Base Definition and 571 Threads

I was trying a simple Darlington circuit with two Darlington-connected NPN transistors. There is an LED in the shorted collectors, connected to a 5V supply, and the base is open. The trivial objective was to see that when you touch two fingers to the base and the supply positive, the LED turns...

Homework Statement If a double-stranded segment of DNA has been found to have 23 purines and 15 thymines, how many guanines are there? Homework Equations purines are adenine and guanine...adenine and thymine should be equal amounts. So, there are 15 adenines. Out of the 23 purines...

Homework Statement Whenever base b is even (b=2k for some integer k) a number H=(d(n-1)d(n-2)...d1d0)b is even <=> d0 is even. Homework Equations The Attempt at a Solution I have formulated a proof for the forward direction (=>) but I am having trouble getting started on a proof for the...

Hello! I was just wondering why the most common base is base 10? It seems kind of arbitrary to me, although I may be overlooking something.

Hi, everyone: I am trying to find a result for the number of bundles (up to bundle iso.) over a fixed base and fixed fiber. For example, for B=S¹ , and fiber I=[0,1] I think that there are two; the cylinder and the Mobius strip. I think that the reason there are...

1. A third baseman makes a throw to first base 38.6 m away. The ball leaves his hand with a speed of 38.0 m/s at a height of 1.4 m from the ground and making an angle of 24.2 degrees with the horizontal. How high will the ball be when it gets to first base? 2. d=V0(t) + 1/2(g)(t^2)...

What is in DNA why can it not read the uracil nitrogenous base during transcription? May I have answer in the molecular level?

Does there exist a database with very specific mathematical definitions, theorems... etc? I've found that some thm's/dfn etc differ from author to author. Not necessarily in meaning, but in the words used to describe them. Is there a place where a precise definition can be found that is agreed...

Homework Statement What I'm supposed to do is to rearrange the this formula -16t^2+Vt+h and solve it for V. V= Initial Velocity t= time (throwing the ball in a parabolic arc) h= height I know what the height is and it is 6ft. I also have the time which is 2.03 seconds. How do I rearrange...

Why is alchemy not real? Did anyone ever figure out how to change base metals into gold? What is the closest anyone has ever come to this? Assuming they haven't , why can't they do it?

I need suggestion on how to make a balloon powered Hovercraft. THE AIM: the aim is to make the hovercraft travell a displacement of tleast 3 meters.. THE CONDITIONS: 1. it has to be powered by no more than a single party balloon. 2. the base of the hovercraft must be a CD. (the...

Hello all, I am new to the forum and hope my question is appropriate for this section. My question is about per-unit notation and calculations. Basically I've been given the resistance, reactance at the primary and secondary windings of a transformer, core losses and inductance, etc. The...

Hi, I have a friend who has a friend who has a data base of 20000+ enteries. This data base was constructed using something called D base nearly twenty years ago. Now, they want to know is it possible to transfer the 20000 odd enteries to a modern data base without having to type in the...

A base is a chemical which reacts with an acid forming water and salt only. Is this definition of base true? If true, metal carbonates are not considered as base (carbon dioxide is also formed during neutralization which violates the definition). Hence, the solution of metal carbonates are...

Homework Statement Hi. I'm reaady to panic right now so if anyone could please take the time to answer my question I would HUGELY appreciate it! I seriously need to get this done soon as I also have a test tomorrow and i just want to cry because I'm getting nowhere... We did a lab...

Hello Physics Forums, Before i get started asking questions i wanted to clarify that i don't need/want a answer, i have an answer after about an hour of searching. The thing is i understand what needs to be done but i do not understand how to do it in C++. I am just hoping to learn from you...

Homework Statement OK so this is my first time actually posting but I have lurked around. I need help with two of my chemistry problems. Problem 1 Decide which one(s) of these answer choices are correct. A buffered solution is one which can be desribed by which of the following...

Just out of curiosity, I was wondering how to solve for x in an expression of the form ax = xb It kinda tripped me out at first.

