Unpacking an 8th Grade Science Standard
Standard
Grade 8th Science
Strand 5: Physical Science
Concept 2: Motion and Forces
PO 1. Demonstrate velocity as the rate of change of position over time.
Learning Sequence
Do
(Process Skills)
END GOAL: demonstrate
Know
(Content)
𝑥
𝑣=
𝑡
Produce
Describe
Describe and represent
Define
Describe
Recognize and represent
Define
Recognize
Describe
One dimensional integer coordinate systems
Relativity of origin in coordinate systems
Physical, measurable quantities as variables (xi, xf, v, t)
Position, initial position, and final position
Difference between vector and scalar quantities
Position can be negative or positive and is a vector quantity
Distance
Distance has no direction and is a scalar quantity
The change between two measurable quantities as being a
difference
Changes in variables by using 
Displacement as x and the change in position
Examples of positive and negative displacement
Two dimensional integer coordinate systems
Instantaneous time and time interval
Time, initial time, final time, change time
Two dimensional coordinate systems with position as a
vertical variable and time as a horizontal variable
Two variable relationships on a 2 dimensional coordinate
system
Data collection techniques for position and time relationships
1 dimensional linear motion (by showing or creating an
example)
motion of an object by describing behavior using position,
distance, displacement and instantaneous time, and time
Represent
Define
Identify
Produce
Compare and contrast
Define
Draw
Discuss
Describe
Observe and summarize
Articulate
Calculate and compare
Discuss
Determine
Discuss
Recognize
Discuss
Write
discusses
Discusses
Identifies
Measures
Discuss and justify
Conduct
Records
Discuss
Discuss
Graphs
Interprets
Discusses
Draws
Discus
Articulates
Identifies
interval
Distance and displacement of an object between various
given time intervals
Data collection methods
Appropriate and inappropriate ways to collect data
Observations and bias
The need for various methods for controlling for
experimental error
Amount of data needed to formulate reliable conclusions
Scientific plans and notes in a place that can be reviewed
again (such as a lab notebook)
Correct scientist units of measure (m, k, s units)
Reasoning for using standardized measuring systems
Units of measure on measuring tools
Something and uses correct notation when recording
measurement
A plan for collecting position and time data for an object
moving in 1 dimension (including a plan for error control,
multiple trials, data collecting, data recording, etc.)
A controlled experiment to collect data for position and time
for an object engaged in 1 dimensional linear motion (teacher
note: with constant velocity)
Data with correct units, observational notes while using
appropriate organizational structures (data tables, sentences,
lists, etc.)
Data points represent specific, isolated points in time using
the terms instantaneous time, position, meters, centimeters,
seconds
Inferences between data points (one to another) using terms
time intervals, distance, displacement, initial position, final
position, initial time, final time, meters, centimeters, seconds
Data points on graph using appropriate units of measures and
labels (ex: 2 sec, 4 cm)
Meaning of data points on graph (why it is not a line yet, why
points may not be in an obvious pattern) while using
appropriate units of measure
How scientists can use graphs to mathematically model
reality and why numbers always have units of measure
Best fit line
The meaning of a best fit line and acknowledges that the line
is not an exact representation of the data
How graph, data, explanation, observations all represent the
motion of the object using terms and proper units of measure
Position, displacement, distance, time (interval and
instantaneous) using their graph (including positive or
negative when appropriate)
Define
Discuss
Identify
Articulate
Use
Calculate
Articulate
Define
Articulate
Use
Speed as a scalar quantity dependent on distance and time
interval
The units of measure of speed meters/sec
/ = per and discuss what that might mean (for every…, in a…,
etc.)
That speed is how far something goes every one unit of time
(without using the word per)
Mathematical notation to represent speed
∆𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒
𝑠𝑝𝑒𝑒𝑑 =
∆𝑡
Or
𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒𝑓𝑖𝑛𝑎𝑙 − 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒𝑖𝑛𝑖𝑡𝑖𝑎𝑙
𝑠𝑝𝑒𝑒𝑑 =
𝑡𝑓 − 𝑡𝑖
Speed of object using graph using two points and appropriate
units of measure
Speed and the meaning including units of measure (ex: 2 m/s
Velocity as a vector quantity dependent on displacement and
time
Velocity as how far something ended from where it started
(in the time interval) for every one unit of time (without
saying per)
Mathematical notation to represent velocity (also see
equivalency between both)
𝑥 −𝑥
∆𝑥
𝑣=
or 𝑣 = 𝑓 𝑖
∆𝑡
Calculate
Compare and contrast
Discuss
𝑡𝑓 −𝑡𝑖
Velocity of object using two points and appropriate units of
measure
Speed and velocity calculations
when speed and velocity may be the same and when it will be
different
Objective for First Lesson
Students will describe position as a vector by representing 3 examples (two positive, one negative) on a
student produced one dimensional coordinate system.
Do
(Process Skills)
Produce
Describe
Describe and represent
Define
Know
(Content)
One dimensional integer coordinate systems
Relativity of origin in coordinate systems
Physical, measurable quantities as variables (xi,
xf, v, t)
Position, initial position, and final position