Friday

October 9, 2015
Total # Posts: 22,103

**Math please help**

need standard deviation sigma
*December 3, 2014*

**science**

We do not have your figure so can not help much.
*December 3, 2014*

**Pre-Calc/Trig...**

You are welcome.
*December 3, 2014*

**Pre-Calc/Trig...**

It is like compound interest (1+r)^n 2,000 * (1.05)^12 12 not 11 because it is at the END of the hour at end of hour we have 1.05 times the initial amount the original + .05 * original = original (1 + .05)
*December 3, 2014*

**Physics**

937 N m = 691 foot pounds
*December 3, 2014*

**Physics**

Torque * angular velocity = power 176 hp = 131,243 Watts or N m/s 1340 rpm = 140 radians/s so Torque = (131,243 / 140) Newton meters
*December 3, 2014*

**Pre-Calc/Trig...**

a r^(n-1) 9^2 (1/9)^4 1/81
*December 3, 2014*

**solving exponential functions**

do you mean 2^(7-x) = 1/2 ???????? 2^(7-x) = 2^-1 7 - x = -1 x = 8 OR (7-x) log 2 = log .5 (7-x) = -1 again :)
*December 3, 2014*

**Statistics**

I am not sure about that hint. I think it is .9^15 = .206
*December 3, 2014*

**physics - no way**

before collision the light glider has kinetic energy of (1/2)5(36) there is no way the final kinetic energy of the system can be more than that but you say the heavy glider has speed 6 AFTER collision (1/2)8(36) That is impossible so there is no point in doing the conservation...
*December 3, 2014*

**Pre-Calc/Trig...**

a r(n-1) An = 6 (2/3)^(n-1)
*December 3, 2014*

**Calculus**

(16)^2 a + (16) b + c = 46 (18)^2 a + (18) b + c = 64 (20)^2 a + (20) b + c = 60 is 256 a + 16 b + 1 c = 46 324 a + 18 b + 1 c = 64 400 a + 20 b + 1 c = 60 you can solve that by substitution or elimination but I go to a Gauss Jordan calculator http://www.gregthatcher.com/...
*December 3, 2014*

**algebra**

let z = x^2 z^2 - 29 z + 100 = 0 ( Z-25 )( z- 4 ) = 0 z = 25 then x = +5 or -5 or z = 4 then x = +2 or -2
*December 3, 2014*

**Math**

1.055 S = 38560.25
*December 3, 2014*

**Algebra 1**

4^1 = 4 4^2 = 16 4^3 = 64 4^4 = 256 4^x or four to the x power (not 4x)
*December 3, 2014*

**English**

Facts: It is difficult to escape the influence of television. If you fit the statistical averages, by the age of 20 you will have been exposed to at least 20,000 hours of television. You can add 10,000 hours for each decade you have lived after the age of 20. The only things ...
*December 3, 2014*

**English**

d.)After the politician had broken his promises, the general public viewed his pledges skeptically. b.)If you were taller, you could try out for the basketball team. I have no idea what indicative mood is but thought it expressed fact such as I AM wealthy. I do not have the ...
*December 3, 2014*

**Please tell us what the rest of the question is**

I have no idea what the angular velocity is or if it is rolling without slipping or whatever
*December 3, 2014*

**Pre-Calc/Trig...**

You are welcome.
*December 3, 2014*

**Pre-Calc/Trig...**

log y = log b + log x
*December 3, 2014*

**2 math ?s**

sin T + cos T cot T sin T + cos T cos T/sin T (sin^2 T + cos^2 T ) /sin T 1/sin T which is csc T ============================= LOL, subtract cos^2 T from both sides 1 = cos^2 T + sin^2 T what else is new :)
*December 3, 2014*

**3 Math**

That IS the property a*b = b*a It is true all the time until you get to matrix multipication
*December 3, 2014*

**english**

http://www.yourdictionary.com/metaphor
*December 3, 2014*

**social studies**

http://digital.library.okstate.edu/encyclopedia/entries/I/IN015.html
*December 3, 2014*

**Science**

LOL, well mass is conserved OVERALL but that includes the CO2 smoke pouring out the stern of your toy motorboat. To make it work out right, you better catch all the products :) see: http://chemistry.about.com/od/chemicalreactions/f/What-Is-The-Equation-For-The-Reaction-Between...
*December 3, 2014*

**Algebra**

Just write the words as symbols n = 2 r - 10
*December 3, 2014*

**physics**

Vi = 250 sin 45 = 125 sqrt 2 initial up u = 125 sqrt 2 forever horizontal v = 125 sqrt 2 - 9.81 t v at top = 0 9.81 t = 125 sqrt 2 solve for t at top h = Vi t - 4.9 t^2 solve for h at top total time in air = 2 t d = 2 u t
*December 3, 2014*

