Tuesday
July 7, 2015

Posts by Damon


Total # Posts: 21,431

art
Make an educated guess. I am sure you will be correct. http://www.pbs.org/faithandreason/gengloss/enlight-body.html
December 12, 2014

algebra
complete the square to find the vertex if you do not know calculus 16 t^2 -32 t -48 = -h t^2 - 2 t - 3 = -h/16 t^2 - 2 t = -h/16 + 3 t^2 - 2 t + 1 = -h/16 + 4 = -1/16(h-64) (t-1)^2 = -(1/16) (h-64) max height is vertex at t = 1 second and h = 64 ft c) t^2 - 2 t - 3 = 0 (t-3)(t...
December 12, 2014

physics 1
Yes, but be sure to use distances in meters not cm (1.61 meters apart)
December 12, 2014

Physics
Use conservation of momentum to get initial speed of bullet/block system (m+M)V = m v so V =mv/(m+M) calculate (1/2) (m+M) V^2 then (m+M) g h = (1/2) (m+M)V^2 calculate V then go back to v = (m+M)V/m
December 12, 2014

Math
You are looking for the sum of the series? r (not d usually, that is for arithmetic) = 3 not 1/3 a = 1/27 1/27 * 3 = 1/9 1/9 * 3 = 1/3 etc then for sum of first n terms a(1-r^n)/( 1-r ) If so, yes that is for the first n terms but watch out. If you want the sum for an infinite...
December 12, 2014

Math
sister has 2 n yes boy has arithmetic sequence a1 = 2 d = 2 an = a1 + (n-1) d = 2 + (n-1)2 or an = 2n sum from n = 1 to n = n S = (n/2)(a1+an) = (n/2 )(2 + 2n) S = n + n^2 you got twice as many somehow
December 12, 2014

correction
The formulas are for the END of the year so do it for 14 years, then add that 15th deposit of 3150 (tricky wording)
December 12, 2014

Math Check!!
You get e^rt for EACH deposit for its time t 3150 [ e^14(.04) + e^13(.04) + ....e^.04] I am sorry I do not know an easy way to do that
December 12, 2014

Math Check!!
sorry, no. Your formulas are for ONE deposit at the start, not for annual deposits. Look up "amount of a sinking fund" S = 3150[ 1.04^n - 1 ] /.04
December 12, 2014

calculous (check)
By the way, on earth I think it travels 16, not 13 feet with no air resistance in the first second and d = 32, not 26 but perhaps your book is on another planet.
December 12, 2014

calculous (check)
in general an = a 1 + (n-1) d so I think f(n) = 13 + (n-1)26 that is how far it falls DURING second number n now I bet F(n) is the total distance fallen which should approximate d = 16 t^2 if we are talking feet and seconds and g = 32 ft/s^2 that is the sum of our sequence ...
December 12, 2014

Math
3937.44
December 12, 2014

physics
Glad that is settled :)
December 12, 2014

magic
How on earth would I know what this problem is asking for? Is the floor tilted? Is someone pushing? Is there a spring involved somewhere with constant k Newtons/meter ?
December 12, 2014

Algebra
by the way I would call 1994 x = 0 1996 x = 2, 1998 x = 4 , 2000 x = 6, 2001 x = 7, 2004 x = 10 then add 1994 to t at the end.
December 12, 2014

Algebra
http://www.xuru.org/rt/pr.asp you need fifth degree a x^5 + b x^4 etc to go through all the six points but can use fourth all right and get a least square fit.
December 12, 2014

physics
y component = -185 x component = -60 speed = sqrt(185^2 + 60^2) tan angle south of west = 185/60 angle south of west = 72 72+180 = 252 in math convention counterclockwise from +x axis 270-72 = 198 in navigation convention clockwise from north (about SSW)
December 12, 2014

algebra parenthess needed
(5/3) x or 5x/3 ??????? or maybe you mean 5 /(3x+3)
December 12, 2014

science
water to ice
December 12, 2014

science
air is about 80% Nitrogen and 20% Oxygen both of which are matter. guess again 3) volume is correct 4) is correct although actually chemical bonds are electrical in the end.
December 12, 2014

algebra
3 v + (1/2) y = 40 half is half, not twice
December 12, 2014

Science
seems to be pretty ductile.
December 12, 2014

math
18 = 3*3*2 15 = 3*5 LCM = 3*3*2*5 = 90 minutes so 1:30
December 12, 2014

Math
juice + bottle = 2.00 or j + b = 2.00 j - b = 1.50 ===============subtract 0 + 2 b = .50 b = .25
December 12, 2014

Chemistry
55+ 273 = 328 K He = 4 g/mol so we have 10 moles P1V1/(n1 T1) = P2V2/(n2 T2) 22.4/273 = 1.05 V2/(10*328) V2 = 269 dm^3 side of cube = 6.48 dm = 64.8 cm or 0.648 m
December 12, 2014

