FORCE VECTORS

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FORCE VECTORS

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ENERGY (E)
Mechanical Energy System
Force
Fluid Energy System
Pressure
Electrical Energy System
Voltage
Thermal Energy System
Temperature difference
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Mechanical Energy
Mechanical energy is ME PE KE
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The Prime Mover of the Mechanical Energy System
is
FORCE What is it?
Force is a push or a pull
Force can
Make an object start/stop moving or move faster
or slower
Change an objects direction
Change an objects shape
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Sir Isaac Newtons 2nd Law
Force equals mass times acceleration
or F M x A
Mass lbs or Kg
Acceleration ft/s/s or m/s/s
So if F M x A then F kgm/s2 or Newton
(N)
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Force Vectors
A quantity with both magnitude and direction
is called a vector
ie push the cart for 200 to the backyard
drove 35 mph to the east (velocity)
A quantity with just a magnitude is a
scalar measurement
ie 76 degrees 45 mph (speed)
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Force Vectors
Vectors represent magnitude and direction through
arrows
45 mph
East
Referenced to horizon or East/West
line.also, magnitude is determined by scale 1
10 mph
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North of East
North of West
South of East
South of West
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G 8 lbs
45 lbs of Force
30 degrees
Approx. 8 lbs of resistance
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100 lbs
45 lbs
30 deg
Approx 100 lbs of resistance
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1 10 lbs 4.5
45 lbs
30 deg
4.5
This is stated as 45 lbs _at_ 30 deg. north of
east
Use a ruler and protractor to be precise.
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When forces are 180 deg apart
20 lbs
10 lbs
simply subtract20 lbs 10 lbs R R 10
lbs
Resultant (R) 10 lbs _at_ East
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When forces act in the same direction
10 lbs
20 lbs
simply add.10 lbs 20 lbs R
R 30 lbs _at_ E
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When forces have a zero resultant, or a net sum
of zero
the forces are said to be balanced.
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When forces have a resultant, or net sum.
the forces are unbalanced.
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45 lbs
30 deg.
W
E
Scale 1 10-lbs
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To add vectors 45 lbs _at_ 30 deg N of E and 20 lbs
_at_ W use graphical method
150 deg
45 lbs
R
30 deg.
W
E
20 lbs
Scale 1 10-lbs
Measure R for Magnitude and Direction
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Finding the R
R 3.75
R
72 deg
W
E
If 1/10lb x 3.75/X then, X 37.5 lbs
So R 37.5 lbs _at_ 72 deg N of E
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Lets try a problem
4 N _at_ 45 deg N of E
6 N _at_ West
4 N
45 deg
R
6 N
Resultant (R) 4.5 N _at_ 43 deg N of W
Scale 1 2 N