science 8 mechanics

advantage of da Vinci

surgical robotic arm that enables surgeons to preform operations inside people through very small incisions plus less recovery time

advantage of combine harvester

machine that cuts and threshes grain saves time and human power

advantage of roman aqueduct

system of pumps and sloped channels that transport water from sources in the country into the cities, used gravity to get water to cities instead of huuling in buckets/tanks/barrels

advantage of sakia

series of buckets attached to a long rope which raised water; used animals, more water could be raised up; faster than one bucket at a time

advantage of archimedes screw

large screw designed to move large volumes of water, saved time/energy

first class lever description

rigid bar, fulcrum between effort and load

second class lever description

rigid bar, load between effort and fulcrum

third class lever description

rigid bar, effort between load and fulcrum

inclined plane description

flat sloped surface

wedge description

flat surface that tapers to a point

screw description

cylinder with groove cut in a spinal

first class lever two examples

teeter totter, crowbar

second class lever two examples

wheelbarrow, nutcracker

third class lever two examples

forearm, broom

inclined plane two examples

ramp for wheelchairs, mountain road

wedge two examples

knife, paper cutter

screw two examples

screw, auger

fixed pulley description

grooved wheel fixed in place

fixed pulley two examples

winch, flag pole

moveable pulley description

grooved wheel moves up and down with load

moveable pulley two examples

hoist, crain

wheel and axle description

two wheels of different sizes secured together

wheel and axle two examples

doorknob, steering wheel

first class lever advantage

reduces effort force

first class lever disadvantage

increases distance

second class lever advantages

reduces effort force

second class lever disadvantages

increases distance

third class lever advantages

reduces effort force

third class lever disadvantages

increases distance

inclined plane advantages

reduces effort force

inclined plane disadvantages

increases distance

wedge advantages

Reduces effort force

Wedge disadvantage

Increases distance

Screw advantage

reduces effort force

screw disadvantage

increases distance

fixed pulley advantage

changes direction of force

fixed pulley disadvantages

does not reduce effort force

moved pulley advantages

reduces effort force

moved pulley disadvantage

increases distance

wheel and axle advantages

can increase or decrease effort

wheel and axle disadvantages

distance can be increased depending on which wheel is the driver

simple machines can be used to obtain four effects. what are they?

-Change direction of force

-multiply force

-increase or decrease speed

-transfer force

define complex machine

made up of several simple machines

define system

group of parts that work together to preform a function

define subsystem

group of parts that preform a specific function

bedroom door overall function

enclose or open a room

subsystem doorknob function

engage or release the latch

subsystem latch function

bolt or open the door

subsystem slab/panel function

provide material to enclose/open the room

subsystem hinge function

pivot

what is a linkage

device that transfer energy from source to object

three examples of a linkage

belt, chain, gears

what is the function of a transmission

transfer energy from energy to wheels

what are gears

wheels with teeth on circumference

what is a gear train

two or more gears meshed

what is the driving gear

gear directly attached to energy source

what is a driven gear

gear that turns because it is meshed to driving gear

what are the three function that gears can preform

-increase speed of rotation

-decrease speed of rotation

-reverse direction of rotation