# Vectors and FBDs

```PHYSICS 11
TODAY:
• Vectors and Displacement
One dimensional motion is the simplest form of motion
Example: A train can go only in one dimension
forward – backward along the tracks
What about the motion around the train???
Earth is spinning on its axis ,
so the train must be spinning
with Earth
What about the motion around the train???
At the same time, Earth is
spinning,
around the sun, and so is
the train
What about the motion around the train???
At the same time, the
sun and the rest of
solar system is
moving through our
galaxy
We choose a reference point at a specific time and
place against which we will measure changes in
position of the train
motion, WE MUST MAKE
THINGS SIMPLER!
We choose a reference point at a specific time and
place against which we will measure changes in
position of the train
It is called…
A system for specifying the precise location of an
object in space and time
STATION 1
For example: a departing
station along the train’s route
might be a great frame of
reference
As an object moves from one position to another, the
length of the straight line drawn from its initial to
the final position is called:
- Each arrows shows the magnitude (size) and direction
of a series of a dog’s trips
- The arrows are called VECTORS
- To give the direction of a vector we use two conventions:
NUMERICAL
COMPASS
(CARDINAL)
DIRECTION
What is the geckos'
displacement?
What if I changed zero on the meter
stick to the gecko’s initial position?
What would be its displacement
then?
Displacement vs Distance
WORLD MAP
Homework!!
- To determine the angle of the resulting displacement,
- To determine the angle of the resulting displacement,
we use TRIGONOMETRY
GRAPHICALLY
Pythagorean Theorem
and tangent function
(hypotenuse)2 = (leg 1) 2 + (leg 2) 2
leg 2
leg 1
opposite leg
tangent of angle  =
opposite
opposite leg
tangent of angle  =
opposite
2
d =
2
x +
2
y
d = 1928 km
Δy
𝜽 = tan−1 ( )
Δx
𝜽 = 37.0˚
What is the velocity that the car must
maintain in order to stay underneath the
plane?
opposite leg
sine of angle  =
hypotenuse
cosine of angle  =
hypotenuse
You need
to find vx
vx
cos(𝜽) = (
)
vplane
vx = cos(𝜽)(vplane)
You need
to find vx
vx = cos(𝟐𝟎˚)(𝟗𝟓 km/h)
vx = 𝟗𝟎 km/h
You need
to find vx
Sand trap
Tee shot
Putting green
Worksheets on Vectors
Operations
```