Thursday

October 23, 2014

October 23, 2014

Total # Posts: 141

**physics**

A car engine accelerates at a constant rate from 170 rpm to 3050 rpm in 7 seconds. I have found that at t=0, the angular velocity (omega)=17.8 rad/s, the angular acceleration (alpha)= 43.1 rad/s^2, the tangential acceleration = 7.76 m/s^2, and the centripetal acceleration is ...
*April 27, 2009*

**Pre-calculus**

Given the following values for f(t): t : f(t) 3 : -7 6 : 6 9 : 19 12 : 6 15 : -7 18 : 6 a) What is the period, frequency, midline, amplitude, maximum, and minimum? b)Find a possible formula for f(t) c)Find the domain and range of f(t) d)Find a formula for an inverse function ...
*March 26, 2009*

**college earth science and astronomy**

Thank you very much bobpursley! This has been quite the challenge to learn without the benefit of a teacher. I want to run my answers past and see if I have calculated correctly. energy= 250 * 2.5 = 625 Calories Then solar energy flux will be 250 *2.5 (625) / 63.6 * 10 (636) ...
*March 18, 2009*

**college earth science and astronomy**

This isn't homework as much as I am trying to learn this on my own. I am trying to perform an experiment on solar power. I measured and recorded the volume (V= 250 mL) and mass (M= 250 g) of water in a cup. I then recorded the initial temperature(32 degrees celcius) of the...
*March 18, 2009*

**Chemistry**

I had to find the numbers of atoms in 2 Al (NOsubscript 3)subscript 3. I got 16, but the answer in my book is 26. Who is incorret? Thanks!!!
*March 4, 2009*

**social studies**

Are you asking about symbols used in ancient writing? If you are, an example is hieroglyphics (don't trust me that I spelled that right). Hope I helped you!
*January 20, 2009*

**Another algebra**

Determine the number of positive integers n that satisfy: 1/2 < n/n+1 < 99/101 I don't know how to solve this besides plugging in random numbers, which would take all day. Any other suggestions for a faster way to solve it? Thank you!
*January 20, 2009*

**Algebra**

What is the length of the interval of solutions to the inequality 1 ( is less than or equal to) 3-4x (is less than or equal to) 9? I presume that I just plug in numbers for x? The problem is, that all the positive numbers I've tried have made them way less than one, when ...
*January 20, 2009*

**math**

Try to make two equations, one for each phone company. First plan: y = .10x + 18 Second plan: y = .15x Try plugging in numbers until the two equations have the same y. If you need anymore explanations, just respond back. Hope I helped!
*January 20, 2009*

**Math**

woooow really mature. "yo moma" oh that's so funny...what are we, in third grade? it's "aflyerquacker"
*January 5, 2009*

**english**

what should i do if i can't come up with a title for an essay? is it alright for it to be untitled?
*October 29, 2008*

**science**

ecologists usually study a specfic populaions of organisms rather than studying the entire species why?
*September 16, 2008*

**Physics**

V=k*q/r so for the above equation, there should without square!
*February 1, 2008*

**english**

What is the basic plot of Titus by Shakespere? It doesn't have to be detailed. I think it's about the guy who like kills someone and bakes them in the pie? i don't know if i have it right
*November 18, 2007*

**inverse function question**

Hey, I'm having trouble fully understanding absolute value graphs and I've been asked find the largest value of a so that f^-1 exists for the function: f: (-efinity,a) --> R where f(x)= logel2x-1l *note: i have used 'l' to represent the straight line ...
*November 8, 2007*

**Physics**

Ah, it's right. Thanks alot!
*October 27, 2007*

**Physics**

The cable of an elevator of mass M = 1020 kg snaps when the elevator is at rest at one of the floors of a skyscraper. At this point the elevator is a distance d = 18.4 m above a cushioning spring whose spring constant is k = 6500 N/m. A safety device clamps the elevator ...
*October 27, 2007*

**Physics**

Um are you saying Wtotal = [(1020)(9.8)-6678] (18.4+x) ?.. In that case, I did the quadratic and got x=17.33m, but still wrong answer :( argg
*October 27, 2007*

**Physics**

Wtotal = [(1020)(9.8)-6678] 18.4 = 61051.2J 61051.2J = 1/2 (6500)x^2 x = 4.33m STill wrong :( Help
*October 27, 2007*

**Physics**

The cable of an elevator of mass M = 1020 kg snaps when the elevator is at rest at one of the floors of a skyscraper. At this point the elevator is a distance d = 18.4 m above a cushioning spring whose spring constant is k = 6500 N/m. A safety device clamps the elevator ...
*October 27, 2007*

**Another binomial distribution question**

hi, i'd also really like some help for another binomial distribution question, i have no idea where to start... the question is: A manufacturer makes 10,000 ball point pens per day and estimates that 400 will be defective. She decides that if a random sample of 10 pens ...
*August 25, 2007*

**binomial distribution**

hey, i'd really appreciate some help with this question: A medical treatment is successful 75% of the time. A hospital wishes to treat a group of patients. How many patients should they take so that the probablity that all are cured is 1/10? I know that p=0.75 and q=0.25 ...
*August 25, 2007*

**maths**

hey, i would really appreciate some help solving for x when: sin2x=cosx Use the identity sin 2A = 2sinAcosA so: sin 2x = cos x 2sinxcosx - cosx = 0 cosx(2sinx - 1)=0 cosx = 0 or 2sinx=1, yielding sinx=1/2 from cosx=0 and by looking at the cosine graph, we conclude that x=pi/2 ...
*July 17, 2007*

