Science chapter 2

Magnitude

The quantity of force

newton (N)

unit to measure forces

friction

The force that resists the movement of objects sliding or rolling over one another

static friction

The force that holds emotionless object where it is, preventing it from being moved across another object surface

sliding friction

The force that acts like a break when one surface slides over another surface

simple machine

A device that requires a single force to work, made up of only one or two parts

gravitational force

pull of the Earth

magnetic force

magnetic pull, magnetic push

electrical force

static cling, static electricity, force of an electric current, force of lightning

mechanical force

muscular force, hurricane force, slap shot, punch

tensile force

tightening

compressive force

crash, squash, squeeze, press, pinch, grip

rotational force

twist, turn, wring, coil, twirl

fulcrum

The pivot point of the liver

frictional force

rubbing, abrasion, roughness, force of resistance

load arm

The part of the labour that extends from the fulcrum to the mass being moved

effort arm

The part of the lever that extends from the foreground to where the force is being applied

input force

The effort force applied to the lever

output force

The force the lever applies to the load

load force

The force that the input force has to overcome in order to cause movement

benefits of: inclined place

decreases the amount of force needed to move an object to a certain height

benefits of: wedge

able to split, cut, or separate objects

benefits of: screw

a screw is an inclined plane that has been cut into a central core. Like a tiny ramp that goes in a circle, letting you push things together or lift things with less effort.

benefits of: lever

lifts things easily (with less effort). changes the direction of force (push down on one side and able to lift something up another)

benefits of: gears

speed up or slow down motion. Changes direction of motion

benefits of: pulleys

used to help lift heavy loads or change direction of a force. Device with wheels and axles to make pulling objects easier

benefits of: wheel and axle

moves things faster (reduces friction so things roll not drag). helps move/turn objects (uses less force)

class one lever

fulcrum is between the load force and the input force (LFI)

class two lever

load force is between the fulcrum and the input force (FLI)

class three lever

input force is between the fulcrum and the load force (FIL)

examples of a class one lever

seesaw, balance scale, scissors

examples of a class two lever

wheelbarrow, stapler, paper cutter

examples of a class three lever

fishing rod, baseball bat, hockey stick