Wednesday
April 1, 2015

Posts by Damon


Total # Posts: 20,759

Algebra 2
if so then 5 -2.5 sqrt 3 + 2.5 i -2.5 sqrt 3 - 2.5 i
March 8, 2015

Algebra 2
x^3 = 125 x = 5 works you do not say if you also do complex numbers
March 8, 2015

physics
40 * 5 60 * 5 * 0.40 Joules
March 7, 2015

physics
force down = m g = 63*9.81 N mass accelerated = 63+10 = 73 kg a = F/m = 9.81 (63/73) m/s^2
March 6, 2015

Social Studies
Although the astrolabe has origins traced back over 1,500 years, it was highly developed in the Islamic world by 800 and was introduced to Europe from Islamic Spain (Andalusia) in the early 12th century. It was the most popular astronomical instrument until about 1650, when it...
March 6, 2015

linear programming - suspect not correct problem statement
x = paper y = cans p = 500 x + 350 y y </= 200 x </= 200 x >/= 10 y >/= 80 I do not understand last constraint, redundant if y</=200 rectangle corners at (10, 80) (10,200) (200, 80) (200,200) well, go ahead and evaluate p at each corner but obviously mas at (...
March 6, 2015

algebra
6, 12, 18, 24 is 4 4/24 = 1/6 1 - 1/6 = 5/6 permutations of 12 things 4 at a time is n!/(n-r)! = 12!/8! = 12 * 11 * 10 * 9 = 11,880 if it is a number I would call it quatitative.
March 6, 2015

Math
B 5 to 15 is one to three not one to five C 3/5 = painting/sculpture so 3/8 = painting/total 5/8 = sculpture/total 3/8 * 24 = 9 5/8 * 24 = 15
March 3, 2015

maths
45 = 5*3*3 60 = 5*3 *2*2 so we need 5*3*3*2*2 = 180
February 28, 2015

Physics
North: 4 + 1.2 sin 35 East 1.2 cos 35 + 1.3
February 28, 2015

Math
That seems to work.
February 28, 2015

Physics
Vi = 26.5 sin 30.9 = 13.6 v = Vi - g t at top v = 0 9.81 t = 13.6 at top t = 1.39 seconds up u = 26.5 cos 30.9 u = 22.7 d = u t = 22.7*1.39 = 31.6 meters
February 28, 2015

Physics
Weight does not matter. v = sqrt (2 g h)
February 27, 2015

statistics
http://davidmlane.com/hyperstat/z_table.html
February 27, 2015

Vocabulary
We could calculate it all right. It was so lethargic it was frigid.
February 27, 2015

Chemistry Need Help
You only have 1.50 mol of Cl2 so you are only going to get 3.00 mol of ClF You have 0.25 mol of excess F2 left over.
February 27, 2015

Math
prob of not getting=(1 - prob of getting) (not getting)(not getting)(getting)
February 27, 2015

algebra
235 - 15 x = 55 15 x = 235 - 55 15 x = 180 x = 12
February 26, 2015

Math
u dot v = |u||v| cos T |u| = sqrt(9+4) = sqrt 13 |v| = 4 u dot v = 12 + 0 = 12 so 12 = 4 sqrt(13) cos T cos T = .832 T = 33.7 degrees do the second one the same way
February 24, 2015

Vectors: A car travels 59.5 miles then makes a 90
I thought I did it your way :) All I did was get the angle, you got the distance (hypotenuse)
February 24, 2015

Vectors: A car travels 59.5 miles then makes a 90
53 + 56.6 counterclockwise from west or 109.6 which is 109.6 - 90 = 19.6 degrees east of South
February 24, 2015

Vectors: A car travels 59.5 miles then makes a 90
the angle counterclockwise from west is 53 + tan^-1(90.3/59.5) that will end up in quadrant 4, east of south
February 24, 2015

Vectors: A car travels 59.5 miles then makes a 90
But good job so far Hanky.
February 24, 2015

