NORTHERN ILLINOIS UNIVERSITY PHYSICS DEPARTMENT Physics 253 – Basic Mechanics Fall 2016 Lab #11 Lab Writeup Due: Mon/Tue/Wed/Thu, Nov. 28/29/30, Dec. 1, 2016 Read Giancoli: Chapter 10 (Lecture Notes #13) Rolling Apparatus In this experiment a sphere, disk, and cylinder are rolled down an inclined plane with a raised guide to keep it on the track. Two photogates are positioned over the track to measure the velocity of each object at the position of each photogate. Each photogate only records the elapsed time between the when the object enters and leaves the photogate. The experimenter must determine the width d of the object as seen by the photogate detector to determine the velocity through each photogate. Theory Velocity is the time rate of change of position of an object. If the width, d , of an object and the time, t , it takes to pass a point are both known, the average velocity is ave d v t   (1) Angular velocity is the time rate of change of the angle of a rotating object, measured in radians per second (rad/sec). For an object that rolls without slipping the angular velocity is related to its linear velocity as v d R R t     (2) The resistance of an object to a force (the inertia of an object) is caused by the object’s mass. The resistance of an object to a torque (a force that causes a rotation) is caused by the object’s moment of inertia (which is related to the object’s mass and how far the mass is from the axis of rotation: 𝐼~𝑚𝑅2). This is why when a figure skater on ice brings in her arms she rotates faster—her moment of inertial is smaller because more of her mass is closer to her body (her effective radius decreases). Decreasing the moment of inertia makes it easier for her to rotate (her rotational inertial decreases). Objects in motion possess kinetic energy K . If the object is rolling it has kinetic energy due to the forward motion of its center of mass, CM K , and its rotation, rotK . Translational kinetic energy is based on the mass and velocity, 21 2CM CM K mv . Rotational kinetic energy about the center of mass is based on the moment of inertia and angular velocity, 21 2 CMrot K I  . 2 21 1 2 2 CM CMK mv I   (3) Using Eq. (2) we can convert velocity to angular velocity:  2 2 2 2 2 2 1 1 1 1 2 2 2 2 CM CMK mR I I mR I        (4) Notice that we have derived the parallel-axis theorem: 𝐼 = 𝐼𝐶𝑀 + 𝑀ℎ 2 where, in the situation for this lab, the object rolls about an axis at the point where it touches the ramp, thus ℎ = 𝑅. As a disk rolls down a slope the gravitational potential energy, gU mgh , is converted into kinetic energy and thermal energy thermalE caused by sliding rather than rolling. If the initial and final angular velocities are i and f , then the relationship for the conservation of e

1. NORTHERN ILLINOIS UNIVERSITY
PHYSICS DEPARTMENT
Physics 253 – Basic Mechanics Fall 2016
Lab #11
Lab Writeup Due: Mon/Tue/Wed/Thu, Nov. 28/29/30, Dec. 1,
2016
Read Giancoli: Chapter 10 (Lecture Notes #13)
Rolling
Apparatus
In this experiment a sphere, disk, and cylinder are rolled down
an inclined plane
with a raised guide to keep it on the track. Two photogates are
positioned over the track
to measure the velocity of each object at the position of each

2. photogate. Each photogate
only records the elapsed time between the when the object
enters and leaves the
photogate. The experimenter must determine the width d of the
object as seen by the
photogate detector to determine the velocity through each
photogate.
Theory
Velocity is the time rate of change of position of an object. If
the width, d , of an
the average velocity is
ave
d
v
t
(1)
Angular velocity is the time rate of change of the angle of a
rotating object,

3. measured in radians per second (rad/sec). For an object that
rolls without slipping the
angular velocity is related to its linear velocity as
v d
R R t
(2)
The resistance of an object to a force (the inertia of an object)
is caused by the
object’s mass. The resistance of an object to a torque (a force
that causes a rotation) is
caused by the object’s moment of inertia (which is related to the
object’s mass and how
far the mass is from the axis of rotation: �~��2). This is why
when a figure skater on
ice brings in her arms she rotates faster—her moment of inertial
is smaller because more
of her mass is closer to her body (her effective radius
decreases). Decreasing the moment
of inertia makes it easier for her to rotate (her rotational inertial

4. decreases).
Objects in motion possess kinetic energy K . If the object is
rolling it has kinetic
energy due to the forward motion of its center of mass,
CM
K , and its rotation, rotK .
Translational kinetic energy is based on the mass and velocity,
21
2CM CM
Rotational kinetic energy about the center of mass is based on
the moment of inertia and
angular velocity,
21
2 CMrot
2 21 1
2 2
Using Eq. (2) we can convert velocity to angular velocity:

