Posts by Damon

Total # Posts: 30,560

Math typo
area is proportional to length dimension squared for similar objects D^2/d^2 = A/a Howevr what you typed makes no sense. 1. diameter of basketball is not in square inches If the diameter is 9.5 inches, the area is not 1810 area = 4 pi r^2 =4*3.14*4.75^2 =283 in^2 by the way ...

Chinese
This might help: https://www.mdbg.net/chinese/dictionary?page=worddict&wdqb=zhe&wdrst=0

Algebra
2(1+pi^3) ? about 64

Algebra 2
when is it zero (cross x axis?) z (z^2 +7 z +10) = 0 z (z+2)(z+5) =0 so at z = 0 , z = -2 , z=-5 if z<-5 try z = -6 -6(-4)(-1) is -24 so NO then between -5 and -2 try -3 -3(-1)(2) = +6 so YES between -1 and 0 try -.5 -.5(1.5)(4.5) = - so NO bigger than 0, try +1 1(3)(6) = ...

Math
Hmmm Writeteacher practicing presidential tweets :)

Physics
m g = 5*10 = 50 Newtons (on earth)

Physics
moved down 1.8 not 5.3 meters

History
mean, they were wicked mean.

Math
F = k x 15 = k *10 k = 1.5 check: 24 = 1.5 x x = 16 sureenough so 1.5 oz/inch = 1/1.5 inches/oz = 2/3 = 0.6666.... in/oz

Math
o + y = 21 o = 7 + 6 y so 7 + 7y = 21 y = 2

Math
.075*original = 0.39 so original = 5.2 (must be an old text book) new = 5.2*1.075 = 5.2+.39 I hope :)

Algebra 1
24 = 1.20 x

Physics
100 cm = 1 meter g = -9.81 m/s^2 (1/2) m v^2 = m g h v = sqrt (2 g h) v = sqrt (2*9.81*1)

Physics
t1 = 5/11.3 = .4425 hour t2 = 5/14.9 = .3356 hour waiting time = difference= .1069 hr = 6.415 minutes = 6 minutes and 25 seeconds

science
agree (but Googled :) https://www.google.com/search?q=size+of+milky+way+galaxy+in+light+years&ie=utf-8&oe=utf-8

Physics
phase 1 a = 58.8 and t = 5 Hi = (1/2) a t^2 = 29.4*25 = 735 meters Vi = a t = 58.8 * 5 = 294 m/s Phase 2 a = -9.81 m/s^2 v = Vi - a t v = 294 - 9.81 t v = 0 at top t = 30 seconds more h = 735 + 294(30) -4.9 (30^2) = 735 + 8811 - 4410 = 5136 meters

math
sum of distances from point on ellipse to foci = 2a where a is long semisaxis = 3 so 2 a = 6 = string length b = 2 (short semiaxis) center to focus =sqrt(3^2-2^2) = sqrt(5) = 2.236067977 feet which is tough with a ruler :)

math
4 a y = x^2 4 a (8) = (36/2)^2 32 a = 18^2 a = 10.125 in vertex to focus = a = 10.125 inches

whoops
Sorry about that, it said net !

Chemistry
well KBr is likely to be aqueous and ionized, if it is not then you have KBr solid and not the ions on the right. H+ + Br- + K+ + OH- --> K+ + Br- + H2O

Physics
Ah, so there is a question :) a = 3.6/.11 m/s^2 d = (1/2) a t^2 or to make it really easy average speed = 3.6/2 = 1.8 m/s distance = 1.8 m/s * .11 s

Physics
a = (3.6 -0)/.11

math
slope = 1/5 y intercept = 1 y = (1/5) x + 1 or 5y = x + 5

physics
F = - .69 m g = m a so a = -.69 g v=Vi + a t v = 18.0 - .69 g t v = 18 - .69(9.81)(1.29)

Chemistry
You are welcome :)

Chemistry
same number of mols of NaCL so half as many per liter 0.250 M

Physics
(a) no acceleration so +280 N (b)max friction force = 62*9.8*0.70 so -425 N

Algebra2
yikes c. if D = r t then t = D/r (you KNOW that :) 30 yards/6.47 yards/sec = 4.64 sec You KNOW it would not take him 194 seconds !!!! d. Julio runs at 9.11/2 = 4.555 yards/second 40 yards/ 4.555 yards/sec =8.78 seconds Which you already know is TWICE as long because half the ...

