Tuesday
January 27, 2015

Posts by Damon


Total # Posts: 20,428

physics
the charge on a proton is equal in magnitude and opposite in sign to the charge on a electron. Therefore if an atom has the same number of electrons as it has protons, it is neutral. Otherwise it is called an "ion".
November 11, 2014

Physics
c) (1/2) m v^2 = answer to b d) The reason they want is that the person would have reached terminal velocity where air drag up = weight down before falling 5000 meters. The reason they forgot about is that the diver also has the constant horizontal velocity of the airplane the...
November 11, 2014

Did I get this right?
yes, correct but perhaps you better multiply out and collect like terms for example 3x^2 + x^2 = 4 x^2
November 11, 2014

physics
weight = .010*9.8 = .098 Newtons x = .05 m k = 1.96 N/m omega = sqrt (k/m) = 2 pi f so f = 2.23 T = 1/f = .45 seconds
November 11, 2014

Derivatives
for starters x^3[ 4(5x-1)^3 (5) ] + 3 x^2 (5x-1)^4
November 11, 2014

Square Roots
11^2 = 121 12^2 = 144
November 11, 2014

math
yes, that makes sense. Did she get 26 ( 50/2 + 2/2 = 25+1 = 26 or did she come up with something else entirely?
November 11, 2014

World History Answer Check (Ms. Sue)
I like your other answers.
November 11, 2014

World History Answer Check (Ms. Sue)
2. What was the effect of total war on ordinary citizens during World War I? A: Because of total war, ordinary citizens underwent rationing of goods. =================================== True in the world outside the war zone, such as in the US. However ordinary French or ...
November 11, 2014

Math
I do not know what power you are raising twelve to if you mean 2 + (12)^2 then 2 + 144 = 146
November 11, 2014

physics
I need to know how far the center of mass of a blade is from the axis. If we assume the blade is a uniform rod with cg at its center (unlikely) then the moment of inertia about its end is: I = (1/3) m L^2 so for 3 we have just I = 1 m L^2 = 159 * 3.69^2 = 2165 kg m^2
November 11, 2014

Math
200 n = 3000 2 n = 30 n = 15
November 11, 2014

Physics
u = horizontal velocity = 3.2 cos 40 forever Vi = initial up velocity component = 3.2 sin 40 v = Vi - 9.8 t h = 1.175 + Vi t - 4.9 t^2 at ground, h = 0 so 4.9 t^2 - Vi t - 1.175 = 0 solve quadratic for t, use positive solution then range = u t
November 11, 2014

Statistics
well, just using what iss given and assuming it is true probability that woman uses computer at work = .72 so probability not = 1-.72 = .28 Binomial distribution prob 5/5 yes = C(5,5) .72^5 *.28^0 = 1 * .72^5 * 1 = .72^5 = .193 (second answer) so prob that someone does not = 1...
November 11, 2014

physics
seesaw :) 1 x = 35.5(1.27*10^-10 - x) 36.5 x = 45.1 * 10^-10 x = 1.24 * 10^-10 in other words right beside the Cl atom
November 11, 2014

physics
find the well depth in meters. I doubt if it is really just 10 cm deep but if really true then 0.10 meter multiply mass in kilograms by g, about 9.8 meters/second^2 to get weight force multiply that force by the depth to get work done.
November 11, 2014

question
I believe so.
November 10, 2014

Math
d = 4 t d + t = 20 5 t = 20 t = 4 d = 16 16-4 = 12
November 10, 2014

Math help please!!!!!
24/10 = 30/x 24 x = 300 x = 12.5 I am assuming that x and 10 are along the wall and not the ground.
November 10, 2014

PHYSICS
dW = p A dr dW = p 4 pi r^2 dr integrate W = p (4/3) pi (r final^3 - r initial^3) W = p (final volume - initial volume)
November 10, 2014

Trigonometry
sin^-1 (1.2 /4.4 )
November 9, 2014

Physics
F = m a 150 lbs = 68 kg Fscale up - m g down = m a Fscale up = m g + m a = 150 pounds + 68* 10 newtons = 150 pounds + 680 Newtons 680 Newtons = 153 pounds so 150 + 153 is about 300 pounds
November 9, 2014

math
65/60 is to the right of 1 on a number line. The result is positive. +
November 9, 2014

Physics
Thanks, I just went and looked, might do that but I am pretty busy here when I am not coaching our sailing team or whatever.
November 9, 2014

Physics
I will go look though.
November 9, 2014

Physics
I am a retired professor, do this for fun.
November 9, 2014

Physics
You are welcome.
November 9, 2014

Physics
Ah, here: http://earthsky.org/earth/tides-and-the-pull-of-the-moon-and-sun ( former clammer and lobsterman here :)
November 9, 2014

