| A | B |
|---|
| physical changes | do not change what the object or substance is when it changes shape or size |
| chemical changes | change a substance into another substance and cannot be changed back |
| reactant | the substance before the chemical change |
| product | the new substance after the chemical change |
| force | a push or pull that acts on an object measured in Newtons |
| gravity | pulls things down; the larger the object the greater the gravitational pull |
| friction | slows things down when two materials rub against each other |
| Net force | equals zero when force is the same on both sides |
| air resistance | friction in the air that slows falling objects down |
| No air resistance | all objects fall at the same rate with the same acceleration |
| magnetism | a non-contact force that acts at a distance |
| balanced forces | act on an object in opposite directions and cancel each other out |
| unbalanced forces | can move or stop objects |
| acceleration | the rate at which an objects's speed or direction changes |
| motion | how objects move |
| speed | how fast an object is moving |
| inertia | the ability of an object to resist any change in motion |
| energy | cannot be made or destroyed, can change form, can move from object to object |
| kinetic energy | energy of motion that depends on mass and speed of an object |
| potential energy | stored energy depends on mass and height off the ground |