math
1 - ( [1-cos^2]/[1+cos] ) = ? cos 1 - (1-cos)(1+cos)/(1+cos) = ? cos 1 - (1-cos) = ? cos yes cos = cos :)

Physics
g = 9.81 = v^2/R at bottom m(9.81 + 4v^2/R) using v from part A

science - Yes correct
Yes, correct

PreCalculus
The right hand side says sin x You must make the left hand side come out sin x That is what I did Yes, I also used sin^2 + cos^2 = 1 in saying 1 - cos^2 = sin^2

Math help
first divide I get x^2 + 7 x +(7+k) with R = 3+k second divide I get x^2 + 4 x + (k-8) with R = -2k+12 so k+3 = -2k+12 3 k = 9 k = 3

Calculus 1
at some time between 2:00 and 2:10 if it is continuous and differentiable the acceleration must hit the average acceleration. (25 -20) mph/(10/60 hour) or in more usual units (36.67 - 29.33) ft/sec/600 seconds

science
x = 2 t + (1/2)(2) t^2 and x = (1/2)(6) t^2 so 3 t^2 = 2 t + t^2 2 t^2 -2 t = 0 t (2 t - 2) = 0 t = 1 x = 3

math
yes one could say though if you are into arithmetic and geometric sequences 80 + 70/100 + 70/10,000 .... 80 + .70 + .70/100 +.70/100^2 + .70/100^3 .. = 80 + .70(1/.99) geometric sequence sum

Algerba 2
yes, when t = 0, h = -20+20 = 0 if you are graphing (t,h) yes when t = 0, h = 0 (0,0) h = 0 when t is 0 and 4 (0,0) and (4,0)

science
I can not make a drawing here. You have to draw the parallelograms with adjacent sides at the given angles to each other and the answers are the diagonals.

maths
s = b + 6 s+3 = 2 (b+3) = 2 b + 6 b+6 +3 = 2 b + 6 3 = b s = 9

Math
x = 10^(3y) log x = 3 y log 10 = 3 y y = (1/3) log x x = log2(4y) 2^x = 4 y y = (1/4)2^x

math
.95^n = .5 n log .95 = log .5

physics
.00625 *365 = 4.50625 v v= .506 m/s yes average speed during stop = .506/2 = .253 m/s time to stop = .15 / .253 = .593 second acceleration = change in speed/time = -.506 /.593 = -.854 m/s^2 F = m a = 4.50625 *-.854 = -3.85 Newtons Ke initial = .5 * .00625 * 365^2 = 416 J Ke ...

physics
to find the total you add, not subtract. first car = 15480 yes second car = -20160 so disagree p = 15480-20160 = - 4680 total mass = 1700 kg 1700 v = -4680 v = - 2.75 m/s (1/2)860(18^2)+(1/2)840(24^2)-(1/2)(1700)(2.75)^2

physics
first half of flight: u = 27.5 cos 41 = 20.75 m/s forever Vi = 27.5 sin 41 = 18 m/s initial speed up v = 18 - 9.81 t at top v = 0 9.81 t = 18 t = 1.84 seconds upward 2 t = 3.68 seconds in air 3.68 seconds* 20.75 m/s = 76.3 meters range h = 18 (1.84) -4.9(1.84)^2

physics
(1/2) m v^2 = m g h v = sqrt (2 g h) (not T) v = 17.1 (not 1.7 ) average speed during fall = 17.1/2 = 8.57 m/s time to fall = 15/8.57 = 1.75 seconds Kim - it is dropped, not going up

I do not know biology.
....and therefore can not help you and my answers might just confuse you. However the same rationale applies to physics and chemistry and please do not mislead students.

Math
d = 7 j d+5 = 4(j+5) 7j+5 = 4 j + 20 3 j = 15 etc

Locus
6 y = -8 x + 1 is original line slope = -8/6 = - 4/3 we want a parallel line, so same slope y = -4x/3 + b so what is b ? line perpendicular to these has slope = 3/4 find a point on original line for example (0,1/6) now perpendicular line through that point is 1/6 = (3/4)(0) + ...

help meee
200 = pi r^2 h cost= c = 2 pi r h (.03) + (2)pi r^2(.05) c = 2 pi (.03 rh +.05r^2) but h = 200/pi r^2 so c = 2 pi (.03 r)(200/pir^2) + 2 pi(.05 r^2) c = 2 pi (6/pir + .05 r^2) c = 12/r + .1 pi r^2 dc/dr = 0 at min 0 = -12/r^2 + .2 pi r 12 = .2 pi r^3 r = 2.67 cm check my ...

