Science & Mathematics - 6 February 2007

2007-02-06 23:59:09 · 9 answers · asked by ROBERT G 1 in Biology

Yes this is my homework, blah blah blah, but I can not figure out what the formula is to calculate the odds. I know that the chances of being 1/2 heads and 1/2 tails is about 25% and that 4 heads and 6 tails is about 20%. I am unable to show a formula that calculates these odds. I am a slow learner with algabra and need TLC in this area......Your thoughts and ideas will be appreciated..............................have a great day

2007-02-06 23:57:31 · 3 answers · asked by Anonymous in Mathematics

2007-02-06 23:55:49 · 2 answers · asked by hellomoto 2 in Medicine

Ocassionally your reflection from a glass window will have two images slightly separated from each other. This is bc__

a. the light is refracted

b. colors interfere

c. the window is of poor quality

d. both the front and back surface of glass reflect

e. no light can pass through the glass

2007-02-06 23:50:45 · 11 answers · asked by Anonymous in Physics

2007-02-06 23:49:30 · 4 answers · asked by paritosh k 1 in Physics

2007-02-06 23:48:36 · 5 answers · asked by Cathy R 1 in Geography

2007-02-06 23:43:30 · 7 answers · asked by dizzyandconfused 2 in Physics

1. In selecting the wire size for a line cord, you should remember that
A. No. 16 is larger than No. 12.
B. No. 14 carries more current than No. 18.
C. No. 8 is smaller than No. 10.
D. No. 4 carries less current than No. 6.

2. Which one of the following appliance parts gets the hardest service?
A. Switch
B. Thermostat
C. Heating element
D. Line cord

3. The color used for the hot side of house wiring is
A. green.
B. white.
C. gray.
D. black.

4. An AWG No. 16 line cord with type HPN insulation has an ampacity of
A. 12 amp.
B. 13 amp.
C. 15 amp.
D. 17 amp.

5. To heat a room quickly, some electric room heaters are provided with
A. a heavy metal case.
B. a motor-driven fan.
C. a push-button switch.
D. an automatic thermostat.

6. If the current flowing through an electric heater increases from 6 to 12 amp while the voltage remains the same, the heat produced by the heater will be
A. reduced one-half.
B. unchanged.
C. two times the original heat.
D. four times the original heat.

7. The wires used in a heating element are usually made of
A. copper.
B. steel.
C. aluminum.
D. Nichrome.

8. Why does a thermostat blade bend when heated or cooled?
A. It is made of two different materials.
B. There is a difference in temperature between the blade ends.
C. Different currents are applied to each end.
D. Mechanical pressure is caused by the high resistance.

9. When you are checking an electric heating appliance, the first test made should be for
A. excessive leakage.
B. the normal voltage supply.
C. an open circuit.
D. low resistance.

10. Why should you NOT repair heating elements by soldering?
A. Solder does not conduct electric current.
B. Solder joints are mechanically too weak.
C. Solder melts at the operating temperature of the heater.
D. Soldered joints have too high a resistance.

11. What type of selector switch can be used to control the heat output of three elements connected in parallel?
A. SPST switch
B. DPST switch
C. DPDT switch
D. Shorting-bar-type switch

12. Thermostats used in electric irons differ from those in small room heaters in that they are
A. smaller in size.
B. operative at higher temperatures.
C. connected directly to the appliance plug.
D. mechanically more fragile.

13. How can you clean out the scales in an electric iron without taking the iron apart?
A. By blowing out the holes with compressed air
B. By scraping the tank and tubes with a drill bit
C. By brushing the clogged tubes with a stiff wire brush
D. By rinsing the tank and holes with a water-diluted chemical

14. Bus bars are used in an electric iron as
A. thermostat supports.
B. heat-adjusting resistors.
C. connectors between the thermostat and the element.
D. electrical terminals.

15. The water in a spray iron is prevented from returning to the tank by the action of a
A. suction tube.
B. check valve.
C. water pump.
D. pressure spring.

16. The heating element in an electric iron is in good working order if the resistance across the terminals of the element reads approximately
A. 0 ohms.
B. 15 ohms.
C. 120 ohms.
D. 1000 ohms.

17. Why does the heat of the heating element stop when the desired temperature in an electric iron is reached?
A. The thermostat blade opens electrical contacts.
B. The circuit through the element is closed.
C. The switch bypasses the thermostat.
D. The contacts on the blade touch.

18. Jumpering out the resistors in a resistance-controlled three-speed fan will cause the motor to
A. run at highest speed.
B. run at medium speed.
C. run at lowest speed.
D. stop immediately.

19. A fan equipped with a gearbox is capable of
A. running at three speeds.
B. being tilted downward.
C. oscillating from side to side.
D. reversing the direction of the motor.

20. If the fan blades rattle while the fan is turning, you can stop the noise by
A. oiling the blades.
B. adjusting the blade angles and the blade tip position.
C. tightening the motor end bells and motor mounts.
D. cleaning the blade surfaces.