Vectors: A car travels 59.5 miles then makes a 90
Remember it did not just ask for distance (scalar) but also direction (vector).
February 24, 2015

Science
You are welcome. Now remember how I did that because there is much confusion. If we were only in a satellite looking down on it, it would be easy :)
February 24, 2015

Science
I do not know if you know about conservation of angular momentum so will assume not. imagine a low over New York. I particle of air from up around Albany is drawn South to the low. HOWEVER The particle was moving east with the surface of earth toward the sunrise at some speed ...
February 24, 2015

Algebra 1
You are welcome again :)
February 24, 2015

Algebra 1
2 y = x + 6 2 y = x + 6 identical, same line, infinite solutions x + 7 y = 34 x + 7 y = 32 parallel lines, never cross, no solution
February 24, 2015

maths typo maybe ?
Why would you buy 4 times as many pizzas as drinks ??? anyway p = 4 d 112 = 12 p + .5 d so 112 = 48 d + .5 d 112 = 48.5 d d = 2.31 p = 111 I am sure you have this backwards d =
February 24, 2015

Mathematichs concepts
I am inclined to agree with you.
February 24, 2015

Algebra 1
You are welcome.
February 24, 2015

Algebra 1
4y +3 = 3y +x is y = (x - 3) then 2 x + 4 (x-3) = 18 6 x - 12 = 18 6 x = 30 x = 5 etc
February 24, 2015

typo ?
does not look right, -x^1 ?
February 24, 2015

algebra
(2x+1)(x+2) = 2 x^2 + 5x + 2 sure enough That is the way to check it without bothering to ask us :)
February 24, 2015

algebra
w = A/L w = (2 x^2 - 11 x + 5)/(2 x - 1) = (2x-1)(x-5) / (2x-1) = x-5
February 24, 2015

Chemistry Honors
R = 62.4 L Torr K−1 mol−1 T = 273 + 25 = 298 K n = 2 mol V = 10.4 L and P = n R T/V = 2 * 62.4 * 298 / 10.4
February 24, 2015

Earth Science to Ms.Sue (urgent )
The Cenozoic is sometimes called the Age of Mammals, because the largest land animals have been mammals during that time.
February 24, 2015

Earth Science to Ms.Sue (urgent )
http://www.google.com/search?q=cenozoic+era&ie=utf-8&oe=utf-8
February 24, 2015

Earth Science to Ms.Sue (urgent )
https://www.google.com/search?q=cenozoic+era&ie=utf-8&oe=utf-8
February 24, 2015

algebra
(t-8)(t+1)
February 24, 2015

algebra
x^2 + x - 6 = (x-2)(x+3) divide that by (x-2) and you get (x+3) :)
February 24, 2015

Algebra
Hey, that looks like the last one I did (x+1)(x-4) / (x+1) = x-4
February 24, 2015

Physics
average speed = .25 mi / 5.2 s so top speed = 2 * average speed if a is constant so Vf = .5 mi /5.2 s if you want that in mi/h multiply by 3600 s/h so Vf = 346 miles/hour Vf = a t .5/5.2 = a (5.2) a = .01849 miles/s^2 makes more sense if in feet/s^2 multiply by 5280 feet/mile ...
February 24, 2015

math
x^2 + x - 2 - x^2 + 6x - 9 7 x - 11
February 24, 2015

math
17 is a prime number so the LCD is 21*17 = 357 11/21 * 17/17 = 187/357 9/17 * 21/21 = 189/357 189 is bigger than 187
February 24, 2015

Math - Algebra 1
3.6 /12 = monthly interest rate = r b(t) = 9000 (1 + r)^12t c(t) = 40*12 t C(t) = 9000 (1 + r)^12t + 40*12 t
February 24, 2015

physics
when the angle is in quadrant II 53.4 degrees left of north then east component is - sin then north component is + cos if you want the angle from the x axis then it is 90 - 53.4 = 36.6 then you could use cos and sin like you want because sin (90-x) = cos x cos (90-x) = sin x :)
February 24, 2015

