Science & Mathematics - 19 July 2007

Aluminum reacts with sulfuric acid, which is the automobile batteries. if 20.0 grams of Al is placed into a solution containing 115 grams of H2SO4, how many grams of hydrogen gas could be produced?

2007-07-19 05:17:06 · 5 answers · asked by Anonymous in Chemistry

2007-07-19 05:15:33 · 5 answers · asked by srinivasan j 1 in Engineering

2007-07-19 05:14:04 · 10 answers · asked by group_leader_100 1 in Mathematics

We can create AC from DC - the best example is House hold Inverters. We can inturn create DC from AC- Best example is mobile phone charger producing 15 v for ex. So why cant we generate Continuous AC for our house hold equipments and loop the same power needed for generating AC. Just we can loop back DC and generate AC. We have optimum power booster circuits which requires little power to run and boost the input voltage to a max level. Then we can convert to AC again. A little AC can be used to generate DC as a back loop input. So we can get a continous source of electricity for the whole house. Why cant any scientist do this? I am from electronics and comm engineer. But i cant design a machine. But why cant others? We have so many scientist in this world. WHy nobody tried it?

2007-07-19 05:10:55 · 4 answers · asked by ASH 2 in Engineering

I am trying to work the following problem, but I am not sure what is being asked. "Find the negative of the two's complement form of 0.0101100(subscript-2cm)?"

2007-07-19 05:10:17 · 4 answers · asked by wcr98 1 in Engineering

Probably yes, if you consider that weight equals mass times the force of gravity.

However, I mean weight in common sense (or in the sense of mass).

At first, it seems to me that the mass is always constant, regardless of where we are.

But if we took a scale to the Moon, wouldn't the pull of gravity also influence the value that was marked on the scale?

For example, if I weigh 55kg on Earth, would I weigh the same on the Moon?

2007-07-19 05:08:22 · 15 answers · asked by Anonymous in Physics

2007-07-19 05:03:56 · 27 answers · asked by Durango Splubb 1 in Zoology

With school summer vacation starting tomorrow I would like to see the fencing around the electricity UK substation at Fairfield Scalby Stockton-on-Tees repaired as a matter of urgency to prevent the death of another inquisitive child.

2007-07-19 05:02:26 · 4 answers · asked by Anonymous in Engineering

Can you see light on one side and dark on the other as if your seeing night and day

2007-07-19 04:57:56 · 6 answers · asked by Donna H 1 in Astronomy & Space

I know that you can make a lightsaber with a high power laser beam and a block at the end, but is it possible to have a concentrated beam of laser that can only go so far and all that jazz!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!???????????????????????????????????????????

2007-07-19 04:56:54 · 10 answers · asked by Anonymous in Engineering

has anyone evr seen these things & i want to know the mass of these things has been calculated. sometimes it seems that no one hs ever seen these things

2007-07-19 04:52:31 · 10 answers · asked by Cave H 1 in Chemistry

What are some clothing/ accessories that are inappropriate in a lab? And why?

2007-07-19 04:51:59 · 5 answers · asked by Drogba 2 in Chemistry

a) social.
b) omnivorous.
c) tool makers.
d) social and omnivorous.
e) social, omnivorous, and tool makers.


--[I'm leaning toward E ... what do you all think?? Yay/Nay?]

2007-07-19 04:51:24 · 2 answers · asked by Anonymous in Biology

2007-07-19 04:48:38 · 10 answers · asked by meganndavo 1 in Other - Alternative

2007-07-19 04:46:39 · 8 answers · asked by ivorylady753 1 in Weather

Similarities between the two main types of bonding; ionic and covalent

2007-07-19 04:43:26 · 6 answers · asked by Anonymous in Chemistry

2007-07-19 04:35:59 · 6 answers · asked by b1expressway 1 in Engineering

2007-07-19 04:35:44 · 2 answers · asked by TeeHee 3 in Astronomy & Space

i brought a packet of chips in to the plane and when i decided to eat my chips i realised that the packet of chips had beome puffier why is this so?

