22 terms

ch. 5 work and simple machines

transfer of energy when a force moves an object
mechanical advantage
a machine multiplies an input force
causes some of the energy transferred to an object to be converted into thermal energy
ways to make machines work easier
1. increasing the force
2. change the direction of the applied force
increasing the distance over which the force is applied
2 things need for work to be done
1. move the object
2. object must move in the that direction which you move it in
work output of a machine divided by the work input
output work
work doen by the machine
output force
the force applied by the machine
input force
the force you apply to a simple machine
input work
work done by you on the machine
mechanical advantage
ratio of input force to output force (tells you how much better the machine is over you)
third class lever
the input force is applied between the output force and the fulcrum
moveable pulley
a pulley with one fixed end and the wheel is free to move
inclined palne with two sloping sides
block and tackle pulley
a system of pulleys consisting of fixed and moveable pulleys
fixed pulley
pulley that only changes the direction of the applied force
second class lever
output force is located between the input force and the fulcrum
wheel and axle
simple machine consisting of a shaft attached to the center of a larger wheel
first class lever
fulcrum is located between the input and output forces
an inclined plane wrapped around a cylindrical post
inclined plane
a sloping surface such as a ramp
you have not done any work if
you do not move the object