# Work, Power, & Machines What is work Is work being done or not Calculating Work All or part of the as long as ce must act in the direction of the movement.

## Work, Power, & Machines What is work Is work being done or not Calculating Work All or part of the as long as ce must act in the direction of the movement.

Lazenby, Aaron, Features Editor has reference to this Academic Journal, PHwiki organized this Journal Work, Power, & Machines What is work The product of the as long as ce applied to an object in addition to the distance through which that as long as ce is applied. Is work being done or not Mowing the lawn Weight-lifting Moving furniture up a flight of stairs Pushing against a locked door Swinging a golf club YES YES YES NO YES

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Calculating Work All or part of the as long as ce must act in the direction of the movement. Do you do more work when you finish a job quickly Work does NOT involve time, only as long as ce in addition to distance. No work is done when you st in addition to in place holding an object. Labeling work: w = F x d Newton X meter (N m) Which also = (kg x m2) s2 The Joule 1 newton-meter is a quantity known as a joule (J). Named after British physicist James Prescott Joule.

How quickly work is done. Amount of work done per unit time. If two people mow two lawns of equal size in addition to one does the job in half the time, who did more work Same work. Different power exerted. POWER = WORK / TIME The watt A unit named after Scottish inventor James Watt. Invented the steam engine. P = W/t Joules/second 1 watt = 1 J/s watts Used to measure power of light bulbs in addition to small appliances An electric bill is measured in kW/hrs. 1 kilowatt = 1000 W

Horsepower (hp) = 745.5 watts Traditionally associated with engines. (car,motorcycle,lawn-mower) The term horsepower was developed to quantify power. A strong horse could move a 750 N object one meter in one second. 750 N Machines A device that makes work easier. A machine can change the size, the direction, or the distance over which a as long as ce acts. Forces involved: Input Force FI Force applied to a machine Output Force FO Force applied by a machine

Two as long as ces, thus two types of work Work Input work done on a machine =Input as long as ce x the distance through which that as long as ce acts (input distance) Work Output Work done by a machine =Output as long as ce x the distance through which the resistance moves (output distance) Can you get more work out than you put in Work output can never be greater than work input. Mechanical Advantage (MA)  expressed in a ratio WITH NO UNITS!! The number of times a machine multiplies the input as long as ce.

2 types of mechanical advantage IDEAL Involves no friction. Is calculated differently as long as different machines Usually input distance/output distance ACTUAL Involves friction. Calculated the same as long as all machines Different mechanical advantages: MA equal to one. (output as long as ce = input as long as ce) Change the direction of the applied as long as ce only. Mechanical advantage less than one An increase in the distance an object is moved (do) Efficiency Efficiency can never be greater than 100 %. Why Some work is always needed to overcome friction. A percentage comparison of work output to work input. work output (WO) / work input (WI)

1. The Lever A bar that is free to pivot, or move about a fixed point when an input as long as ce is applied. Fulcrum = the pivot point of a lever. There are three classes of levers based on the positioning of the ef as long as t as long as ce, resistance as long as ce, in addition to fulcrum. First Class Levers Fulcrum is located between the ef as long as t in addition to resistance. Makes work easier by multiplying the ef as long as t as long as ce AND changing direction. Examples: Second Class Levers Resistance is found between the fulcrum in addition to ef as long as t as long as ce. Makes work easier by multiplying the ef as long as t as long as ce, but NOT changing direction. Examples:

Third Class Levers Ef as long as t as long as ce is located between the resistance as long as ce in addition to the fulcrum. Does NOT multiply the ef as long as t as long as ce, only multiplies the distance. Examples: Levers!!!!!!!!!!! Mechanical advantage of levers. Ideal = input arm length/output arm length input arm = distance from input as long as ce to the fulcrum output arm = distance from output as long as ce to the fulcrum

2. The Wheel in addition to Axle A lever that rotates in a circle. A combination of two wheels of different sizes. Smaller wheel is termed the axle. IMA = radius of wheel/radius of axle. 3. The Inclined Plane A slanted surface used to raise an object. Examples: ramps, stairs, ladders IMA = length of ramp/height of ramp Can never be less than one. 4. The Wedge An inclined plane that moves. Examples: knife, axe, razor blade Mechanical advantage is increased by sharpening it.

5. The Screw An inclined plane wrapped around a cylinder. The closer the threads, the greater the mechanical advantage Examples: bolts, augers, drill bits 6. The Pulley A chain, belt , or rope wrapped around a wheel. Can either change the direction or the amount of ef as long as t as long as ce Ex. Flag pole, blinds, stage curtain Pulley types FIXED Can only change the direction of a as long as ce. MA = 1 MOVABLE Can multiply an ef as long as t as long as ce, but cannot change direction. MA > 1

MA = Count of ropes that apply an upward as long as ce (note the block in addition to tackle!) Fe A combination of two or more simple machines. Cannot get more work out of a compound machine than is put in.

## Lazenby, Aaron Features Editor

Lazenby, Aaron is from United States and they belong to Profit: The Executive’s Guide to Oracle Applications and they are from  Redwood City, United States got related to this Particular Journal. and Lazenby, Aaron deal with the subjects like Business; Databases; Information Technology Industry; Investing

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