2007-07-19 04:32:40 · 4 answers · asked by blushyyy 1 in Physics

i have heard that people said that we only have 3 fingers on our hand. your thumb and your pinky is is not a finger. is that true?

2007-07-19 04:32:29 · 8 answers · asked by xiomara724 2 in Biology

a straight line with constant velocity u = 10 m/s.

The shortest distance between the path of RR and the cactus is 50 ft. When he runs past the cactus WEC ambushes him, and begins chasing him with speed v = u = 10 m/s.

The velocity of WEC is always directed towards RR.

What is the distance between them after sufficiently long chase?


Position when the chase begins:
WEC
--|
--|
--v
50ft
--|
--|
--|
--RR---u> ------ ----- ------ ----- ------ -----

2007-07-19 04:31:08 · 4 answers · asked by Alexander 6 in Physics

Question #1: Describe how significant digits in a measurement can indicate the precision of the instrument used to take the measurement.

Answer: The measurements recorded should include all the numbers that are known with certainty plus one digit (the rightmost digit) that is estimated. Thus, significant digits clearly show the precision of the instrument used.

Question #2: Determine how many significant digits are in the following numbers: a. 20.009 b. 0.00876 c. 45.000
d. 34500 e. 234.614

Answer:
a. Five
b. Three
c. Five
d. Three
e. Six

Are they right? Thanks for your help!

2007-07-19 04:29:40 · 4 answers · asked by Steven M 3 in Chemistry

We were feeding birds bread and someone approached us and said white bread caused foot deformities in wild birds. I have not been able to verify this.

2007-07-19 04:26:01 · 5 answers · asked by dvryh 1 in Zoology

If a silver spoon placed in a cup of coffee absorbs 193.2 cal of heat causes the coffee to cool 0.75oC, what is the mass of the coffee? (Assume ccoffee = 1.0 cal/gCo) Give answer in kg.

2007-07-19 04:25:49 · 3 answers · asked by JT78 1 in Other - Science

Do you think it could get all the legalities and meet all the requirements to own? Would the government take it away from me if I accomplished it?

2007-07-19 04:20:47 · 10 answers · asked by a2z_alterego 4 in Engineering

x^y
x^(1/2)
x^(1/3)
(x+y)/z
y*z
a-b
a+b
a/b=c/d

I don't speak English very well that's why I'm asking

2007-07-19 04:14:49 · 13 answers · asked by Anonymous in Mathematics

I hav studied that we can convert a DC to AC. But for perfect AC we need a rotor to rotate around a magnetic field and thus we get AC.There are generators which run on diesel/ fuels in general. We hav Invertors which convert DC to AC depending on their capacity.So why nobody created a equipment which can generate AC without any continuous source like fuels/ Battery.My question is very clear.Is it not possible to create a POWER PRODUCING MACHINE which can GENERATE POWER FROM DIESEL IN THE BEGINNING TO START / BATTERY TO START AND THEN CONTINUOUSLY PRODUCE AC.Just looping the power generated by the generator to AN ELECTRICAL CIRCUIT so that it gets the power and so it can generate more power needed for a full house.Making it a loop.Getting power AS INPUT AND Generating ELECTRICITY.If we have this kind of machine then we dnt need to pay government for the electricity.we dnt need to burn so much coal. If we didnt burn coal for electricity then we can save atmosphere too.Y NOBODY DID THIS?

2007-07-19 04:12:35 · 6 answers · asked by ASH 2 in Engineering

2007-07-19 04:11:32 · 4 answers · asked by Helen 1 in Chemistry

compare the two main types of bonding; ionic and covalent.

2007-07-19 04:08:16 · 4 answers · asked by Anonymous in Chemistry

use factortheorem to verify in the question that q(x) is a factor of p(x).
Factor Theorem
x-a is a factor of polynomial p(x) if p(a) = 0.

2007-07-19 04:07:02 · 14 answers · asked by rishabh g 1 in Mathematics