Physics
190 N/78 kg ----->the 2.4 m/s^2 is correct. It is up if you feel heavier.

physics
13 is the distance, however displacement is a vector. x = 5 (east is right) y = -13 (south is down A = angle south of east tan A = 13/5 A = 69 degrees angle counterclockwise from x (east) = 360 - 69 = 291 magnitude = 13

Algebra
if top is .5625 and printed height = 7.75 then bottom + .5625 + 7.75 = 9 bottom = 9 - 7.75 - .5625

algebra
dx = -1 - 6 = -7 dy = 14 - 16 = -2 d = sqrt [(-7)^2 + (-2)^2 ] = sqrt(49 + 4) = sqrt(53) = 7.28 = 7.3 to nearest tenth

Geometry
https://www.jiskha.com/display.cgi?id=1507597009#1507597009.1507597209

Geometry
just did

History
yes

math
x = distance man from pole y = distance tip of shadow from pole (y-x)/6.2 = y/11 11(y-x) = 6.2 y 4.8 y = 11 x y = 2.29 x dy/dt = 2.29 dx/dt = 2.29 * 4.5 = 10.3ft/s

History
I think not c maybe google huguenot

U,S, History (please help)
I was calling you because of the stuff I am glad you deleted :)

Ms Sue
ah, hummm and yes it is Madison. Do you know why?

one number error
time = 5.55 * 2 pi /44.4 rad/s = .785 seconds to accelerate acceleration = alpha = change in omega/ change in time = 88.8/.785 = 113 rad/s^2 and of course 77.7 = I (113)

Physicss
torque = I alpha where alpha = d omega/dt = angular acceleration now velocity proportional to time so average angular velocity = 88.8/2 = 44.4 rad/s does 5.55 *2pi radians so time = 5.55 * 2 pi /44.4 rad/s = .0765 seconds to accelerate acceleration = alpha = change in omega/ ...

Algebra
You said to use substitution but there is no practical reason not to use elimination and I did so automatically for the second half of the problem, sorry.

Algebra
well, we both used elimination at one point or another, going back a bit we had -8x + z = -25 and we know +2x +2z = 4 so use z = 8x -25 to substitute in the last one 2x +2(8x-25) = 4 18 x -50 = 4 18 x = 54 x = 3 again, whew !

Algebra
get rid of y so you can use the third eqn y = 8-x-z so -4x + 4(8-x-z) + 5z = 7 -8 x + z + 32 = 7 -8x + z = -25 and we know +2x +2z = 4 -16x +2z =-50 + 2x +2z = 4 --------------- -18 x = -54 x = 3 now go back

Math
Well, I suppose 10 * 12 = 120

Physics
You are welcome.

Physics
first the shooter: horizontal velocity = us = 7.8 m/s forever vertical velocity = vs = - g t =-9.81 t at .42 s this is - 9.81*.42 = -4.12 m/s now the water horizontal velocity = u= 7.8 + 11*.707 = 15.6 m/s forever vertical velocity =vw = -4.12 + 11*.707 = 3.66 AT .42 s use u...

Physics your turn
Hey I just did the two satellites. You do this the same way.

Physics
initial momentum = 5.5*10^3*0 +7.5*10^3*.2 =1.5*10^3 final is the same (5.5+7.5)*10^3 v = 1.5*10^3 v = .115 m/s initial ke = (1/2)(7.5*10^3) .2^2 = .15*10^3 = 150 Joules final ke = (1/2)(13*10^3) .115^2 = .0865*10^3 = 86.5 Joules now do it the other way around with first sat ...

Physics! Please help!!
320+725 = 1045 g = 1.045 kg friction force = 1.045*9.81 * .4 F - friction force = 1.045 * 2.25 m/s^2

Physics
weight of brick = m g = 23 * 9.81=226 N friction resistance maximum = 226*.17= 38.4 N on brick: T - 38.4 = 23 a so a= (T-38.4)/23 on weight 19*9.81 - T = 19 a so a = (186-T)/19 23(186-T) = 19(T-38.4) solve for T, the tension in the thread.

Physics
I guess potential energy is zero when entire rope lies on table :) ************************************** Since no Joules are lost in this problem, the total mechanical energy remains ZERO ************************************* That is the end but if you really want to make a ...

