Wednesday

September 2, 2015
Total # Posts: 21,874

**math**

296/8
*December 10, 2014*

**Algebra**

256 = (1/2)(32) t^2 because 32 ft/s^2 is g in obsolete units which no one but math teachers remember.
*December 10, 2014*

**Physics >.<**

momentum before = 5000*15 + 500*0 momentum after = 5000*9 + 500*V they are the same (Newton #1) so 5000*15 = 5000*9 + 500 V
*December 10, 2014*

**Physical Science**

sure, thermal is good
*December 10, 2014*

**Physical Science**

You put lots of windows on the South side to heat up a massive wall or water tank inside the windows. That is called passive heating system. Solar energy is electromagnetic radiation. It must be converted to heat energy for example by being absorbed by a black sheet of paper ...
*December 10, 2014*

**Physics**

which one floats?
*December 10, 2014*

**Pysical Science**

Well, yes, radiation flows through empty space, the others do not which is why a vacuum bottle works but not perfectly :)
*December 10, 2014*

**typos**

which is it? why 2 equal signs? if you mean y = -2 x^2 - 6 x + 10 then complete the square -2 x^2 -6 x = y - 10 x^2 + 3x = -y/2 + 5 x^2 + 3 x + 9/4 = -y/2 +5 + 9/4 (x+3/2)^2 = -(1/2) (y -29/2) vertex at x = -3/2 and y = 29/2
*December 10, 2014*

**ratios**

1.2 (band posters) = (movie posters) 1.2 b = 24 b = 24/1.2 = 240/12 = 20
*December 10, 2014*

**physics**

a negative acceleration in classical mechanics. It can mean other things in other areas of physics.
*December 10, 2014*

**physics**

a = F/m a = 405/175 vf = a t where vf is final speed at .245 meters and t is acceleration time average speed = vf/2 .245 = average speed * t .245 = ( vf/2) t so vf t =.49 but vf = a t so a t^2 = .49 (same as d = (1/2) a t^2 ) solve for t then Vf = a t
*December 10, 2014*

**Calculus**

You are welcome.
*December 10, 2014*

**AP calc bc**

h^2 + x^2 = 625 at t = 0 x=20so h = 15 2 h dh + 2 x dx = 0 dh = -(x/h) dx dh/dt = -(20/15 ) dx/dt = -(20/15).18
*December 10, 2014*

**College Algebra**

so just do it for t = 1 , 2.5 and 3
*December 10, 2014*

**College Algebra**

t = 1, t = 3 and t = 4 plug and chug eg for t = 1 (which is 8am) 500 * 2^(1/2) 500 * 1.414 = 707
*December 10, 2014*

**Physics HELP!**

50 g = .050 kg = m sinusoidal motion kinematics: x = A sin wt v = Aw cos wt a = -Aw^2 sin wt = -w^2x givens: A w^2 = 15 A w = 3.5 so 3.5 w = 15 w = 15/3.5 radians /second first answer Newton #2 F = -kx = m a so -k x = -m w^2 x or w^2 = k/m w = sqrt (k/m) 15/3.5 = sqrt (k/.050...
*December 9, 2014*

**physics**

http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/dopp.html
*December 9, 2014*

**Can you check my Math answer please?**

when f' changes sign, that is max or min (first derivative test) moving right on x axis f' changes sign, goes - at left maximum to get back up to right maximum, f' must change sign again from - to + that is a minimum
*December 9, 2014*

**physics**

r = 2.19 sin 14.8 = .559 meters radius centripetal a = Ac = omega^2 r =v^2/r Look at tension in wire now tan 14.8 = mg/mAc = 9.8/Ac so Ac = 9.8/tan 14.8 = 37.1 m/s^2 so v^2/r = 37.1 v^2 = 37.1* .559 = 20.7 v = 4.55 m/s or for angular rate omega omega^2 r = 37.1 omega^2 = 66.4 ...
*December 9, 2014*

**MATH HELP! Complex Interest**

I think you mean compound not complex 850 (1.048)^10 - 850 and 850(.048)(10) 850 (.598) and 850(.480)
*December 9, 2014*

**Math**

You are welcome.
*December 9, 2014*

**Math**

(1/20) n = 3/4 = 15/20 n = 15 check: 15 pieces * 1/20 long = 15/20 = 3/4 sure enough
*December 9, 2014*

