Dasha's Work Input/Work Output Page Here are links to my other pages ~ Home Page~ Friction~ Calculating ~ Practice-Quiz~ Practice-Quiz Answer~ Bibliography~ The more efficient the machine, the lower the input work ( the work put into doing the task) will be. You always want someone to do the minimum amount of work. To get the lowest amount of input work is hard because work equals distance times force, and the more distance the less force and the less distance the more force. That is why you have to balance out the two as well as possible to get a small amount of input work. Mechanical efficiency depends on the output work ( the work required to do the task) divided by the input work. The smaller the input work or the smaller the denominator, the bigger the number or the bigger the efficiency will be in the end.
DEFINITIONS:
WORK INPUT- The work required to do the task
WORK OUTPUT- The work put into doing the task
Notes
Input Work (Win) and Output Work (Wout) are part of the calculation for Mechanical Efficiency (ME). For example ME=Wout/Win x 100
You find out the Output Work by using the weight of the object you are trying to move and multiplying it by the height you want to get it to. For example Wout = 200N x 3m
You find out the Input Work by using the force you used to move the object and multiplying it by the distance that you moved it. For example Win= 100N x 2m
REMEMBER: You always want the input work to be less because that way the efficiency will be higher. For example ME= (Wout)60J / (Win)200J x 100= 30%, but 60J/120J x 100= 50%
Examples
A man is trying to lift a 500N rock 2m in the air.---- If you multiply that together it would be output work. The man uses a lever, he had to use a force of 200N and he pushes his side of the lever down 4m.------ If you multiply that together it would be the output work. The you divide the output work by the input work, multiply it by 100 and you get the mechanical efficiency.
A mover is trying to get a 640N box up 3m.----- Output work. the mover uses a ramp, she had to use a force of 450N and a distance of 6m to get the box to that height.----- Input work. Then you divide the output work by the input work, multiply it by 100 and you get the mechanical efficiency.
A girl needs to get her weight of 10N, 1m in the air.------- Output work. She decides to use a pulley. she uses a force of 4N and pulles her side of the rope 2m in the air.------ Input work. You take the output work and divide it by the input work, multiply it by 100 and you get the mechanical efficiency.
Here are links to my other pages
~ Home Page~ Friction~ Calculating ~ Practice-Quiz~ Practice-Quiz Answer~ Bibliography~
The more efficient the machine, the lower the input work ( the work put into doing the task) will be. You always want someone to do the minimum amount of work. To get the lowest amount of input work is hard because work equals distance times force, and the more distance the less force and the less distance the more force. That is why you have to balance out the two as well as possible to get a small amount of input work. Mechanical efficiency depends on the output work ( the work required to do the task) divided by the input work. The smaller the input work or the smaller the denominator, the bigger the number or the bigger the efficiency will be in the end.
DEFINITIONS:
WORK INPUT- The work required to do the task
WORK OUTPUT- The work put into doing the task
Notes
REMEMBER: You always want the input work to be less because that way the efficiency will be higher. For example ME= (Wout)60J / (Win)200J x 100= 30%, but 60J/120J x 100= 50%
Examples