Wednesday

July 27, 2016
Total # Posts: 26,562

**I do not know /unanswerable question**

Because of the gear ratio between pedal and wheel rim I have no idea how fast her foot moves to make the bike go 8m/s. Different gears give different foot forces for the same bike speed.
*January 22, 2016*

**Huh**

What do you mean? Use parentheses.
*January 22, 2016*

**math**

x^2 - 3 x - 7/2 = 0 x = [ 3 +/-sqrt (9+14) ]/2 A = [ 3 + 23]/2 = 13 B = [ 3 - 23] / 2 = -10 (a) (x- A/B)(x-B/A) = 0 (x +13/10)(x+10/13) = 0 x^2 + (269/130) x + 1 = 0 130 x^2 + 269 x + 130 = 0 etc etc etc
*January 22, 2016*

**Science**

But you show Na O and Cl (but you show O as 0 Sodium Hypochlorite has oxygen in it, not zero) the only one left is H
*January 22, 2016*

**Trigonometry**

I assume you mean degrees and not minutes h is the height we want x is distance to the monument from the closer point tan 38 = h/x tan 32 = h/(55+x) x = h/tan 38 = 1.28 h tan 32 = h/(55 + 1.28 h) 34.4 + .8 h = h h = 172
*January 22, 2016*

**Science**

LOL, is it the filtered orange juice ? The answer is the only chemical element mentioned here, Hydrogen peroxide.
*January 22, 2016*

**physics**

I guess the boat is anchored? 6 m/2 s = 3 m/s Note: That is the speed of the crest or "phase velocity". The speed of the group of waves, the "group velocity" is (1/2) of that if they are deep water waves. Energy is propagated at the group velocity. In real ...
*January 22, 2016*

**Algebra 2 pt 2**

here is the height versus time t h = 70 + 150 t - 16 t^2
*January 22, 2016*

**math**

(7/8)(4/5) = (7/5)(1/2) = 7/10 = 0.7 yards^2 7/20 = 0.35
*January 22, 2016*

**Algebra 2**

here is the height versus time t h = 70 + 150 t - 16 t^2
*January 22, 2016*

**Algebra 2**

Well, who does feet any more but anyway in that system g = -32 ft/s^2 v = Vi - g t v = 150 - 32 t at the top, v = 0 so 0 = 150 - 32 t t = 4.69 seconds to the top h = Hi + Vi t - (1/2)gt^2 h = Hi + Vi t - 16 t^2 h = 70 + 150 t - 16 t^2 so at the top h = 70 + 150(4.69) -16 (4.69...
*January 22, 2016*

**Algebra**

k +(k+4) + 2(k+4) = 36 4 k + 12 = 36 4 k = 24 now you finish
*January 22, 2016*

**science**

change in L/L = 25*10^-6 (T-20) .1/80 = 1/800 = 25* 10^-6 (T-20) T-20 = 10^6/2*10^4 =50 T = 70 deg C
*January 22, 2016*

**physics 1**

cos 69 = h/8.7
*January 21, 2016*

**Physics**

2 pi radians/rev ( 2.5 rev /3.6 s) = 4.36332313 radians/second
*January 21, 2016*

**math**

I do not know if you mean -1 < -(1/5) x or -1 < -1/(5x) I will assume the first. 1 > (1/5)x reverse arrow when multiplying by negative quantity 5 > x or x < 5 ============ always check if x = 0 is -1 < -(1/5) 0 ????? yes -1 < 0
*January 21, 2016*

**Math**

a r^2 = 10 a r^6 = 6250 (10/r^2)r^6 = 6250 r^4 = 625 = 25*25 = 5*5*5*5 so r = 5
*January 21, 2016*

**compounded errors :(**

dF/dr = -2kr/r^4 = -2 k/r^3 so dF = (-2 k /r^3) dr
*January 21, 2016*

**science, typo left k out**

dF/dr = -2rk /r^2 so dF = (-2k/r)dr
*January 21, 2016*

**science**

by the way the difference in R between one side of earth is tiny compared to R If you have had calculus think: F = k/r^2 dF/dr = -2r /r^2 so dF = (-2/r)dr so you can calculate a small change in F due to a small change in r
*January 21, 2016*

**science**

I assume you can do F = G Msun Mman / R^2 but the tide is more complicated and depends on the moon. Look at: http://scijinks.jpl.nasa.gov/tides/
*January 21, 2016*

**math**

120 + 2 x = 180 x = 30 degrees for the other two angles cos 30 = (YZ/2)/6 cos 30 = yz/12 yz = 12 cos 30
*January 21, 2016*

**math**

(12/21)* 100
*January 21, 2016*

**math**

S = top + bottom + sides top = pi r^2 bottom = pi r^2 sides = 2 pi r h that will be in square inches (in^2) there are 144 square inches per square foot so S * 1500 / 144
*January 21, 2016*