**math**

1 n and 20 c 2 n and 15 c 3 n and 10 c 4 n and 5 c 5 n
*December 3, 2014*

**Physics**

assume metric ton of 1000 kg tension = m g = 30*10^3 *9.81 Newtons area = pi r^2 5*10^-3/10 = 30*10^3*9.81 /[pi r^2 *2*10^9]
*December 3, 2014*

**Precalculus**

(x^2-2x+1) - (y^2-4y+4) - 4 = 0 (x-1)^2 - (y-2)^2 = 4
*December 3, 2014*

**ap calc**

been there , done that: http://www.jiskha.com/display.cgi?id=1324077814
*December 2, 2014*

**Physics**

h = Hi + Vi t - 4.9 t^2 0 = 32 + Vi (6) - 4.9(36) 6 Vi = 144.4 so Vi = 24.1 m/s up u = 161/6 = 26.8 horizontal tan theta = Vi/u Vo = sqrt (u^2 + Vi^2)
*December 2, 2014*

**calc found one mistake**

integral r^3 dR dT from 0 to 4 and 0 to 2pi 2 pi (4)^4/4 = 128 pi on the bottom SAVE that on the top, x^2+y^2 = r^2 = 4 and z^2 = 16 so you have (r^2+16)r dr dT from 0 to 4 and from 0 to 2 pi so 2 pi [ (4^3)/3 + 16 (4^2)/2 ] note over 3 2 pi (64/3 + 256/2) = 298.67 pi you do ...
*December 2, 2014*

**calc**

draw a picture x^2 + y^2 = 16 is a circle of radius 4 it extends up as a round cylinder from z = 0 to z = 4 and we must also integrate over the top and bottom Now as Mathmate told you it is easier to do this in polar coordinates because it is a cylinder with its centerline up ...
*December 2, 2014*

**Physics**

Ac = omega^2 R = V^2/R
*December 2, 2014*

**Physics**

What DonHo wrote is correct, but it asks for omega, the angular speed
*December 2, 2014*

**Physics**

v^2/r =omega^2 r = g = 9.81 m/s^2 omega^2 = 9.81/50.5 (radians/sec)^2
*December 2, 2014*

**calc**

x^2 + z^2 = r^2 is a circle with radius r read what mathmate wrote for you.
*December 2, 2014*

**MATH**

how many ways to combine five things three at a time? n!/[r!(n-r)!] 5!/[3!(2!)] 5*4/2 10 ========================== 4 along each long side with no ends 5 along each short side including end posts 9*2 = 18
*December 1, 2014*

**Please help Damon**

You are welcome.
*December 1, 2014*

**Please help Damon**

looks right to me
*December 1, 2014*

**physics**

Just follow my way using the diameter and multiply by 4 at the end. A = pi d^2/4
*December 1, 2014*

**physics**

r = .019/2 = .0095 you have a decimal point off in the diameter too
*December 1, 2014*

**physics**

.5/306 = .00163, not .0163
*December 1, 2014*

**physics**

whoops I used diameter use 4*1.45 = 5.8 m/s
*December 1, 2014*

**physics**

I get 1.45 m/s
*December 1, 2014*

**physics**

area of pipe * speed of water = Q = flow volume/second area = pi (.019)^2 volume = 0.5 m^3 time = 5.1*60 = 306 so pi (.019)^2 V = .5 m^3/306 s solve for V in m/s
*December 1, 2014*

**History Help?**

He is called the father of Texas because he brought the 300 anglo colonist families in to a land grant he obtained from the Spanish before Mexico split from Spain.
*December 1, 2014*

**Calculus**

2/12pi = 1/(6pi) agree
*December 1, 2014*

**Calculus**

dV/dt = 2 cm^3/s dV/dh = surface area = pi r^2 dV/dt = dV/dh * dh/dt so dh/dt = dV/dt / pi r^2 so you need r, the radius of the surface 2 cm up from the bottom of the 4 cm radius sphere I do not remember the length of a circle sector halfway from the center to the edge, look ...
*December 1, 2014*

**Physics**

the hint is the answer v = sqrt (2*9.8*.5) from m g h = (1/2)mv^2 is 2 g h = v^2 the potential energy of a chunk of water at the surface is its kinetic energy exiting at the bottom you can do it with Bernouli if you want to get sophisticated :) p + rho g h + (1/2) rho v^2 = ...
*December 1, 2014*

