Machines
4
How do machines help people work? Using force in order to move an object a certain distance. Work is measured in an unit called joule (J). W= F X D Multiply the force and distance to measure work. Lesson 1
description
Transcript of Machines
How do machines help people work?Using force in
order to move an object a certain
distance.
Work is measured in an unit called joule
(J).
W= F X DMultiply the force and distance to measure work.
Lesson 1
Work and Machines
Machine
Any device that helps people do work.
Simple Machines
Made of one or two parts.
Nail clippers and chopsticks.
Compound Machines
Has one or more simple machines among its parts.
Cars, trucks, airplanes.
How machines help
They make it easier to work
A car jack and a crowbar are examples of machines that
increase the amount of force to lift or move an object
Other machines change the distance over which force must be
applied.
Machines and Friction
Not all the energy you put into machine is used to do work because some energy is lost
due to friction.
Friction is created when the moving parts of a machine
rub together.
There are ways to reduce friction.
Friction creates heat and slows down machine´s
parts.
Using wheels and rollers.
Coating the machine parts with grease , oil
or wax.
