# Posts by Damon

Total # Posts: 29,623

**Social Studies**

Particularly this excerpt: "Japan had been closed to the outside world for 250 years. When foreign people entered Japanese waters, even if they were shipwrecked by accident, they were interned in jails and some of them were killed (Lubor 33). The reasons for the Japanese ...

*January 4, 2017*

**Social Studies**

Ah yes, this is short and sweet http://willamette.edu/~rloftus/perry.html

*January 4, 2017*

**Social Studies**

I am looking for a link for question 2

*January 4, 2017*

**Social Studies**

no, no

*January 4, 2017*

**Social Studies**

Now for question 2, perhaps we better look at the start of American-Japanese relations. Did you read about only the Dutch being allowed there before that fleet arrived?

*January 4, 2017*

**Social Studies**

here is a wiki for Goa: http://www.google.com/search?q=goa+india&ie=utf-8&oe=utf-8

*January 4, 2017*

**Social Studies**

Well, I suppose I could give you some link to a wiki or something, but first think about it. The Portuguese ended it all in India long this after with Goa. Can you imagine a little country like Portugal marching around India ? They were sea farers

*January 4, 2017*

**Social Studies**

In question 1, remember we are talking about the Portuguese, not some tea company.

*January 4, 2017*

**Social Studies**

Ah, what do you think? The answer to question 2 is petty dramatic and amazing.

*January 4, 2017*

**Pre calc**

y = m x + b y = -(3/2) x +3/4 or 4 y = -6 x + 3

*January 4, 2017*

**History**

Well, my choices would be: 1. Prince Henry the Navigator, Bartolomeu Dias, Vasco da Gama .... so D 2.I would say B 3. See question 1.

*January 4, 2017*

**Math**

65*50 = 6500/2 = 3250 ft^2 so 1625/3250 $/ft^2

*January 4, 2017*

**American Government**

County responsibility is now chiefly law enforcement (sheriff and county jail) and registry of deeds and such. However it still exists and the towns and cities have not take over all county responsibilities.

*January 4, 2017*

**American Government**

Although our ounty government has been largely eliminated over the last decade, we still have a sheriff etc. Our town governments operate much like our city governments, although often having a Board of Selectmen instead of a City Council. Both towns and cities are often run ...

*January 4, 2017*

**American Government**

http://en.wikipedia.org/wiki/Essex_County,_Massachusetts

*January 4, 2017*

**Physics**

I think it is a dip and v^2/R = 0.15*9.81

*December 30, 2016*

**Physics**

density = 1000 kg/m^3 is easier :) You do not say if you want gage pressure or absolute pressure I will assume gage rho g h = 1000*10*25 =2.5 *10^5 Pascals or N/m^2 if you want absolute pressure add one atmophere or about 1*10^5 for a total of 3.5*10^5 Pascals

*December 30, 2016*

**Physics**

You already said the speed of the boat through the water was 2 m/s The speed over the land is 2-.8 = 1.2 m/s

*December 30, 2016*

**physics**

v^2/R = g or it loses contact m g(h-D) = .5 mv^2 v^2 = g R = .5 g D so m g(h-D) = .5 m *.5 g D =.25 mgD h-D = .25 D h = 1.25 D

*December 30, 2016*

**Math**

anything^0 = 1 so x^3/x^3 = x^0 = 1 y^6/y^6 = y^0 = 1 so 1

*December 29, 2016*

**asthmatics**

assuming it is the height that is 9.5 outside volume = 23 * 15.5 * 11 inside volume = 20 * 12.5 *9.5 now subtract the inside from the outside

*December 29, 2016*

**maths**

Thank you rabin for entertaining the math tutors :)

*December 29, 2016*

**Chemistry**

(750-726)/(20-10) = 2.4 (800-750)/(40-20) = 2.5 (880-800)/(70-40) = 2.7 (960-880)/(100-70)= 2.7 slope increasing a bit but 2.7 seems a reasonable guess slope = (x-960)/(150-100) (x-960)= 50(2.7) x = 960 + 135 = 1095