**Pre-cal**

2 [ (b/2)+10 ] + b </= 100 b + 20 + b </= 100 2 b </= 80 b </= 40 so 40 cm
*January 21, 2016*

**Chemistry**

Iron must be wicked expensive where you live.
*January 21, 2016*

**social studies**

No problem, good luck :)
*January 21, 2016*

**social studies**

Not my thing, but I thought their thing was calendars.
*January 21, 2016*

**Chemistry**

Half as many O2 molecules produced as H2O2 molecules disintegrated
*January 21, 2016*

**Calculus**

no |-1| = 1
*January 21, 2016*

**Physics**

m g h / time 40 * 10 * 30 * .15 / 6 in Joules per second or watts
*January 21, 2016*

**Woodrow Wilson**

There are good things to say about him, but consider: http://www.nationalreview.com/article/345274/progressive-racism-paul-rahe
*January 21, 2016*

**Science**

He swung one of the bats with all his might, (but bunted with the other?)
*January 21, 2016*

**Science**

6. seems to be missing. I disagree about 8.
*January 21, 2016*

**SCIENCE ASAP HELP PLEASE**

NO !
*January 21, 2016*

**SCIENCE ASAP HELP PLEASE**

mass of earth = 5.98 * 10^24 kg Venus 4.82 * 10^24 radius of earth = 6.38 * 10^6 m Venus 6.31 * 10^6 for comparison: Jupiter mass = 1.89*10^27 kg and r = 7.18*10^7 m
*January 21, 2016*

**Check 2 of my world history answers??**

Please do. That is what it is about.
*January 21, 2016*

**Check 2 of my world history answers??**

Hoover was a modern Republican before his time. No way he would raise taxes or take over businesses. He decided to leave the problem to his successor. He was a good engineer though.
*January 21, 2016*

**Check 2 of my world history answers??**

Read John Steinbeck, "Grapes of Wrath".
*January 21, 2016*

**Check 2 of my world history answers??**

No, drought and resulting dust clouds over the plains caused by the farmland drying out and blowing in the wind was a major problem. I wonder what on earth "lack of stock available" means.
*January 21, 2016*

**Math**

(x+h)^3 = (x+h)(x^2 + 2 hx + h^2) = x^3 + 2 h x^2 + h^2 x + 1 h x^2 +2h^2 x + h^3 -------------------------- = x^3 + 3 h x^2 + 3 h^2 x + h^3 now subtract x^3 f(x+h) - f(x) = 3 h x^2 + 3 h^2 x + h^3 NOW let x = 1 :) = 3 h + 3 h^2 + h^3 ========================== Now I did that ...
*January 21, 2016*

**Math**

7 * 4 = 28 28+3 = 31 so we have 31/7 pounds divide by 4 31/28 1 3/28 pounds
*January 21, 2016*

**Science physic**

force * distance = work done = change in potential energy = m g h F * .5 = 60 * 9.81 * .5
*January 21, 2016*

**geometry**

Your figure does not show here. However if it has center at (a , b) then it is (x-a)^2 + (y-b)^2 = r^2
*January 20, 2016*

**Social studies**

the vice president also serves as the ?
*January 20, 2016*

**Physics**

initial momentum = .021 *195 final momentum = (.021+1.6)Vi Vi = 2.53 (1/2) m Vi^2 = m g h h = Vi^2/2g
*January 20, 2016*

**Math**

Maybe you mean triple? if so 3 = (x)^5 log 3 = 5 log x log x = .095424 x = 1.2457 so 24.6 %
*January 20, 2016*

**maths**

4*3*9 = 108 50 + 12*25 = 350 350 - 299 = 51 10^6/10^3 = 10^3 = 1000 8cm / 8 km so 1 cm / 1 km
*January 20, 2016*

**Precalculus**

any point on the perpendicular bisector of AB satisfies your requirement. what is the slope of AB ? slope = (8-2)/(7+5) = 6/12 = 1/2 so the perpendicular has slope m = -2 It must go through the midpoint of AB which is at: x =(7-5)/2 = 1 y = (8+2)/5 = 2 or (1,2) so 2 = -2(1) + ...
*January 20, 2016*

**physics**

what again ? Google Einstein e = m c^2
*January 20, 2016*

**math**

(46 + 35 + 46 + 35) / 100
*January 20, 2016*

**Physics**

Google Einstein e = m c^2
*January 20, 2016*

**physics**

Defining z axis up: area of base of cylinder A= pi r^2 where r = 20 cm = .20 meter height of cylinder = .10 meter volume of cylinder V= pi r^2 h = pi (.2)^2 (.1) weight of cylinder W = g V = 10 V in Newtons b) +W c) -W d) W/A in Newtons/meter^2 or Pascals
*January 20, 2016*