Yo yo yo. What up homies? I am once again humbled to be in need of your gracious assistance. I did all the work this time. I would just like some fresh minds to double check. I am driving two relays with http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=FMMT493CT-ND" is the...

x^2 - 11x + 22 = 0 the roots are x= 3 and x = 6 what's the base of the numbers? ok what I've done is I found the roots in decimal system which are x1 = (11+sqrt(33))/2 and x2 = (11-sqrt(33)/2 then I said x1 = 3 and x2 = 6 so we have 3 = (11+sqrt(33)/2 <=> 6 = 11+sqrt(33) <=> -5...

Homework Statement a dam of height H has a hole half way down to the base. how far outward from the base does the stream hit the ground? Homework Equations The Attempt at a Solution i think you have to use bernoulli's equation right? first find velocity then distance x right?

Homework Statement f(x,y,z)=exy and x5+y5=64 Find Max and MinHomework Equations ∇F = <yexy, xexy> λ∇G = <5x4λ, 5y4λ> The Attempt at a Solution yexy = 5x4λ xexy = 5y4λ x5+y5=64 No idea where to go from here...

Homework Statement Is H3CC(=O)CH2CH3 more likely to act as a Lewis Acid or Lewis Base? Explain your choice. Same for HCO2H (formic acid)Homework Equations N/AThe Attempt at a Solution Since a Lewis Base donates electron pairs, and the oxygen in H3CC(=O)CH2CH3 has two lone pairs, I reasoned...

http://img19.imageshack.us/img19/2692/chptitration.jpg http://img130.imageshack.us/img130/6351/titrationfigure1.jpg 1.)For the titration of strong acid and strong base, and at the beginning of the curve, how to explain the big amount of base added only increase a little of the pH value...

I recently did an experiment with the following reaction: NH_4^+ + OH^-<-->NH_3+H_2O I added phenolphthlein, which is magenta in the presence of base. Now, I have to explain, after adding certain chemicals why I have certain color. The one color change I am having trouble explaining...

Could anyone help with a problem I have been asked to solve at work. Unfortunately I haven’t done anything like this since college (over 12 years) and am a bit confused now. We have an assemblied unit, consisting of an aluminium base and cover with a PCA clamped between. The unit is clamped...

Homework Statement NaOH(aq) + HCl(aq) ------> NaCl(aq) + H2O(l) 50mL of 1.0M HCl and 50ml 1.0M NaOH was mixed. Total heat is 2826J. If the density of 0.5M NaCl produced in this reaction is 1.02g/mL: a) What is the mass of the solution? b) Moles of water formed c) Moles of NaCl formed d) Molar...

base representation please help~ It is known that if asks+as-1ks-1+...+a0 is a representation of n to the base k, then 0<n<=ks+1-1. Now suppose n=asks+as-1ks-1+...+a0 and m=btkt+bt-1kt-1+...+b0 with as,bt not equal to 0, are two different representations of n and m to base k, respectively...

base representation please help~ It is known that if asks+as-1ks-1+...+a0 is a representation of n to the base k, then 0<n<=ks+1-1. Now suppose n=asks+as-1ks-1+...+a0 and m=btkt+bt-1kt-1+...+b0 with as,bt not equal to 0, are two different representations of n and m to base k, respectively...

base current in transistor flows due to recombination of electrons and holes. Explain

Homework Statement The number 4312 in base ten is (4*10^3) + (3*10^2) + (1*10^1) + (2*10^0) 4312 in base six is (4*6^3) + (3*6^2) + (1*6^1) + (2*6^0) which is 980 therefore 4312 in base six is equal to 980 in base 10 QUESTIONS: a) does 124 in base 5 represent an odd number...

Homework Statement I am reading Ramamurti Shankar Quantum mechanics and I have a thing where is "vector base", how can I understand this "vector base"? please tell me what it means that I can ex. solve equation in eigenvector base? what it means that somewhere is a vector base? I need this to...

Homework Statement after titrating sodium hydroxide with hydrofluoric acid, a chemist determined that the reaction had formed an aqueous solution of 0.020 mol/l sodium fluoride. determine ph of the solution Homework Equations The Attempt at a Solution Ka of HF= 6.3X10^-4 NaOH +...

Homework Statement See the pic (I know, its not clear but still). Homework Equations The compound is reacting with a base. The pic shows the alpha hydrogen taken out by the base. Why in both the compounds that alpha H is taken out which is not near Chlorine. Why not the H which is near the...