21. The recommended way to hold a loose hub on a fan is by
A. riveting.
B. soldering.
C. welding.
D. cementing.

22. Quiet operation of a fan depends mostly upon the
A. weight of the blades.
B. material of the blades.
C. motor balance.
D. balance of the blades.

23. The blades of small fans are made of
A. aluminum.
B. steel.
C. tin.
D. copper.

24. A modern variable-speed fan does NOT use
A. a tapped inductor.
B. a multiple-winding motor.
C. an electronic speed control.
D. a dropping resistor.

25. An attic fan, or power ventilator, may have its power inadvertently tapped from
A. an upstairs bathroom.
B. an attic lighting circuit.
C. a basement service.
D. an air conditioning circuit.

2007-02-06 23:42:16 · 2 answers · asked by Chad A 1 in Engineering

I'm doing my chemistry and I would love some one to tell me the answer! Or something similar...
is it something to do with van der waals? I can't find it anywhere! I need it for friday!! Please save my soul - my teacher will kill me!!!

2007-02-06 23:38:59 · 7 answers · asked by smiley 2 in Chemistry

I'm doing a project and at the minute, I'm just doing my project plan. I'm stuck already. I'm doing it about 'Conflict/Blood diamonds in Ivory Coast'. What do you think the geographical factors are? and more so, 'What does geograpical factors cover or mean'?

2007-02-06 23:37:43 · 3 answers · asked by Anonymous in Geography

Explanation: At which location in Great Britain are there an equal number of people to the North as to the South; and an equal number to the West as to the East. Perhaps this is the REAL centre of Great Britain, as a nation of people.

2007-02-06 23:36:02 · 10 answers · asked by znmex3r 1 in Geography

I'm doing a project and at the minute, I'm just doing my project plan. I'm stuck already. I'm doing it about 'Conflict/Blood diamonds in Ivory Coast'. What do you think the geographical factors are?

2007-02-06 23:33:26 · 2 answers · asked by Anonymous in Geography

for example the formula for a circle is pi r squared

2007-02-06 23:26:33 · 15 answers · asked by r wall 3 in Mathematics

my left arm, hand, and leg sometimes get num

2007-02-06 23:24:24 · 3 answers · asked by joelruvalcaba 1 in Biology

2007-02-06 23:21:09 · 22 answers · asked by Anonymous in Mathematics

find the equation of the line that contains the point whose coordinates are (1,2) and has a slope -1.

2007-02-06 23:21:01 · 11 answers · asked by Anonymous in Mathematics

2007-02-06 23:20:51 · 6 answers · asked by glessa darling 1 in Earth Sciences & Geology

Please help me.... I really beg you...This is a research work and have to be passed on Friday...THANK YOU VERY MUCH,..GOD BLESS,,,...,,...

2007-02-06 23:16:33 · 3 answers · asked by caye y 1 in Astronomy & Space

In a standard column?

2007-02-06 23:16:10 · 8 answers · asked by pat_the_hustler 1 in Mathematics

Because I'm getting the feeling that the Midwest won't be thawing out until June.

2007-02-06 23:15:23 · 5 answers · asked by LA Law 4 in Weather

2007-02-06 23:10:20 · 6 answers · asked by priyanka r 1 in Earth Sciences & Geology

2007-02-06 23:09:51 · 6 answers · asked by sanjiv k 1 in Botany

2007-02-06 23:08:18 · 1 answers · asked by Anonymous in Physics

2007-02-06 23:05:51 · 18 answers · asked by WELL SAID ERFMAN JACK 2 in Astronomy & Space

pls answer my question....I really beg You..THANK YOU!!!!

2007-02-06 23:05:35 · 2 answers · asked by caye y 1 in Astronomy & Space

Why u believe that Pluto is not a planet ?? and if it is due to annoucement of some community of scientist on what basis they have removed the honour of Pluto of being a planet.

2007-02-06 23:05:19 · 12 answers · asked by AJ 2 in Astronomy & Space

another 1% and who knows maybe we will start evolving, get smarter
imagine if we used all of our brain power thats 10 times smater than we are now

do u guys believe in evelution they say that every 1000 years an animal or race evolves
just recently they have found a type of jelly fish of the coast line of australia that has an eye i mean WTF!!!
do u think humans will evolve???

2007-02-06 23:04:18 · 4 answers · asked by !!David!! 2 in Biology

1. does knowledge of newton's law of motion help save lives?
( example)
2. Examples of situations where the knwledge of these concept will be invaluable.

2007-02-06 23:02:39 · 4 answers · asked by starbrightlight 1 in Physics

Will aqueous solutions of each of the following salts be acidic, basic, or neutral?

A) CaCl2
B) KBr
C) KHCO3
D) NaHS
E) CsI
F) (CH3)2NH2Br
G) KClO4
H) Na2SO4

Thanks for the help!

2007-02-06 22:59:27 · 2 answers · asked by thesekeys 3 in Chemistry

Two cylindrical vessels of equal crosssectional area 'A' contain water upto heights 'H1' and 'H2'. The vessels are interconnected so that the levels in them become equal. Calculate th work done by the force of gravity during the process. The density of water is P

2007-02-06 22:58:16 · 1 answers · asked by Anonymous in Physics