Kosky, Balmer, Keat and Wise: Exploring Engineering, Fourth Edition
3.17. An electric cart can accelerate from 0 to 60. mph in 15 s. The Olympic champion sprinter
Usain Bolt2 can run 100.0 m in 9.69 s. Which would win a 100.0 m race between this cart and
the world champion sprinter? (A: The sprinter wins by 16.7 m!)
Need: _____ (sprinter or cart)
Kosky, Balmer, Keat and Wise: Exploring Engineering, Fourth Edition
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
A B C D
t, s d, mv, m/s a m/s2
0 0 0 4.0
1 2 4 4.0
2 8 8 4.0
3 18 12 4.0
4 32 16 4.0
5 50 20 4.0
6 72 24 4.0
7 98 28 4.0
8 128 32 4.0
9 144 27 -4.57
10 160 23 -4.57
11 176 18 -4.57
12 192 14 -4.57
13 208 9 -4.57
14 224 5 -4.57
15 240 0 -4.57
8
9
10
11
12
13
14
15
16
17
18
19
A B C D
t, s d, mv, m/s a m/s2
0 =C9*A9 =$K$1*A9/$K$2 =$K$3
=1+A9 =0.5*C10*A10 =$K$1*A10/$K$2 =$K$3
=1+A10 =0.5*C11*A11 =$K$1*A11/$K$2 =$K$3
=1+A11 =0.5*C12*A12 =$K$1*A12/$K$2 =$K$3
=1+A12 =0.5*C13*A13 =$K$1*A13/$K$2 =$K$3
=1+A13 =0.5*C14*A14 =$K$1*A14/$K$2 =$K$3
=1+A14 =0.5*C15*A15 =$K$1*A15/$K$2 =$K$3
=1+A15 =0.5*C16*A16 =$K$1*A16/$K$2 =$K$3
=1+A16 =0.5*C17*A17 =$K$1*A17/$K$2 =$K$3
=1+A17 =$B$17+0.5*$C$17*(($K$4-$K$2)-($K$4-A18)) =$K$4*$K$1/($K$4-$K$2)+D18*A18 =$K$5
=1+A18 =$B$17+0.5*$C$17*(($K$4-$K$2)-($K$4-A19)) =$K$4*$K$1/($K$4-$K$2)+D19*A19 =$K$5
45
5
10
Acceleration,
m/s2
1
2
3
4
5
J K
vmax. m/s 32
, s 8
a/m/s2 4
tmax, s 15
a/m/s2 =(0-K1)/(K4-K2)
Kosky, Balmer, Keat and Wise: Exploring Engineering, Fourth Edition
Copyright, Elsevier, 2015
25
(2 – 1) = 18.4, 2 = 23.4 s.
3 = 24.9 s.
Second segment of journey:
Kosky, Balmer, Keat and Wise: Exploring Engineering, Fourth Edition
3.23. You are a driver responding to the traffic light in the previous exercise. If it was correctly
designed according to that problem, at what distance from the light should you be prepared to
make your “to stop or not to stop” decision? Assume you are a safe driver who neither speeds up
to get through the yellow light nor stops more suddenly than the deceleration rate of −5.0 m/s2.
Need: Distance to stop for yellow light = ____ m.
Kosky, Balmer, Keat and Wise: Exploring Engineering, Fourth Edition
Options
Canons
a) Choose
Route A
b) Choose
Route B
c) Ask to be
relieved
Hold
paramount the
safety, health
and welfare of
the public.
Does not
apply
Does not
apply
Does not
apply
Perform
services only
in the area of
your
competence
Meets canon
Meets canon
Meets canon
Issue public
statements
only in an
objective and
truthful
manner
Silence here is
an untruthful
public
statement
Silence here is
an untruthful
public
statement
Meets canon
Act for each
employer or
client as
faithful agents
or trustees
Hiding facts is
not acting as a
faithful agent
or public
trustee
Hiding facts is
not acting as a
faithful agent
or public
trustee
Meets canon
Avoid
deceptive acts
Deceptive
Deceptive
Meets canon
Conduct
themselves
honorably …
Dishonorable,
in that even
though you
avoid
benefiting
your niece, the
consideration
has distorted
your judgment
Dishonorable
in putting
family before
duty
Meets canon
In summary, once you see a conflict of interest exists, the ethical choice is to disqualify
yourself. The first canon reminds engineers that the safety concern must be given a very heavy
weight. This suggests the likelihood that escalating at least to option b) is probably ethically
necessary.
Kosky, Balmer, Keat and Wise: Exploring Engineering, Fourth Edition
Options
Canons
a) Go along
b)
Appeal
to
higher
level
c) Quit
d) Write state
representative
e) Call
reporter
Hold
paramount the
safety, health
and welfare of
the public.
Does not
meet canon
Meets
canon
Does not
meet canon
Meets canon
Meets canon
Perform
services only
in the area of
your
competence
Meets
canon if
you accept
competence
of superior
Meets
canon
Meets canon
You may not
be a
competent
public
spokesman
You may
not be a
competent
public
spokesman
Issue public
statements
only in an
objective and
truthful
manner
Silence
here is an
untruthful
public
statement
Meets
canon
Meets canon
Meets canon
if letter is
objective and
truthful
Risks letting
reporter
decide what
is objective
and truthful
Act for each
employer or
client as
faithful agents
or trustees
Meets
canon
Meets
canon
Meets canon
Going over
heads of
management
is not being a
faithful agent
Going over
heads of
management
is not being
a faithful
agent
Avoid
deceptive acts
Meets
canon
Meets
canon
May be
deceptive if
done
without
giving
reasons
Meets canon
Meets canon
Conduct
themselves
honorably …
Meets
canon
Meets
canon
May be
dishonorable
if it results
in safety
being swept
under rug
Meets canon
Meets canon
unless done out
of spite or
attention seeking
Since various canons favor various options, this is a problem of weighting the options. The word
“paramount” in the 1st canon is controlling. Do option b) and then d) if necessary.