Machines & WorkWhat Is a Machine?A machine is a device that is designed to make work easier. Machines are not necessarily complex. For example, screwdrivers and hammers are types of simple machines.Input & Output ForcesWork is done when a force causes an object to move. The work you do on a machine is called work input, and the force you exert is known as input force. The work the machine does is called work output, and the machine’s force exerted on an object is known as output force. input forceoutput forceoutput distanceinput distanceCalculating Work Input & Output The input force times the input distance equals the work input. Similarly, the output force times output distance equals work output. The work output of a machine will never be greater than the work input.input force x input distance = work inputoutput force x output distance = work outputinput forcedistanceoutputforcesmaller input forceover greater distancegreater output forceIncreasing the Input ForceSome machines make work easier by allowing us to exert a greater input force over a shorter distance, in order to achieve a greater output distance. When using a hammer, you exert a large amount of input for a short distance on the handle, while the head of the hammer exerts a smaller output force that is applied over a greater distance.Changing DirectionFor some machines, the direction of the exerted force is changed, while the input and output forces and distances remain equal. A pulley allows us to lift an object by pulling down on a rope rather than having to lift the object up. output distanceinput distanceinput forceoutput forceinput forceoutput forcesize of input forcedirectionof input force © Copyright NewPath Learning. All Rights Reserved. 94-4457Visit www.newpathlearning.com for Online Learning Resources.Machines Make Work EasierMachines don’t change the amount of work that is done, but they do make work easier. A machine can help us by changing the size or the direction of the input force, or both.Decreasing Input ForceSome machines make work easier by allowing us to exert a smaller input force, while achieving a greater output force. To do this, the input force must be exerted over a greater distance. For example, when loading a heavy box onto a truck, it is easier to push the box up a ramp than to pick it up. Pushing the box requires less input force, but it is applied over a greater distance.A machine is a device that is designed to make work easier. Machines are not necessarriiiiiiiiiiiiilllllllllllllllyyyyyyyyyyyyyyyyy complex. For example, screwdrivers and hammers are types of simple machines.Work is done when a force causes an object to move. The work you do on a machhhhhhhiiiiinneis called work input, and the tforce you exert is known as input force. The workkkkkkkkkkkk ttthhhhhhhhhhhhe machine does is called work output, and the machine’s force exerted on aaaaannnnnnn objeccccctttttttttttttt iiiiiiiiiiiisss known as output force. input forceoutput forceoooooooooooooooouuuuuuuuuuuuuuuttttttttttppppppput ddddddddddisttttttttttaaaaaaaaaaannnnnnnnnnnncccccccccccceeeeeeeeeeeeeeeiiiiiiiiiiinnnnnnnnnnnnnnnnnnput dddddddddddddddddiiiiiiiiisssssssssssstttanceThe input force times the input distance equals the work input. Similarly, the output force times output distance equals work output. The work output of a machine will never be greater than the work input.input force x iiinnnnnnnnnnnnnnpppppppppppppppuuuuuuuuuuuuuuuuuttttttttttttt ddddddddddddiiiiiisssssssssttttttttttttaaaaaaaaaaaaannnnnnnnnnnnccccccccccccceeeeeeeeeee = work inputttoutput force x ouuuuuuuuuuuuuttttttttttttppppppppppppuuuutttttttttttttt ddddddddddddiiiiiiiiiisssssssssssstttttttttaaaannnnnncccceeeee ========== worrrkkkkkkkkkkk ooooooooooouuuuuuuttttttttttttttttpppppppppppputpnnnnppppppp tttttpuuuuuuuuppppppiiiiiii ppppppppppppppppuuuuuuuuuuuppppppnnnnnnnnnnnnnnniiiiiiiiiiiiiiiii ppnnnnnnnpppppppppp ttttttttttpppppppuuuuuuutttttttttttppppppuuuuuuuuuuuuuuppppppuuuuuuiiiiiiiinnnnnnnnnnnnnnnnnnnnnnpppppppppppp tttttttttttt ppppppuuuuuuuuuuuuuuppppppppppppnnnnnnnnnnnnnnnnnnnnnnnniiiiiiiiiiiiiiiiiiiiii