Friday

April 18, 2014

April 18, 2014

Total # Posts: 16,161

**Chemistry**

2.)What is the volume in liters of a kilogram of ice at 0 degrees Celsius? given 0.9167 g/cm3 at 0 °C which is 1.09 cm^2/g (1.09 cm^3/g)(1 L/1000 cm^3)(1000 g/kg) = 1.09 L/kg by the way : "a pint is a pound the world around" :) (VERY approximate) a pint is about ...

**Chemistry**

number 1 requires the gas law in one way or another at STP a mole of gas occupies 22.4 liters as a check STP is 273 K we are at 293 K I guess we are at one atm, it does not say V = 5 liters P = 1 atm T = 293 R = 0.0821 liter·atm/mol·K PV = n R T n = PV/RT = 1 * 5...

**Chemistry**

Great, good luck !

**Chemistry**

well you can do it in what I think are much more difficult ways Like say I need to go from km to cm well a km is 1000 meters and a meter is 100 cm so a km is 100,000 cm so multiply your 72 km/h by 100,000 to get 7,200,000 cm/h now deal with the hours 1 hour = 60 min and each m...

**Chemistry**

by the way, I use it so much that I remember 3600 s/h but (60 min/h)(60 s/min) min cancels and I have (3600 s/h)

**Chemistry**

if something is the same top and bottom, I call it one. for example 100 cm / 1 meter = 1 in my world, but the units change without changing the value so 72 km /h (1000 m/1km)(100 cm/m)(1h/3600s) km cancels h cancels m cancels and I am left with cm/s now do the calculation 2000...

**Physics**

Conservation of Momentum does not have exceptions. There are no external forces on this system. Its momentum does not change. Period. A

**physics**

F = m Ac = m v^2/r also F = mu m g so mu g = v^2/r mu = v^2 /(g r) in other words the ratio of centripetal acceleration to g static, tires not slipping A and C. You have a typo. They are the same

**probability**

Huh? if the probability of a toss being heads is .5 then it is .5 no matter what happened earlier.

**math**

there is one and only one value of y for each value of x so it is a function and it also is a relation between x and y

**math**

you do not pay fifteen cents for the first .1 mile. It is included in the 72 cents. However if it is 15 cents for 1/10 mile, then it is 1.50 per mile and I think that .15(6-.1).1 should really be .15(6-.1)/.1 anyway whoever wrote that then did the calculation correctly .72 + 1...

**Science - Please Help!**

You are welcome :)

**Science - Please Help!**

average velocity vector= displacement vector/time average speed scalar = distance traveled scalar/time a scalar only has magnitude, like miles or miles/hour a vector has BOTH speed and direction. for speed and distance you only need a speedometer and and odometer. for velocity...

**Math**

I thought you said x^3 + x^2 x^2 + x^2 is just 2 x^2

**Math**

x^2 (x+1) ????

**Physics.**

100 x = 50*12 x is 6 the ball went right so the person goes left It is that conservation of momentum thing.

**Math ~ Check Answers ~ASAP**

You are welcome :)

**Math ~ Check Answers ~ASAP**

but ANY even number can be divided by 2 so 2 and 4

**Math ~ Check Answers ~ASAP**

Now really, if in danger or in doubt, try it with a calculator. If none on your desk, use Google :)

**Math ~ Check Answers ~ASAP**

yes something that ends in five will not be divisible by an even number.

**Math ~ Check Answers ~ASAP**

A five on the right is a dead giveaway.

**physics**

13 degrees from vertical T = tension T cos 13 = m g so T = m g/cos 13 solve for T T sin 13 = horizontal force so T sin 13= k Q^2/(2*.17* sin 13)^2

**calculus**

given the student's use of strange exponent notation it might be |x^2 + 1/x^2 | http://www.wolframalpha.com/input/?i=|x^2+%2Bx^-2|

**math**

28/12*28/12 = 5.444 ft^2 per tile 102 * 18 = 1836 ft^2 (kitchen for a huge school I assume) 1836/5.444 = 338 tiles

**Help Pleasee!!**

Your team mate is skating forward. Pass the puck ahead of your forward. If you pass to where your team mate is now, it will be behind when it gets there.