5. 1 1 1 1
2 2 2 2
Notice that we have derived the parallel-axis theorem: � =
��� + �ℎ
2 where, in the
situation for this lab, the object rolls about an axis at the point
where it touches the ramp,
thus ℎ = �.
As a disk rolls down a slope the gravitational potential energy,
converted into kin
caused by sliding rather than
, then the relationship for
the conservation of energy is:
�� + �� = �� + �� + ∆��ℎ�����
.
1
2
���

6. 2 + ��ℎ� =
1
2
���
2 + ��ℎ� + ∆��ℎ����� (5)
This equation [and using Eq. (4)] can be rearranged to solve for
the moment of inertia
about the center of mass, ���. Sliding (or slipping) is
relatively small (hopefully), so
neglecting the thermal energy it generates gives:
.
2
2 2
2 ( )
f i
CM
i f
mg h h
I mR

7. (6)
Data Collection
(1) Measure the mass and diameter of each object. Record this
in your logbook.
(2) Measure the height of the track at each photogate. This
gives you fh and ih .
Carefully measure the distance between the photogates (make
certain they are
roughly 80 cm apart). This gives you L . Put a short strip of
paper tape 10 cm up the
track from the 1st photogate. This will be the starting point for
your measurements
Also measure the height of this starting point: this give you
starth .
(3) Put a short strip of paper tape on the track between the
upper photogate. Holding the
sphere in place, mark on the tape the center of the sphere when
it just begins to
interrupt the photogate beam as indicated by the red light.
Next, allow the sphere to

8. roll down the track through the gate until it no longer interrupts
the photogate beam
(the red light turns off) and mark on the tape the center of the
sphere at this point.
Record the distance between the marks as
sphere
id . Do the same for the disk and the
cylinder to get
disk
id and
cylinder
id . This gives you the width d of each object as seen
by the photogate detector.
(4) Repeat Step (3) for the lower photogate and record the
distances
sphere
fd ,
disk
fd , and
cylinder
fd in your logbook.
(5) Start the Logger Pro program, and release the sphere from
rest at the starting point
(10 cm from the 1st photogate). Record the times measured by
the computer (both in

9. an Excel spreadsheet and in your lab notebook). Make certain
to label which pair of
times are for the upper and lower photogate.
(6) Repeat the measurement from the same starting point a total
of six times. Find the
your lab notebook.
(7) Repeat Step (6) for the disk and the cylinder.
Analysis
Everything up to the race is to be completed before you leave
lab. Show the TA your
results from (1) to (8) before leaving lab. Writup due is a Word
document.
(1) Find CMI for the sphere, disk, and cylinder using Eq. (6).
(2) Using the table on the last page of this handout, calculate
the theoretical values of
CMI for the sphere, disk, and cylinder.
(3) Compute the percent error of CMI for each object:

10. 100%
Experimental Theoretical
Error
Theoretical
(4) Comment on the accuracy of your measurements and why
there may be a
discrepancy.
(5) Which one of the objects is the fastest? (That is, which one
makes it to the bottom of
the ramp first?)
(6) Test your prediction by racing the sphere, disk, and cylinder
(2 at a time) to see
which one is fastest. Use the wooden ramp located at the front
of the lab class. Did
all go according to your prediction?
(7) Give a simple explanation as to why the fastest object won
the race.
(8) Using Eq. (6), find CMI for the sphere, disk, and cylinder
using your starting point

11. the same values as
before?
(9) Compute the percent error of CMI for each object for these
new values. Comment
on whether there is an improvement or not.
(10) Draw a free body torque diagram, and write down
Newton’s 2nd Law for
translations and rotations. The rest of the questions below are
only for the sphere.
(11) Using Newton’s 2nd Law for rotations, solve for the
angular acceleration of the
sphere.
(12) Insert this angular acceleration into the kinematical
equation of motion to
determine the angular velocity (Eq. M2):
the starting point (which is zero), (b) when

12. st photogate.
for the sphere? Give
the percent error.
(15) Calculate the coefficient of friction (and its uncertainty)
using the measured value
assuming slipping occurs
from start to finish.
(16) Calculate the coefficient of static friction assuming no
slipping occurs. Note: I
did this in class.
(17) Is slipping (or sliding) occurring? [Use your results of
Parts (13) to (16)]
*

13. Technical innovation and organizational effectiveness in
Starbucks
*
Starbucks
Starbucks coffee company is a coffeehouse chain founded in
1971 in Seattle, United States.
Today, the company operates all over the United States and also
in other countries such as South Korea, Japan and Canada.
The company’s growth has been as a result of its distinct taste,
quality, and customer.
The company employs a servant leadership approach where the
managers, leaders and supervisors emphasize support for
employees thus ensuring growth to everyone.
Starbucks has been a major coffee distributor across the globe
and is still looking forward to improve its sales to ensure its
succeed especially with the increased competition today.
*
*
Technical innovation and organizational effectiveness in
StarbucksOrganizational effectiveness is central to the
company’s success.
However, the organizational effectiveness depends on the firm’s
ability to have a proficiency innovation track.