ppfffffffffffffffffffffffffffffffooooooofffffffffffooooooooofffffffffffffffffffffffffffffffffffffcrcccceeeeeeeeedisssttttttaaaaaaannnnnnceooooooooouuuuuuuutttttttttttttttpppppppputtttttfffffffffffffoooooooooorrrrrrrccccccccccceeeeeeeeeeeesmmmmalllllllllllllller input forceovvvvvvvvvvvveeeeeeeeeeeeeeerrrrrrrrrrrrrrrr gggggggreater distancegreater output forceSomeeeeee mmmmmmmmmmmmmaccccccccccccchhhhhhhhhhhhhhhhhiiiiiiiiiiiiiinnnnnnnnnnnnnnnnneeeeeeeeeeeeesssssssssss mmmmmmmmmmmmmmmmmaaaaaakkkkkkkkkkkkkkkeeeeeeeeee wwwwoooooooooooorrrrrrrrrrrrrrrkkkkkkkkkkkkk eeeasssssssssssiiiiiiiiiiiieeeeeeeeeeeeeeerrrrrrrrrrr bbbbbyy allowwwwwwwwwwwwwwiiiiiiiiiiinnnnnnnnnnnnnnnggggggggggggggg uuuuuuuuuuuuss to eeeeeeeeeeeeeeexxxxert a greater input force over ashoooorrrrrrrrrrrrrtttttttttttttter dddddddddddddiiisssssssssssssstttttttttttttttaaaaaaaaaaaaaaannnnnnnnnnnnnnnnnnncccccccccceeeeeeeee,,,,,,, iiiiiiiiiiiiinnnnnnnnnnnnnnn order to aaaaaaaaaaaaaaaccccccccccccchhhhhhhhhhiiiiiieevvvveeeeeeeeeeeeee aaaaaaaaaaaaaaa gggggggggggggggreaterrrr oooooooooooouuuuuuuuuuuutttttttttpppppppppppppppppuuuuuuuuuuuuuut distance. When using a hammer, ryooooooooouuuuuuuuuuuu exxxxxxxxxeeeeeeeerrrrrrrrrrrrrtttttttttttttttt aaaaaaaaa lllllllllllllaaaaaaaaaaarrrrrrrrrrggggggggggggggggeeeeeeeeee aaaaaaaaaaammmmmmmmmmmmmmooooooooouuuuuuuuuunnnnnnnnnnnnnnnnnttttttttttt of inpuuuuuuutttttttttttt fffffffffffffoooooooooooooooorrrrr aaaa ssssssssssshhhhhhhhhhhhhhhhooooooooort dissssssssstttttttttttttttaaaaaaaaaaaaaannnnce on the handle, while the head oooooooooooffffffffffffffff thhhheeeeeeeeeeeeeee hhhhhhhhhhhhhhhhhhhhhhhaaaaaammmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmeeeeeeeeeeeeeeeerrrrrrrrrr eeeeeeeeeeexxxxxxxxxxxeeeeeeeeerrrrrrrrrrrrrttttttttttttttttssssssssss aaaaaaaaaaaaaa sssssmmmmmmmmmaaaaaaaaaaaaaaallllllllllllllllllllllllllllllllllllllllleeeeeeeeeer outpuuuuuuuuttttttttttttt ffffffffffffffoooooooooooorrrrrceeeeeeeeeee tttttttttttttthhhhhhhhhhhhhhhaaaaaaaaaaaaaatttttttttttt is applied over a greater distance.For someeeeee mmmmmmmmmmmmmmmmmmaaaaaaaaaaccccchines, the direction of the exerted force is changed, while the input and output fooooooorrrrrrrrrrcccccccccccccceeeeeeeeeeeeeesssssssssss and distances remain equal. A pulley allows us to lift an object by pulling dowwwwwwwwwwnnnnnnnnnnnn ooooooooooooonnnnnnn a rope rather than having to lift the object up. output distanceinput distancepinput foprceoutputforceinput forceooooooooooooooooouuuuuuuuuuuuuuuuutttttput forcesize of input forcedirecccccccccccccttttttttttttttiiooooooooooooonnnnnnnnnnnnnnnof inppppppppppppuuuuuuuuuuuuuuttttttttttttttt fffffffffffffffooooooooooooorrrrrrrrrrrrcccccccccccccce MMMMMMMMMMMMMMaaaaaaaachines don’t change ttttttttttthhhhhhhhhhhhhhhhhheeeeeeeeeeeeeee aaaaaaaaaaammmmmmmmmmmmmmooooooooooooouuuuuunt of work that is done, but they dddddddddddddooooooooooooooooo make work easier. A machhhhhhhhhhhhhhhhhhiiiiiiiiiiiiinnne can help us by changing the size ooooooooooooooorrrrr theeeeeeeeeeeeee ddddddddddddddiiiiiiiiiiiiiiirrrrrrrrrrrrectioooooooooonnnnn oooooooooooffffff ttttthhhhhhhheeeee iiiiinnnnnnnpppppppppuuuuuttttttttttt ffforce, or both.SSSSSSSSSSSSSSSoooooooooooommmmmmmmmmmmmme machines mmmmmmmmmmmmmmmmmmaaaaaakkkkkkkkkkkkkkkkkkkeeeeeeeeeeee work easier by allowing us to exert a smaller input ffffffffffffffoooooooooooooooorrrrrrccccccccccccce, whileeeeeeeee aaaaaaaaaaaaaccccccccccccchhhhhhhhhhhhhhhieving a greater output force. To do this, theiiiiiiiiiiiiinpuuuuuuuuuttttttttttttt fffffffffffffffffoooooooooooooorrccccceee musssssssssttttttttt bbbbbbbeeeeeeeeee exerted over a greater distance. For example, whhhhhhhhheeeeeeeeeeeeennnnnnnnnnnnnnnnn lllllllllllllllloaaaaaaaaaaaddddddddddddddddddddiiiiiiiiiiiiinnnnnnnnnnnnnnng aaaaaaaaaaaa hhhhhhhhhhhhhhhhheeeeeeeeeeeeavy box onto a truck, it is easier to push the box uuppppppppppppppppp aaaaa rrrrrrrraaaaaaaaaaaammmmmmmmmmmmmmmmmmmmppppppppppppppppppppp tthhhhhhhhhhaaaaaaaaaaannnnnnnnnnnnnnn ttttttttttttto pick it up. Pushing the box requires less input forccceeeeeeeeeeee,,,,,, bbbbbbbbbbbbuuuuuuuuuuttttttt iiiiiiiiiittttttttttttt iiiiiiiiiiissssssssssssssss aaaaaaaaaaaaapplied over a greater distance.
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