**physics**

122 * 17.34/9.81

**Physics**

string tension T force up = T cos 30 = .866 T force horizontal = T sin 30 = .5 T radius = 0.30 sin 30 = 0.15 so .5 T = m v^2/r and m g = .866 T so T = 1.15 m g .5 (1.15) m (9.81) = m v^2/.15 v^2 = .846 v = .92 m/s

**Physics**

P V = n R T P/T = n R/V = constant here T1 = 273 + 9 T2 = 273 + 31 P1 = 76 + 400 P2 = 76 + x where x is new gage pressure P2/T2 = P1/T1 so P2 = (T2/T1) P1 x = P2 - 76

**Physics**

That sounds about right. One atmosphere is about 101,325 Pascals that is about 10 meters of water so about 10,000 Pascals/meter

**Physics**

rho g h = 1000 kg/m^3 * 9.81 m/s^2 * 1.6 m in Pascals depth does not matter, looking for difference

**calculus I**

T = angle up from center of sphere to intersection of cylinder and sphere r = 10 height of cylinder = 2 r sin T radius of cylinder = r cos T volume of cylinder = V = pi(r^2 cos^2 T)(2 r sin T) = 2pi r^2 (cos^2 T sin T) dV/dT = 0 for max = cos^3 T - 2 sin^2T cos T = cosT ( cos^...

**math**

ten periods at .057 per period 1.057^10 = 1.74 for five one year compoundings: x^5 = 1.74 5 log x = log 1.74 = .24055 log x = .04810984 10^log x = x = 1.117 or 11.7 %

**Math**

Harriet 1/4 nisha (1/2)(3/4) = 3/8 1/4 + 3/8 = 5/8 so 3/8 is left (3/8)n = 6 n = 16

**Physics**

time upward = 3.3/2 =1.65 s v = Vi - 9.81 t v = 0 at top 0 = Vi - 9.81 (1.65) Vi = 16.2 m/s h = Vi t - 4.9 t^2 h = (16.2)(1.65) - 4.9 (1.65)^2 h = 13.4 meters (good throw)

**physics**

I guess you mean on a planet with g = 17.34 m/s^2 ? 122 * 17.34/9.81 = 216 lb

**physics**

4 times 1/(.5r)^2 = 1/.25 r^2 = 4/r^2

**Physics**

Ke at beginning = (1/2)m (3.6)^2 loss in potential = gain in Ke = m (9.8)(8.3) Ke at end = (1/2) m v^2 = (1/2)m(3.6)^2 + m (9.8)(8.3) cancel m multiply by 2 v^2 = 3.6^2 + 2 (9.8)(8.3) solve for v

**Science - Please Check This Answer**

You are welcome :)

**Science - Please Check This Answer**

.45 m/s * 25 s = 11.25 yes

**Algebra**

You are welcome :)

**Algebra**

(x-4)^2 = k (y+4) from vertex put in some other point like (2,0) (2-4)^2 = k (4) 4 = 4 k k = 1 so I propose (x-4)^2 = y + 4 check with another given point like (5,5) Hey (5,5) should be (7,5) !!!Typo? Try (3,-3) and (5,-3)

**Math**

5 a + 3.5 c = 3750 a + c = 900 solve by substitution or elimination

**Science**

5. Water is water. H2O. Its state (ice, liquid, steam) is a physical property.

**Science**

3 - HEAT CONDUCTIVITY !!!!

**Science**

1. Which of the following is an example of matter? (1 point) leaves shadows light from the sun sound -------------------------- They want you to say "leaves". Being a physicist I might argue about that, but you better say leaves.

**Math**

You are welcome :)

**Math**

Your question essentially provides the answer with no further ado: y = -3 x + 2

**Math**

you need both a radius and an angle to convert from polar to x,y coordinates x = r cos theta y = r sin theta if you mean radius of 1 (unit vector then x = 1 cos pi/4 y = 1 sin pi/4 since cos pi/4 = sin pi/4 = sqrt 2 /2 x = 1 sqrt 2 /2 and y = sqrt 2 /2

**U.S. History**

For me it was Dec 7,1941 because my mother and I had to drive up to a friend's house in the mountains because our next door neighbor's house was hit and our neighborhood was all under fire by Japanese airplanes. I never got to go back to my school in Honolulu and we mo...

