Saturday
April 19, 2014

Posts by Damon


Total # Posts: 16,161

Calculus
perpendicular to the direction 1 i - 1 j + 2 k Vxi + Vyj + Vzk if perpendicular dot product is 0 Vx - Vy + 2 Vz = 0 also parallel to plane x+y+z = constant 2 so normal to the normal to that plane 1 i + 1 j + 1 k Vxi + Vyj + Vzk Vx + Vy + Vz = 0 so we have Vx - Vy + 2 Vz = 0 Vx...

Calculus
going from the first point to the second dx = 3 dy = -2 dz = 4 so my line direction is 3 i -2 j + 4 k and my line in parametric form is (1,0,1) + (3, -2, 4) t at intersection x = 1+3t y = -2 t z = 1+4t and we know x + y + z = 10 2 + 5 t = 10 t = 8/5 so x = 1 + 24/5 = 29/5 y = ...

Calculus
(1+4t) +2 (4t) -(2-3t) = -1 solve for t then use that t to find x, y z

Calculus
see http://www.jiskha.com/display.cgi?id=1391198824 for the method

Calculus
we have two points in that plane (8, 0, -2) and (6, 3, 3) a vector through those points has direction (6-8)i + 3 j + (2+2)k = -2 i + 3 j + 4 k so we have two vectors parallel to plane, their cross product is normal to the plane i j k -2 5 2 the given line direction -2 3 4 the ...

math
original p = 2 w + 2 L final p = 2 (3w) + 2 (2L) 2 (3w) + 2 (2L) = 92 + 2 w + 2 L 3 w + 2 L = 46 + w + L 2 w + L = 46 That is all I can say unless I know something more, for example that the original or final rectangle is a square.

physics
force = rate of change of momentum change of velocity = 15+17.4 = 32.4 m/s rate of change of momentum = mass per second * change of velocity = 33.6 kg/s * 32.4 m/s = 1089 kg m/s^2 or Newtons

Math palette of problems
(2/9) gal / (3/5) buc = x gal/1 buc multiply top and bottom of left fraction by 45 10 gal/27 buc = x gal/1 buc 10 gal = 27 buckets 10/27 gal = 1 bucket

pre cal
See below http://www.jiskha.com/display.cgi?id=1391134584#1391134584.1391136919

Math Pre-Cal
2 x^2 -12 x - 6 = y x^2 - 6 x - 3 = y/2 x^2 - 6x = y/2 + 3 x^2 - 6 x + 9 = y/2 + 12 (x-3)^2 = (1/2)(y + 24) vertex at x = 3 and y = -24

Math Pre-Cal
to do it with algebra, complete the square

Math Pre-Cal
If you do know calculus, find the derivative and set it equal to zero (the slope is 0 at a max or min) 4 x -12 = 0 so x = 3 then y = 2x^2-12x-6 = 2(9) -12(3) -6 =18 - 36 - 6 = -24 that vertex is a minimum because y gets big as x gets big

Math Pre-Cal
If you do not know calculus you must find the vertex of that parabola.

Math help
If you know that x = 3 for example Then use 3 instead of x in the next equation and all will be well.

Math
(x-p)(x-q) = x^2 + b x + 12 p q = 12 b = +/-(p+q) p and q must be the same sign and product 12 so 1) p = 1, q = 12 2) p = 3, q = 4 3) p = -1 , q = -12 4) p = -3, q = -4 so b = 13 b = -13 b = 7 b = -7 try those x^2 + 13 x + 12 = (x+12)(x+1) x^2 - 13 x + 12 = (x-12)(x-1) x^2 + 7...

English
You are welcome :)

English
inflicts I think

math
assuming they all eat lunch and 75% buy their lunch then 25% bring their own lunch .25 * 480 = 120 bring lunch

Social studies
we agree about 2 because I think railways were just a few years later but the last one is surely Adams-Onis which settled the matter of Florida and the west to California with Spain at least for the time being.

Social studies
The Munroe Doctrine was around 1823 I think.

Social studies
The Erie Canal certainly increased the population of New York and accelerated it beyond Philadelphia and Boston but as far as the entire northeast is concerned I would pick growth of factories and trade throughout the region.