Physics
maximum high and low tides occur when the earth, moon and sun are co-linear. That is at full moon and new moon. Such tides are called "spring tides" and occur about twice a month.
November 9, 2014

Physics
Yes 0 free falling weightless :)
November 9, 2014

Physics
Backup link :) http://www.jiskha.com/display.cgi?id=1282164495
November 9, 2014

Physics
Like - "weightless" :)
November 9, 2014

Physics
No !!! ZERO no force on scale - in free fall, accelerating downward at 9.81 m/s^2
November 9, 2014

Physics
Total force on person = m g = m a in free fall. No external force on person from scale
November 9, 2014

physics
ke = .5 m v^2 + .5 I w^2 I = m r^2 w = v/r so ke = .5 m v^2 + .5 m r^2 v^2/r^2 ke = m v^2 v = 2.1 * 3.8 = 8.0 m/s so ke = 5.6 *64 Joules = m g h = 5.6 g h so 64 = g h h = 64/9.8 sin 17.7 = h/distance up ramp so distance up ramp = h.sin 17.7
November 9, 2014

Physics
see this similar reply http://www.jiskha.com/display.cgi?id=1415568126
November 9, 2014

Chemistry
How do you find the amount of water that reacted 2 mol of phenylmagesium bromine?
November 9, 2014

Chemistry
If there are 25 mg of water in a typical drop of water, how many drops of water would react completely with 2 mmol of phenylmagnesium bromide? How do I set up the problem?
November 9, 2014

Physics
sum of vectors, not product Pa =3.2[ 2.3 i + 4.2 j] = 7.36 i +13.44 j Pb =2.9[ -1.8 i +2.7 j] =-5.22 i +7.83 j P = (7.36-5.22) i +(13.44+7.83) j
November 9, 2014

Physics
initially p1 = 4 i + 2 j p2 = -3i + 3 j total p = 1 i + 5 j final p must be the same final p1 = px i + py j p2 = 6 i - 3 j px + 6 = 1 px = -5 vx = -5/2 = -2.5 py -3 = 5 vy = 5/2 = 2.5 so v = -2.5 i + 2.5 j
November 9, 2014

physics
no question was asked
November 9, 2014

Physics
m g h + (1/2)m v^2 = total energy = constant h is height above hanging straight down mg(2-2 cos 30)+.5m*9 = total energy = m g (2 -cos max angle when v = 0) notice m has nothing to do with this problem, cancels = mg(2-cos45) +.5 m v^2
November 9, 2014

Physics
Ke - work done against friction = (1/2)kx^2 (1/2)mv^2 - .3 m g (.2+x) = (1/2)(800)x^2 (1/2)*2*9 -.3*2*9.8(.2+x) = 400 x^2 solve quadratic for x why are you talking about m g h ??? it fell on horizontal plane?
November 9, 2014

Math
b did both draw Venn diagram fri---both- weekend |20-b | b |29-b| 20-b + b + 29-b = 40 49 - b = 40 b = 9 11 fri , 9 both , 20 weekend
November 9, 2014

Calculus
You are welcome.
November 9, 2014

Calculus
Do you mean? y= (x^3+8)/(x+2) ???? or what you typed? If my guess is correct then (bottom dtop/dx -top d bottom/dx)/bottom^2 =[(x+2)(3x^2)-(x^3+3)(1)]/(x+2)^2 =[3x^3+6x^2-x^3-3]/(x+2)^2 = (2x^3+6x^2-3)/(x+2)^2
November 9, 2014

calc
x y = 50 2 x + y = p 100/y + y = p dp/dy = 0 for min = -100/y^2 + 1 y = 10 x = 5 p = 20 feet of fence
November 9, 2014

Algebra
if x = 6 then f(x/2) = f(3) = 4 y = 4/2 = 2 (6,2)
November 9, 2014

Algebra
if x = 3 then f(x) = 4 so y = 4 + 4 = 8
November 9, 2014

Physics, please!
I used g = -10, you do it with your g
November 8, 2014

Physics, please!
I guess he kicked it horizontally? Hi = 22 0 = Hi - (1/2)(10) t^2 4.4 = t^2 t = 2.1 seconds goes 17 meters horizontal in 2.1 seconds u = 17/2.1 = 8.1 m/s
November 8, 2014

Physics
F = mu m g work = F d = mu m g d Ke lost = (1/2) m Vo^2 Vo^2 = 2 mu g d mu = Vo^2/(2gd)
November 8, 2014