**physics**

F = G M m /(r^2) = m g = G M (3m)/(.25 r^2) = 12 G M m/r^2 so 12 m g = 12 * 80 * 9.81 = 9418 Newtons

**Algebra**

2. 3z^2 - 22 = 56 My Work: 3z^2 - 22 + 22 = 56 + 22 = (sq root of)3z^2 = (sq root of)78 = 3z/3 = 8.831760866 = 2.94 ---------------------------- 3 z^2 = 78 z^2 = 26 z = sqrt(26) = 5.10

**Algebra**

1. 5x^2 - 526 = -651 My Work: 5x^2 - 526 + 526 = -651 + 526 (sq root of) 5x^2 = (sq root of) -125 = 5x/5 = 11.18033989/5 = 2.24 ----------------------------- The square root of a negative number is imaginary, not a real number anyway 5 x^2 = -125 x^2 = -25 x = 5 i

**us history (please help!!)**

I think the Missouri Compromise did both. It established a boundary between slave and non-slave (which did not work out all that well) and it also traded admission of Maine (free) for Missouri(slave).

**physics**

3/ 0.3 = 10 m/s

**Math**

http://kc3rd.pbworks.com/f/cylinder.pdf

**MATH ALGEBRA**

If a cubic always try dividing by (x-1) and by (x+1) first to see if 1 or -1 is a root. In this case: x = -1 , 1/3 , -2 1/2 if all else fails: http://www.solvemymath.com/online_math_calculator/algebra_combinatorics/polynomial_calculator/polynomial_roots.php

**physics**

h = (1/2)(9.8)(4.59)^2

**math**

FSU = .99(200) so FSU = 198 I assume no FSU people left the party, like no way they would leave a party before it was over:) 198 = .98 (people left) so people left = 194 so 6 people left the party

**trig**

tan 31 = h/580

**PHYSICS !!**

momentum before = momentum just after .045 * 165 = 2.045 * Vi solve for Vi, the inital velocity fater collision Ke = (1/2)(2.045)(Vi^2) initial kinetice energy of bullet-block system That Ke will be the work done by friction: Ke = F * d = mu m g * d m cancels so so 0.4 (9.81) ...

**algebra**

x - 1 > 2 x > 3 or 1 - x > 2 -x > 1 x < -1 so everything to the right of x = 3 and everything to the left of x = -1

**units? " or '**

are you sure it is 2 feet thick and 12 feet wide? I will assume 2" and 12" that is 2 board feet per foot (2 inches thick by 1 foot wide) so 240 board feet *80 =19,200 pesos

**history**

I do not think so. IWW was oriented to the rank and file workers.

**Physics 130**

You are welcome :)

**Physics 130**

Is it on a level road? If so m g + 20 sin 30 15 * 9.81 + 10

**chemistry**

potassium oxide as far as I know

**andrew jackson**

Trail of tears - bad no US bank bad or good? supported slavery - bad supported democracy and liberty (for some people) - good

**Science**

say specific heat of water = k (does not matter here) 10 k (100 - T) = 20 k (T - 40) 1000 - 10 T = 20 T - 800 1800 = 30 T T = 60 deg C

**astronomy**

m g = G M m /r^2 m gmars = G (M/10)m /(.5r)^2 = GMm/r^2 * (1/10)/(.25) = (.4) G M m / r^2

**chemistry**

50 g * heat of vaporization of water I do not know if you are using calories or Joules or BTU. Use whatever but convert your grams properly

**Math**

-8x + 28 = -36 8 x = 64 x = 8

**Math**

(4/5) / (20/3) ??? (12/15) / (100/15) 12/100 3/25

**Algebra II**

x^2 + 80 x - 500 = 0 x = [ -80 +/- sqrt (6400 + 2000) ] /2 x = [ -80 +/- 91.7 ] / 2 use + result x = 5.82 so 6

**Calculus Help Please!!!**

f(x+h) = (x + h) + 1/(x+h) = [(x+h)^2 + 1] /(x+h) = [x^2 + 2 x h + h^2 + 1 ] / (x+h) f(x) = (x^2+1)/x f(x+h) - f(x) =[x^2+2xh+h^2+1]/(x+h) - (x^2+1)/x = x^3+2x^2h+h^2x+x -(x^2+1)(x+h) -------------------------------- x^2 + hx divide by h x^3+2x^2h+h^2x+x -(x^2+1)(x+h) --------...