14. Organizational effectiveness can be described as a concept of
the way a firm is effective in achieving the outcome it intends
to have.
*
Technological innovationThe technological innovation system is
a notion created within the field of scientific that servers in
explaining the rate and nature of technological change (Nelson
& Rosenberg, 2013).
Due to its increased use of technology, Starbucks sells its high
quality product and services at increased premium prices thus
helping the company to beat its competitors.
The companies high quality of product and good customer
experiences also prove to be a difference from other coffee
brands.
The company has engaged in increased usage of technology to
ensure increased sales and more profits as it also looks forward
to ensure the customers are loyal.
*
*
Why Starbucks is so innovativeIt listens to the feedback from
its customers and has embraced its customer’s feedback for a
ling time as illustrated in mission statement.
It listens to the heart of its customers as opposed to overlooking
things. Thus, its analytical abilities are very important.
It follow the intuition of its customer.
The company keeps engaging in innovative practices to ensure

15. it beats off competition from other companies and to ensure
better services for the customers.
*
*Technical innovation and organization effectiveness however
differ as the former depends on how the employees employ
different aspects in the company to ensure success.
On the other hand, organizational effectiveness refer to the
increased success of the company in terms of its service
delivery, treatment of the workers, customer reviews and profits
made (Van Grove, 2010).
Starbucks engages in innovation where it creates new
knowledge to deal with practical problems and most importantly
to ensure that it deal with arising competition in the market.
Difference between technical innovation and organization
effectiveness
Technical innovation differ from organization effectiveness in
that the former depends on the way employees uses different
aspects to ensure success while the latter refer to increased
success in operational management.
*
The company has effectively engaged in the use of social media
platforms for different types of assignments.
Starbucks was named the most popular social media brands by
an online analytics and statistics provider in 2010.
The company also has a Mobile App which it launched in early
2011. the latter app was available in Blackberry, iPhone and
Android where one can only add his or her Starbucks card
number where one can purchase, check their balance and track
rewards (Gallaugher & Ransbotham, 2010).

16. Different types of technology available in Starbucks
The company uses social media platforms and a mobile app as
forms of technology.
*
*
Different types of technology available in StarbucksThe
company also purchased the Coffee Equipment Co. which is
known for its single-cup coffee maker referred to as clover.
The clover employs the use of precise technology and a
calculated algorithm in brewing coffee within a single degree of
the ideal temperature and produce the right flavor (Van Grove,
2010).
The clover also control how long the grounds and water interact
and the flow of water brewing.
The clover units are connected through Ethernet port to ensure
that the Starbucks network is able to manage the details and
diagnostics of each unit.
*
Different types of technology availableStarbucks
social media space incorporate several social media platforms
including Foursquare, Facebook and Twitter. The company uses
these platforms to ensure that its customers can access its
products with ease and can also put reviews on the services

17. provided (Gallaugher & Ransbotham, 2010).
On the other hand, Starbucks also has a mobile app that one can
add his or her Starbucks card number.
The clover has also been in place to ensure that customers can
get the right flavor for the product.
The company employs the use of social media platforms, mobile
apps and also clover.
*
*
Most appropriate technology for StarbucksThe company
has a digital network which serves as makeshift office and
meeting place supported by the unlimited Wi-Fi which available
in its stores.
The company made a move of expanding its online offering in
2010 to its customers with its Digital Network.
The digital network is in partnership with Yahoo and Starbucks.
Once one connect to the Starbuck free Wi-Fi, it is easy to land a
page for the digital network thus allowing one to check in with
Foursquare and Log in Starbucks card (Gallaugher &
Ransbotham, 2010).
The company allow one to access their starbucks cards that
ensure increased sales.
*
*
Best Technologies
The best of these technologies is the use of social media

18. platforms especially due to the increased growth of these
platforms among different people today.
Social media platforms ensure that the company can increase
their sales as they are able to increase the number of people
who know about their products.
Social media platforms provides a platform for advertisement,
and promotion for the company thus is the best platforms for
increased productivity.
Social media platforms are the best for the company.
*
*
Best technology for improving the organization’s efficiencies or
competencies while also reducing riskThe Starbuck Digital
Network is the best technology for the improvement of the
companies competencies or efficiency and to ensure that it
lowers risks (Gallaugher & Ransbotham, 2010).
The digital network aids the customers to learn about the
company’s news while it also come in handy for entertainment
and lifestyle channels for most customers.
The starbucks digital network also comes in handy to ensure
increased adaptability of the company.
*
*
Mobile transaction volumeThe mobile transaction is reasonable
for technology experts as it aids in predicting the use of mobile
payment apps in the use of credit cards and cash.