Algebra 2
4x(x-6)-x(x-2)=-24 4 x^2 - 24 x - x^2 + 2 x + 24 = 0 3 x^2 -22 x + 24 = 0 18 and 4 I bet (3x - 4)(x - 6) ??? yes x = 4/3 or 6
November 8, 2014

Algebra 2
6 x^2 - 13 x + 6 = 0 we want 6 * 2 and a 1 to get 13 or 9 and 4 (3 x - 2)( 2x - 3 ) ah, 9 and 4 x = 2/3 or 3/2
November 8, 2014

Algebra
speed up = u -c speed down = u+c d = speed * time 3 = (u-c)1.5 3 = (u+c)1 1.5 u - 1.5 c = 3 1.5 u + 1.5 c = 4.5 --------------------- add 3 u = 7.5 u = 7.5/3 3 = 7.5/3 + c c = (9-7.5)/3 = 2.5/3 = .83333333333333333333333333
November 8, 2014

S.S.
Civil Rights Act of 1964? People are still discriminating against black people, particularly in the South
November 8, 2014

Algebra 2
we know that 7*7 = 49 and 49+1 = 50 so we know what to do 7 p^2 - 50 p + 7 = 0 (7 p - 1) ( p - 7) = 0
November 8, 2014

Calculus (math)
I tried method 2 but gave up about an hour ago. I do not think there is any trick, just plug and chug.
November 8, 2014

Calculus
if you were supposed to use feet instead of meters as your other problem that I just saw, use 32 ft/s^2 for g not 9.81 m/s^2
November 8, 2014

Calculus
a = g = -9.81 m/s^2 v = -gt = -9.81 t h = Hi - (1/2) g t^2 = Hi - 4.9 t^2 b) h at t = 0 = Hi h at t = 3 = Hi-4.9 t^2 = Hi - 44.1 m/s average = (-44.1)/3 = - 14.7 m/s c) at 0 v = 0 at 3 v = -9.81*3 = -29.4 m/s at 6 v = -9.81*6 = -58.9 m/s d) well I am not about to Google Hi Hi...
November 8, 2014

calculus
I mean e^x as x --> big negative is 1/e^big positive
November 8, 2014

calculus
e^-a = 1/e^a
November 8, 2014

calculus
e^x as x --> big negative is 1/e^big negative
November 8, 2014

calculus
Thought I answered this -x/e^x e^x >> x for large x
November 8, 2014

Math
C --> y S --> 3 y J --> 3 y + 50 y + 3 y + 3 y + 50 = 7 y + 50
November 8, 2014

Calculus
Oh good grief, feet :( old text had initial speed 16 ft/s up ? I guess ? h = 32 + 16 t - 16 t^2 0 = 32 + 16 t - 16 t^2 solve quadratic t = [ -16 +/- sqrt ( 256+2048) ] /-32 t = 2 seconds v = dh/dt = 16 - 32 t = 16 - 64 = -48 ft/s
November 8, 2014

Algebra 2
4 x^2 + 2 x - 2 = 0 2 ( 2 x^2 + x - 1) = 0 (2x-1)(x+1) = 0 x = 1/2 or -1 5 x^2 + 34 x - 7 = 0 (5x-1)(x+7) = 0 etc
November 8, 2014

Algebra 2
http://www.gregthatcher.com/Mathematics/GaussJordan.aspx x= 1, y=2, z = 3
November 8, 2014

Calculus
x --> + oo of -x/e^x
November 8, 2014

Physics
sqrt (251^2 + 80^2)
November 7, 2014

Physics
How long to fall 10 meters? 10 = (1/2)(10) t^2 solve for t, time in air then 4 meters = u t solve foe u
November 7, 2014

Science Help!!!!
Yes, first it is burned in the engine to make CO2 The CO2 is used in photosynthesis to make wood and leaves and stuff, releasing the O2 for us to breathe.
November 7, 2014

physics
Problem entirely vertical assuming your straight line is horizontal Vi = 10 sin 46 v = Vi - g t delta h = Vi t - (1/2) g t^2
November 7, 2014

CAL
f'(x) or d f(x)/dx y' or dy/dx maybe?
November 6, 2014

Calculus
-4 cos^3 x^4 sin x^4 (4 x^3) = - 16 x^3 cos^3 x^4 sin x^4 how that is tan x2 whatever that is I can not imagine
November 6, 2014

Math
log 9 - log 300 2 log 4 + 4 log 3
November 6, 2014

Science
F2 + F1 = .450 (.750) F2 - F1 = .240 (.750) -------------------------- 2 F2 = .690(.750) etc
November 6, 2014

