Friday
August 22, 2014

Posts by Damon


Total # Posts: 17,967

Science
1. b agree 2. a and d, yes, double covalent 3. b, d e yes, but highly radioactive metal 4. d yes 6. yes a, b 8. not sure about 8 but would guess group 1 (b) 9. No, a row is a "period" (b)
June 4, 2014

physics
dx/dt = b t^2 so x = (1/3) b t^3 + starting x
June 4, 2014

science
mass of one liter of water = 1 kg Archimedes says: F = m g = 1 kg * 9.81 m/s^2 = 9.81 Newtons
June 4, 2014

Algebra - Steve!! Help!
By the way, that would be impossible without changing the pressure as well.
June 4, 2014

Algebra - Steve!! Help!
V T = k *** IF *** I assume this is true then: 500 * 2.5 = k = 1250 so 100 T = 1250 T = 12.5 C I guess that is the answer they want, but in fact V T = constant ONLY if you use degrees KELVIN which is degrees C + 273 so really 500 * 275.5 = k = 137,750 so 100 T = 137,750 T = ...
June 4, 2014

Physics
Huh ? Are you doing relativity? The force on it is constant, q*E so the acceleration is constant, forever if it were not limited by approaching the speed of light.
June 3, 2014

Physics
You are welcome.
June 3, 2014

Physics
Watts is power (Joules/second)
June 3, 2014

physics
6000 + 2500 = 8500 kg = m m g = weight = 9.81 * 8500 F = weight + m a F = 9.81* 8500 + .5 * 8500 = 87,635 N T = 9.81*2500 + .5 * 2500 = 25,775 N
June 3, 2014

physics
Ac = v^2/r if you increase v, then v^2 increases by the square of the ratio new Ac = (16/9) old Ac = (16/9)12 = 21.3 m/s^2
June 3, 2014

Physics
1/R = 1/5 + 2/5 + 1/10 = (2+4+1)/10 = 7/10 so R = (10/7) k Ohms =1.44 k Ohms
June 3, 2014

math 1 question!!!!!!
- (3/5) a
June 3, 2014

math
y = m x 9 = m * 5 m = 9/5 so y = (9/5) x or 5 y = 9 x ------------------------- or easier way x/y = 11/1.5 11 y = 1.5 x
June 3, 2014

Physics
You are welcome.
June 3, 2014

Physics
V/R = i = 45/15 = 3 amps
June 3, 2014

Math
combinations of 7 taken 4 at a time C(7,4) = 7! /[ 4!(3!)] = 7*6*5/(3*2) = 35
June 3, 2014

Physics
T = tension mass 1 = 30/g mass 2 = 20/g for mass 1 m a = m g - T (30/g)a = (30/g) g - T for mass 2 (20/g) a = T - (20/g)g add the two equations (50/g) a = (10/g) g so a = g/5 or about 9.81/5 = 1.96 m/s^2 that is Part B go back and get T for part A then for part C chain tension...
June 3, 2014

Calculus
2 x^2 + 4 x h = 600 h = (600 -2 x^2 )/4x or h = (300 - x^2)/2x v = x^2 h v = (1/2)( x)(300 -x^2) v = (1/2)(300 x - x^3) dv/dx = (1/2) (300 - 3 x^2) = 0 for max or min so x = 10 then x^2 = 100 h = 10 v x^2h = 1000
June 3, 2014

science
For electricity: coal, wood, gas, running steam generator , or diesel generator or solar, geothermal, water wheel, wind turbine choice depends on where you are, do you have water power available? geothermal handy? strong winds? Southern exposure to sun?
June 2, 2014

rounding
Yes
June 2, 2014

Algebra
4 sqrt 10 - 1 sqrt 10 = 3 sqrt 10
June 2, 2014

Algebra
well, it is hard for me to graph here so eliminate y by subtracting the second equation from the first x^2 + 5 x -50 = 0 (x-5)(x+10) = 0 so x = 5 or x = -10 if x = 5, then y = -10 if x = -10 then y = 35
June 2, 2014