Typo
copied your result, should be I CLAIM Beta-subX = -3.20 ft SIN(53.4) = -2.56 Beta-subY = 3.20 ft COS(53.4) = 1.90
February 24, 2015

physics
Because the angle 53.4 is left from the Y axis, not up from the X axis. They tricked you with the west of north that is left of the Y axis DRAW the picture.
February 24, 2015

physics
This is right: Alpha-subX (for the x component) Alpha-subX = 81.6 ft * cos(31.7) = 69.426 Alpha-subY (for the y component) Alpha-subY = 81.6 ft * sin(31.7) = 42.878 This is WRONG Beta-subX = 3.20 ft cos(53.4) = 1.907 Beta-subY = 3.20 ft sin(53.4) = 2.569 I CLAIM Beta-subX = -3...
February 24, 2015

physics
But going west is NEGATIVE x
February 24, 2015

physics
Yes, exactly BUT THE SECOND ONE was west of north x distance = 69.4 -3.2 sin 53.4 = x y distance = 42.9 + 3.2 cos 53.4 = y d = sqrt (x^2 + y^2) tan of angle north of east = y/x
February 24, 2015

Physics
the mass is proportional to the number of mols n2/n1 = m2/m1 P1 V1 = n1 R T1 so n1 = P1 V1/R T1 P2 V2 = n2 R T2 so n2 = P2 V2/R T2 n2/n1 = m2/m1 = (P2 V2/P1V1)(T1/T2) 6/4.9 = (P2*2/75*5)(323/273) solve for P2
February 24, 2015

physics
in one revolution the tire goes 2 pi r = pi D feet = pi (2) feet which is (2 pi/5280)miles (2 pi/5280)n = 60,000 miles (part b) 2 pi n = number of radians (part a)
February 24, 2015

Algebra
x > y x + y = 6 x - 2 y = 9 ------------subtract 0 + 3 y = -3 y = -1 x = 7
February 23, 2015

algebra
The volume of anything pointy with straight sides is (1/3) base area * height V = (1/3)(pi)(25)^2 (7.2) same V for second one (1/3)(pi)(25)^2 (7.2)=(1/3)(pi)(15)^2 h so 625 (7.2) = 225 h h = (625/225)(7.2) In fact you never even need pi
February 23, 2015

physics
If A stopped and it was elastic then the B has the same as A had (1/2)(.55)(v^2)
February 23, 2015

algebra
Move right five 8.9 * 10^-5 move left two 4.56981 * 10^2 Due to your lack of showing your attempt I can not tell why you were having trouble with this.
February 23, 2015

Science
.9189189189..... But some of the ice floats above the water. Something must be holding it below water.
February 23, 2015

Electricity and magnetism
but the force decreases with distance as 1/x^2 F = k/x^2 we want W = integral F dx from x = d1 to x = d2 W = k integral (dx/x^2) = k (-1/x) from x = d1 to x = d2 = k/d1 - k/d2
February 23, 2015

maths
each year p(y) = .92 p(y-1) when y = 0, p = 5300 when y = 1, p = .92 * 5300 when y = 2, p = .92*.92 * 5300 when y = n, p = .92^n * 5300 think compound negative interest :) p = .92^y * 5300
February 23, 2015

Math
Yes, any real x except x = 1
February 23, 2015

calculus
aaaarrrrrgggggghhhhh !!!!
February 23, 2015

calculus
I will just do two dimensions for demo a) A dot (B+C) = AxBx + Ax Cx + AyBy + AyCy does that equal AxBx+AyBy + AxCx+AyCy Yes, it does b) A X (B+C) = A X (Bx+Cx)i +(By+Cy)j i j k Ax Ay 0 (Bx+Cx) (By+Cy) 0 find determinant [Ax(By+Cy) - Ay(Bx+Cx) ]k k direction of course [ AxBy...
February 23, 2015

