unlike your everyday experience, where you go to an after school job and earn money, work in physics...
TRANSCRIPT
![Page 1: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/1.jpg)
![Page 2: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/2.jpg)
Unlike your everyday experience, where you go to an
after school job and earn money, work in physics does
not pay for your car insurance.
Work has a special meaning in physics.
![Page 3: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/3.jpg)
Work is done on an objectwhen a force is applied to an object and the object is displaced.
Units: Newton x Meter (Nm)
Work is a scalar quantity
Do not confuse applying a force with doing work.
Work is only done if the object moves a distance.
Pushing or pulling on an object may make you sweat but you do no work unless it moves.
W Fd cosOnly the force parallel to the direction
of the displacement does work.
units Nm J Joule:
Work = Force x displacement (cosine of angle for the portion of the force parallel to the distance traveled)
![Page 4: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/4.jpg)
A teacher applies a force to a wall and becomes exhausted.
A book falls off a table and free falls to the ground.
A waiter carries a tray full of meals above his head by one arm across the room. (Careful! This is a tricky question.)
A rocket accelerates through space.
Read the following five statements and Read the following five statements and determine whether or not they represent determine whether or not they represent
examples of work.examples of work.
NO
NO
YES
YES
![Page 5: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/5.jpg)
Power
![Page 6: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/6.jpg)
In Physics Power is the Rate of Doing
Work
PW
t
Fd
t
cos
PowerWork
time
unitsNm
sW Watt:
![Page 7: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/7.jpg)
A watt is a small unitIf you lift a glass of water (~2N) to
your mouth (~0.5 m) in 1 second you do one joule of work and you are doing work at rate of one watt
Since a watt is relatively small, power is often measured in
kilowatts (kW)
![Page 8: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/8.jpg)
Simple Machines
![Page 9: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/9.jpg)
Simple Machines
A simple machine is an object with few moving parts that redirects an
applied force to perform work. Usually a simple machine is
used to reduce the force needed to perform a task.
![Page 10: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/10.jpg)
![Page 11: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/11.jpg)
Simple Machines and Rube Goldberg
![Page 12: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/12.jpg)
Work and Machines• Force of Effort - Fe - The amount of force
that is applied to the machine.
• Force of Resistance - Fr - The amount of force that the machine applies.
• Distance of Effort - de - The distance the force of effort is applied.
• Distance of Resistance - dr - The distance the machine applies the force.
![Page 13: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/13.jpg)
Force of Effort
Force of ResistanceForce of Resistance
![Page 14: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/14.jpg)
Force of Effort
Forc
e o
f R
esi
stan
ce
Distance of E
ffort
Dis
tan
ce o
f R
esi
stan
ce
![Page 15: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/15.jpg)
L e
v e
r
![Page 16: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/16.jpg)
F1 = Fr = Force of Resistance
F2 = Fe = Force of Effort
D1 = dr = Distance of Resistance
D2 = de = Distance of Effort
Fulcrum = Pivot Point
Lever
![Page 17: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/17.jpg)
Lever ClassesFirst Class Lever
Second Class Lever
Third Class Lever
Fulcrum - Resistance - Effort
Effort - Fulcrum - Resistance
Fulcrum - Effort - Resistance
![Page 18: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/18.jpg)
First Class Lever
![Page 19: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/19.jpg)
![Page 20: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/20.jpg)
![Page 21: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/21.jpg)
Pulleys redirect the force of effort.The number of pulleys and their arrangement can reduce the amount of effort force needed to raise a particular load. The number of lifting strands will
determine the advantage to using a pulley system
![Page 22: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/22.jpg)
1 Lifting Strand
2 Lifting Strands2 Lifting Strands
3 Lifting Strands 3 Lifting Strands
Pulleys
How How many many lifting lifting strands strands for each for each pulley pulley system?system?
![Page 23: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/23.jpg)
![Page 24: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/24.jpg)
![Page 25: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/25.jpg)
Wi = Work Input – The Amount of Work applied to the machine
Wo = Work Output – the Amount of Work transferred by the machine
Wi = Fede
Wo = Frdr
Fe=Force of Effort
Fr=Force of Resistance
de=Distance of Effort
dr=Distance of Resistance
![Page 26: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/26.jpg)
Mechanical Advantage = MAF
Fr
e
Ideal Mechanical Advantage = IMAd
de
r
EfficiencyW
W
F d
F dxo
i
r r
e e
100 00
EfficiencyMA
IMAx 100 0
0
![Page 27: Unlike your everyday experience, where you go to an after school job and earn money, work in physics does not pay for your car insurance. Work has a special](https://reader036.vdocument.in/reader036/viewer/2022062518/56649e9f5503460f94ba24a3/html5/thumbnails/27.jpg)