19. Mobile transactions are easy to use as most people can access
the service every everywhere they are.
Thus, the company can make more sales at a given period which
will translate to more sales.
Mobile technology aids in predicting the use of mobile payment
apps in the use of credit cards and cash.
*
*
How the technology reduces riskThe Starbuck
Digital Network comes in handy in lowering the risks as it
allow the use of Starbucks card which in turn plays a major role
in ensuring long lines in the company’s stores that have barred
its sales for a long time are avoided.
The company has been faced by increased traffics in its stores
especially during the morning and the evening times.
Since customers will be able use the Starbucks cards especially
in these peak hours, it will be easy to increase sales and to
ensure the customers are happy with service delivery within the
company.
Technological innovations allow the use of Starbucks card
which in turn plays a major role in ensuring long lines in the
company’s stores that have barred its sales for a long time are
avoided
*
*
Impact of the Starbucks Digital Network on organization

20. cultureThe digital network will come in handy in defining the
way the company conducts its business.
It will also ensure a good relation between the company and its
customers (Gallaugher & Ransbotham, 2010).
It will also impact the company’s decision making process as
there will be less staff required for service delivery.
It will also improve the employee’s loyalty to the company.
The startbucks digital network will define the conduction of a
business, ensure good relation and ensure good decision
making.
*
Mobile transaction network
Conclusion
Technical innovation and organizational effectiveness are some
of the most important role of the human resource management.
They are also the main dimension of the HRM with the system
strategy being used to facilitate technology innovation through
knowledge management.
Furthermore the organization effectiveness is enhanced by the
creation of a positive organization culture and to ensure high
performance of systems.
*

21. ReferencesGallaugher, J., & Ransbotham, S. (2010). Social
media and customer dialog management at Starbucks. MIS
Quarterly Executive, 9(4).Nelson, R. R., & Rosenberg, N.
(2013). Technical innovation and national systems. National
innovation systems: A comparative analysis, 322.Van Grove, J.
(2010). First Look: Starbucks Digital Network Is Here.
GRADING GUILD
· Expansion Project Management Plan Phase 2 Grading Guide
Content
60 Percent
Points Available
X
Points Earned
X
Additional Comments:
All key elements of the plan are summarized in a substantive
way, and include an analysis of the following:
· Project scope statement
· Project charter
· Work breakdown structure in Microsoft® Project
Professional®
· Communication plan
· Project schedule in Microsoft® Project Professional®
· Time and cost estimation methods
· Project budget
· Risk management plan

22. · Change control management plan
· The steps taken to assemble, develop, and manage the project
team
· An explanation of how students will manage project execution
· An explanation of the importance of project sponsorship and
project leadership during project execution
· A method of measuring and reporting project progress and
performance, including
· An explanation of rationale for method choice.
· The project retrospective and project closedown process,
including
· A determination how steps relate to each other and to the
overall project structure
· Includes a project progress and performance evaluation for the
project addressed
· Explains specific actions planned and why
· Includes references from the textbook and scholarly articles
that support the main points
Organization / Development
20 Percent
Points Available
X
Points Earned

23. X
Additional Comments:
· The paper is at least 700 words in length.
· The introduction provides sufficient background on the topic
and previews major points.
· The conclusion is logical, flows from the body of the paper,
and reviews the major points.
· Paragraph transitions are present, logical, and maintain the
flow throughout the paper.
Mechanics
20 Percent
Points Available
X
Points Earned
X
Additional Comments:
· Formatting or layout and graphics are pleasing to the eye
(font, colors, spacing).
· Rules of grammar, usage, and punctuation are followed, and
spelling is correct.
· Sentences are complete, clear, and concise.
· Sentences are well constructed, strong, and varied.
· APA guidelines are followed.

24. Total Available
Total Earned
X
d = 3.1 cm
d = 3.1 cm
d = 3.1 cm
L = 80.3 cm
Sphere Cylinder
#
Time 1
Time 2
∆ Time
1
1.0954
3.1867
2.0913
2
4.566
6.6608
2.0948
3
1.2642
3.3577
2.0935
4
4.9092
7.0019

25. 2.0927
5
1.0541
3.347
2.2929
6
0.731
2.823
2.092
#
Time 1
Time 2
∆ Time
1
0.5118
3.0105
2.4987
2
0.4058
2.8946
2.4888
3
0.4009
2.9557
2.5548
4
5.6688
8.2965
2.6277
5
0.9205
3.5549
2.6344
6
2.9158
5.6252

26. 2.7094
Disk
#
Time 1
Time 2
∆ Time
1
3.7523
6.0506
2.2983
2
1.847
4.1497
2.3027
3
0.7989
3.149
2.3501
4
0.1152
2.4285
2.3133
5
0.076
2.4448
2.3688
6
2.4867
4.7698
2.2831