ENF 1104. Kinematics Activity Introduction

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Nov 13, 2013 (3 years and 4 months ago)

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ENF 1104. Kinematics Activity

Introduction

(V. Rouillard


2010)



(Photographs courtesy RIT)


Preamble

Following yet another convincing win by Roger
Federer

at the Australian Open, his
opponent, Irma
Badlouzhur
, from the Peoples’ Republic of
Naugudatsphort

has
decided to lodge a formal protest.
Badlouzhur

alleges that, apart from being far
better looking,
Federer

used a “magic” racquet that has a coefficient of restitution
(
CoR
) greater than unity and therefore illegal.








ENF 1104. Kinematics Activity


Introduction
(V. Rouillard


2010)

Federer: Handsome

Badlouzhur
: Very ugly


Preamble (cont’d)


The Australian Tennis Federation (ATF), which is responsible for organising the
tournament, decided to deal with the protest by commissioning tests to
determine the coefficient of restitution of
Federer’s

racquet. This was undertaken
by an independent laboratory, Rebound Labs Inc., based in the small European
state of Lichtenstein. Unfortunately (or perhaps suspiciously), before the results
were released, the main building of Rebound Labs Inc. caught fire destroying the
test samples (
Federer’s

racquets) as well as most of the test data. Needless to say
allegations of ‘foul play’ and ‘suspicious circumstances’ were reported in the
popular press and other news media.





ENF 1104. Kinematics Activity


Introduction
(V. Rouillard


2010)


Preamble (cont’d)

Fortuitously, files containing high
-
speed video footage of two of the tests were
salvaged from the remains of the building and handed
-
in to the ATF by the
Lichtenstein authorities. The ATF protest committee, being past tennis players and
having little understanding of kinematics, have approached you for assistance.


ENF 1104. Kinematics Activity


Introduction
(V. Rouillard


2010)

Video preview


Instructions on how to access the image sequences are in the hand
-
out)


The challenge

The ATF needs to know whether the video footage can be used to determine the
type of test carried
-
out on
Federer’s

racquet and whether accurate estimates of
the coefficient of restitution can be made from the footage. Specifically, the
following questions / issues need to be addressed and included in your report:




ENF 1104. Kinematics Activity


Introduction
(V. Rouillard


2010)


The challenge (cont’d)






ENF 1104. Kinematics Activity


Introduction
(V. Rouillard


2010)

(e) What is the coefficient of restitution between the ball and the racquet? This
must be accompanied by a thorough discussion on the uncertainty of your
estimates. Discuss your results in the context of rules for tennis. You also
need to advise the ATF on better ways of determining the
CoR

of tennis
request.




(a) Were the tests carried
-
out in free
-
fall or was the ball launched from a
machine?


(b) If the tests were carried in free
-
fall, was the gravity field constant? Your
response must be accompanied by a short discussion on the effects of
altitude on gravitational acceleration.




(c) If the gravitational field during the tests was constant what was it?




(d) What are the variations in displacement, velocity and acceleration of the
tennis ball with respect to time? This must be accompanied by a discussion
on how these relate to theory.




Deliverables and assessment

Team Preparatory task (compulsory)

Start during session 1 , complete in own time (team work) , hand0in to facilitator
during session 2.


Technical report (6 marks)

Team technical (written) report to be completed and submitted to your designated
facilitator before the start of the first session of week

8. After it is assessed, you
may collect you report from you facilitator along with comments and feedback on
your effort.


Reflective journal (2 marks)

The submission deadline for the reflective journal is the same as that of the
report.


Quiz (4 marks)

Duration: 50 mins. To be undertaken during the last hour of the last session. The
quiz is a closed
-
book session and is to be attempted by each student individually
(no team work allowed)


examination conditions will apply.

ENF 1104. Kinematics Activity


Introduction
(V. Rouillard


2010)

Schedule of activities

ENF 1104. Kinematics Activity


Introduction
(V. Rouillard


2010)

Week 6

Lecture

I
ntroductory lecture on kinematics. Important information regarding the video
footage will also be given during this s
ession.

Session 1


Familiarisation session
.
S
tart to work on Team
Preparatory

T
ask
and brain
-
storm your team’s approach to tackling the challenge.

Own time

Complete

team
p
reparatory

task.

Session 2

Review team
p
reparatory

task and

further brain
-
st
orm your team’s approach to
tackling the challenge.

Own time

Work as a team to analyse both files

containing high
-
speed video footage.

Week
7

Lecture


Attend lecture on applications of kinematics.

Session 1


Present your results and
preliminary a
nalysis,

undertake further analysis
, start
working on report.

Own time

Prepare your report

Session 2


Present

draft of report to facilitator
and obtain feedback. Quiz.