8th Grade Science Chapter 1
Terms
undefined, object
copy deck
- force
- a push or a pull
- Newton
- the strength of a force measured in SI units (internal system of units)
- net force
- the combination of all forces acting on an object; the net force determines whether an object moves and also in which direction it moves
- unbalanced forces
- can cause an object to start moving, stop moving, or change direction
- balanced forces
- equal forces acting on one object in opposite directions
- friction
- the force that two surfaces exert on each other when they rub against each other
- static friction
- the friction that acts on objects that are not moving
- sliding friction
- occurs when two solid surfaces slide over each other
- rolling friction
- when an object rolls across a surface, rolling friction occurs (rolling friction is easier to overcome than sliding friction)
- fluid friction
- occurs when an a solid object moves through a fluid (fluid friction is the easiest to overcome)
- gravity
- a force that pulls objects toward each other
- mass
- a measure of the amount of matter in an object
- weight
- the force of gravity on a person or object at the surface of the planet
- free fall
- when the only force acting on an object is gravity
- air resistance
- objects falling through air experience a type of fluid friction