Physics
T = 2 pi sqrt (L/g) 3.3 = 2 pi sqrt (1.5/g) sqrt(1.5/g)= .5252 1.5/g = .276 g = 5.44 m/s^2 around half earth g

Calculus
l) (g)^2 + (h)^2=1 so 2 g g' + 2 h h' = 0 g g' = -h h' g' = -(h/g) h' 2)g' = h^2 and h' = -g g'/h h' = - g h^2/h = -gh that is part a then If h has a max, then h' has a zero - g h = 0 ? either g = 0 or h = 0 if h is max, look for zer...

Physics
time in air = 3.33 so time ascending = 3.33/2 = 1.665 v = 0 at top = Vi - 9.81 (1.665) so Vi = 16.3 m/s average speed up = 16.3/2 time up = 1.665 so distance up = 13.6 meters

science
By the way, if the ship had a hole in the bottom, so that it filled with water, it would sink just like the nail.

science
Archimedes says: Force up on ship or nail - weight of water displaced which is density of water times g times VOLUME OF WATER DISPLACED. In the case of the ship, assuming it is not full of water, the volume of water displaced includes the volume of the inside of the hull which...

science
Hey, many of these are trivial and I am sure you do not need our help with them. Please just post the ones you are having trouble with and show your attempt at solutions.

math
yes, 100 * 100 = 10^4 = 10,000

Finite Math
The break even point is where the revenue equals the cost 290 x = 250 x + 5000 40 x = 5000 x = 125 so 125,000 beanie babies

math
hypotenuse

math
well, easy think of some 1/2 + 1/2 = 2/2 = 1 1/3 + 2/3 = 3/3 = 1 sum of tops must equal denominator when denominators are the same that means you need to put them over a common denominator, but you have to do that to add them anyway.

Math/Algebra
10 + .4*5 = 12 10 + .4*8 = 13.2 10 + .4*4 = 11.6 it may be bumpy but: There is one and only one output value for every input value. Therefore it is a function.

Calculus
c) as t --->oo v ---->1/t = 0 d) 500 = 5 + .5 ln (t^2+1) 495 (2) = ln(t^2+1) 990 = ln (t^2+1) e^(990) = t^2 + 1 oh, my, calculator overflow :)

Calculus
dx/dt = t/(1+t^2) that will be maximum when the derivative d^2x/dt^2 = 0 d^2x/dt^2 = [(1+t^2)1 -t(2t) ](1+t^2)^2 0 when numerator is zero 0 = 1 + t^2 - 2 t^2 0 = 1 - t^2 t^2 = 1 so max or min at t = 1 we know it is max because v decreases with big x a ) so max v = 1/2 at t = 1...

Finite Math
a) 5,000 no matter how many b) 250/1000 for each c) 250 (100) + 5000 = d) answer to c) / 100,000

Linear Algebra!
I could also say the dot product of vector 1 and vector 2 is 0 if they are perpendicular V1 = 1 i - 2 j V2 = a i + b j V1 dot V2 = a -2 b = 0 so no matter what t is, a = 2 b V2 = 2 i + 1 j or 4 i + 2 j or in general V2 = (2 i + 1 j) t

Linear Algebra!
1 i - 2 j slope = -2 our slope = -1/-2 = 1/2 vector direction = 2 i + 1 j so r = (1i +0j) + (2 i + j) t

Calculus
dy/dx = 2/2 = 1 so y = x + b 0 = 3 + b b = -3 so y = x - 3 if x(t) = k t for example then y(t) = x(t) - 3 y(t) = k t - 3

physics
(1/2) m v^2 = m g h v^2 = 2 g h v^2 = 2 * 9.81* 1.36 v = 5.17 m/s so the change in velocity from top to bottom is 5.17 acceleration is constant so average speed = 5.17/2 = 2.58 m/s so it took 3.6 /2.58 = 1.39 seconds for the block to get down the slope the velocity changed fro...

Math
well, we know that both are y so 6x-5 = -x+9 7 x = 14 x = 2 then y = -x+9 = -2+9 = 7

Social Studies
I would not blame Hitler on his childhood myself. However I might look at his First World War experiences closely.