*December 28, 2016*

**calculus**

http://www.mathsisfun.com/calculus/differential-equations-homogeneous.html LOOK at the example at the end :)

*December 28, 2016*

**Physics**

This might help: http://www.slideshare.net/ahmedqadoury/periodic-and-aperiodic-sounds-2

*December 28, 2016*

**Physics**

I am sorry I can not because if you do a Fourier transform on even a spike you can express even an impulse as a sum of periodic signals. However there are articles on non-periodic vibrations in the technical literature. I question if they are really that but anyway take a look...

*December 28, 2016*

**math, algebra**

120 + 7 x = 11 x so 4 x = 120 x = 30

*December 28, 2016*

**Matt**

2.54 cm/in L in cm = L in inches (2.54 cm/in) so 2.54 times as many centimeters as inchess

*December 28, 2016*

**Science**

MASS IS CONSERVED! Until you get to Einstein and Special relativity, the total mass is CONSTANT. .015 + .050 = .065 kg

*December 28, 2016*

**Math**

time = t vf t = 260 vp t = 320 so 260/vf = 320/(vf+15) 320 vf = 260 vf +260(15) 60 vf = 390 3 vf = 39 vf = 13 km/hour

*December 28, 2016*

**SAT Math Question?**

L --- 1/3 job/hr S ---1/5 job/hr together 1/3 + 1/5 = 8/15 job/hr (8/15 j/h)(1 h) = 8/15 job done that leaves (15-8)/15 = 7/15 to do (1/5)job/hr * t = 7/15 job t = 35/15 hr for S to finish 35/15 hr * 60 min/hr = 140 min

*December 28, 2016*

**algebra**

3j(j^2-17j +70) =3j (j-10)(j-7)

*December 26, 2016*

**algebra**

9 r^2 - 30 r + 25 = 0 (3 r -5)(3r-5) = 0 r = 5/3 and 5/3 repeated, parabola just touches r axis

*December 26, 2016*

**algebra**

2(2a^2-5a+3) is 2(2a-3)(a-1)

*December 26, 2016*

**algebra**

64 z^2 - 1 That is the difference of two squares remember a^2-b^2 = (a-b)(a+b) so (8z-1)(8z+1)

*December 26, 2016*

**nobody knows**

Did you try to copy and paste? That does not work.

*December 26, 2016*

**physics**

Assuming that they are in series, 1.2 amps goes through each so current density = 1.2 /(pi d^2/4) for each

*December 26, 2016*

**calculus too hard**

Use Steve's solution if no typos in problem statement.

*December 26, 2016*

**calculus too hard**

I am still not sure it is right maybe dx/dt = k(a-t) ?? if so try x = c + p t - kt^2/2 then dx/dt = p -kt then p = ka and if c = 0 then dx/dt = 0 +ka -kt = k(a-t) so then x = ka t - k t^2/2

*December 26, 2016*

**typos?**

I think you might mean dx/dt = k(a-x) but what is c?

*December 26, 2016*

**Maths**

tan 60 = X1/1 tan 30 = X2/1 d = X2 - X1 v = d/t t in hours = 10 s /(3600 s/hour)

*December 25, 2016*

**math**

angles OBA and OCA are right angle BOC is 90-40 = 50 ABC =180 - 20 - 90 = 70 = ACB

*December 25, 2016*

**Maths**

1.12 p = 15,000

*December 25, 2016*

**Calculus 3**

No, because multiply by sqrt 14 which is |n|

*December 25, 2016*

**Calculus 3**

n = 3 i +2 j + k we want F dot n = |F| |n| cos angle but we are given that |F| cos angle is 3 z/sqrt14 so what is |n|? sqrt (9+4+1) = sqrt 14 ha, that helps :) so F dot n = 3 z so do the integral of 3 z over the surface