**AP Calc**

well on my calculator 84 -14*4) = 28
*December 1, 2014*

**AP Calc**

4x +y = 84 so y = (84-4x) Volume = x^2 y = x^2(84-4x) V = 84 x^2 - 4 x^3 dV/dx = 0 for max or min 0 = 168 x - 12 x^2 0 = x (168-12 x) x = 0 not very useful so x = 168/12 = 14 y = length = 28 interesting, length twice the side dimension
*December 1, 2014*

**Algebra 1**

Graph those points. There is no instance where you have more than one value of y for a value of x. Therefore it is a function.
*December 1, 2014*

**math error**

99*50 = 4950
*December 1, 2014*

**math**

try 1 to 5 1 + 2 + 3 + 4 + 5 = 15 that is five numbers the middle one is 3 which is (1+5)/2 so try 1 to 99 that is 99 numbers the middle one is (1+99)/2 = 50 so try 99*50 =100*50 - 99 = 4901 ================================ try 1+3+5 = 9 which is 3 (1+5)/2 = 3*3 try 1+3+5+7 = ...
*December 1, 2014*

**MATH**

app makes x journeyman makes 3 x master makes 4.5 x 8.5 x = 5950 x = 700 etc
*December 1, 2014*

**physics**

no L the same, g different
*December 1, 2014*

**physics**

L/g important, not m
*December 1, 2014*

**physics**

k and m the same
*December 1, 2014*

**Algebra 2**

we have a circle with radius 2 sqrt5 and center at the origin and a parabola that looks like: 6 y = x^2-28 y = (x^2-28)/6 opens up (holds water) zeros at x = +/- sqrt 28 so vertex at x = 0 then y of vertex at -28/6 NOW SKETCH A GRAPH now do algebra x^2 + y^2 = 20 x^2 - 6 y = ...
*December 1, 2014*

**Algebra 2**

Very similar to the one I just did for you, another parabola intersecting a circle
*December 1, 2014*

**sci**

nm it is b :) despite its name, the radiator works by warming the air around it which rises and circulates around the room (convection)
*December 1, 2014*

**algebra 2**

13+x = +/- 5 sqrt(10) x = -13 +/- 5 sqrt(10)
*December 1, 2014*

**sci**

Heat goes from hot to cold by itself to move it from cold to hot requires work, like an air conditioner I would have chosen D
*December 1, 2014*

**Math**

m mN mN^2 mN^3 .......mN^(n-1) number on day n = m N^(n-1)
*December 1, 2014*

**physics**

force = change in momentum/change in time or m A if m is constant change in momentum/3 = 200 change in momentum = 3*200 kg m/s
*December 1, 2014*

**math**

12 x = 96 so x = 96/12 then 2 x + 2 (12) = perimeter
*December 1, 2014*

**sci**

yes microwaves are electromagnetic radiation
*December 1, 2014*

**Science**

14.) Answer = Habitat Destruction Yes 15.) Answer = Carbon Dioxide - I Think yes, Methane is worse but fossil fuels produce CO2 16.) Answer = ___________ reverse 17.) Answer = Ozone Layer yes 18.) Answer = ___________ non-point source 19.) Answer = ___________ cost - benefit ...
*December 1, 2014*

**Rounding up and down**

Here is the rationale I gave for an earlier problem, for what it is worth :) ========================= Math - Damon, Monday, December 1, 2014 at 2:08pm to the nearest tens place 55 would be called 60 54.9999999999 would be 50 but 55.00000000001 would be 60 so if it starts with...
*December 1, 2014*

**Rounding up and down**

if <5, then 0 if 5 or more, then 10 .34 2. .351 ---> .4 .562 ---> .6 .545 ---> .5 whew .445 ---> .4 3. .351 --> .35 .562 --> .56 .545 --> .55 ***** .445 --> .45
*December 1, 2014*

**math....**

distributive property of multiplication -p(p) + -p(-q) + -p(8) = -p^2 + pq - 8p
*December 1, 2014*

**Calculus**

You have to say what is the lower limit and what is the upper limit of your integral to do a definite integral I guess your function is f(x) = x for x < 1 and f(x) = 1/x for x >/= 1 (-2)^3 = -8 so when x<1 integral = -8 [x^2/2 upper-x^2/2 lower] and for x >/= 1 ...
*December 1, 2014*

**Physics**

capacitance = charge/unit voltage C = coulombs / volts
*December 1, 2014*

**physics**

Force = change in momentum/change in time 100 = change in momentum / 5 change in momentum = 500 Newton meters or Joules
*December 1, 2014*

**Math**

55 would be called 60 54.9999999999 would be 50 but 55.00000000001 would be 60 so if it starts with 55 it is 60 It does not make a whole lot of sense, but one must decide consistently :) 5 is 10 but 4.99999999 is 0
*December 1, 2014*