Algebra
if -3m = 0, then the whole thing is 0 so if m = 0, the whole thing is 0 if (2m-5) is 0, the whole thing is 0 so if m = 5/2, the whole thing is 0 so the solutions are m = 0 and m = 5/2
June 2, 2014

when the energy of a sound wave is transferred to
Hey, what do you think the answers are and why ? You can figure it out even if you do not know much physics.
June 2, 2014

math HELP!!!!!!
You are welcome :)
June 2, 2014

math HELP!!!!!!
16/40 = x/700 2/5 = x/700 x = 1400/5 = 280
June 2, 2014

physics
m g h
June 2, 2014

math HELP!!!!!!
Yes, C
June 2, 2014

math HELP!!!!!!
no review your text about valid sampling and bias
June 2, 2014

MATH!!!
V = 156 + 4.5 (t - 12)
June 2, 2014

Algebra
16 t^2 -20 t - 6 = - h in obsolete English units when does h = 0? t = [ 20 +/- sqrt (400 + 384) ] /32 t = [ 20 +/- 28 ] /32 t = 48/32 = 1.5 seconds (ignore the negative t) for vertex complete the square assuming no calculus may be used 16 t^2 -20 t = - h + 6 t^2 - (5/4) t = -h...
June 2, 2014

Math
p(f) = 3/20 p(first) = 3/20 = .15 p(second) = 2/19 = .105 p first and second = .15 * .105 = .0158 first fail, second pass = 3/20 * 18/19 first pass second fail = 17/20 * 3/19
June 2, 2014

Physics
.050 Vo = 1.050 v so v = .0476 Vo initial Ke = (1/2)(.05)Vo^2 final Ke = (1/2)(1.05)v^2 100 (.05 Vo^2 - 1.05 v^2) /.05 Vo^2 100 (.05 Vo^2 - .00238 Vo^2)/.05 Vo^2 = 95.2 % of initial energy is lost
June 2, 2014

Physics
(1/2)(1200)(900) = 540,000 joules m g h = 1200 * 9.81 * h = 540,000 h = 45.9 meters
June 2, 2014

College Algebra
x (x-9) =0 x = 0 and x = 9 are correct ps I bet they meant: x^2 - 9 = 0 (x-3)(x+3) = 0 x = 3 or x = -3
June 2, 2014

Math
arithmetic series see http://www.mathwords.com/a/arithmetic_series.htm here a1 = 30 and d = 4 and n = 10
June 2, 2014

What is the coefficient of x?
-5
June 2, 2014

Physics
R = 10 + 8 + 27 i = 9/R for each Vn = i * Rn the sum of Vn better equal 9
June 2, 2014

Math
a + c = 390 a = 2.25 c so 2.25 c + 1 c = 390, solve for c then for a Revenue = 8 a + 3 c
June 2, 2014

Math
You are welcome.
June 1, 2014

Math
tan angle = 34/12
June 1, 2014

science
When you post a question again and again and no one replies, perhaps there is something missing in the question that renders it incomprehensible. We have no idea where or what you are talking about, on a beach or in a bottle or what else is behind your question.
June 1, 2014

algebra2/ Trigonometry
24+22+14+12 = 72 marbles yellow = 14/72 = .1944.... or about 19.4 % do the others the same way
June 1, 2014

Geometry
You are welcome.
June 1, 2014

Geometry
Volumes scale as the CUBES of corresponding lengths of similar figures (25/35)^3 = (5/7)^3 = 125/343
June 1, 2014

typo
I have no idea what you mean there are about 6*10^23 anythings per mole just like there are 12 anythings per dozen
June 1, 2014

trigonometry ans.
You are welcome.
June 1, 2014

trigonometry ans.
right, you asked for nearest foot
June 1, 2014

trigonometry ans.
tan 53 = height/distance yes, 66 to nearest foot The right angle is at the foot of the tree. ALWAYS draw a picture tan 53 = opposite (tree) / adjacent(along ground the hypotenuse is along your line of sight, not used here
June 1, 2014

physics
momentum after momentum before sum of m after v after = sum of m before v before .16 (27.5) + (68) v = 68.16 (2.55) solve for v second skater: (60.5+.16) v = .16(27.5) solve for second skater v
June 1, 2014

