Chapter 7 Machines… Making work easier
a device that makes work easier
We Will Write A Custom Essay Sample On Chapter 7 Machines… Making work easier
FOR YOU For Only $13.90/page
a device that does work with only one movement
by changing the force your exert in size, direction, or both
effort force and the resistance force
the force applied to the machine
the force applied by the machine to overcome resistance
Energy is always conserved. Therefore, you can never get more work out of the machine then you put into it.
a machine in which work input equals work output.
ideal machines do not exist
the number of times a machine multiplies the effort force
levers, pulleys, wheel and axle, inclined planes, screws, and the wedge
a bar that is free to pivot, or turn, about a fixed point.
seesaw, can opener, tennis racket
the fixed point of a lever
the part of the lever on which the effort force is applied
the part of the lever that exerts the resistance force
IMA=length of effort arm
length of resistance arm
the positions of the effort force, resistance force, and the fulcrum
fulcrum located between the effort and resistance forces. Usually used to multiply force, can also be used to multiply distance
resistance located between the effort force and the fulcrum. Always multiplies force
effort force located between the resistance force and the fulcrum. Can’t multiply force. MA always less than one. It increases speed.
a pulley is a grooved wheel with a rope or a chain running along the groove.
2. They are called fixed and movable pulleys
fixed and movable pulleys combined to make a system of pulleys
a simple machine consisting of two wheels of different sizes that rotate together
doorknobs, faucets, ice-cream maker
modified wheel and axle machines
a sloping or slanted surface used to raise objects. A ramp is an example of an inclined plane
an inclined plane wrapped in a spiral around a cylindrical post
an inclined plane with one or two sloping sides
chisels, knives, ax blades
the lever and inclined plane
the measure of the amount of work done in a specific amount of time
watts, It equals 1 joule/second
a combination of two or more simple machines
the science of designing artificial replacements for parts of the human body that are not working properly
the ratio of the useful work put out by a machine to the work put into that machine; efficiency is always less than 100 percent
W=F x d
W = F x d
in e e
W = F x d
out r r
in = out
When you push down on the hammer, the claw pulls it up. It changes the direction of the force.
you are changing the size.
lever, wheel and axle, gear, and the pulley
wedges, screws, and inclined plane