Wednesday

December 7, 2016
Total # Posts: 28,388

**sorry**

I did not notice the second part. L * w = 68200 2 L + 2 w = 1460 L = 730 - w (730-w)w = 68200 730 w - w^2 = 68200 w^2 -730 w + 68200 = 0 w = [ 730 +/- sqrt(532900-272800)]/2 w = [730 +/-510 ]/2 w = 110 or 620 L = 620 and w = 110

*August 14, 2016*

**idea**

L * w = 68200 however unless you know more about the ratio of L to w, there are an infinite number of solutions.

*August 14, 2016*

**Math**

7 quarters/8 dimes is not 8 dimes / 7 quarters

*August 13, 2016*

**Help- Precalc**

since sin α < 0 α is in quadrant 3 or 4 since tan α is +, that puts α in quadrant 3 -5,-7, sqrt 74 triangle since csc β > 0, β is in quadrant 1 or 2 since cot β is -, β is in quadrant 2 -3, 5, sqrt 34 triangle now sin (a-b) = sin a...

*August 13, 2016*

**Math**

a-b = 4 a^2-b^2 = 80 (a-b)(a+b) = 80 4 (a+b) = 80 a+b = 20 a-b = 4 ------------ add 2 a = 24 a = 12 so b = 8

*August 13, 2016*

**physics**

v = g t = 9.81 t at t = 9, v = 9.81 * 9 at t = 10, v = 9.81 * 10 average speed during tenth second 4.9 (19) distance during tenth = 4.9 * 19 * 1

*August 13, 2016*

**Use parentheses**

I do not know what are your numerators and denominators.

*August 12, 2016*

**car rental agency**

a is 60 + .22 x b is 56 + .26 x when does 60 + .22 x = 56 + .26 x .04 x = 4 x = 100 miles

*August 12, 2016*

**Algebra 1**

http://www.dictionary.com/browse/irrational--number

*August 12, 2016*

**Better**

2 sqrt 5 = sqrt 20 sqrt 5 = 2.236067977 IRRATIONAL

*August 12, 2016*

**propability**

By the way I am assuming that death is a failure ;)

*August 12, 2016*

**propability**

4/20 = 2/10 = 0.2 Ik versta wel.

*August 12, 2016*

**physics**

Mass does not change with g, weight does. You seem to be using feet/pounds units so g = 32 ft/s^2 approx on earth Mass = 150 /32 slugs g other = 32 * (34/15)

*August 11, 2016*

**Science -Please answer**

I think your control is no cleanser.

*August 11, 2016*

**Trigonometry**

tan (angle) = 20/12 so angle = tsn^-1 (20/12)

*August 11, 2016*

**Science 1 question help plz thank you**

Basing a conclusion on too little data is not an ethical error but a scientific planning and execution error. Google ethical definition eg: http://www.dictionary.com/browse/ethics

*August 10, 2016*

**Pre algebra**

well, look at it here and there x always left of y on number line x=-2 y=-1 -> x-y = -1 and |x-y|=1 x= 8 y= 10 -> x-y = -2 and |x-y|=2 in fact if x < y then x-y is ALWAYS - and |x-y| = y-x so I conclude y-x

*August 10, 2016*

**check my spanish 3**

Do I have to write a sentence with it or can I just state the verb?? Sorry, it's a stupid question but I just want to make sure I'm correct

*August 9, 2016*

**check my spanish 3**

escriba la forma del verbo indicado en el tiempo indicado yo/ tener/ futuro My answer is tendré

*August 9, 2016*

**math**

163.50 ( 6/11 ) = 88.18

*August 9, 2016*

**math**

3*7*11 = 231 and 2+3+1 = 6 so that does it, 231 ====================== three times that would have a sum of 18 so 3*231 = 693

*August 9, 2016*

**Maths**

a = 5 p/7 p = a + 92 so a = 5(a+92)/7 7 a = 5 a + 460 2 a = 460 a = 230

*August 9, 2016*

**messed up physics**

acceleration is the rate of change of velocity A = dV/dt The ratio is not meaningful. Did you get this language from a book?