Geometry
ok, always sketch a graph
June 1, 2014

Geometry
It gets smaller.
June 1, 2014

help
You are welcome.
June 1, 2014

help
tan 12 = 40/d d = 40/tan 12 = 188 meters ! If that diver is wearing a hard hat, he is going to be a wreck himself by the time he gets there and it will take so long that he will need to make decompression stops upon ascent to avoid getting the bends. Move the stupid ship !
June 1, 2014

Geometry
You are welcome.
June 1, 2014

Geometry
https://www.khanacademy.org/math/geometry/similarity/triangle_similarlity/v/similarity-postulates
June 1, 2014

Geometry
http://www.regentsprep.org/Regents/math/geometry/GP11/LsimilarProof.htm
June 1, 2014

Geometry
ratio of areas of similar figures is ratio of corresponding lengths squared 20/16 = 5/4 so 25/16
June 1, 2014

algeba/can you please ck my answer
1598 * 1.05 = 1677.90 total cost with tax 1677.90 * .14 * 3 = 704.72 total interest so total amount to be paid = 2382.62 divide by 36 months = 66.18 per month Note this "add on rate" is a rip off. As you pay the principal back, the amount you owe should decrease. If ...
June 1, 2014

Algebra 1
Nasty !!! at 2:30 m
June 1, 2014

Algebra 1
Oh delete the x = 5, denominator of original is 0 Not in domain
June 1, 2014

Algebra 1
{ (6x-14) + (x^2-5x) ] /[2(x-5) ] =16/[2(x-5)] x^2 + x - 14 = 16 x^2 + x - 30 = 0 (x-5)(x+6) = 0 x = 5 or -6
June 1, 2014

math
7 n = 400 - 190
June 1, 2014

statisticsWere did i go wrong thank you
I am happy to help. You are welcome :)
June 1, 2014

statisticsWere did i go wrong thank you
mean = 97 correct difference and square of difference -14 196 -1 1 3 9 3 9 9 81 sum of squares = 296 variance = 296/5 = 59.2 square root of variance = standard deviation = 7.69
June 1, 2014

whoops, order wrong
then divide by n then take the square root
June 1, 2014

statisticsWere did i go wrong thank you
http://www.mathsisfun.com/data/standard-deviation-calculator.html
June 1, 2014

statisticsWere did i go wrong thank you
then take the square root, then divide by n
June 1, 2014

statisticsWere did i go wrong thank you
The differences SQUARED
June 1, 2014

Physics
u = 1540 cos 52 = 948 the whole time Vi = 1540 sin 52 = 1214 at start v = Vi - 9.8 t 0 = 1214 - 9.8 t t = 124 seconds to top so 2 t = 248 seconds in the air (part B) range = u * 2t = 234,871 meters or 235 km
May 31, 2014

Statistics/I am confused
difference from mean = 115-105 = 10 below mean variance = 25 so standard deviation = 5 so z = -10/5 = -2 it is two standard deviations below mean for z = 2 look up in normal table http://davidmlane.com/hyperstat/z_table.html probability = .0228
May 31, 2014

algebra
|+1 +0 | |-2 +3 +8 | |+0 -1 | |-3 +5 -1 | = | -2 +3 +8 | | +3 -5 +1 | so (-2,3), (3,-5), (8,1)
May 31, 2014

geography
Just some suggestions 1. Location maybe in Southern California on the west coast of USA. 2. Place What defines this place? Hollywood? Freeways? 3. Human interaction with environment You have to mention smog and the use of cars and air conditioning. You have to point out that ...
May 31, 2014

math
(y+6)^2 + (-6)^2 = 100 y^2 + 12 y + 36 + 36 = 100 y^2 + 12 y - 28 = 0 (y-2)(y+14) = 0 y = 2 or -14 y = 2 is on your list
May 30, 2014

Math
Note the tangent is perpendicular to the radius where it hits the circle.
May 30, 2014

Math
21/2 is rational but not integer and it is more than 5 and more than 2 so a square would solve the problem. put points at (21/2, 21/2) in quadrant 1 then its image (-21/2, 21/2) in quadrant 2 then (-21/2, -21/2) in quadrant 3 and (21/2,-21/2) in quadrant 4.
May 30, 2014

