Science & Mathematics - 14 December 2007

an electronics firm makes two types of switching devices. type A takes 4 minutes to makes and requires $3 worth of materials. type B takes 5 minutes to make and requires $5 worth of materials. when the production manager reviewed the latest batch, he found that it took 35 hours to make these switches with a materials cost of $900. how many switches of each type were produced for this latest batch?

2007-12-14 17:31:08 · 6 answers · asked by sweetypie1288 1 in Mathematics

pls give tips and great websites too. please explain thoroughly your answer, like if you're going to say practice, state what to practice. thank you guys

2007-12-14 17:23:08 · 12 answers · asked by Anonymous in Mathematics

y = -x^2 + 2x

2007-12-14 17:19:46 · 4 answers · asked by Anonymous in Mathematics

There are 7 shelves on a bookshelf. If on hardback book is roughly the size of 2 paperback books, and each shelf can hold approx. 45 paperback books, then which of the following could be the total number of books to be shelved on and completely fill this particular bookcase?
a. 285 paper/15 hard
b. 315 paper/15 hard
c. 15 paper/15 hard
d. 15 paper/285 hard
e. 150 paper/165 hard

2007-12-14 17:18:32 · 10 answers · asked by helen 2 in Mathematics

Which of the following is NOT true of anticoagulants?


a. They may be given over prolonged periods of time without regard to prothrombin times.

b. Warfarin is the oldest and most frequently used anticoagulant.

c. Oral anticoagulants have a delayed onset of action.

d. Patients taking anticoagulants must be watched carefully for excessive bruising, bloody stools, bleeding gums, and blood in the urine.

e. Warfarin has a long list of drug interactions.

Which of the following is NOT a use for antihistamines?


a. rhinorrhea

b. coughs and colds

c. motion sickness

d. chest congestion

e. insomnia

Which of the following is NOT true about the treatment of hyperlipidemia?


a. Medications are the first line of treatment for hyperlipidemia.

b. Diet modification and exercise are needed in treating hyperlipidemia.

c. Hypolipidemics are used to reduce elevated cholesterol and LDL levels.

d. Hypolipidemics are used to reduce the risk for coronary artery disease.

e. All of the above statements are true.

Which of the following is NOT true regarding the treatment of cardiac dysrhythmias?


a. Cardiac dysrhythmias are cured by the medications that are used in treatment.

b. Cardiac dysrhythmias occur when calcium, sodium, and potassium ions that regulate the electrical impulses of the heart are disturbed.

c. The medications for cardiac dysrhythmias are in four distinctive groups.

d. Antidysrhythmics control rhythm by correcting or compensating for the altered rhythm.

e. Alcohol and nicotine should be avoided while taking antidysrhythmics.

Which of the following are routes of administration for nitroglycerin?


a. sublingual tablets

b. oral tablets

c. ointment

d. transdermal patches

e. all of the above

2007-12-14 17:16:23 · 3 answers · asked by Anonymous in Medicine

2007-12-14 17:13:13 · 5 answers · asked by Anonymous in Mathematics

plan has a $22 one time activation fee, and charges .10 a minute. the second plan has no activation fee, and charges .14 cents a minute. After how many minutes of calls will the two plans be equal?

2007-12-14 17:10:44 · 4 answers · asked by Trisha 2 in Mathematics

I forgot :(

2007-12-14 17:08:47 · 13 answers · asked by Axis Flip 3 in Mathematics

I was given two planes in the form ax + by + cz = d
If you have their normals (a,b,c),

Say, u = (2,-1,2)
and v = (1,2,-3)

Can you easily tell if these are the same plane?

________________

u.v = -6

and

u is not a non 0 multiple of v so therefore not parallel.

What is the last test to see if the planes are coincidental?