Physics
force down = 9.81*12 max friction force = 9.81 * 12 * mu forward force - friction force = m a 15 - 9.81*12 * mu = 12 (.2)
November 6, 2014

Math
I do not think so I think h = 300 - 16 t^2 she is accelerating DOWN 100 = 300 - 16 t^2 t^2 = 200/16 t = 10 sqrt 2 / 4 = 2.5 sqrt 2
November 6, 2014

Physics easier
http://outreach.phas.ubc.ca/phys420/p420_04/sean/
November 6, 2014

Hurricane Project for Physics Class
Physics (hard) http://www.psfc.mit.edu/library1/catalog/online_pubs/iap/iap2013/emanuel.pdf
November 6, 2014

Hurricane Project for Physics Class
Physics (hard) http://www.psfc.mit.edu/library1/catalog/online_pubs/iap/iap2013/emanuel.pdf
November 6, 2014

Hurricane Project for Physics Class
Click on hurricane in the upper right corner
November 6, 2014

Hurricane Project for Physics Class
http://coast.noaa.gov/hurricanes/#app=c64c&88cd-selectedIndex=1
November 6, 2014

Calculus
no v = w^2 h = (2300/3) h but h = (2300 -w^2)/4w
November 5, 2014

Calculus
v = w^2 h A = 2300 = w^2 + 4 w h 4 w h = 2300 - w^2 h = (2300 -w^2)/4w so v = w^2 [ (2300 -w^2)/4w ] v = 2300 w/4 - w^3/4 4 dv/dw = 2300 -3 w^2 = 0 for max w^2 = 2300/3 w = 27.7 cm etc
November 5, 2014

Math
2 w + 2 L = 18 so L = 9-w A = w L = 9 w - w^2 w^2 - 9 w = -A find vertex by completing the square for max A w^2 - 9 w + (9/2)^2 = - (A-81/4) (w -9/2)^2 = - (A-81/4) w = 9/2 for max area by the way that means 2 w = 9 and therefore 2 L = 9 so it is a square with sides = 9/2
November 5, 2014

Physics
No. To start it moving you must overcome the static friction. After that it gets easier. 648 * .86
November 5, 2014

algebra
sum of arithmetic series a1 = 1 d = 2 an = a1 + (n-1) d so a700 = a1 +(699)(2) sum = (a1 + a700)/n
November 5, 2014

calculus careful with parentheses
do you mean what you wrote 7 + 3 x^.5 or do you mean 3 [x+7]^.5 ??????????? anyway (x+1)(derivative of second) + (second) (1)
November 5, 2014

Calculus I
using T for theta dR/dT = (Vo^2 /9.81) cos2T (note max range when T = 45 degrees :) ) 100 dT/T = 2 dT = .02 T = .02 * pi/6 dR = (Vo^2 /9.81) cos2T dT 100 dR/R = cos 2T dT / sin 2T
November 5, 2014

physics
m g h = (1/2) m v^2 so h = (1/2) (v^2/g) mass has nothing to do with it
November 4, 2014

RIGHT TRIANGLE TRIG
You are welcome.
November 4, 2014

RIGHT TRIANGLE TRIG
sin 65 = h/150 assuming that the string hypotenuse is straight
November 4, 2014

Physics- linear acceleration
Find out how far the wagon went in 19 seconds d = (1/2) a t^2 = (1/2)(.3)(19)^2 each revolution or 2 pi radians the wheel rolls 2 pi r meters so divide d by (2*pi*.374) to find how many turns then multiply that by 2 pi to get radians (1/2)(.3)(19)^2 /.374
November 4, 2014

Math, Please Help! I don't understand!
I guess x is right and y is up final x = initial x + change in x final y = initial y + change in y beginning x = -2 moves one right -2 + 1 = -1 beginning y = -5 moves 3 up -5 + 3 = -2 b) (-1 , -2)
November 4, 2014

Algebra
f(f(x)] = p(px+q) + q f[f(f(x)) = p[p(px+q) + q] + q = p^2(px+q) + pq + q p^3 x + p^2 q + pq + q = 8 x + 21 = (p^3-8)x + p^2 q + pq + q = 21 this can not be a function of x or it would not be constant 21 so p^3-8 = 0 p = 2 4 q + 2q + q = 21 q = 3
November 4, 2014

Algebra
1. slope = 3 y = 3 x + b so to find b 2 = 0 + b b = 2 y = 3 x + 2 2. same way but slope = -1
November 4, 2014

Physics
find change in momentum .145(27+32) force = change in momentum/time = change in momentum /(1.5*10^-3 )
November 4, 2014

Physics
131 * 9.9 .00932 * 618
November 4, 2014

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