a device that makes doing work easier
force that is applied to the machine (Fin stands for input force)
force applied by the machine (Fout stands for output force)
work done by you (example - applying work to a crowbar) (Win)
work done by the machine (example - the crowbar lifting a lid as you apply force on the crowbar) (Wout)
is equal to force times distance
Fin Din = Fout Dout
the ratio of the output force to the input force
is a measure of how much of the work put into a machine is changed into useful output work by the machine.
machine that does work with only one movement
is a bar that is free to pivot or turn around a fixed point
1st class lever
the output force is always in the opposite direction to the input force
3rd class lever
the input force is applied between the output force and the fulcrum. the output force is always less than the output force.
2nd class lever
ithe output force is located between the input force and the fulcrum. the output force is always greater that the input force. the output force is exterted between the input force and the fulcrum.
ideal mechanical advantage of a lever
IMA can be calculated for any machine by dividing the input distance by the output distance
a grooved wheel with a rope, chain, or cable running along the grove. It can change the direction of the input force or increase input force, depending on whether the pulley is fixed or movable
wheel and axle
a simple machine consisting of a shaft or axle attached to the center of a larger wheel.
IMA of wheel and axle
radius of wheel divided by radius of axle
a sloping surface such as a ramp that reduces the amount of force required to do work
IMA of inclined plane
length of slope divided by height of slope
an inclined plane wrapped in a spiral around a cylindrical post
an inclined plane with one or two sloping sides
two or more simple machines that operate together
the amount of work done in the second