*August 9, 2016*

**Math**

60/12 = 5

*August 8, 2016*

**sign error**

d^2 -10 d - 25 = 0 d = [ 10 +/-sqrt (100+100) ]/2 = 5 +/- .5 sqrt (200) = 5 +/- 5 sqrt 2 use + so 5 sqrt 2 left of zero = - 7.07

*August 8, 2016*

**Physics**

You show a charge at x = 5 but you ask for the E field there It is UNDEFINED. 1/r^2 as r--->0 is infinite r is simply the distance between the charge and the location where you compute E to the left of 5, the E field due to + q at 5 is left (repels) however the E field due ...

*August 8, 2016*

**Math**

You are welcome.

*August 8, 2016*

**Math**

s = 2 m s = b/5 but m = 23 so s = 2 m = 46 but b = 5s so b = 230

*August 8, 2016*

**Chem**

You are welcome ;)

*August 8, 2016*

**Chem**

LOL, hint - it is below freezing point of water with no antifreeze

*August 8, 2016*

**Math**

x + 2x + 3x = 480 6 x = 480 x = 80 2x = 160 3x = 240

*August 8, 2016*

**Math**

You are welcome :)

*August 8, 2016*

**Math**

one tile area = .1*.1 = .01 m^2 total area = 2.4 m^2 2.4 /.01 = 240/1 = 240 tiles

*August 8, 2016*

**algebra**

y = (3/4) x - 3 so slope = 3/4 y = (3/4) x + b 3 = (3/4)8 + b b = -3 so y = (3/4) x - 3 or 3/4 = (y-3)/(x-8)

*August 8, 2016*

**Science**

You are welcome :)

*August 8, 2016*

**Science**

I too would have picked A and C.

*August 8, 2016*

**Math**

yes

*August 8, 2016*

**Math**

k = y/x = 350/40 dollars/hour

*August 8, 2016*

**Science**

Some would argue about C. However I agree that C is fundamentally science because the planting dates and predicted climate in the almanac are based on observed data over the years. Of course the seed catalog also tells you when to plant what in which zone without pretending to...

*August 8, 2016*

**Calc**

slope = f' = 6 x - 5 x^4 at x = 1 slope = m = 6(1)-5(1)^4 so m = 1 y = 1 x + b to get b 7 = 1(1) + b b = 6 so y = x + 6

*August 8, 2016*

**Applied Stats**

You are making a mountain out of a mole hill I think: .24 * 20 is the number that have been told 20 - .24*20 = number that have not been told

*August 8, 2016*

**physics**

weight = force = 25*9.8 N force = k x 25 * 9.8 = 700 x

*August 8, 2016*

**statistics**

This is really linear programming, not statistics. p = 4 a + 6 b That is the objective function we wish to maximize 1 a + 3 b </=240 wood constraint 3 a + 4 b </=360 plastic constraint 2 a + 1 b </=180 steel constraint graph those three constraint lines with a on x ...

*August 8, 2016*

**math**

78 cos (180-165)

*August 7, 2016*

**physics**

Can you not break 2H2O molecules into 2H2 and O2 ? So what is wrong with B ?

*August 7, 2016*

**physics**

a compound is fixed proportion, like two H and one O an atom is fixed proportion, 100% HOWEVER a mixture is not necessarily a fixed proportion. Could be sand, water and cannon balls mixed in any proportions A

*August 7, 2016*

**physics**

A mixture is joined in a fixed proportion?

*August 7, 2016*

**algebra 2**

You're** Happy now??

*August 6, 2016*

**algebra 2**

Thanks so much!!! Your the MVP

*August 6, 2016*

**algebra 2**

Create a set of data with 5 numbers that satisfy all of the following conditions: 1. the range is 10 2. the mean is 20 3. the median is 22

*August 6, 2016*

**Math**

2 x + 2(x-6) = 32 4 x - 12 = 32 4 x = 44 x = 11

*August 4, 2016*

**Physics**

a = change in speed/ time = 16/4 = 4 m/s^2 average speed = (8 + 24)/2 = 16 m/s so distance = 16 * 4 = 64 meters

*August 4, 2016*

**Math**

slope = 5 = (y - -1) /(x - -2) so 5 = (y+1)/(x+2) so y+1 = 5(x+2)

*August 4, 2016*

**biomechanics**

Three times as far.