*December 25, 2016*

**Calculus 3**

http://tutorial.math.lamar.edu/Classes/CalcIII/SurfIntVectorField.aspx boundary in first quadrant means x from 0 to 2 and y from 0 to 3 (sketch that thing)

*December 25, 2016*

**math**

89/18 =4 + something 4 * 18 = 72 89 -72 = 17 left over

*December 25, 2016*

**Physics**

well, sure the tension does work, but the idea is that you do not have to get into the innards of this system because its kinetic energy is described by the (1/2)(m1+m1)v^2 and (1/2) I omega^2 and its potential energy by the m g h of the two objects. You could solve the whole ...

*December 24, 2016*

**sorry, read -1 not -3**

-3(-2) = +6

*December 24, 2016*

**MATH**

y = -1 x +42 slope = -1 = change in y/change in x if change in x - -1 then change in y /-2 = -1 so change in y = -1 (-2) = +2

*December 24, 2016*

**Physics**

max ke = max Pe = m g h h = r (1-cos 60) = r/2 so max (1/2) m v^2 = m g r/2 max v^2 = g r T = m g + m v^2/r T = m (g + g) = 2 m g = 2(.05)(10) T = 1 Newton

*December 24, 2016*

**physics**

4 *10 = 40*v v = 1

*December 24, 2016*

**Physics**

q = c v same q on each v1+v2 = 100 q/c1 +q/c2 = 100 q/4 + q/2 = 100 3 q/4 = 100 q =400/3 on each now same v on each and total charge=800/3 and total c = 6 v = q/c = 800/18 = 44.4 volts

*December 24, 2016*

**algebra**

let's see we need 5*5-1 in the middle something of form (5c ) ( 5) (5c-1) (c +5)NO that gives +24, we want - (5c+1)(c-5) = 5c^2 -24c -5 progress so (5c+d)(c-5d) = 5c^2 -24cd -5d^2 done

*December 23, 2016*

**physics**

Ac = g there = v^2/R = omega^2 R omega = 2 pi radians/24 hours =2 pi radians /(24*3600)seconds R is given so find omega^2 R

*December 23, 2016*

**Specialist Mathematics**

|x+y| two possibilities A: x+y B: -x-y = -(x+y) if A: x+y is maximum when both are + then x+y = |x|+|y| if B: -(x+y) has same absolute value as A etc

*December 22, 2016*

**History -**

I think I might have picked C because some of them are in South America and Asia and the Middle East.

*December 22, 2016*

**Linear Relations MATHS**

You are welcome

*December 22, 2016*

**Linear Relations MATHS**

That means 3/4 of the way along the line segment from A to B That means 3/4 in x and 3/4 in y in x -4 +(3/4)(6 - -4) = -4+ 3*10/4 = = -16/4 +30/4 = 14/4 = 3 1/2 in y 6 + (3/4)(-7-6) = 6- 13*3/4 = 24/4-39/4 = -15/4 = -3 3/4 so (3.5 , -3.75) In part B same deal but times 3, not ...

*December 22, 2016*

**Math**

36 = .6 p so p =36/.6 = 360/6 = 60

*December 22, 2016*

**math help**

does "cross product" or "vector product" ring a bell? the cross product of two vectors is perpendicular to both +i +j +k +2 +1 +1 +1 -1 +2 (2+1)i +(1-4)j + (-2-1)k = 3i -3j -3 k

*December 22, 2016*

**History - Help**

http://www.fsmitha.com/h2/ch14-4.htm

*December 22, 2016*

**History - Help**

You are welcome.

*December 22, 2016*

**History - Help**

Yes, see https://en.wikipedia.org/wiki/Westphalian_sovereignty

*December 22, 2016*

**Mathematics**

50 (30/25) = 2*30 = 60

*December 22, 2016*

**Social Studies**

Where should I start???? Load and unload ships, trucks, trains, and planes or in the case of ports at the mouth of rivers (New Orleans, Rotterdam), transfer cargo between river barges and seagoing ships. Builds and repair ships and port facilities. Do the paper work and number...

