Science & Mathematics - 25 August 2006

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What is the proper way to turn off a positive voltage supply with a NPN transistor?

I want to turn off a load that requires about 200mA. I am only familiar
with the common emitter setup for a NPN transistor, which cant be used
to turn off a positive voltage supply. I am unsure of the proper
technique for the other setup that allows for the control of a positive
voltage. Thanks.

2006-08-25 13:37:15 · 7 answers · asked by Anonymous in Engineering

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Is Pluto not a planet anymore???

I mean they just considered it as a White Dwarf now. Plus we would have to make a new theme to memorize the eight planets, and what about the books in school, wouldn't they be wrong now if they had Pluto as our planet? This sucks

2006-08-25 13:35:57 · 26 answers · asked by Earl 2 in Astronomy & Space

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what is the interest on $3690.00 at 3% for 747 days?

2006-08-25 13:35:00 · 10 answers · asked by eileen s 1 in Mathematics

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Can anyone put these in order from least to greatest? The one who gets it right first wins 300 yahoo points!!!

Correct Order
1.7 miles
2.250 yards
3.3,140 inches
4.2.3 km
5.7,240 feet
6.355 meters
7.4,325 cm
8.225 decimeters
9.1 gigameter
10. 16,000,000 mm

2006-08-25 13:34:10 · 13 answers · asked by pioasap 1 in Mathematics

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How do you make copper cyanide.?

what temp do you need it at
is it illegal
and generally any info you know about it

2006-08-25 13:33:27 · 5 answers · asked by Anonymous in Chemistry

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Another math question i can't figure out..?

(px)y= : ?

2006-08-25 13:24:54 · 13 answers · asked by azmattaz06 2 in Mathematics

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lab safety?

should one wear contacts in a science lab

what would happen if we wore contact lenses in the science lab

2006-08-25 13:20:32 · 6 answers · asked by me 2 in Other - Science

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Trig help! I'm taking Cal2, but I never had trig. Can somebody explain the basic pi circle to me?

I understand the Calculus concepts, but the trig trips me up, esp. the sin, cos, etc. I've seen some sort of circle that uses pi and the square root of 2, but I don't have a copy, and I don't know what it means. Can anybody point me in the right direction? My hs didn't offer trig, and now I'm in college, and I'm having to play catch-up. Thanks in advance!

2006-08-25 13:11:34 · 7 answers · asked by kacey 5 in Mathematics

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Me again about the magnet honor class?

now they put me in 10th grade, i have magnet classes such as Chemistry, physic, Algebra2. Thanks for the answers.

2006-08-25 13:11:06 · 4 answers · asked by riya 1 in Mathematics

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Are modern 9mm handguns waterproof?

If I drop a Glock or something in the water, or it rains hard on it, can I still fire it?

2006-08-25 13:10:28 · 11 answers · asked by Reno 2 in Engineering

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Math Question i need help on..?

The last week of a month a car dealership sold 12 cars. A new sales promotion came out the first week of the next month and the sold 19 cars that week. What was the percent increase in sales from the last week of the previous month compared to the first week of the next month?

58%
119%
158%
175%
200%
???

2006-08-25 13:10:07 · 5 answers · asked by azmattaz06 2 in Mathematics

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Family being made sick?

How can a person find out if persons are pressurising water pipes to force chemical based substances in through the pipes to make families sick? How possible is it to do this? As we know a family that is possibly having this done to them. These are legitimate questions and not paranoia, who can we turn to with authority that will not destroy the family for asking? Also this family we know of has a gas hot water system under their house and their are possibly people squirting something in the top of the hot water system so that when it ignites quite toxic vapours are forced up through the floorboards to make the young children and the parents sick. Please can someone help with advice and serious repliers only.

2006-08-25 13:06:59 · 11 answers · asked by worried 1 in Chemistry

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