physics
LOL - That same old impulse thing again. find change of momentum = final m v - initial mv (doing only component perpendicular to wall, v = 10 sin 60 inbound v = - 10 sin 60 outbound change in v = 2 * 10 sin 60 Force = change in momentum/time It only acted perpendicular to the ...
February 22, 2015

chemistry
22.41 - 21.30 = 1.11 mL so 8.7 g/1.11 mL = 7.838 g/mL or g/cm^3 almost 8 times density of water by the way which is how you remember it.
February 22, 2015

ap physics
I can not see your graph but use the logic from the other problem I just helped you with. F = m a = m dv/dt impulse = integral F dt = final mv - initial m v
February 22, 2015

AP physics
Force = change in momentum/time = m a when m is constant so Force * time = change of momentum, called impulse impulse = force * time = change of momentum final momentum = .278 (22.4) initial momentum = .278 (-16.2) change = .278 (22.4 - {- 16.2} ) = .278 (38.6) = 10.7 kg m/s (...
February 22, 2015

math
sure enough :)
February 22, 2015

math
x [(102 x - 228 )/6] +51 = 200 (102 x - 228 )/6 = 149 102 x - 228 = 894 102 x = 1122 x = 11
February 22, 2015

Calculus
the extrema of a function are where the derivative is zero or at the ends of the domain concave or convex depends on sign of second derivative at that extreme. If plus, it holds water (minimum). If negative, it sheds water (maximum).
February 22, 2015

physics
I assume they gave you mu dry and mu wet Ac = v^2/R = v^2/30 inward force needed = m Ac = m v^2/30 max inward force provided = mu m g so v^2 = 30 mu g
February 22, 2015

finite math
prob of red, white then blue = 4/13 * 6/12 * 3/11 prob of red, blue then white = 4/13 * 3/12 * 6/11 prob of white, red then blue = 6/13 * 4/12 * 3/11 prob of white, blue then red = 6/13 *3/12 * 4/11 prob of blue, red then white =3/13 * 4/12 * 6/11 prob of blue, white then red...
February 22, 2015

Math Help!
Oh well, number 2 start at 1 for min 1 + 2 + 3 + 4 ..... = 45 arith series (n/2)[2 + (n-1)(1)] = 45 n + (n/2)(n-1) = 45 n + n^2/2 -n/2 = 45 n + n^2 = 90 n^2 + n - 90 = 0 n = [ -1 +/- sqrt(1+360) ]/2 n = 18/2 = 9 check 1 + 2 + 3 + .....9 = 4.5(2+8) = 45 sure enough
February 22, 2015

Physics
Answer g) first (trick question) F = m a a = 0 so net force on crate = 0 =========================== a) 1 - friction 2 - m g gravity 3 - normal from ramp so three b) gravity, just one c) none are horizontal d)gravity, normal and friction all have vertical components so three e...
February 22, 2015

Physics
up is + a) gravity force down = weight = -m g = -1210*9.81 = -11870 N b) F is positive up F = m a = 1210(-1.4) F = - 1696 N c)gravity pushing down, helicopter pushing up d)lift is up lift - 11870 = m a = -1696 lift = 11870 - 1696 = 10176 N up
February 22, 2015

Vectors Math
Your notation is a mystery to me. The magnitude of the projection of A on to A is |A| cos T where T is the angle between A and B but |A| cos T = |A| |B| cos T /|B| which is A dot B /|B| Now we need a unit vector in direction B That is B/|B| so in the end we need A dot B * B /|...
February 22, 2015

Vectors
"bearing" means what direction you LOOK. "heading" means what direction you point the vehicle. As in: We were heading north when we took a bearing of 90 degrees on a lighthouse east of us.
February 22, 2015

Vectors
Math teachers do not know navigation English. It drives me crazy. You do not head on a bearing. You sail or fly on a heading. the plane is flying on a heading of 200 (about SSW) at 400 km/h the plane is also moving at 100 km/h southwest which is 180+45 = 225 degrees You can do...
February 22, 2015