You try first
What are you stuck on? I would rewrite the first one as 1 z^2 + b z + c = 0 z = [-b +/- sqrt(b^2-4c)]/2 [z+{b -sqrt(b^2-4c)}][z+{b +sqrt(b^2-4c)}]=0 so -b/2=2 so b = -4 .5 sqrt(16-4c) = 3i sqrt (16-4c) = 6i 16-4c = -36 4c = 52 c = 13 z^2 -4z + 13

Finite Math
99 marbles first green = 55/99 second green = 54/98 so (55/99)(54/98) etc for b first green, second red plus first red, second green

Math
A 9000 panels , 900 defective B x panels, .03 x defective panels = 9000 + x defective panels = 900 + .03 x .06 = (900+.03x)/(9000+x)

Algebra 2
same deal, (x-5)^2 or (x+5)^2 a = 10 or -10 (9)(x^2+16/9 x + c/9) 9(x+8/9)(x+8/9) (3x+8/3)(3x+8/3) 64/9

Algebra 2
(x+/-b)(x+/-b) 2 b = 16 b = 8 (x+8)(x+8)=x^2+16 x + 64

MaTh
i-1-i+1+i-1 ......

physics
average speed = 10/2 = 5 distance = 50 so stop time = 50/5 = 10 seconds a = change in speed/change in time =-10/10 = -1 m/s^2 so F = m a mu m g = m a mu = 1/9.81

physics
S 5.5 - 2.8 = 2.7 km W 2.9 km magnitude = sqrt(2.7^2+2.9^2) angle A s of w tan A = 2.7/2.9 angle desired = 180 + A

math
-5*3.15 tricky is percent per day (compound)

Physics!
weight component down = m g cos 34 friction force up = m g cos 34 * mu so mu m g cos 34 + 240 = m g sin 34

physics!
I will assume ox 1 is uphill so it drags back on box 2 and they accelerate together Forces down slope (7.6 +1.6) g sin 31 = 4.74 g Forces up slope (7.6*.2 +1.6*.1) g cos 31 = 1.44 g total mass = 7.6+1.6 = 9.2 kg so (4.74-1.44)g = 9.2 a a = .359 g if g = 9.81 m/s^2 a = 3.52 m/s^2

Physics!
total mass = 14 kg total force down = 7 g - .15 *7 g cos 28 a = total force/14

stats
000 to 999 0 through 9 0 through 9 0 through 9 10^3 = 1000 so 1/1000 I do not know what #3 means either

MATH
Enough already, look up properties. Need to know them.

MATH
Hey, distributive property again! or just common sense 12 + 32 = 44 OR 4*11 = 44

Mathematics
SKETCH IT ! last corner at x = -1, y = -6 top goes from -1 to +6 (how long?) side goes from -6 to +2 (how long?)

MATH
http://www.google.com/search?q=distributive+property+of+multiplication&ie=utf-8&oe=utf-8

Mathematics
distributive property 5*x + 5*3 both numbers even so for starters 2 (3x-5y) 3 and 5 are prime numbers, can not be factored. The end.

math
s+r = 51 so r = 51-s s-6 = 2(r-6) substitute s-6 = 2 (51 - s - 6) = 2(45-s) =90-2s 3 s = 96

Science
liquid ---> gas molecules ---> split up and reform into new molecules

Science yikes!
1. Only the NEUTRON has no charge 2. electrons in nucleus? I think not 3. disagree, not moving, no Ke = (1/2) m v^2 4. What does the word "conservation" mean to you. You better go back and read the chapter. !!!!!

Physics
(1/2) m v^2 = m g h if h = v (1/2)h^2 = g h h = 2g

Physics
v = Vi - g t h = Vi t - .5 g t^2 at height h, v = Vi/2 Vi/2 = Vi - g t g t = Vi/2 t = Vi/(2 g) at height h h = Vi^2/(2g) - .5g (Vi^2/4g^2) h = (1/2)Vi^2/g - (1/8)Vi^2/g h = (3/8) Vi^2/g at max height H, v = 0 0 = Vi - g T where T is time at max h T = Vi/g H = Vi T -.5 g T^2 H...

physics
As far as I know lignum vitae is still used for many stern tube bearings, although probably no longer by the Navy.

sinks, denser than fresh (or most salt)water
None, sinks That density is greater than fresh water, typo? mass = 1.05 *200 = 210 gm so Archimedes says mass of water displaced = 210 gm but water(fresh, out of my geography) is 1.00 gm/cm^2 so 210 g = 1.00 * V of water V of water = 210 cm^3 of water displaced, we need a hunk...

Physics Thrust
I did it for on earth. Bobpursley did it for in space with no gravity.

remember mg :)
g

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