Can someone guide me on how to express (.a1a2a3a4a5) base n as a quotient of base n integers. There is a bar over a3a4a5.

What is 1/7 in base 2? How would you solve for this? Thanks!

I was wondering if base isolation systems are used in the design and construction of skyscrapers. I was reading up on base isolation systems and they seem to be used in normal sized buildings frequently. Anyways, if anyone could give me some examples of base isolation systems being used in...

\int_0^1\int_0^y e^{x^2} dx dy The region I am integrating over should look like this graph, right? I tried switching the bounds but I am left where what I started. since 0 < x < y, and 0 < y < 1 I can switch to 0 < x < 1 , and x < y < 1 leaving me with the integral...

This is my question: When a 17.9 mL sample of a 0.493 M aqueous nitrous acid solution is titrated with a 0.476 M aqueous barium hydroxide solution, what is the pH after 13.9 mL of barium hydroxide have been added? I'm not really sure how to start it? I have the moles of the acids and the...

Homework Statement Consider a titration in which 50.00 mL of .450 M benzoic acid, C6H5COOH, is reacted with 0.2000 M Ca(OH)2. What will the pH be when 60.00 mL of Ca(OH)2 has been added?Homework Equations 2C6H5COOH + Ca(OH)2 -> 2 H2O + Ca(C6H5COO)2The Attempt at a Solution I have determined...

(*sovled) basic C program problem Homework Statement attrached. and one more thing is: if the angle is 90, a statement "This is a right angle." should be appeared in the last rows, else, "This is not a right angle" instead. also, the degee is 90 (interger) but not 90.0 Homework...

Hi ! i am new to these forums.. so i just want to ask whether i am posting my query in the correct forum?? I have a doubt regarding this weak acid - weak base buffer. When the moles of Acid > Base, We use the formula pH = pka + log10 ([salt]/[acid]) to calculate the pH of the Acidic Buffer...

Sam (60 kg) takes off (from rest) up a 50 m high, 10° frictionless slope on his jet-powered skis. The skis have a thrust of 200 N. He keeps his skis tilted at 10° after becoming airborne, as shown in Figure P6.43. How far does Sam land from the base of the cliff? a=F/m I used 50/sin10 to...

Homework Statement convert (352416)_7 to (...)_3 the _7 means base 7 and similarly, _3 means base 3. Idea : convert base 7 to base 10 then base 10 to base 3. I know I can use expansion, 3 * 7^6 + 5 * 7^6 ... to convert it to base 10. but in my exam, we are not allowed to use...

in BJT transistors how can I find the maximum base current? Do we have maximum voltage limitation for base of transistor? consider a resistor between input and base of transistor. I want to use a transistor that its input range is from 3 to 30 volts and its output is 5 volts. how can i do...

If I see a formula that contains LOG, but does not specify as base, how do I know what base they're referring to? Programming languages assume LOG means base e. My calculator assumes LOG means base 10. I've seen math teachers assume it meant base e. If its base anything other than 10 or e...

Now I'm seriously just tired and can't get these, but I don't know why this is wrong at all. This would help if I had a study partner in my physics class (to bounce ideas off of), but no one else in my class is overly strong in the subject. Homework Statement A batter hits a pitched ball...

Homework Statement The solution of 2^(2x+3) = 2^(x+1) + 3 can be expressed in the form of: a + log2b where a, b belong to the set of complex numbers. The Attempt at a Solution (2^3)(2^x)^2 = 2^(x+1) + 3 [8((2^x)^2)] - [2(2^x)] - 3 = 0 Solving the above quadratic for 2^x, I...

Homework Statement This really isn't a calc question so forgive me. Determine which base(radix) is used in the following operation : a ) 1234 + 1234 + 1234 + 1234 = 11101 b ) 19 * 18 = 297 I know the answer to a but am not sure how to get it. What I see is the for a) the answer...

Homework Statement -OCH3, -OH, -NH2, and the fourth choice is an alkyle, ethyne with a neg charge. the picture shows a triple bond attacked to a hydrogen. Homework Equations The Attempt at a Solution I know that OH is a relatively common base and I thought it was strong, but I...