**MATH**

-9 - 3m -3m - m^2 = - m^2 - 6 m - 9
*December 1, 2014*

**MATH**

8 m - 8 n + 64 distributive property
*December 1, 2014*

**Trig**

Vs + Vc = 19.3 cos 33.7 i + 19.3 sin 33.7 j Vs = 17.5 cos 26.3 i + 17.5 sin 26.3 j so Vc x = 19.3 cos 33.7 - 17.5 cos 26.3 and Vc y = 19.3 sin 33.7 - 17.5 sin 26.3 |Vc|^2 = (Vc x)^2 + (Vc y)^2 tan angle N of E = Vc y/ Vc x of course in the real world navigators measure angles ...
*December 1, 2014*

**Physics- formula help**

if it is falling m g down positive F air resistance up a down positive Weight - Fair resistance = m a m a = m g - Fair resistance if the F air resistance were equal to the weight, mg , then the acceleration would be zero m (g-a)
*December 1, 2014*

**CALC 1**

you already have h', the first just take one more x e^x + e^x = e^x (x+1) e^x always + so where x + 1 is + x> -1
*November 30, 2014*

**Calculus**

My arithmetic was wrong, go with Steve !
*November 30, 2014*

**Calculus**

y = (3 -x^3)-(1/3) dy/dx = -(1/3) (3-x^3)^-2/3 (-3x^2) = + x^2 /(3-x^3)^(2/3) E
*November 30, 2014*

**AP Calculus**

since it is a cubic, there will presumably be two f' = 0 = 3 x^2 + 6 x = 3x ( x+2) x = 0 and x = -2 you find f(x) there
*November 30, 2014*

**Calculus**

top = (x+9)^.5 - 3 d top/dx = .5 (x-9)^-.5 ---> oo bottom = x d bottom/dx = 1 --->1 so ----> oo/1
*November 30, 2014*

**Calculus,Reaction rates**

at 1 second d = sqrt(10^2 + 10^2 + 5^2) = sqrt 225 d^2 = 100 + 25 t^2 + 100 t^2 d^2 = 100 + 250 t^2 2 d dd/dt = 500 t v = dd/dt = 250 t/d at t = 1 v = 250/15 = 16.7 ft/s
*November 30, 2014*

**Calculus**

x^2 f' + 2 x f = x [ x f' + 2 f ]
*November 30, 2014*

**Calculus**

dy/dx = slope = m for this ellipse 2 x dx/dx + 6 y dy/dx = 0 at(1,1) 2(1)+6(1)dy/dx = 0 dy/dx = m = -1/3 so y = -(1/3) x + b at (1,1) 1 = -1/3) + b b = 4/3 so y = -(1/3) x + 4/3 or 3 y - -x + 4
*November 30, 2014*

**physics**

V = Vi + a t 40 = 20 + 2 t t = 10 x = 20 t + (1/2) a t^2 x = 200 + 100 x = 200
*November 30, 2014*

**physics**

F = kX 25 (20/10)
*November 30, 2014*

**Science**

a = change in v/change in time a = 60/8.2 = 7.32 horizontal so horizontal force = 94*7.32 = 688 N vertical force up = weight = m g = 94*9.8 = 921 N net force = sqrt(921^2 + 688^2)
*November 29, 2014*

**two step equation-fraction**

if it is 4 + (m/3) = 5/6 then the answer is -19/2 which is -9 1/2 as Steve told you if it is (4 + m)/3 = 5/6 then the answer is -9/6 = -1 1/3 there is no perturbation I can make on what you typed to make it come out -3/2
*November 29, 2014*

**two step equation-fraction**

So maybe you typed the original question wrong maybe you meant: """"""""""""""""""" please help me step by step thanks (4+m)/3=5/6 """"""""&...
*November 29, 2014*

**two step equation-fraction**

6 m/3 = 2 m
*November 29, 2014*

**chemistry**

method is correct and I agree with the aritmetic
*November 29, 2014*

**phyics**

if board mass = m down force = m g so friction force must be m g mu F = m g F = m g/mu
*November 29, 2014*

**Math**

3 x dy/dx + 3 y -4 x +10 y dy/dx = 0 dy/dx (3 x+10y) = (4x-3y) dy/dx = (4x-3y)/(3x+10y)
*November 29, 2014*

**chemistry**

You just ignore the excess compounds. all that is important here is for every 2 mols of H2SO4 you get one mol of CaH4P2O8
*November 29, 2014*

**chemistry**

KOH = 39+16+1 = 56 grams/mol 14.3/56 = .255 mols .255/V = .55/1 V = .464 Liter
*November 29, 2014*