Physics
C = q/V so V = q/C so q1/C1 + q2/C2 + q3/C3 = 58 but q1=q2=q3 becaue where else are the electrons to come from or go to? so 1/C1 + 1/C2 + 1/C3 = 58/ q 10^6 (1/3.83+1/5.89+1/12.9 = 58 /q 10^6 (.508) = 58 / q q = (58/.508)10^-6 V = (58/.508)/3.83 = 29.8 volts
February 21, 2015

College Physics
900(1.0)+ Tright(3) so Tright = 300 N Tright + Tleft = 900 so Tleft = 600 N
February 21, 2015

college physics
been there, done that, see above
February 21, 2015

Physics
C = q/V so V = q/C so V = qA/CA = qB/CB and E = (1/2) q V = (1/2) C V^2 5.7*10^-5 = (1/2)(17*10^-6)V so V = 6.71 volts then 6.71 = (qB/6.9)10^6
February 21, 2015

physics
A steel ball with a mass of 0.65 kg is swinging in a circle with a radius of 1.3 meters at a speed of 17m/s. What is the centripetal force?
February 20, 2015

Physics
3.6m/5 = .72 square root .72= .8485*24m/sec=20.36m it will travel 20.36 meters
February 20, 2015

Physics
A baseball is thrown horizontally from a height of 3.6 meters at a speed of 24 m/sec. How far will it travel along the ground?
February 20, 2015

Math Ms Sue
By the way 4 * 6 = 6 * 4 That is called "Commutative property of multiplication" which is grade three this week for my grandson's class.
February 18, 2015

Math Ms Sue
area of rectangle = length times width 4 * 6 or using your notation 4 x 6
February 18, 2015

physics
Sure looks like zero to me. 2 sin 30 = 1
February 18, 2015

Physics
normal force = m g cos 27.7 friction force up slope = mu m g cos 27.7 gravity component down slope = m g sin 27.7 so m (1.25) = m g sin 27.7 - mu m g cos 27.7 mu g cos 27.7 = g sin 27.7 - 1.25 solve for mu
February 18, 2015

english
because
February 18, 2015

math/Do not understand
These picks are independent. Picking a male student does not affect the following pick of a female student. Therefore the answer is simply the product of the two probabilities. 153 + 357 = 510 males male probability = 153/510 = .3 145 + 355 = 500 females female probability = ...
February 18, 2015

Physics
omega = radians/s = 2 pi/.5 = 4 pi Ac = omega^2 R = (4 pi)^2 * .1 F = m Ac = .012 (4 pi)^2 (.1) increases as omega^2 so 2^2 = 4 times
February 18, 2015

Physics
the total = 14.7 so 3.5 + 1.4 + V3 = 14.7 R3 = V3/(7*10^-3)
February 18, 2015

physics
Ke = .5 m v^2 .5 (7)(2.15)^2 = .5 (.0024) v^2 v^2 = (7)(2.15)^2/.0024
February 17, 2015

physics
(a) 150 * 5.5 Joules (b) no acceleration so work done by friction = 150 * 5.5 mu m g *5.5 = 150 * 5.5 mu = 150/(45*9.81)
February 17, 2015

physics
east distance = x = 4 + 2 cos 50 south distance = y = -2 sin 50 d = sqrt ( x^2 + y^2 )
February 17, 2015

Math
.015(500) + .01 (241.23)
February 17, 2015

math
S(5) = 125 -125 + 4 = 4 v = 3 t^2 - 10 t v(5) = 75 - 50 when is v = 0? 3 t^2 - 10 t = 0 = t(3 t - 10) t = 0 or t - 10/3 a = 6 t - 10 a(2) = 12 - 10 = 2
February 17, 2015

Calculus
he said at (0,0) the slope is 2 That is a line through the origin with slope = 2 y = 2 x + 0
February 17, 2015

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