Physics
8.01 ?

am history
Shiloh It was only a surprise to Grant.

math
well, look here: http://www.mathsisfun.com/geometry/interior-angles-polygons.html

MATH
cars generally run on burning fossil fuel (gasoline, diesel) but even if they run on electricity they increase the effect two ways at least: 1. The elctricity is often generated by burning coal or oil. 2. Even if the electricity is generated using wind or solar power or water ...

physics
Look at this hint (not far off my guess :) http://www.jiskha.com/display.cgi?id=1354300345

physics
baking soda ? I have no idea what you are supposed to say.

Math
if you multiply the scale of the pattern by 2.5 you multiply every dimension by 2.5 However if by 2.5 times bigger you mean the AREA is 2.5 times bigger then you multiply every dimension by the square root of 2.5. I doubt is this is what she means.

English
been there, done that :)

English
Her body slumped against the classroom wall beside the door hoping for the bell to ring.

science(1answer)
Oh sorry, slightly different, train going v for train (1/2) m v^2 = 5,000 * 10^2 for car (1/2) m v^2 = 1300 * 4 * 10^2 = 5,200 * 10^2 so now it is the car number A

science(1answer)
Now really, I have replied three times now. Yes http://www.jiskha.com/display.cgi?id=1391014223

physic
Yes, I get 2.86 * 10^-6

physic
I already replied http://www.jiskha.com/display.cgi?id=1391014223

Science
v = Vi - g t 0 = 20 - 9.81 t at top when v = 0 t = 2.04 seconds h = 12 + Vi t -(1/2) g t^2 h = 12 + 20(2.04) -4.9(2.04)^2 h = 32.4 meters

science (check answers)
http://www.jiskha.com/display.cgi?id=1391017066

science (check answers)
I thought I already replied to this

Physics
C of water is 1 calorie/gram deg C 400 = 1 * 40 (T-20) 10 = T-20 T = 30

Math
1 /(1/3) multiply top and bottom by 3 3 / (3/3) = 3/1 = 3

science(check answers)
(1/2) m v^2 is certainly bigger for the train because (1/2) is the same and v^2 is the same but m is MUCH MUCH bigger so I agree, B

Math
You need the specific heat of water in BTU per gallon deg F Well the specific heat of water is ONE BTU per POUND deg F and a gallon is about 8.33 pounds of water so C = 8.33 BTU/(gal deg F) SO WE NEED btu = 8.33 * 30 * 70 = 17496 btu 17497 BTU = 25000 t so t = 0.7 hours or 42 ...

social studies---check 1 question pls
Samuel Slater did the first spinning mill in the USA and is usually called the father of the American industrial revolution. Francis Lowell started the corporate mill factory system. I think the question could be worded better but think you are right to choose Lowell (besides,...

social studies---check 1 question pls
agree

science(check answers)
(1/2) m v^2 = 30*900 = 27,000 Joules That is C !!!!

Physics
v = Vi + a t 17.9 = 6.6 + 2.3 t

physic
F = k q^2/(.5)^2 = m g sin theta where theta is angle from vertical tan theta = theta in radians = sin theta for small angle = .25 m (half of distance between)/2.5 = 0.1 so q^2 = .5^2 (.3)(9.81)(0.1)/(9*10^9)

math
180 - 110 = 70 6 - 6/4 - 6/3 - 6/8 = 1.75 yes 0.25 22.5 * 4 = 90 yes

Math- Vectors
V2 = 3 i + 7 j + 1 k find vector perpendicular to that V3 = Vx i + Vy j + Vz k if perpendicular then V3 * V2 = 0 3 Vx + 7 Vy + 1 Vz = 0 or Vz = -(3Vx+7Vy) now that vector has to go through the points where y and z are 0 for L1 if y = 0 t = 1/2 and L1 = [3+2 , 5-5 , -1 +1] = [5...

physics
y = Yo + Vi t - (1/2)gt^2 g = 9.8 so (1/2) g = 4.9 so the last term has to be -4,9 t^2

Physics
By the way, since you set out every other needed step for a solution in your problem statement I assume you do not know how to convert miles to kilometers. One very crude way is to remember that 30 miles per hour is about 50 kilometers per hour but even easier and more accurat...