**maths**

hi, i'm having trouble with this question: The cost of running a train at a constant speed of v km/h is C=50+v^2/1000 dollars/hour find the time taken for an 800km journey in terms of v.
*May 24, 2007*

**differentiation**

hey, i'd really appreciate some help differentiating this equation: t= (4+x^2)^(1/2) /3 + (3-x)/5 so that's four plus x to the power of 2 all to the power of 1/2 all over three plus 3-x divided by five... :P Thankyou. I would rewrite it as t= (1/3)(4+x^2)^(1/2) + 3/5...
*May 24, 2007*

**maximum and minimum problems when function unknown**

Hi, can anyone please help me with this problem, i have no idea what to do! The question is: a window frame is in the shape of a semicircle joined to a rectangle. Find the macimum area of a window using 300 cm of framework. i can usually solve these sorts of questions when i&#...
*May 21, 2007*

**equations of tangents and normals**

hi, i'd really appreciate some help solving this question! I am completely at loss here :/ The question is to: Find the equation of the normal to y=loge(x+2) which is parallel to the line with equation y+3x-5=0 I am fine at solving these sorts of equations when they give ...
*May 20, 2007*

**circular (trigonometric) functions**

hi, i need help solving this trigonometric equation: sinx+3cosx=0 i don't know what to do as i can't just diviide the two to create tanx which is what i have been doing in previous questions... yes, you are on the right track sinx = -3cosx sinx/cosx = -3 tanx = -3 so x...
*April 14, 2007*

**exponential and logarithmic graphs question**

hi, i desperately need help solving this question: Find the values of A and k if the general equation of the graph shown is y=Ae^kx where the graph goes through the points (-1,-4) and (-2,-10) do i solve it using simultaneous equations? because i have attempted this yet failed...
*March 21, 2007*

**maths help needed!**

Hi, just a short question. How do i find the x intercepts for the equation y=-2x^3+1 ? I tried to let y equal zero but i could only get as far as x^3=1/2 please help! x^3 = 1/2 is correct. There is only ine x-intercept. It is where x = (1/2)^(1/3) which means the cube root of ...
*March 5, 2007*

**Econ T/F**

yes, its a true or false question is this a true or false question? Suppose that after a price change, the income effect is zero, but the substitution effect is not. For such a good, the quantity demanded is directly related to its price. oh well I think it is true. hummmm. ...
*March 1, 2007*

**Econ T/F**

A consumer with a fixed income buys two goods, X and Y. If her demand for both X and Y are unitary elastic, she must spend an equal amount on each good. take a shot, what do you think, and why? i think false, she doesn't have to spend equal amount?? I agree
*March 1, 2007*

**Econ T/F**

If a consumer is in equilibrium and all prices and her income increase by 25%, she will consume less of those goods that she considers inferior. if false, explain why. Take a shot. What does your economic reasoning tell you? Hint. If all prices and income rise by exactly 25%, ...
*February 28, 2007*

**economics**

According to a survey of U.S. firms, the advertising elasticity of demand is only about 0.003. Does this indicate that firms spend too much on advertising? It does not indicate too much is being spent. A 100% increase in advertising would translate into a .3% increase in sales...
*February 26, 2007*

**maths, please help!**

I need help solving this: 6x^2-x-12=0 I usually could do this yet i have completely forgotten what i need to do seeing as there is a number infront of the x^2 This equation is of the general form a x^2 + bx + c = 0 The solution is always x = [-b +/- sqrt (b^2 - 4ac)]/(2a) = [1...
*February 22, 2007*

**calculus**

hi, just wondering on how i should approach differentiating: loge1/(3-x)^5 can i differentiate it as loge(3-x)^5? sorry i meant to write (3-x)^-5 Hmmmm. You are haveing a brain seizure. Watch this: Ln x^-a= - ln x^a= -a ln x Amazing. So loge1/(3-x)^5= -5 ln(3-x) Check my ...
*February 21, 2007*

**maths**

hi, i would really appreciate some help on simplifying this question: -2(3e^-x-e^x)(-3e^-x-e^x) could this be simplified as -2(3e^-x-e^x)-(3e^-x-e^x) which would then become (-2-1)(3e^-x-e^x) i feel this isn't right however...
*February 21, 2007*

**math**

hi i would really appreciate some help solving this question simultaneously: Find A and B such that x-11/(x+3)(2x-1)= A/x+3 + B/2x-1 Multiply both sides by (x+3)(2x-1) to get rid of the fractions. We end up with this: (x-11) = A(2x-1) + B(x+3) You can solve for A and B more ...
*January 27, 2007*

**math**

I need help differentiating this question: 3e^-4x that's three e to the power of negative 4x. when you differentiate, you get: -12e^-4x thanks, but how come it's not -12e^-4x-1, or do i just not minus a one when the power is a co-efficient? Remember, the differential ...
*January 25, 2007*

**acids and alkalis**

TOOTH PASTE - Alkali OVE CLEANER - Alkali Soz nufin else maybe some more in a minute!!! gtg Bye XXX
*November 4, 2006*

**Geometry?**

I need help with these: Suppose triangleABC ~ triangleJKL with BC = 28, JK = 12, and KL = 42. Find the perimeter of triangleABC if the perimeter of triangleJKL is 72. & Find the scale factor of triangleDEF to triangleXYZ if triangleDEF ~ triangleXYZ, DE=10, XZ=20, and XY=45. ...
*August 24, 2006*