Wednesday

August 24, 2016
Total # Posts: 26,777

**algebra**

c = 2000 + .02 x
*April 20, 2016*

**Physics**

work = m g h = 63.9 * 9.81 * 0.16 * 135 Joules power = work/time here time = 5*60+40 seconds Kjoules = Joules work/1000 food calories = KJoules *(1 Cal/4.1868 Kj)
*April 19, 2016*

**Physics**

Trig, not physics Note they gave you math class angle measured north of east (counterclockwise from x axis), not compass angle as used by navigator or physicist. east 110 cos 25.1 north 110 sin 25.1
*April 19, 2016*

**Calculus I**

dy/dx = 3 ax^2 when x = 4, dy/dx= 48 a = slope but y = 4 x + b has slope of 4 so 48 a = 4 a = 4/48 = 1/12 and y = (1/12) x^3 when x = 4 y = 16/3 -4(4) + 16/3 = b -16 + 16/3 = b b = -32/3 so
*April 19, 2016*

**U.S. History (Check)(REED)**

A: The Pearl Harbor attack was so devastating for America because most of the U.S. Navy was destroyed and 2,403 Americans were killed. ---------------------- Well, most of our battleship navy in the Pacific was destroyed. I agree with your answers, and believe it or not I was ...
*April 19, 2016*

**Chemistry**

What is solubility ****
*April 18, 2016*

**Chemistry**

The molar solubility of a generic substance, Mg(OH)2 ksp = (1.2x10^-11) in 0.10 M NH3 Kb = 1.8 x 10^-5 help me please =)
*April 18, 2016*

**Math**

16 t^2 -112 t +160 = 0 t^2 - 7 t + 10 = 0 (t-5)(t-2) = 0 so at 2 seconds on the way up and at 5 seconds on the way down 0 = 16t (7 - t) crash at t = 7
*April 18, 2016*

**typo**

None of your answers are remotely close to what you asked.
*April 18, 2016*

**Calculus**

f^-1(x) definition is usually the inverse function if y = 7x + 3cos(x) + 2sin(x) substitute x for y and y for x and solve for y x = 7 y + 3 cos y + 2 sin y if x = 2 we want x = 2 2 = 7 y + 3 cos y + 2 sin y y better be in radians y x 0, 3 pi/6 , 7.26 -pi/6 , -.067 - pi/12 , +....
*April 18, 2016*

**Math**

first of all get your notation straight. Use ^ for exponents. Second follow the rule that Collins gave you (sort of): a^b/a^c=a^(b-c) and a^b a^c = a^(b+c)
*April 18, 2016*

**life orientation**

Torturing the teachers with the same question over and over without trying to do the assignment, three times.
*April 18, 2016*

**physics**

If it is perfectly inelastic, no bounce at all, then they are stuck together after the collision and all the momentum is in one 6 kg mass 4*3 - 2*2 = 6 * v before ke = (1/2)(4)(9) + (1/2)(2)(4) after ke = (1/2)(6)v^2
*April 18, 2016*

**Math**

16,000 + .1 s = 20,000 + .03 s .07 s = 4,000 s = 400,000/7
*April 18, 2016*

**Calculus -- Typo?**

the area ABOVE? y = 12??? That is infinite as is the area below y = sin x. There is no "between " I can see here.
*April 18, 2016*

**Geometry**

tan 58 = (84-6) / x
*April 17, 2016*

**english**

Well it is correct English. Of course it is nonsense.
*April 17, 2016*

**Math**

.06 x + .11(35,000 + 4x) = 66350
*April 17, 2016*

**English**

prices rise a lot quickly 4 is all right. 2 and 3 do not sound right.
*April 17, 2016*

**math**

z = (x - mean)/ sigma z = (80 - 70)/15 = 10/15 = 2/3 = .666666666666667 :) If there is more, use http://davidmlane.com/hyperstat/z_table.html
*April 17, 2016*

**logic**

http://amarvk.blogspot.com/2014/06/he-sits-between-two-mats-and-his.html
*April 17, 2016*

**Life orientation**

You can think of three.
*April 17, 2016*

**World History**

Perhaps it will become unpopular? There seems to be no monotonic trend in that direction though.
*April 17, 2016*