Physics
Radius of earth = 6,371 kilometers 248 miles = 399 kilometers so r = 6371+399 = 6770 100 (6371/6770)^2 = 88.6 %

fractions as division word problems
2/5 = 4/10 = 0.4

math
to multiply by 100 move your decimal point two places to the right 53.33 * 100 = 5333

Algebra 1
Radius = r = 3 ft, height = 1.5 ft volume = pi r^2 h = pi (9)(1.5) = 42.4 ft^3

Math help
2) -2x+3y=11 X=4y-3 -2 (4y-3) + 3 y = 11 -8 y + 6 + 3 y = 11 - 5 y + 6 = 11 -5y = 5 y=-1 etc

Math help
1) use 5 y - 1 for x so 5 y-1 + 2y = 13 or 7 y - 1 = 13 7 y = 14 y = 2 now go back and get x x = 5(2)-1 x = 9

Math help
1) use 5 y - 1 for x so 5 y-1 + 2y = 13 or 7 y - 1 = 13 7 y = 14 y = 2 now go back and get x x = 5(2)-1 x = 9

Math
An = 2^n Yes, correct A1 = 2 r = -3 yes, correct

algebra 1
You are welcome :)

algebra 1
pi (2.25 -1) = 1.25 pi = 3.93

algebra 1
R = 1.5 r = 1 pi R^2 - pi r^2 pi (1.5)^2 - pi (1)^2

Vectors
ok weight = m g = 9.81 m 9.81 m sin (Theta) = 215 N where Theta is the angle of the ramp up from horizontal

Vectors
We need to know the slope of the ramp, if friction is important, and if the object is on earth.

Math
You are welcome :)

Math
least common multiple of 6 and 8 is 24 teeth clashing that is 4 turns of the 6 and 3 turns of the 8

physics
The wording of this question puzzles me because if they are in orbit they feel no gravitational force since the centripetal acceleration (v^2/R) exactly balances earth gravity. However if you wish to separate out those two factors then use Forbit = G m Me / Rorbit^2 Fground = ...

I do not understand
do you have a typo or is that something I just do not know about?

calc
z = 2 cosine 60 + 2 i sin 60 z= 2 e^i(60) z^4 = 16 e^i(240) = 16 cos 240 + 16 i sin 240 = 16 (-.5 )+ 16 i(-.866 ) = -8 - 13.86 i

physics
in degrees or radians? 1.834 degrees or .032 radians note, for small angles sin (Theta) = Theta in radians

Math
yes, use x

Math
if i </= 20,000 tax = .15 * i if i> 20,000 tax = 3,000 + 0.20 ( i - 20,000)

science---1 question
yes

chemistry
NaNO3 Na = 23 N = 14 O3 = 3*16 = 48 total = 85 Na = 100 * 23/85 N = 100 * 14/85 O3 = 100 * 48/85

Physics
I will assume the inclined block wins and slips down the hill Force up on inclined block = T force down slope on inclined block = 28 (9.81 )sin 53 - 28 (9.81)(.9)cos53 a = acceleration down slope 28 a = 28 (9.81 )sin 53 - 28 (9.81)(.9)cos53 - T Force down on hang mass = m g = ...

physics
wires are 60 degrees from vertical so T cos 60 = 110 T (1/2) = 110 T = 220 N

science
( T cos 60 = 110 T = 220 N

algebra
a) +(4x-3/6) = +(5-5x/10) b) -(4x-3/6) = +(5-5x/10) c) +(4x-3/6) = -(5-5x/10) d) -(4x-3/6) = -(5-5x/10) a and d are the same, scratch d b and c are the same, scratch c so a) +(4x-3/6) = +(5-5x/10) b) -(4x-3/6) = +(5-5x/10) so solve those last two :)

Engl.
Writeacher knows far more about this subject than I.

Engl.
"planned to seize" looks like a simple predicate to me. If it said: "planned to seize immediately" I would say "planned to seize" was the simple predicate and "planned to seize immediately" was the complete predicate

Engl.
agree

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