**Physics**

the plane and the shell cover the same horizontal distance in time t T = angle up from horizontal u = 1100 cos T = 600,000/3600 m/s so T = 81.3 degrees so Vi = initial speed up = 1100sin 81.3 = 1087 m/s up how long to reach 2500 meters high? 2500 = 1087 t - 4.9 t^2 4.9 t^2 + ...
*January 20, 2016*

**Math**

10 a + b a + b = 7 so a = (7-b) 10 a + b - 10*2 - 7 = 10 b + a 10(7-b)+b-20-7=10b+(7-b) 70 -10b+b-27=9 b+7 36 = 18b b = 2 then a = 5 so 52
*January 20, 2016*

**actually math - series need math teacher**

Not physics until he jumps
*January 20, 2016*

**Calculus**

∫(2x^5+6x)^3(5x^4+3)dx becomes ∫(u)^3 du/2 = (1/2) ∫u^3 du BUT remember to change b = -1 to 2(-1)^5 +6(-6) =-2 -36 = -38
*January 19, 2016*

**Calculus**

lets' try u = 2 x^5 + 6 x then du = (10 x^4 + 6)dx = 2 (5 x^4+3)dx that looks more promising :)
*January 19, 2016*

**Calculus I think not**

du=x^5+3x+C ?? what is that all abot You add a constant to integral is no constraints on it. BUT NOT to the derivative if u = 5 x^4 + 3 then du = 20 x^3 dx period, the end but that is not what you want to do anyway
*January 19, 2016*

**Calculus**

I assumed you were integrating from 0 to x
*January 19, 2016*

**Calculus**

-(x+1)>0 x+1 < 0 x <-1 I seem to agree but try http://www.wolframalpha.com/input/?i=+integrate+6%2F%281%2B2x+%2B+x^2%29 Which agrees
*January 19, 2016*

**Geometry**

5' 4" = 63 " 3' = 36" 14' 3" = 171" 64/36 = h/171 36 h = 64 * 171
*January 19, 2016*

**Math**

I guess you mean y = (3/4) x + 4 and not y = 3 /(4x) + 4 if so then the slope = (3/4) y = (3/4) x + b 7 = 0 + b so b = 7 y = (3/4) x + 7
*January 19, 2016*

**i dont know how to solve this**

add 2 to both sides 3 x > 12 divide both sides by 3 x > 4 the only one greater than 4 is 5
*January 19, 2016*

**i dont know how to solve this**

If you mean: 6 + (2/3) x = 9 then (2/3) x = 3 x = 9/2 If you mean: 6 + 2/(3x) = 9 18 x + 2 = 27 x 2 = 9 x x = 2/9 If you mean: (6+2)/x = 9 x = 8/0 USE PARENTHESES
*January 19, 2016*

**Math**

The tens and the ones add to 16 ?
*January 19, 2016*

**I do not know**

I am having the same trouble and do not see the trick.
*January 19, 2016*

**Math - Help! ASAP**

looks fine to me
*January 18, 2016*

**social studies hurry**

In history? The Tigris and Euphrates rivers. Google Mesopotamia.
*January 18, 2016*

**social studies hurry**

I think everything you need to know is here: http://en.wikipedia.org/wiki/Iraq It is mainly Shia and Kurd and has both rural and urban populations. If I had to choose I might say urban because of Baghdad, Mosul and other big cities.
*January 18, 2016*

**social studies hurry**

What specific region?
*January 18, 2016*

**social studies help**

LOL - yes, Saddam Hussein of Iraq invaded Kuwait to get their oil. There was a war about it.
*January 18, 2016*

**social studies help**

Google Kuwait industry but really, watch the news
*January 18, 2016*

**help on math**

(3*12.5 + 17) * 1.06
*January 18, 2016*

**physics**

initial momentum = 7.05*8.24 + 0 final momentum = 7.05 * v + 1.53*13.2 final momentum = initial momentum
*January 18, 2016*

**social studies hurry**

Post them But you have not been watching the news much if you are having trouble with what Arabia and Iraq (Mesopotamia) look like.
*January 18, 2016*

**math help please**

.8*36.95 + .667*21.42
*January 18, 2016*

**Physics**

orbit circumference = 2 pi *1.9*10^7 miles time for orbit trip = 2.9*10^7 s speed = 2 pi *1.9 / 2.9 miles/second = 4.12 miles/second You did not say what units in miles per hour, multiply by 3600 and get 14,820 miles/hour
*January 18, 2016*