**Math**

1. arithmetic sequence with a = 8 and d = -9 2. geometric series with first term -2 and ratio r = 6 3. geometric again r = (1/9) hey http://www.mathsisfun.com/algebra/sequences-sums-arithmetic.html http://www.mathsisfun.com/algebra/sequences-sums-geometric.html
*April 17, 2016*

**Math **

maybe you mean 2^2 * 2^8 which is 2^10 = 1024 so If I am guessing right about your incomprehensible notation your sister is correct.
*April 17, 2016*

**Physics**

25 = (10/2) t t = 5 seconds to stop a = 10/5 = 2 m/s^2 up F = m a T - m g = m * 2 g = 9.81 so T = 800 (11.81) Newtons
*April 17, 2016*

**no**

=Cx+0.08x14.50 is wrong, very wrong. Try C(x) = .08 x + 14.50 C(40) = .08 (40) + 14.50 = 3.20 + 14.50
*April 17, 2016*

**interest**

.05/12 = .004166667 100 ( 1.004166667)^120 = $164.70
*April 17, 2016*

**interest**

100 (1.05)^10 = $ 162.89
*April 17, 2016*

**Physics**

.25 v = .25 (v/2) + .25 (2) .125 v = .5 v = 4 m/s
*April 17, 2016*

**Math**

C drives for 3 hours to meet M M drives for 2.5 hours to meet C Distance C = 60 * 3 = 180 Distance M = s(2.5) = 2.5 s but we know 180 = .8 d so d = 225 (not 500) distance M = .2 (225) = 45 miles so s = 45/2.5 = 18 mph =================== check 60 * 3 = 180 18 * 2.5 = 45 total ...
*April 17, 2016*

**Math **

student does not know how to type exponents This means 2^2 * 2^8 which is 2^(2+8) or 2^10
*April 17, 2016*

**Algebra**

a = 3 b c = 5 b a + b + c = 72 3 b + b + 5 b = 72 9 b = 72 b = 8 so a = 24 and c = 40
*April 17, 2016*

**Math 4**

20 / 705
*April 17, 2016*

**Math 3**

w(w+2) = 5 w^2 + 2 w - 5 = 0 ( w = [ -2 +/- sqrt (4 + 20) ]/2 w = -1 +/- .5 sqrt 24 have to use the + sign w = 1.45 L = 3.45
*April 17, 2016*

**english**

But, but, I already turned it in, years ago :(
*April 17, 2016*

**Hunger Games**

http://thehungergames.wikia.com/wiki/Nightlock
*April 17, 2016*

**Hunger Games**

I am not going to go up to the attic to fetch the books :) Go to the end of the first book and look maybe. Maybe Snow said something later as well, perhaps when he "visited" the family. That act of defiance really messed the system up :)
*April 17, 2016*

**maths help plz**

I think half of them must be at 0 degrees and half at 180
*April 17, 2016*

**Physics**

well, if nodes at both ends then the wave is twice as long as the string, 4.8 meters (draw it with half a wave on the string and bulge in the middle) how long does it take for 4/8 meters? T = 4.8/450 so f = 450/4.8 = 93.75 Hz which is 94 indeed
*April 17, 2016*

**Literature**

Caring is caring. I do not think there is a scale from 1 to 10.
*April 17, 2016*

**Literature**

If I had to pick, yes
*April 17, 2016*

**Literature**

I tend to agree with you. She did not really have much choice about hunting or defying.
*April 17, 2016*

**algebra**

| (3 n +1) - n | = 19 note difference can be + or - if + 2 n = 18 n = 9 if - -2n = 18 n = -9
*April 17, 2016*

**need Steve**

Not my thing, never got beyond simple Venn diagrams.
*April 17, 2016*

**CALCULUS**

when x = 0, y = 1 that is y axis intercept since x^2 is always + the graph slopes down from 1 to 0 at infinity and it is always in the first quadrant. just sketch it and you will see that the rest is silly.
*April 17, 2016*

**LIFE ORIENTATION**

Where? In some places you can get together with others and protest or go to court. In others you would be thrown in jail or shot for that.
*April 17, 2016*

**Physics**

speed of light is about 3*10^8 meters/seconds so distance = 3*10^8 * (2.6/2) meters
*April 17, 2016*

**Physics**

You are welcome.
*April 17, 2016*

**Physics**

area of big face = .1*.2 = .02 m^2 so min pressure = 10*9.81/.02 Pascals and max = 10*9.81/(.1*.05)
*April 17, 2016*