*August 3, 2016*

**I'm stuck- please help**

when x = 0, cos -pi = -1 when x = pi/4, cos -pi/2 = 0 when x = pi/2 , cos 0 = 1 when x = 3 pi/4, cos pi/2 = 0 etc

*August 3, 2016*

**someone please help me. - Precalc**

ahhhh , but that is the same as y = sin(x) :)

*August 3, 2016*

**physics 1**

unless it is a self propelled ball the acceleration is 1 g down, about 9.81 m/s^2

*August 3, 2016*

**algebra**

2/5 * 5/8 = 1/4

*August 3, 2016*

**Calculus1**

no in quadrant one you get a positive result in quadrant two you get a positive result in quadrant three the result is negative, change it to + so 1+1+ |-1| = 3

*August 3, 2016*

**pre cal Huh????**

Trig identity: sin(u+v)= sin u cos v + cos u sin v

*August 3, 2016*

**biomechanics**

power * time = work so if time the same, look at difference in work done which is change in potential energy m g h 60 g .6 = 36 g Joules 90 g .45 = 40.5 g Joules

*August 3, 2016*

**biomechanics**

ke = (1/2) m v^2 pe = m g h where h is height above one meter (1/2) m v^2 = m (9.8) h v^2 = 2 (9.8) h h = 64/19.6 total height = 64/19.6 + 1

*August 3, 2016*

**Biomechanics**

(1/2) m v^2 = m g h v^2 = 2 g h

*August 3, 2016*

**biomechanics**

to convert km/hr to m/s either use Google or head. for example 7 km/hr(1 hr/3600 seconds)(1000 m/km) = 7 /3.6

*August 2, 2016*

**math**

there are 12 + 5 + 3 = 20 marbles in the bag. We do an experiment to find out how many are blue call the probability of a blue one x She picks blue 4 out of twenty times, which is 20/100 = 0.20 Her fingers must reject blue because one would expect 12/20 = 0.60

*August 2, 2016*

**physics**

average force = change of momentum/time = 3 * 25 / .1 Newtons

*August 2, 2016*

**Chemistry**

sample of silver metal is suspected to be contaminated with zinc. A 0.2365 g portion of this metal is dissolved in nitric acid and the silver ions precipitated with excess aqueous NaCl. After filtering and drying, the mass of the precipitate is found to be 0.2865 g. What was ...

*August 2, 2016*

**Math**

A = (1/2) b h h = b - 2 so 60 = (1/2) b(b-2) 120 = b^2 - 2 b b^2 - 2 b - 120 = 0 (b-12)(b+10) = 0 b = 12 h = 10

*August 2, 2016*

**math again ?**

10, been there, done that

*August 2, 2016*

**math**

Yes, that is the desired answer. However it is not really nearly that easy. Assume you have 3438 in your back pocket. If you take that loan you will pay a total of 3960 so the easy answer is you save 522 ======================= Now the hard part. that is 261 per year interest ...

*August 2, 2016*

**science**

.5 mol in 1/5 of a liter is 2.5 mol in a liter ======================= 1 mol / 1 liter 10 mol in 10 liters

*August 2, 2016*

**maths**

b = 4 g + 3 That is all I can say without the other half of the problem.

*August 2, 2016*

**Chemistry**

for Kelvin add 273 for F F = (212-32)C/100 + 32 = (9/5)C + 32

*August 2, 2016*

**Physics**

If your textbook gave you a problem written that sloppily, best find another book.

*August 2, 2016*

**Physics**

Work is force times the distance moved in the direction of the force. 35 * 42 Joules Is the work done by that force. You do not say if there are also other forces like gravity for example or if the force is in the direction of motion here.

*August 2, 2016*

**Physics**

I assume 100 meters is the height of the hill, not the distance down the slope. loss of potential energy = 80 * 9.81 * 100 normal force on slope = 80 * 9.81 *cos 70 friction force = 0.110 * normal force = 0.110 * 80 * 9,81 * cos 70 distance moved down slope = 100 /sin 70 so ...

*August 2, 2016*

**Physics**

F = k x 54 = k * 0.20 k = 54 * 5

*August 2, 2016*

**Algebra 2**

My answer: The area of the circle enclosed by x^2 + y^2 = 100 is the times larger than the area of the circle enclosed by x^2 + y^2 = 25.

*August 1, 2016*

**Algebra 2**

How much larger is the area of the circle enclosed by x^2 + y^2 = 100 than the area of the circle enclosed by x^2 + y^2 = 25?

