LAB: MOTION ON HILLS-REPORT - North Seattle Community College

LAB: MOTION ON HILLS-REPORT
Planning:
Planning is what we do before coming into the laboratory. This involves writing a
purpose and planning how to make measurements to generate experimental data.
Purpose: Write a purpose statement for this lab in the space below.
What is the Relationship between ___________ and ____________ for the situation
of _________________________________________________________________
Establish a connection: between measured data and the experimental
variables (these are in the purpose statement). .
1. Connecting with an equation. What is the
This lab is about velocity (this variable
equation that allows you to calculate the
is one of the two that should be in the
average velocity from position
purpose statement.
measurements? Give the equation and
give an example of the calculation.
You need to identify
Follow the guideline from page 6 of the handout
how you plan to get
velocity information
“How to Write a Formal Lab Report”. This handout
from position
is from the Lab Materials Tab in Angel.
information
We are measuring position and _________.
2. Connecting from a graph. You should also be able to get velocity information
from an x vs t graph. This is done by looking at the ___________ of the tangent
line.
𝑆𝑙𝑜𝑝𝑒 =
(9 − (−1))𝑚
(5 − 0.8)𝑠𝑒𝑐
𝑚
= 2.4 𝑠
You would then plot 2.4 m/s as
the velocity at 2.8 sec on a
velocity vs time graph.
In the analysis, you will
plot an x vs t graph of your
data, Draw the best-fit line,
use colored pencils to draw in
several (at least 5) tangent
lines, calculate their slopes,
and add the velocities and
times to your formal data table.
Phys. 114: Lab-Motion on Hills-Report
North Seattle Community College: Davene Eyres
rev. 4/15
Lab: Motion on Hills
Page 2
Theory:
After writing the purpose, we need to think about what we expect the relationship to be.
This will be stated in the theory. In this lab, we are looking at the relationship between
velocity and time for an object moving down a hill. To assist you in thinking about the
theory, you should complete each of the following tasks.
1. Draw a motion diagram (strobe photos & velocity vectors with a coordinate system).
x=0
2. Sketch a position vs time graph for this motion. In this case,
you cannot predict specific times and positions that will match
the experiment. The shape of the graph is the important thing
this time.
3. Look up in your text a sentence that talks about motion down a
hill. Give the quote. In parentheses after the quote place:
authors, year, page number as in (Knight, Jones, & Field, 20xx, p. #).
Procedure:
You were given a procedure in the handout. However there are some elements that were
left out of that procedure.
 Give directions for establishing the initial conditions of each run.

Give one additional element of the equipment set-up that you would add to the
steps given in the directions document.
Phys. 114: Lab-Motion on Hills-Report
North Seattle Community College: Davene Eyres
rev. 4/15
Lab: Motion on Hills
Page 3
Data
Individually Create a formal data table as instructed in the directions document.
You should also have velocities that you calculated using the tangent line slopes from
your x vs t graph. Be sure to include these velocities and times as, either an addition to
the formal table you made or as an additional table. Each member of your group should
have created their own individual table. As a group, decide the best answer to each of the
questions in the analysis section.
Analysis
Individually Plot an x vs t graph. Draw the best-fit line, use colored pencils to
draw in at least 5 tangent lines, calculate their slopes, and add the velocities and times
to your formal data table. Alternately, you may create an additional table for this velocity
information.
Individually Plot a v vs t graph. You should have all the velocity and middle time
points from the derived data in your table. (Remember I told you these would be ugly.)
Then, using a different color, add the points from the velocity and time you found from
the tangent lines. Include a key. Draw on best-fit straight line through your data. Using
your best-fit line, write the equation of the line on your graph. Be sure to format it
properly.
Answer the following questions based on the values in the formal data
table:

Explain how the x and t values in the formal data table indicate information about
the velocity of the cart. (Hint: Do the values indicate constant speed, speeding
up, or slowing down? What about the numbers gives you this understanding?)

Explain how the v and t values in the formal data table indicate information about
the velocity of the cart. (Hint: Do the values indicate constant speed, speeding
up, or slowing down? What about the numbers gives you this understanding?)

Are the values in the formal data table what you expected? Why or why not?
Phys. 114: Lab-Motion on Hills-Report
North Seattle Community College: Davene Eyres
rev. 4/15
Lab: Motion on Hills
Page 4
Answer the following questions based on the information you gather
from the x vs t graph:

Explain how the x vs t graph best-fit-line shape indicates information about the
velocity of the cart.

What does the x vs t graph show about the speed of the cart at t=0 sec? Explain
your reasoning.
Answer the following questions based on the information you gather
from the v vs t graph:

Explain how the v vs t graph best-fit-line shape indicates information about the
velocity of the cart

What data derivation technique (calculating in the formal data table or tangent
lines) seemed to give you the best v vs t graph? Explain why.
Using the equation of the best-fit line:
 What is the quantity that is described by the slope? Hint: Look at the slope units.

What is the meaning of the vertical axis intercept?
Phys. 114: Lab-Motion on Hills-Report
North Seattle Community College: Davene Eyres
rev. 4/15
Lab: Motion on Hills
Page 5
What to turn in:
Each individual shall turn in all of the following. Remember to do all
graphs, tables, and writing with your own words, drawings, and
calculations.




This report document with all questions answered.
Formal data table: be sure to include the velocity information from your
tangent lines as an addition to this table or a separate table.
x vs t graph with at least 5 tangent lines. Be sure to use the correct graph
paper.
v vs t graph with your equation of the line in proper format.
Phys. 114: Lab-Motion on Hills-Report
North Seattle Community College: Davene Eyres
rev. 4/15