Essay On Work And Work

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Work and Energy
According to Holt Physical science, work is the “transfer of energy to a body by the application of a force that causes the body to move in the direction of the force” (Holt 378). Work is equal to force multiplied by distance, meaning that in order to do work something has to move. Energy is “the capacity to do work” (Holt 73). Energy is transferred or transformed whenever work is done. Work requires an object to experience a change in position or motion but energy can be present even when nothing appears to be happening. Both work and energy are measured in Joules.
Work
In order for work to be done force has to cause a change in the position or motion of the object in the direction from which the force comes from. Meaning, the object that the force is applied to has to move in order for it to be considered work. So if you tried to push a wall and the distance the wall moved is zero then the work done on the wall is zero. However you are doing work on your muscles in your body. Your muscles contract over and over again and with each contraction a tiny amount of work is being done, but after a while this can add up to a lot of work.
“The distance (or displacement) in work is the distance from the start point to the end point” (ducksters). So if you pick up a book and then put it back down in the same spot the distance is zero. “Distance is used rather than displacement in the simple definition because the force acting may take a windy path” (WORK, ENERGY & POWER). Direction does not matter in work.
Work is often measured in joules. Joules is: newtons times meters, or N X m. One joule is equivalent to 1 kg X 1 kg X m2/s2. “Because these units are equal, you can choose whichever unit is easiest for s...

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...ultiplies the input force…A machine with a mechanical advantage of less than 1 does not multiply force, but increases distance and speed” (Holt 383). ­If something has a MA of exactly 1 it means that the machine has no mechanical advantage or disadvantage.
There are two types of mechanical advantages: ideal mechanical advantage (IMA) and actual mechanical advantage (AMA). Ideal mechanical advantage is the MA of a machine that is ideal. Meaning, the machine is 100% efficient so it doesn’t have the effects of friction. There are no ideal machines, so It’s theoretical and it is calculated using physics principles. The equation for IMA is: IMA= effort distance/ resistance of distance. Actual mechanical advantage is MA of a real machine. It takes in consideration things like friction. The equation for AMA is: AMA=resistance force /actual effort force.

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