Transcript Vectors, Vectors EVERYWHERE

Vectors
OK, so what are these
vector thingamajigs?


A vector is a value / measurement
Vectors have MAGNITUDE and
DIRECTION
– Displacement, velocity, acceleration,
force, momentum, etc.
– As opposed to a SCALAR which only has
magnitude (mass, temperature, time,
etc.)

Use an ARROW
the value
to represent
Remember…
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Don’t make this harder than it needs
to be
We use arrows to represent ANY
vector to SIMPLIFY things
We can then use GEOMETRY / TRIG to
break the vectors down
EXAMPLES
A car moves to the right 286 m
y
x
286 m
DISPLACEMENT
VECTOR
EXAMPLES
A girl walks south at 0.2 m/s
N
E
0.2 m/s
VELOCITY
VECTOR
EXAMPLES
A person pulling a rope to the left 30°
above the horizontal with a force of 10 N
y
10 N
30°
FORCE
VECTOR
x
Adding Vectors
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A + B = B + A = R (Resultant)
ALWAYS add Tip To Tail (T3)
A
y
B
A
R
B
B
A
x
EXAMPLE:
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You are crossing a river:
– Current is moving at 1.2 m/s
– You can swim at 0.85 m/s
NO CURRENT
vs + vc = vR
Vector Components

Every vector has an x and y
component (depends on coordinates)
y
Ay
Ax + Ay = A
A
Ax
x
Solving for Components
y
A = 15 m/s
Ay
30°
x
Ax
Components
y
V0y
V0
θ
x
V0x
Practice Problem #1

You are lost in the wilderness and
when you try to go and find help, you
just end up getting more lost. You
realize you walked (from your starting
point) 264 m at 280° and 118 m at
25° (all compass headings). What is
your final displacement from your
start?