**L.O**

Because most of what we know aout what is going on in politics comes from the media and if it is controlled by the government, then we only get to hear what the government wants us to hear. Of course there are other threats such as financial control of the media by a small ...
*April 17, 2016*

**Math**

8 * 10 = 80
*April 17, 2016*

**math**

sum of x values = 45 3*.14 + 6*.05 + 9*.36 + 12*.35 + 15*.1 = 9.66 9.66/45 = .215 that 6 , .05 point looks like either a typo or an outlier
*April 17, 2016*

**Hmm, I can not help**

Not having the drawing I can not do moment arms. You need the distances.
*April 17, 2016*

**mensuration**

area = 4 * 305 Which I suspect is a typo unless it is a carpet for a wedding at Taj Mahal perhaps 4 * 3.05 ??? cost = area * 42
*April 17, 2016*

**math**

I bet B starts at 80, not 8 and runs at speed v A runs at speed 2v t = 100/2v Bdistance run = v t = v(100/2v) = 50 so B is still 80 - 50 = 30 meters away
*April 16, 2016*

**Math**

sum = = m + m+1 + m+2 + m+3 but n+1 = m+3 so m = n-2 sum = 4 m + 6 = 4(n-2)+3 =4 n -8+3 = 4 n - 5
*April 16, 2016*

**Math**

10 Look at a table of binomial coefficients
*April 16, 2016*

**algebra**

300 = 5000 (.7)^n .06 = .7^n log .06 = n log .7 so n = log.06/log.7 = 7.89 years
*April 16, 2016*

**Math**

I agree, although I never thought of it that way :)
*April 16, 2016*

**American History**

Yes, A, opening up international trade helped (hear that Mr Trump?)
*April 16, 2016*

**Algebra**

cost = 2 n- 4 2n-4 > 8 2 n > 12 n > 6
*April 16, 2016*

**distribution**

http://davidmlane.com/hyperstat/z_table.html
*April 16, 2016*

**distribution**

http://davidmlane.com/hyperstat/z_table.html
*April 16, 2016*

**hey**

I am not going to just do these for you. I already took the subject (in 1958). What are your answers?
*April 16, 2016*

**pro**

p correct = .25 1-p = .75 p(0 correct)= C(10,0).25^0*.75^10 p(1 correct)= C(10,1).25^1 *.75^9 p(2 correct)= C(10,2).25^2 *.75^8 c(10,0) = 1 of course C(10,1) = 10 C(10,2) = 45 add the three probabilities C(10,1)
*April 16, 2016*

**Math**

order matters here so permutations not combinations n!/[ n-r] ! 14 !/ 9! right 14 * 13 *12 * 11 * 10
*April 16, 2016*

**physics**

Flutist hears the difference or "beat" frequency http://hyperphysics.phy-astr.gsu.edu/hbase/sound/beat.html
*April 16, 2016*

**I vote for C**

I would pick C Radiocarbon dating is usually for absolute age, but comparing samples you are likely to use ratios , perhaps even of C14 again. see: http://www.parks.ca.gov/?page_id=24000
*April 16, 2016*

**science help pls pls**

LOL, another questionable question. Are you inland somewhere? Duration is how long the waves last, not the answer Fetch is how far across the bleak ocean the wind and waves have traveled to reach you. When waves build up they start short and low, but as they travel and the ...
*April 15, 2016*

**science pls help**

Well, yes sort of as a deep water wave approaches shallow water it slows down, not really due to friction but due to the theoretical velocity of waves in deep and shallow water. In deep water V = k sqrt (wavelength) in shallow water V = K sqrt (water depth) the transition from...
*April 15, 2016*

**huh?**

area scale ratio is 1/4 so every length of a small one is 1/2 the big one's length the perimeter of the big one is 60 so the perimeter of each small one is 30 and the total is 120, not 70 SO A is FALSE B is true 10*17.3 C FALSE as shown above D false obviously 173/4 in fact
*April 15, 2016*

**Science**

You are welcome.
*April 15, 2016*

**Science**

so to get the temp in deg C from your scale multiply the number you read on the straw by (47/n) and add 20 T = (temp range/n) x + Tlow
*April 15, 2016*

