Kermit Learns
Kinematics Quantities
Don’t let the
details leave
you in the
dust!
KL physics 10
Kinematics is…
The physics of
how
an object moves:
How
far
does it go.
How
fast
does it go.
How
fast
it gets faster or slower.
How
long
does it take.
Vector
Scalar
Distance
Displacement
Speed
Instantaneous Speed
Velocity
Acceleration
Watch for these vocabulary words.
Vector and Scalars, Huh?
Magnitude
–
a measure of the size, amount or quantity of an object
(how many, how much)
Example:
Sai
wears an
extra large
t

shirt
My physics book has a
mass of 3 kg
.
Scalar

a quantity that has
magnitude
only.
Example: I waited for
30 minutes
.
He
drove
75 mph
.
Vector
–
a quantity that has
magnitude
and
direction
.
Example: You drive
50 miles
east
.
The plane flies
300 mph
south
.
Distance vs.
Displacement
How far did it travel?
Start
Finish
distance
Displacement
is the difference in
position from start to finish.
The symbol is
𝑑
.
The unit for displacement is meters
Distance
is the length of the path
from start to finish.
The symbol is d.
The unit for distance is meters
An object travelling in only one direction will have the same distance and displacement.
Speed
vs
Velocity
How fast is it moving?
Speed
Velocity
A measure of how fast an object’s
position changes.
A measure of how fast
an object position
changes and the direction of motion
The ratio of distance traveled to time
interval
Velocity is the ratio of displacement to
time interval
Scalar (magnitude only)
Vector (magnitude and direction matter)
The symbol for speed is v
The symbol for velocity is
𝑣
Measured in units of m/s.
Velocity is measured in units of m/s
An object traveling in one direction only will have the same speed and velocity.
Instantaneous Speed
Good news! No equation!
This is the speed at a single instant in
time.
When you check your speedometer
you are checking instantaneous
speed.
Kermit wants to know…
What if I want to change my speed?
Possible responses:
Too bad for you.
Why would you do that?
Isn’t this speed good enough?
What do you mean?
I’m sure there’s some physics to
learn about.
Acceleration
How fast did it get faster or slower
or did it turn the corner?
Acceleration
It is a change in velocity.
(speed and/or direction)
Vector (direction and magnitude)
The ratio of velocity to time interval
The symbol for acceleration is
𝑎
.
Acceleration is measured in units of m/s
2
.
If an object is speeding up, slowing down or changing direction it is accelerating.
Apply this to your life…
When you are riding in a car think about how
the direction and speed are changing as the car
moves along.
Is the speed constant?
Is the direction changing?
Is the velocity constant?
Is the
car accelerating?
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