**physics**

Xray or Gamma ray
*January 18, 2016*

**physics**

E = h f = 6.626 *10^-34 f Joules 1 ev = 1.6 * 10^-19 J so E is 15*10^3 *1.6*10^-19 J = 24 * 10^-16 Joules so 24 * 10^-16 = 6.626*10^-34 f f = 3.62 * 10^18 Hz now go look at your spectrum if it is by wavelength lambda = 3*10^8/(3.62*10^18) = .828 * 10^-10 = 8.28 * 10^-11 meters
*January 18, 2016*

**math help please**

1.2 * 7.65 * 40
*January 18, 2016*

**Math fourth grade**

1 and itself
*January 18, 2016*

**math**

x and y in first quadrant if sin x = 1/4, we will need cos x sin^2 x + cos^2 x = 1 cos x = sqrt( 1-1/16) = sqrt (15/16) = (1/4) sqrt 15 similarly if cos y = 1/5 sin y = sqrt (1- 1/25) =sqrt (24/25) = (1/5)sqrt 24 now with sin x = .25, cos x = .25 sqrt 15 and sin y = .20 sqrt ...
*January 18, 2016*

**Physics**

The package has the same horizontal velocity component as the plane. (Note- if you drop a bomb at low altitude, turn your airplane immediately after release) Fall of 235 m 235 = (1/2)g t*2 = 4.9 t^2 t = 6.93 seconds to fall horizontal problem d = u t d = 69.4 * 6.93 = 481 ...
*January 18, 2016*

**Physics**

First vertical problem: Vi = 75.2 sin 34.5 = 42.6 m/s v = Vi - g t g = 9.81 m/s^2 so v = 42.6 - 9.81 t at the top, v = 0 t = 42.6/9.81 = 4.34 seconds to top 2 t = 8.68 seconds total in air range = 8.68 * 75.2 cos 34.5 at t = 1.5 v = Vi - g t = 42.6-9.81(1.50) = 27.9 m/s u = 75...
*January 18, 2016*

**Math ASAP**

-6w - 30 - 9 = -6 w - 39 ========================= 2 x + 3 x - 3 x = 2x -6 + 18 = +12 so 2 x + 12
*January 18, 2016*

**Pre-Calc**

1/sin^2x = 4 so sin^2 x = 1/4 so sin x = +1/2 or -1/2 four solutions, yes
*January 18, 2016*

**Physics**

It fall more than a meter? checking Yes, 1.129 m ========================== sorry, I am used to y up Vi = 250 sin T u = 250 cos T t = 120/u = 120/250 cos T h = Hi + Vi t - 4.9 t^2 here we on the same level so h = Hi 0 = Vi t -4.9 t^2 t (4.9 t - Vi) = 0 obviously it is at ...
*January 18, 2016*

**Physics**

momentum before = momentum after 50 * 10 + 100 * 0 = 150 * v
*January 18, 2016*

**Chemistry**

The pressure depends on the average (1/2)mv^2 of the gas molecules but it is (1/2) m v^2 that you get from kinetic theory and not (1/2) v^2 the gas has the same kinetic energy at temperature T no matter what its mass might be. see: http://hyperphysics.phy-astr.gsu.edu/hbase/...
*January 18, 2016*

**Physics**

in time t vehicle A travels distance d vehicle B travels distance (d-819.017) 93.602 t = d 44 t = d-819.017 so 44 t = 93.602 t -819.017
*January 18, 2016*

**Chemistry 101**

12.52 lbs = 5.68 kg = 5680 grams well first of all the volume of water does not change. The same water is still there unless it splashed out. However the final volume of stuff in the cylinder increases by the volume of lead which is 5680 grams (1 cm^3/11.3 grams) = 503 cm^3 = ...
*January 18, 2016*

**ap physics**

m2 g = m1 v^2/r
*January 18, 2016*

**AP Physics**

Vi = 4 sin 25 down so = -1.69 m/s u = 4 cos 25 forever = 3.63 m/s Hi = 1.2 h = Hi + Vi t -4.9 t^2 0 = 1.2 - 1.69 t - 4.9 t^2 4.9 t^2 + 1.69 t - 1.2 = 0 t = [ -1.69 +/- sqrt(2.86+23.5)]/9.81 t = .815 seconds d = u t = 3.63 * .815 = 2.96 meters
*January 18, 2016*

**check earlier volume of pipe **

Check earlier problem. diameter not radius was given
*January 18, 2016*

**Chemistry 101**

r = 6.5/2
*January 18, 2016*

**Physics**

same as any other distance = speed * time problem time = (.97/20) seconds of course we did not use the diameter bit but perhaps there is a part B ?
*January 18, 2016*

**Math**

You are welcome.
*January 18, 2016*

**Math**

ok BOTTOM/SIDE = bottom/side 9/x = 4/2 which happens to be what we did.
*January 18, 2016*