Simple Machines Flashcards
Equation to find work
work= force x distance
- if the distance you move an object increases, the force required decreases
Mass
- amount of matter an object contains
- mass of an object cannot change unless a part of the object is lost or another part is added
- measured in kg
Effort
the force you put in to move or change the position of an object
load
the weight of the object being lifted or carried
Ist class lever
LiFE
- direction changer
- force multiplier
2nd class lever
ELF
-Force multiplier
3rd class lever
LEaF
-speed multiplier
Force multipliers
- change small applied force into larger resultant force
Example: tweezer, crowbar
Speed multiplier
Slow speed into faster resultant speed
Example: Car wheels, egg beaters
Direction changers
-machines that change the direction in which a force acts
Example: blinds
Can a machine be a speed+force multiplier?
No machine is both a speed and a force multiplier because then you’d get more work out than you put in
Work
- energy required to move an object over a certain distance
- measured in joules (J)
relationship equation of work input and work output
work input=work output (approximately)
(Fe x De)=(Fl x Dl)
Less useable energy comes out that what was put in because energy can be lost due to heat loss, friction, etc.
Efficiency of a machine (as a %)
energy output/ energy input x 100
MA (Levers)
dE/dL
fL/fE
Speed multiplier or force multiplier?
Speed multiplier = mechanical advantage 1