*August 1, 2016*

**Physics**

stored potential energy = (1/2)k x^2 = (1/2)(400)(.04)^2

*August 1, 2016*

**pre cal**

hypotenuse = sqrt (3+9)= sqrt 12 = 2 sqrt 3 sin = sqrt 3 / hypotenuse cos = 3/hypotenuse etc

*August 1, 2016*

**physics**

h = Vi t - 4.9 t^2 so 42 = 2 Vi -4.9*4 solve for Vi then when is h = 0 again? 0 = Vi t - 4.9 t^2 0 = t (Vi - 4.9 t) t = 0 at start of course then it comes back to ground at t = Vi/4.9

*August 1, 2016*

**Chemistry**

If the pH of a 0.46 M aqueous solution of a weak base is 9.2, estimate the Kb of the base:

*August 1, 2016*

**maths**

p = r - 15 p+5 = (1/2)(r+5) 2 p +10 = r+5 2 p = r - 5 2 p = 2 r - 30 ----------------- 0 = -r +25 r = 25

*August 1, 2016*

**Calculus**

let y = x+3 then dy =dx (y-3) ln y dy = y ln y dy - 3 ln y dy = y ln y dy - 3/y let u = ln y then dv = y dy so v = (1/2)y^2 and du = dy/y so (1/2)y^2 ln y -(1/2)ydy -3/y (1/2)y^2 ln y - (1/4)y^2 - 3/y but remember y = x + 3 :)

*July 31, 2016*

**Typos**

P(A or B) = P(A) + P(B) - P(both A and B) P(A or B) = P(A U B) P intersection which is both at once and your upside down U is P(A)P(B) = .5*.3 = .15 so P(A U B) = .5 + .3 - .15 = .65

*July 31, 2016*

**Math**

P(A or B) but not both = P(A) + P(B) - P(both A and B) P(A or B) = P(A U B) P intersection which is both at once and your upside down U is P(A)P(B) = .5*.3 = .15 so P(A U B) = .5 + .3 - .5 = .65

*July 31, 2016*

**mathfinish your question please**

sum of what equal to what?

*July 31, 2016*

**math**

How bad could it get? 1+2+3+4 = 10 so at least five slips to be sure to get a sum greater than ten.

*July 31, 2016*

**Math**

one way 2 + 1 + 2 + 1 - 4 = 2

*July 31, 2016*

**Math**

http://www.bankrate.com/partners/sem/mortgage-calculator-rates.aspx?s_kwcid=AL!1325!3!114614083448!e!!g!!mortgage+calculator+with+taxes&ef_id=V54ISwAAAH4QPBQk%3a20160731141643%3as

*July 31, 2016*

**English**

You are correct. Chang is not change.

*July 30, 2016*

**math**

Hard to say from your description. But if something came down from height h and had no loss of energy due to friction or whatever then the kinetic energy is equal to the potential energy at the start (1/2) m v^2 = m g h or v = sqrt (2 g h) = sqrt ( 64 h) in the ancient foot ...

*July 30, 2016*

**Calculus AB**

....but the last one I did was fun :)

*July 30, 2016*

**Calculus AB**

a better be 0 if it is the same for + and - x c better be 4 if 2^2 - c = 0 and (-2)^2 - c = 0 so far y = b/(x^2-4) if x = -1 y = b/-3 = 3 so I guesss b = -9

*July 30, 2016*

**Calculus AB**

tan slope angle 1 = m1 tan slope angle 2 = m2 so angle 1 = tan^-1 m1 angle 2 = tan^-1 m2 so theta = angle 2 - angle 1 = tan^-1 m2 - tan^-1 m1 tan theta = tan (a - b) where a =tan^-1 m2 and b =tan^-1 m1 so tan theta = (tan a-tan b)/(1+tan a tan b) [trig identity] = (m2 -m1)/(1...

*July 30, 2016*

**Calculus AB**

(x-r)(x-s) = x^2 + b x + c x^2 - rx - sx + rs = x^2 + b x + c

*July 30, 2016*

**Maths**

1/3 = 2/6 1/2 = 3/6 so 1/6 on wafers so 2/3/1

*July 30, 2016*

**please use one name**

ah come on

*July 30, 2016*

**Calculus AB**

5, 12, 13 right triangle here so sec = 1/cos = 13/5 then 3, 4 , 5 tan = 1/cot = 4/3 so sin = 4/5 so 13/5 - 4/5 = 9/5

*July 30, 2016*