**Physics**

If they stick together then momentum is conserved x momentum before = m v y momentum before = m v x momentum after = 2 m U cos theta y momentum after = 2 m U sin theta so 2 U cos theta = v 2 U sin theta = v or cos theta = sin theta so theta = 45 degrees cos theta = cos 45 = sq...

**Physics**

ritzi as in spikey sea urchins? If a collision is elastic, no kinetic energy is lost. That is what an elastic collision means.

**maths**

nope , four times area = pi r^2 NOT pi r (2r)^2 = 4 r^2

**English**

I would have said: The team members are .....

**English**

How about The book club likes.... or The book club like.... Seen in that perspective, the book club appears to be singular :)

**English**

If you can drop it out and the remaining sentence still is reasonable, it is subordinate. eg: Brett is class president. Bonnie is also studying computer science. Ann just started working here today

**gibberish**

Whatever font you are using is not showing up properly on my screen.

**Geometry A**

( y - (-4) ) / ( x -(-6) ) = 3 y+4 = 3(x+6) y = -4 + 3 x + 18 y = 3 x + 14

**Math**

3/Which food makes up the largest part of most American's diets? About how much of that food does the average Americaneat in 4 years? Answer: Dairy products 582 Round. 600 *. 4 4 600* 4= 2,400 -------------------- 582 * 4 = 2328 round to 2000

**Math**

2/ About how much fish does an average American eat in 3 years? Answer : 51 Round. 50 * 3. * 3 50* 3= 150 ----------------------------- 51 * 3 = 153 yes 150

**Math**

1/ About how much chocolate does an average American eat in 5 years? Answer: 13 Round 10 * 5 *5 10 * 5= 50 ------------ Round at the end 13 * 5 = 65 so I get 70

**Math**

Ruby and Marielle are working on a project. If ruby finishes 4/8 of the project and Marielle finishes 3/8 , how much of the project is left? Answer: 4/8_3/8= 1/8 ------------------- Well, your answer is right but for the wrong reason together they did 4/8 + 3/8 = 7/8 that leav...

**Navier-Stokes eq**

by the way, results are not a function of angle a (theta). All partial derivatives wrt theta are assumed zero.

**Navier-Stokes eq**

You have got to be kidding :) That is far too much for me to produce here but below is a link to the subject worked out: http://faculty.kfupm.edu.sa/CHE/usamah/CHE204/CHE204-HD22%20-%20Flow%20Through%20Circular%20Pipe.pdf

**physics - Huh ?**

I have no idea because I do not know the mass or the spring constant.

**algebra**

1 < x < 4

**physics**

(a) rotation around sticky hinge (b) rotation of screw (c) rotation around fulcrum of lever

**Math**

[ 7 +/- sqrt (49 - 12) ] / 2 = 3.5 +/- .5 sqrt (37) 6.541 or .459

**algebra**

6|6-4x| = 8 x + 4 + sign 6 (6x-4) = 8 x+4 36 x - 24 = 8 x + 4 28 x = 28 x = 1 negative sign 6(4x-6) = 8 x + 4 24x - 36 = 8 x + 4 16 x = -40 x = 5/2 so 5/2 or 1

**algebra**

(19.88 + 20.12) /2 = 20 middle of range can be + or - .12 from there | w - 20 | = distance from middle so | w - 20 | < .12

**math**

.15 x = 435 so x = 435 / .15

**math**

.38*560 paste that into a Google search boxsw

**physics**

177 (12+32)/32 = 243 I get but anyway 177 (32 -32) = 0

**Physics**

60 *1000/3600 =16.7 m/s average speed during stop = 8.33 m/s time to stop t = 35/8.33 = 4.2 s acceleration = - 16.7/ 4.2 = 3.98 m/s^2 m a = mu m g mu = a/g 3.98 / g = .405

**physics**

r^2/rearth^2 = 4/3 r = rearth *sqrt (1.33) = 1.15 rearth height = r - rearth = .15 rearth

**algebra**

T e = 3 u T e/3 = u

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