Statistic
5. 115 - 100 = 15 z score means how many standard deviations away from mean so 15/10 = 1.5 A+ :)
May 30, 2014

Statistic
http://easycalculation.com/statistics/standard-deviation.php
May 30, 2014

Multiply write the result in scientific notation.
(9*10^4)(8*10^6) = 72^10^10 = 7.2*10^11
May 30, 2014

physics
10 * 44 = 440 meters
May 30, 2014

geometry
volume = (1/2) (4/3) pi r^3 = (2/3)pi r^3 so 486 pi = (2/3) pi r^3 so r^3 = (3/2)(486) = 729 area of half of hemisphere = (1/2) 4 pi r^2 = 2 pi (729)^(2/3) = 162 pi
May 30, 2014

physics
a = F/m a = (2.36 cos 44.8 ) /.22
May 29, 2014

algebra
Evaluate 3p/q when p=2 and q=6. Answer:1 YES Use < > or = for __ to write a true sentence: 0.001 __ 0.0010 Answer:< Question 3 _______________ = ___________________ Evaluate -3/8 - 5/8. Answer:7 Question 4 ____________________ -8/8 = 1 __________________ Evaluate: 84...
May 29, 2014

engineering mechanics
Just look at the solved problems linked below. This problem may be the most common in all of algebra and beginning physics :) Remember and hour is 3600 seconds.
May 29, 2014

math
Equations have = signs
May 28, 2014

trig
(1 + tan^2A)(1 -sin^2A) but (1 - sin^2 A) = cos^2 A and (cos^2A/cos^2A + sin^2A/cos^2 A) = 1/cos^2 A so we have (1/cos^2 A)(cos^2 A) which is 1
May 28, 2014

math
tan theta = 9/175
May 28, 2014

Math
Nor do I. Have you mixed up two problems?
May 28, 2014

math
11 + 5 = 16
May 28, 2014

Science
Mass does not depend on gravitational constant anywhere. 5 kg is 5 kg b) m g = 5*9.81 N
May 28, 2014

ENGLISH
Pretty Calf says exactly why.
May 28, 2014

math
Find LCD 40 = 2*2*2*5 25 = 5*5 10 = 2*5 so 2*2*2*5*5 = 200 so 15/200 , 32/200 and 20/200 3/40 1/10 4/25 B
May 28, 2014

precal help asap
There are in fact an infinite number of solutions I would try each of the choices I have my calculator set on degrees so 2pi = 360 tan^2 (360/3 ) = 3 Yes that works tan 180 does not work tan -60 does not work tan 300 = nope so only A
May 28, 2014

algebra/please help I have been wrong twice
You are welcome.
May 28, 2014

algebra/please help I have been wrong twice
p(oil) = 1/40 p(gas) = 1/20 p(oil and gas) = 1/800 so (1/40)(395,000) = 9875 (1/20)(125,000) = 6250 (1/800)(520000) = 650 So I get 16,775 income - 25,000 expense = -8225 They expect to lose money I think.
May 28, 2014

PRECAL MULTIPLE CHOICE
sin A/a = sin B/b sin B = (b/a) sin A = 1.036 no solution (sin may not be greater than 1)
May 28, 2014

math
f' = -12 x^2 + 16 x + a f" = -24 x + 16 sheds water when when f" is negative holds waster when f" is positive f" is 0 when x = 2/3 sheds water when x < 2/3 holds water when X>2/3 so B
May 28, 2014

math
f(4) = 64 f(1) = 1 63/3 = 21 = average slope in interval f' = 3 x^2 = 21 x = +/- sqrt 7 in interval x = sqrt 7 = c so A
May 28, 2014

Physics
g is about 32 ft/s^2 in these obsolete units 61.8 miles/hr * 5280 ft/mi * 1 hr/3600seconds = 90.6 ft/s 7 * 32 = 224 ft/s^2 a = change in v/change in tim 224 = 90.6/t t = .4 seconds
May 28, 2014

Science
+2e
May 28, 2014

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