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- Exercises for propositional
Problems on propositional logic,
including truth-tables, boolean algebra, and inference rules.
Please write logic formulas using the syntax
previously defined ,
using
(or for brevity,
F
),
(or
T
),
¬, ∧, ∨, and ⇒.Except where directed, use only these connectives.
You can
download WaterWorld if you like.
At Rice University, WaterWorld is installed on OwlNet, in
/home/comp280/bin/waterworld .
Propositional logic
[Practice problem
solution provided.]
Your friend Tracy argues:
It is bad to be depressed.
Watching the news makes me feel depressed.Thus, it's good to avoid watching the news.
Regardless of whether the premises and conclusion are true,
show that the
argument is not,
by showing it doesn't hold for all domains.Replace
depressed
and
watching news
with
expressions which leave the premises true,but the conclusion false
(or at least, what most reasonable people would consider false).
Lots of possible counterexamples.
It is bad to be depressed.
Doing homework makes me depressed;so it's good to not do my homework.
Or,
It is bad for people to be in physical pain.
Childbirth causes pain.Therefore childbirth needs be avoided by all people.
If the original conclusion is really correct,
Tracy needs to elucidate some of his unspoken assumptions.
The flaw seems to be along the lines of,
avoiding bad in the short run
may not always be good in the long run
(or equivalently, sometimes you have to
choose the lesser of two evils).No, you weren't asked to name a specific flaw,
and reasonable people can differ on precisely what the flaw is.(And, formal logic is not particularly helpful here.)
Nonetheless, uncovering hidden assumptionsin arguments often helps understand the real issues involved.
For fun,
pick up the front page of the daily newspaper,and see how many arguments use faulty rules of inference and/or
rely on unspoken premises (which not all might agree with).In particular, political issues as spun to the mainstream press
are often riddled with error,even though there are usually reasonable arguments on
both sides which policy-makers and courts debate.
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[Practice problem
solution provided.]
An acquaintance says the following to you:
Chris claims knowledge is more important than grades.
But she spent yesterday doing an extra-credit assignmentwhich she already knew how to do.
Therefore, she's a hypocrite and deserves no respect.
Regardless of whether the premises and conclusion are true,show that the
argument is not,
by showing it doesn't hold for all domains.Replace
knowledge
and
grades
with expressions which
give you true premises, but a false conclusion(or at least, what most reasonable people would consider false).
Exaggerate
knowledge
to something more important,
and
grades
to something less important.
Terry claims that encouraging human-rights
is more important than playing Tetris.But Terry played Tetris yesterday
rather than volunteering with
Amnesty International .
Most people wouldn't condemn Terry as a hypocrite just
because of this; even the most dedicated of people areentitled to
some free time.
If your friend wants to prove Terry hypocritical,they'll have to provide further evidence or arguments.
Or similarly,
Politician X
claims to support science funding,
but voted against a proposal to shift all Medicare funds to NASA.
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Questions & Answers
Three charges q_{1}=+3\mu C, q_{2}=+6\mu C and q_{3}=+8\mu C are located at (2,0)m (0,0)m and (0,3) coordinates respectively. Find the magnitude and direction acted upon q_{2} by the two other charges.Draw the correct graphical illustration of the problem above showing the direction of all forces.
To solve this problem, we need to first find the net force acting on charge q_{2}. The magnitude of the force exerted by q_{1} on q_{2} is given by F=\frac{kq_{1}q_{2}}{r^{2}} where k is the Coulomb constant, q_{1} and q_{2} are the charges of the particles, and r is the distance between them.
Muhammed
What is the direction and net electric force on q_{1}= 5µC located at (0,4)r due to charges q_{2}=7mu located at (0,0)m and q_{3}=3\mu C located at (4,0)m?
what is the change in momentum of a body?
Capacitor is a separation of opposite charges using an insulator of very small dimension between them. Capacitor is used for allowing an AC (alternating current) to pass while a DC (direct current) is blocked.
Gautam
A motor travelling at 72km/m on sighting a stop sign applying the breaks such that under constant deaccelerate in the meters of 50 metres what is the magnitude of the accelerate
What is Thermodynamics
Muordit
velocity can be 72 km/h in question. 72 km/h=20 m/s, v^2=2.a.x , 20^2=2.a.50, a=4 m/s^2.
Mehmet
A boat travels due east at a speed of 40meter per seconds across a river flowing due south at 30meter per seconds. what is the resultant speed of the boat
50 m/s due south east
Someone
which has a higher temperature, 1cup of boiling water or 1teapot of boiling water which can transfer more heat 1cup of boiling water or 1 teapot of boiling water explain your . answer
I believe temperature being an intensive property does not change for any amount of boiling water whereas heat being an extensive property changes with amount/size of the system.
Someone
temperature for any amount of water to boil at ntp is 100⁰C (it is a state function and and intensive property) and it depends both will give same amount of heat because the surface available for heat transfer is greater in case of the kettle as well as the heat stored in it but if you talk.....
Someone
about the amount of heat stored in the system then in that case since the mass of water in the kettle is greater so more energy is required to raise the temperature b/c more molecules of water are present in the kettle
Someone
physics, biology and chemistry
this is my Field
ALIYU
field is a region of space under the influence of some physical properties
Collete
what is ogarnic chemistry
determine the slope giving that 3y+ 2x-14=0
WISDOM
Another formula for Acceleration
pratica A on solution of hydro chloric acid,B is a solution containing 0.5000 mole ofsodium chlorid per dm³,put A in the burret and titrate 20.00 or 25.00cm³ portion of B using melting orange as the indicator. record the deside of your burret tabulate the burret reading and calculate the average volume of acid used?
how do lnternal energy measures
Esrael
Two bodies attract each other electrically. Do they both have to be charged? Answer the same question if the bodies repel one another.
No. According to Isac Newtons law. this two bodies maybe you and the wall beside you.
Attracting depends on the mass och each body and distance between them.
Dlovan
Are you really asking if two bodies have to be charged to be influenced by Coulombs Law?
Robert
like charges repel while unlike charges atttact
Raymond
What is specific heat capacity
Specific heat capacity is a measure of the amount of energy required to raise the temperature of a substance by one degree Celsius (or Kelvin). It is measured in Joules per kilogram per degree Celsius (J/kg°C).
AI-Robot
specific heat capacity is the amount of energy needed to raise the temperature of a substance by one degree Celsius or kelvin
ROKEEB
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Source:
OpenStax, Intro to logic. OpenStax CNX. Jan 29, 2008 Download for free at http://cnx.org/content/col10154/1.20
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