**Science**

You must have made marks at two different known temperatures, Tlow and Thigh Label Tlow 0 label Thigh something then every 5 mm make a mark label them 1,2 ,3 etc until you reach Thigh let's say Thigh is at 67 degrees C and Tlow was at 20 deg C then your range was 67 - 20...
*April 15, 2016*

**chemistry**

double amount of water, same NaCl, half the concentration
*April 15, 2016*

**Equations**

Plug and Chug 3 s + 5 a = 1150 but s+a = 300 so a = 300-s 3 s + 5 (300-s) = 1150 3 s + 1500 - 5 s = 1150 2 s = 350 s = 175
*April 15, 2016*

**Math/Algebra**

S = 4 x M = 3 x B = 2 x total = 9 x = 2178 so x = 242 M = 3 x = 726
*April 15, 2016*

** no way**

a , b b - a = 29 5 a = 2 b what result is one? Makes no sense. Ignoring that. 5 a = 2 (a+29) 3 a = 87 a = 87/3
*April 15, 2016*

**L.o**

Afraid of strangers
*April 15, 2016*

**School**

No, it is not.
*April 15, 2016*

**where?**

I live in Massachusetts. We do not elect judges anywhere.
*April 15, 2016*

**math**

downstream speed = u + 4 upstream speed = u - 4 20 = (u+4) t 10 = (u-4)t so 20/(u+4) = 10/(u-4) 10 u + 40 = 20 u - 80 10 u = 120 u = 12 miles/hr
*April 15, 2016*

**English**

1. lower than usual price 2. at whatever price In 3 through 6 it is the price of the product, not the product, which is 30% off.
*April 15, 2016*

**Math--Parametric Equations**

for the center: x = 24 cos 45 * t = 17 t y = 24 sin 45 * t = 17 t relative to center initial angle of point from x axis Ai = 90 degrees (on y axis) r = 1.5 Xrel = r cos A Yrel = r sin A A = 90 + (360*3)t A = 90 + 1080 t cos A = cos (90 + 1080t) = -sin(1080 t) trig identity sin...
*April 15, 2016*

**Algebra**

3, whoa, climbing faster try y(n+1) = 3 y(n) geometric ratio is always 3 or r = 3 y = 1.4 * 3^(x) try x = 4 y = 1.4 * 3^4 = 1.4 * 81 = 113.4 it worked
*April 15, 2016*

**Algebra**

2. constant d again y = m x + b y = 2.3 x + 3
*April 15, 2016*

**Algebra**

1. note constant d = 2 arithmetic sequence straight line of slope 2
*April 15, 2016*

**Math**

right :), sorry mistook < for =
*April 15, 2016*

**Math**

ah, 4^4 * 4^4 = 4^8 like 10^1 * 10^1 = 10^2 NOT 10^1 try C)
*April 15, 2016*

**Math**

yes, yes, but numbering messed up.
*April 15, 2016*

**Physics**

You are welcome.
*April 15, 2016*

**Physics**

T = 15/25 = .6 second C = 2 pi R = 2 * 3.14 * .95 = 5.97 meter a) v = C/T = 9.94 m/s b) v^2/R = 9.94^2/.95 = 104 m/s^2 wow, 10 g c) F = m a = .025*104 = 2.6 Newtons
*April 15, 2016*

**Physics**

Just add
*April 15, 2016*

**Algebra**

good grief, g = 32 ft/s^2, old text :) T = 2 pi (L/32)^(1/2) T = 2 pi (4/32)^.5 = 2.22 seconds
*April 14, 2016*

**HISTORY HELP plsssssssss**

Well, it said it was "good" if it came from the "Maker of the world".
*April 14, 2016*

**Math**

A = L * w Perimeter = L + 2 w = 36 so L = 36-2w A = (36-2w)w -2 w^2 + 36 w = A w^2 - 18 w = -A/2 w^2 - 18 w + 81 = -A/2 + 81 (w-9)^2 = -(1/2)(A-162) vertex at w = 9 area = 162 ft^2 ==================== check if w = 9 L = 36 - 18 = 18 area = 162, sure enough
*April 14, 2016*

**Math**

x(x+5) = x^2 + 5 x
*April 14, 2016*

**Math - Please check!**

1. yes 2. yes 3. pi*3.5^2 = 38.5 yes
*April 14, 2016*

**i really need help with science pls help**

If the results are conflicting I would pick A If the results are from different branches of the same study area I would pick B
*April 14, 2016*