
| speed | The distance an object travels in one unit of time. |
| Newton’s Laws of Motion | Three physical laws that are the foundation of mechanics and describe the relationship between a body and the forces acting upon it, and its motion in response to the forces. |
| mass | A measure of how much matter is in an object. |
| weight | A measure of the force of gravity on an object. |
| gravity | The force that pulls objects toward each other. |
| force | A push or pull exerted on an object. |
| newton | A unit of measure that equals the force required to accelerate one kilogram of mass at a rate of one meter per second per second. |
| work | The product of force and distance when a force is used to move an object. |
| simple machine | Any of the basic mechanical devices for applying force such as an inclined plane, wedge, lever, screw, pulley, or wheel and axle. |
| mechanical advantage | The number of times the force exerted on a machine is multiplied by the machine. |
| friction | A force that one surface exerts on another when the two rub against each other. |
| ratio | The quantitative relation between two amounts of numbers showing the number of times one value contains or is contained by another. |
| output force | The force exerted on an object by a machine. |
| input force | The force exerted on a machine. |
| joule | A unit of work equal to one newton-meter. |
| machine | A device that changes the amount of force exerted or the direction in which force is exerted. |
| efficiency | The percentage of the input work that is converted to output work. |
| net force | The overall force on an object when all of the individual forces acting on an object are added together. |
| unbalanced force | A nonzero net force that changes an object's motion. |
| balanced force | Equal forces acting on an object in opposite directions. |
| law of conservation of momentum | The rule that the total momentum of objects in an interaction does not change. |
| centripetal force | A force that causes an object to move in a circle. |
| momentum | The product of an object's mass and its velocity. |
| inertia | The tendency of a moving object to continue in a straight line or a stationary object to remain in place. |
| friction | A force that one surface exerts on another when the two rub against each other. |
| power | The rate at which work is done, or the rate at which energy is transformed. |
| motion | The state in which one object's distance from another is changing. |
| reference point | A place or object used for comparison to determine if an object is in motion. |
| meter | A unit of measure used for measuring the length or distance between two points. |
| slope | The steepness, or slant, of a line on a graph. |
| plate | One of the major pieces that make up Earth's upper layer. |
| linear | Term used to describe a relationship between variables whose graph is a straight line. |
| nonlinear | Term used to describe a relationship between variables whose graph is not a straight line. |
