Science & Mathematics - 31 October 2007

I need to provide power for 5 minutes and then turn it off for 30 minutes and then again 5 minutes ON, 30 minutes OFF, for 2-3 days. Power is provided from the car battery 12VDC, less than 10 amps.
Thanks,

2007-10-31 06:28:08 · 6 answers · asked by ERKAN B 2 in Engineering

A toaster using a Nichrome heating element operates on 120V. When it is switched on at 20.0 Celsius, the heating element carries an initial current of 1.35A. A few seconds later the current reaches the steady value of 1.23A.

a) What is the final temperature of the element? The average value of the temperature coefficient of resistivity for Nichrome over the temperature range is 4.5*10^-4 (1/Celsius).

b) What is the power dissipated in the heating element initially?

c) What is the power dissipated in the heating element when the current reaches a steady value?

Appreciate the help :)

2007-10-31 06:26:44 · 1 answers · asked by Hannah 4 in Physics

2007-10-31 06:25:37 · 34 answers · asked by Anonymous in Mathematics

Adult tickets for the senior class play cost $5 each and the student tickets cost $3. A total of 1060 tickets costing $4500 were sold. How many student tickets were sold?

2007-10-31 06:25:37 · 9 answers · asked by wish on a star 1 in Mathematics

2007-10-31 06:24:02 · 5 answers · asked by billdokme 1 in Zoology

2007-10-31 06:23:04 · 4 answers · asked by xoxjaime06xox 1 in Mathematics

7. 7x^2+5x-2
8. 3x^2-8x-3
9. 2x^2-8x+8
10. 12x^2+8x+1

2007-10-31 06:22:33 · 2 answers · asked by Diamond E 1 in Mathematics

2007-10-31 06:20:30 · 3 answers · asked by Anonymous in Biology

2007-10-31 06:19:00 · 3 answers · asked by irien 1 in Biology

Is it because the brain prosseses information faster or cause it only prosseses vital information?

2007-10-31 06:17:37 · 10 answers · asked by Asklar 1 in Physics

2007-10-31 06:13:53 · 41 answers · asked by ameeker 3 in Weather

2007-10-31 06:12:27 · 4 answers · asked by Anonymous in Physics

a. Mar mediterraneo

b. Golfo de Vizcaya

c. Oceano Atlantico

d. Oceano Pacifico

2007-10-31 06:11:55 · 6 answers · asked by Anonymous in Geography

a. Pamplona

b. Paris

c. Papagayo

d. Nueva York

2007-10-31 06:11:18 · 12 answers · asked by Anonymous in Geography

2. 3x^2+10x+8
3. 5x^2+24x+27
4. 4x^2-12x+8
6. 9x^2+37x+4

2007-10-31 06:09:40 · 5 answers · asked by Diamond E 1 in Mathematics

2007-10-31 06:08:48 · 2 answers · asked by Sandy 1 in Geography

1. Simplify:
5/3+2i
2. The area of a room with length "3-2i" and width "4i" is

3+i

8+12i

-8+12i

-8i2+12i

3. The conjugate of the complex number "3+2i" is
3-2i

3+2i

-2i

3


Thanks so much!!

2007-10-31 06:07:20 · 3 answers · asked by stringsdepotplus 2 in Mathematics

For instance, when humans travel to mars and spend several months to years in space with no gravity. Does it affect their internal organs and blood pressure?

2007-10-31 06:05:23 · 6 answers · asked by bdhartma 2 in Astronomy & Space

I'm studying Markovnikov's rule and I know that the addition of HX to an alkene, the X goes on the C that has the most alkyl group, but i just see that C1 only contains the ethyl group, where is the other alkyl group?? and how does C2 even have 1 alkyl group??

2007-10-31 06:04:01 · 2 answers · asked by Anonymous in Chemistry

2007-10-31 06:03:38 · 12 answers · asked by prem.pachar 1 in Geography

2007-10-31 06:03:00 · 1 answers · asked by Anonymous in Biology

2007-10-31 06:01:48 · 6 answers · asked by azalia 1 in Geography

At a football game, 200 souvenirs were sold, some at $1.50 each and the rest $2.50 each. If the proceeds from the sales totaled $389, how many of each kind were sold?

2007-10-31 06:01:12 · 8 answers · asked by wish on a star 1 in Mathematics

a. Morocco

b. Portugal

c. France

2007-10-31 05:58:47 · 16 answers · asked by Anonymous in Geography

2007-10-31 05:57:02 · 7 answers · asked by <3 1 in Geography

2007-10-31 05:55:49 · 6 answers · asked by Anonymous in Geography

2007-10-31 05:55:25 · 23 answers · asked by Anonymous in Geography

Ions are electrically charged particles that are formed when certain compounds are dissolved in water. These solutions will conduct electricity. The Swedish scientist Svante Arrhenius coined the term ion (which means wanderer) to explain why solutions of electrolytes will conduct an electric current. When an electrolyte forms into a solution, it dissolves or dissociates into ions, a process called ionization. If a substance does not ionize, it will not conduct an electric current. Electrolytes include most acids, bases, and salts. Some conductors include hydrogen and sodium chloride, copper sulfate, and potassium nitrate. Substances that are not electrolytes include distilled water, sugar water, and most organic compounds. Which of the following is a nonelectrolyte?



A) H 2 SO 4 (sulfuric acid)
B) HCL (hydrochloric acid)
C) C 3 H 8 (propane gas)
D) NaCl (table salt)

2007-10-31 05:53:08 · 16 answers · asked by lil_nisha142000 1 in Chemistry

University thearter sold 463 tickets for a play. Tickets cost $24 per adult and $12 per senior citizen. If total receipts were $7224, how many senior citizen tickets were sold?

2007-10-31 05:52:43 · 5 answers · asked by Anonymous in Mathematics

2007-10-31 05:47:40 · 6 answers · asked by Anonymous in Astronomy & Space