*December 21, 2016*

**math**

(0,5800) and (5,7420) (7420-5800)/5 = (y-5800)/(x-0)

*December 21, 2016*

**math**

Well I showed you that the first choice is NOT a solution to the equation. However It might not be the only one. Check them all.

*December 20, 2016*

**math**

Try each of them for example -52 = -5(10) - 4 -52 = -54 I do not think so check the others as well.

*December 20, 2016*

**Math**

You are welcome.

*December 20, 2016*

**Math**

L,w,h area = 2 Lw + 2 Lh + 2wh = 600 so Lw+Lh+wh = 300 but L = 3w so 3 w^2 + 4 w h = 300 now V = L w h = 3 w^2 h so h = V/3w^2 3 w^2 + 4 w(V/3w^2) = 300 4 V/3w = 300 - 3 w^2 (4/3)V = 300 w - 3 w^3 we want d(4/3)V /dw = 0 300 = 9 w^2 w = (10/3)sqrt 3 L = 10 sqrt 3 w L = 100 so...

*December 20, 2016*

**physics**

I agree but wonder about the straight line. There is not enough gravity to hold them down, but there is still a force toward the earth center so I think the departure path would curve.

*December 20, 2016*

**Math**

You never know who will be online. All you can do is post the question. There are a lot of math teachers who check in here.

*December 20, 2016*

**Math**

Yep, it's right :)

*December 20, 2016*

**calculus**

right triangle 3,4,5 or 60,80,100 x= 60 y = 80 z = hypotenuse = 100 dx/dt = 80 dy/dt = 100 z^2 = x^2+y^2 2 z dz = 2 x dx + 2 y dy z dz/dt = xdx/dt +y dy/dt 100 dz/dt =60*80+80*100 dz/dt = 6*8+80 dz/dt = 128 km/hr

*December 20, 2016*

**History**

Heavens! Look at a map. What is the biggest river in the now United States? Texas where the beef comes from for Richmond is west of the river. Remember that fleet coming up from the Gulf of Mexico ("Damn the torpedoes" :)

*December 20, 2016*

**another no way**

You try first. I already took the course.

*December 20, 2016*

**No way**

I do not see any attempt by you to do these problems. I already took this subject and do not need the practice. You try first. Also read what you typed.

*December 20, 2016*

**Math**

25-13 = 12 which is the sum of the two bases at the ends h is the height area of rectangle in the middle = 13 h x is base of one triangle (below the 10) so 12-x is the other(below the 15 (12-x)^2 + h^2 = 225 x^2+h^2 = 100 ---------------------subtract 144-24x = 125 x = 19/24 ...

*December 20, 2016*

**math**

(9/14)(35,000) =

*December 20, 2016*

**Math**

Yes but do the division 9/3 = 3 laps/min 30/6 = 5 laps/min 20/5 = 4 laps/min Mary does the most laps /min

*December 20, 2016*

**math**

s = 3d d + 3d = 116 4 d = 116 d = 29 so s = 87

*December 20, 2016*

**Math (please help!!)**

It is also the incenter B http://www.google.com/search?q=incenter+of+triangle&ie=utf-8&oe=utf-8 and point of concurrency C http://www.google.com/search?q=iconcurrency+of+perpendicular+bisectors&ie=utf-8&oe=utf-8 and D

*December 20, 2016*

**30 to what ?**

30deg to horizontal or vertical? In either case, use Snell's law.

*December 20, 2016*

**math**

5 per year 5*20 = 100 twenty years

*December 20, 2016*

**history**

Clove production, slaves See: www.blackpast.org › Geography: Global African › Africa › KenyaSeyyid Said, also known as Said ibn Sultan, was a resourceful and energetic sultan ... moved the capital from Arabia to Zanzibar in order to initiate clove production...

