Question | Answer |
the force of friction causes objects to... | slow down |
the force of gravity causes objects to... | accelerate downward |
friction | the force that one surface exerts on another when 2 rub against each other |
friction acts in an _____ direction to the object's direction of motion | opposite |
friction _____ motion | opposes |
the strength of friction depends on: | 1. the type of suface2. how hard the surfaces push together |
3 types of friction: | 1. sliding friction2. rolling friction3. fluid friction |
sliding friction | 2 solid surfaces sliding across each other |
rolling friction | creates less friction than sliding, requires less force |
fluid friction | fluid keeps surfaces from making direct contact and thus reduces friction-least amount of friction |
fluid- | liquid or gas |
what is used in machines to reduce friction | oil |
free fall | when the only force acting on a falling object is gravity |
an object in free fall ____ as it falls | accelerates |
in free fall, gravity is a _____ force | unbalanced |
the acceleration due to the force of gravity is _____ | 9.8 m/s |
all objects in free fall accelerate regardless of_________ | mass |
although your ____ would be the same on a different planet or moon, your ____ would be different | mass, weight |
the force of gravity on earth's moon is about _____ that on earth | 1/6 |
gravity depends on: | 1. mass2. distance |
gravity | the force that pulls objects towards earth |
projectile | an object that is thrown |
air resistance | a type of fluid friction |
terminal velocity | the greatest velocity of an object in free fall |
weight | the force of gravity on a person or object on the surface of the planet |
gravity | the force that pulls objects towards earth |
projectile | an object that is thrown |
air resistance | a type of fluid friction |
terminal velocity | the greatest velocity of an object in free fall |
weight | the force of gravity on a person or object on the surface of the planet |