**maths**

2pi Rminute - 2 pi Rhour/12
*December 9, 2014*

**math**

plug and chug s to start 1/2 s after store 1/4 s after bakery 1/8 s after music so s/8 = 6 s = 6*8 = 48
*December 9, 2014*

**science**

a mol of H2O has mass of 2+16 = 18 grams so we have 9.2/18 = .511 mols of H2O that is .511 mols of H2 .511 * 6.02*10^23 = 3.08*10^23 molecules of H2
*December 9, 2014*

**Algebra 2**

In general you might find this handy: http://davidmlane.com/hyperstat/z_table.html
*December 9, 2014*

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

You are welcome.
*December 9, 2014*

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

Look at A if x = -2, y = -1/9 + 2 never bigger than 2 if x = +2, y = -9 + 2 goes big - Look at B if x = -2, y = -1/9 - 2 if x = +2, y = -9 -2 goes big - Look at C if x = -2, y = -1/.125+2 if x = 0, y = 2 if x = +2, -.125+2 approaches 2 Look at D also stays close to 2 A is the ...
*December 9, 2014*

**Pre-Algebra help PLZ!!**

You are welcome.
*December 9, 2014*

**Pre-Algebra help PLZ!!**

3 (7500 r) = 900 7500 r = 300 r = .04 or 4%
*December 9, 2014*

**math**

8*7 = 56 7*3 = 21 so 58/7 - 22/3 (58*3)/21 - (22*7)/21 20/21
*December 9, 2014*

**algebra 1**

1.75*27 = 47.25 (1.-.4)(47.25) = .6*47.25 = 28.35
*December 9, 2014*

**physics**

location of c is (200,-200) location of d x = 200 - 100 cos 45 y = -200 + 100 sin 45 keep heading NW obviously distance = a to d: = 200 sqrt 2 - 100
*December 9, 2014*

**Euler's method help in Calculus?????**

graph all that and you will see that Euler slopes slant way below the real exponential curve. You need a higher order method to do this.
*December 9, 2014*

**Euler's method help in Calculus?????**

now let's see how we did dy/dx = x y dy/y = x dx ln y = x^2/2 y = C e^(x^2/2) when x = 0, y = 3 so y = 3 e^(x^2/2) when x = 2 y = 3 e^2 = 22.1
*December 9, 2014*

**Euler's method help in Calculus?????**

That Anonymous is me, Damon. By the way there are lots of Euler methods. I took the first order one by default because you did not specify.
*December 9, 2014*

**Math**

(x+1.5)(x+1.5) = x^2 + 1.5 x + 1.5 x + (1.5*1.5) = x^2 + 3 x + 2.25 get it?
*December 4, 2014*

**Algebra 1**

(Y1-Y2)/(X1-X2) = (y+3)/(x-6) (-3 +9)/(6+4) = (y+3)/(x-6) 6/10 = 3/5 = (y+3)/(x-6) 5(y+3) = 3(x-6) your turn
*December 4, 2014*

**Algebra 1**

(-4+4) = 0 = -5(3-3) Yes, agree
*December 4, 2014*

**Algebra 1**

well just try them 1. -5 + 4 = -5(-7) no way 2. -4+4 = -5 (-8) hardly now you try
*December 4, 2014*

**Algebra 1 HUH ?**

An infinite number of them. I think you forgot to post a finite list.
*December 4, 2014*

**Survey of Mathematics**

50 (3) = 30 + 0.40 m
*December 4, 2014*

**Algebra**

555 = .09 x + .08 (3x) + .06 (7000 - 4x)
*December 4, 2014*

** Needs American history help - Revolution era**

Not my thing, sorry.
*December 4, 2014*

**social studies**

I only replied to 1. because you suggested that there was no Boston Tea Party. I just happened to be one of the shipwrights who rebuilt the fishing dragger Vincie N into the Boston Tea Party replica brig BEAVER for display at the Tea Party site in Fort Point Channel in Boston...
*December 4, 2014*

**social studies**

1. I live near Boston and think not c
*December 4, 2014*

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

assuming the log is base ten 10^y = 10^log x = x otherwise for any base b b^y = b^logb(x) = x
*December 4, 2014*

**physics**

the downstream problem is perpendicular to and therefore independent of (except in time) the across problem 400 = 10 t t = 40 seconds then d = 2 t = 80 m
*December 4, 2014*

**Math Help**

yes
*December 3, 2014*

**Math**

3.5 meters is 350 centimeters 17 centimeters is way smaller.
*December 3, 2014*

**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*