*December 20, 2016*

**Social Studies**

push --> potato famine and nasty bosses drive people out pull ---> jobs and land draw those people as immigrants to Ellis Island.

*December 19, 2016*

**calcululs help me**

4x^2+8xy+9y^2-8x-24y+4=0 8xdx+8xdy+8ydx+18ydy-8dx-24dy=0 (8x+18y-24)dy= -(8x+8y-8)dx dy/dx = (-4x-4y+4)/(4x+9y-12)agree numerator = 0 when x+y=1 yes find d/dx(dy/dx)of (-4x-4y+4)/(4x+9y-12) = [(4x+9y-12)(-4dx-4dy)-(-4x-4y+4)(4dx+9dy)]/dx[(4x+9y-12)]^2 =4[(4x+9y-12)(-dx-dy)+(+...

*December 19, 2016*

**chemistry**

ZnO + 2HCl ---> ZnCl2 + H2O By the way H2O is ...... Zn = 65 g/mol O = 16 g/mol H = 1 g/mol Cl =35.5 g/mol 13.64 g ZnCl2 * 1 mol/(65+71)g = mols of ZnCl2 now you should be able to continue.

*December 19, 2016*

**American History**

I think A) http://millercenter.org/president/biography/monroe-foreign-affairs

*December 19, 2016*

**error !**

I multiplied by distance not time average speed = v/2 distance = .25 = t (v/2) t = .5/v then 3 v = 20 *.5/v 3 v^2 =10 v^2 = 10/3 v = sqrt(10/3) ================== check 3 v = 20 * t 3 sqrt (10/3)= 20 * .5/sqrt(10/3) 3 (10/3) = 20 * .5 yes

*December 19, 2016*

**physics**

change in momentum = force * time 3 v = 20*.25

*December 19, 2016*

**algebra 2**

ticket price p = 231/n p-4.5 = 231/(n+3) 231/n - 4.5 = 231/(n+3) 231(n+3)-4.5(n^2+3n) = 231 n 231*3 -4.5 n^2 - 13.5n = 0 4.5 n^2 + 13.5 n - 693 = 0 n = 11 or -14 so 11 =========================== check 231/11 = 21 231/14 = 16.5 yes, diff = 4.50

*December 19, 2016*

**Physics**

In other words unless there was energy input from a explosion on impact or something, no way the big block took off at 4.0 m/s

*December 18, 2016*

**Physics**

huh? .5*5 *2.9^2+.5*10*2.1^2 = 43.1 Joules .5*5 *0.9^2 + .5*10* 4^2 = 81.1 81.1-43.1 = 38 Joules more Something exploded :)

*December 18, 2016*

**American History**

ah come on !!!!

*December 18, 2016*

**calculus**

I assume you mean x^2 - x y - y^2 = 5 2 x dx - x dy -y dx - 2 y dy = 0 (2y-x)dy = (2x-y)dx dy/dx = (2x-y)/(2y-x) slope is undefined (vertical) when 2y-x = 0 or x = 2y so x^2 - x y - y^2 = 5 4y^2 -2y^2-y^2 = 5 y = +/-sqrt 5 then x = +/- 2 sqrt 5

*December 17, 2016*

**calculus**

surface area in m^2/radius in meters is meters radians is arc, no units so meters per radian

*December 17, 2016*

**algebra**

If any one of those three factors is zero, then the product is zero so z = 0 works z-1 = 0 works so z = 1 works z+3 = 0 works so z = -3 works therefore z = 0 or 1 or -3

*December 17, 2016*

**Algebra 1- Urgent**

In your table in part B the ratio is for example 10406.04/10303.01 = 1.01 check: 10303.01/10201 = 1.01 sure enough so that is increasing by ONLY ONE percent per year

*December 17, 2016*