Chemistry
at STP 1 mol is 22.4 liters n = P V/R T 1 = 1*22.4 /R(273) R = 22.4/273 Now our problem 1 = 1 * 18.2 *273/ (22.4)K K = 222 222-273 = - 51 deg C
December 12, 2014

Algebra
or y = (11/4) x - 8
December 12, 2014

Algebra
yes
December 12, 2014

Algebra
y = (9/7) x + 1
December 12, 2014

Algebra
9 x - 7 y = -7
December 12, 2014

Algebra
Only if you really mean y = (9/7) x + 1 or in other words y = 9x/7 + 1
December 12, 2014

math
yes
December 12, 2014

algebra
or y = (1/3) x -2
December 12, 2014

math
well, lets do it all in inches first 42 in + 2.5 ft (12 in/ft) + 1.5 yds(36 in/yd) = 42 + 30 + 54 = 126 inches 126 in (1 ft/12 in) = 10.5 feet 10.5 ft (1 yd/3 ft) = 3.5 yards
December 12, 2014

Physics/Calc
If in feet it is math not physics so here g = 32 ft/s^2 v = Vi + a t a = -32 so 140 = 20 - 32 t t = 3.75 seconds h = Hi + Vi t - 16 t^2 0 = Hi + 20 (3.75) - 16 (3.75)^2 solve for Hi
December 12, 2014

algebra
4*5 or 2*10 or 1*20 so 9 or 12 or 21
December 12, 2014

math
100 (.64/7.2)
December 12, 2014

Physics/Calc
been there, done that
December 12, 2014

mystery question
Without parentheses to tell me what is exponent and what is times what I do not have the slightest idea.
December 11, 2014

rates and unit rates
You are welcome.
December 11, 2014

rates and unit rates
a) four times three minutes b) 6 times a divided by 60 with any remainder being minutes for example 72 minutes /60 minutes/hr = 1 12/60 hours or 1 hour and 12 minutes
December 11, 2014

Algebra 2
e^(2n-2) = 1.47 2n-2 = ln 1.47 = .3857 2n = 2.3857 n = 1.19
December 11, 2014

Algebra 2
3.4 e^(2-2n) = 5 or what?
December 11, 2014

Algebra
How much do they have? 2 + 1 3/4 = 3 3/4 = 15/4 each gets (15/4)/3 = 5/4 James put in 2/(15/4) of the total =8/15 Karen put in (7/4)/(15/4) = 7/15 of total James (8/15) * $ 2 = $ 1.07 Karen (7/15) * $ 2 = $ 0.93
December 11, 2014

science
huh ? (1/2) m v^2 = (1/2)(0.150)(2500) Joules
December 11, 2014

sheba universty collage
x = 0 1 read n if n = -1, go to 2 if n > x then x = n go up to 1 2 print x end
December 11, 2014

Mathematics - Mystery
please elaborate
December 11, 2014

Physics
(1/2)(60) v^2 = 12,000 Joules v = 20 meters/second 20 *3.6 = 8.2 km/h
December 11, 2014

math
You are welcome.
December 11, 2014

math
7 pi (4^2) = h pi (3^2) 7 *16 = 9 h h = 7 (16/9)
December 11, 2014

math
That does not make any sense to me.
December 11, 2014

math
5/6 - 4/6 = 1/6 1/6 + what = 2 (1/4) twice because average of two things is sum over two 1/6 + what = 2/4 = 3/6 what = 2/6 = 1/3
December 11, 2014

calculus
v = dx/dt = 6 t^2 - 18 t + 12 a = dv/dt = d^2x/dt^2 = 12 t - 18 a is 0 when t = 18/12 = 3/2 = 1.5 seconds then v = 6(2.25) - 18(1.5) + 12
December 11, 2014

Physic
There is no new force on the center of mass of the system so it keeps accelerating downward at 9.8 m/s^2 so do the second part first. h = 2000 - 60(10) - 4.9(100) First part, let m1 = 1 kg and m2 = 1 kg before p = (m1+m2)60 = 120 kg m/s after p = m1 V1 + m2 V2 = V1 + 80 p ...
December 11, 2014

science: question
in general autoclaving is indeed heating
December 11, 2014

Calculus
0 </= t </= 9 dx/dt = v = 1 sin (pi t/4) Now I suspect a typo and you mean for 0 </= t </= 9 when is v positive ? from t = 0 to pi t/4 = pi or t = 0 to t = 4 v is + from t = 4 to t = 8 v is negative from t = 8 to t = 9 we are starting the next cycle and t is ...
December 11, 2014

6TH GRADE MATH
I can not very well draw a number line with my keyboard but start at ten move right 2 because -5x has to be bigger than ten by 2 we are at -5 x = 12 if - 5x = 12 then 5x = -12 so go left to -12 now x is one fifth of that -12 or -12/5 which is a bit to the left of -2
December 11, 2014

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

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