2007-12-14 16:49:37 · 4 answers · asked by Anonymous in Mathematics

2007-12-14 16:45:14 · 19 answers · asked by Auntie Marie SueB 3 in Paranormal Phenomena

2007-12-14 16:42:22 · 16 answers · asked by skie 2 in Astronomy & Space

Can it stand for high surge current with short duration, for example the starting current in a switching power supply??

2007-12-14 16:42:21 · 3 answers · asked by A learner 1 in Engineering

(the ones that go moo)

2007-12-14 16:42:21 · 11 answers · asked by jubjub firefly 2 in Agriculture

2007-12-14 16:42:16 · 6 answers · asked by Trisha 2 in Mathematics

or would our space ships have to start mysteriously disappearing ..say on the way to Mars before we know?

2007-12-14 16:40:44 · 12 answers · asked by bush l 1 in Astronomy & Space

Some scientists have postulated that the life in the Universe is possible because we live in the Goldilocks zone or the a narrow band of right conditions. For instance, if a single one of the zones were altered, stars would never form, the universe may fly apart, DNA would not exist and so on. What do you think, it is evidence for design, or is it just a asymmetry?

2007-12-14 16:32:36 · 6 answers · asked by Anonymous in Physics

i've heard a number of strange things about 2012 and i want to know if anything is really going to happen. also it is a cool number =).
but one story i heard on youtube was a planet is going to hit us December 12 2012 and other weird stuff

2007-12-14 16:30:08 · 19 answers · asked by supergohan_2478 3 in Astronomy & Space

2007-12-14 16:27:59 · 11 answers · asked by LILREDGAL 1 in Geography

Wat kind of rock is it? (Is it igneous, metamorphic, or sedimentary?)
I no it's a mineral..... but on this question it asks wat kind of rock it is..... So I'm bummed...

2007-12-14 16:26:02 · 8 answers · asked by Anonymous in Earth Sciences & Geology

2007-12-14 16:21:35 · 3 answers · asked by Anonymous in Physics

Among those who have traveled into outerspace, what are the names of the individuals who have traveled the farthest away from Earth?

2007-12-14 16:20:05 · 9 answers · asked by gsfortis 2 in Astronomy & Space

Health related(radiation)? Interested if deals with health! Anyone know of any places I can look?

2007-12-14 16:19:10 · 2 answers · asked by Teresa 1 in Biology

4-(-6)
--------- = and please explain
-5

2007-12-14 16:11:25 · 9 answers · asked by Christina A 1 in Mathematics

2007-12-14 16:11:05 · 3 answers · asked by Anonymous in Astronomy & Space

Ok so, Me and my friend are talking about black holes.

And he says that theres no such thing as a black hole being
smaller than earth.
I say that theres a such thing IS a such thing.

So, I even googled it. And it said that the smallest black holes
are about 10-35 meters.

So....If you know anything about black holes, Please tell.

Also, Can the sun one day become a black hole?

2007-12-14 16:07:58 · 11 answers · asked by Anonymous in Astronomy & Space

2007-12-14 16:06:55 · 5 answers · asked by Pansy 4 in Medicine

Epsom salts that are used as a laxative consist of MgSO4 * 7H20. How many grams of Mg are present in 0.0250 mole of MgSO4 * 7H20, which is 9.86% Mg.

The answer I calculated is 0.297g Mg, but I'm not sure if it's correct. Thanks for your help!

2007-12-14 16:03:58 · 5 answers · asked by Steven M 3 in Chemistry

do you think the out come would of been different?

2007-12-14 16:01:36 · 8 answers · asked by saveitok 6 in Physics

2007-12-14 15:54:12 · 10 answers · asked by missyej 1 in Mathematics

We have an Automatic/Electric fan in the house that i use every single night. Regardless how cold it is. Last night it was about freezing temperature (live in Cali) and i had it in full blast. I did have a blanket and a sweater on though. People think its crazy... i dont really know why and how to explain it...what do you think? ...some kind of OCD??? lol

2007-12-14 15:45:02 · 6 answers · asked by Erci Bryant 2 in Weather