Wednesday

July 23, 2014

July 23, 2014

Total # Posts: 17,498

**math**

x</= 500 room rent = r = 400 + i x = 500 - (8/4)i cash = [ 500 - (8/4)i ] [400 +i] cash = c = (500-2i)(400+i) c = 20,000 - 300 i - 2i^2 dc/di = 0 for max or min = -300 - 4 i d^2c/di^2 = -4 so max i = -300/4 = -75 for max x = 500 -2(-75) = more rooms than we have so we can n...

**Math**

10 - 3 = 7 18 + 2 = 20 so 7 x + 20

**my mistake !**

then -12 + c = 3 c = -15 No, +15 !!!! put in y = 11 at x = 1 to get d 11 = -1 -6 -15 + d d = 33

**calculus**

I assume you mean y or f(x) = -x^3 +bx^2 +cx + d if so y' = -3 x^2 + 2 b x + c and y" = -6 x +2 b at x = -5 , y' = 0 -75 -10 b + c = 0 at x = 1 , y' = 0 -3 + 2 b + c = 0 so 2 b + c = 3 -10 b + c = 75 -----------------subtract 12 b = -72 b = -6 then -12 + c = 3...

**?**

Sorry, I do not know what that means.

**math**

(5282+4689+3029+6390) / 4 =4847.5 = 4848

**physics**

I assume that a Mg is a "megagram, a term I have never heard before. In that case we have 4*10^6 grams which is 4,000 Kilograms 4,000 * 30 = 120,000 kg m/s south

**physics**

F = G M m/R^2 = m v^2/R so v^2 = G M/R G = 6.67 * 110^-11 M = 6 * 10^24 Re = 6.38*10^6 meters Ra = 6.38*10^6 + .418*10^6 Rb = 6.38*10^6 + .731*10^6

**physics 1**

F = G Mm/R^2 = m v^2/R v^2 R = G M = 6.67*10^-11 * 5.98*10^24 v^2 R = 39.9 * 10^13 v T = circumference = 2 pi R so R = v T/(2 pi) R = v [1.77*10^4/(2 pi)] R = 2.82*10^3 v so v^3 (2.82*10^3) = 39.9 * 10^13 v^3 = 14.1 * 10^10 = 141 * 10^9 v = 5.2 * 10^3 v = 5,200 m/s

**log**

2 = e^.09 t ln 2 = .09 t = .6931 t = 7.7 years

**Trig**

2 sin 3x = 2[ 3 sin x-4 sin^3 x] = 6 sin x - 8 sin^3 x 4 sin 2x = 4[ 2 sin x cos x ] = 8 sin x cos x so 6 sin x - 8 sin^3 x + 8 sin x cos x 2 sin x [ 3 - 4 sin^2 x + 4 cos x ]

**Algebra**

for similar objects volume goes up proportional to cube of the length dimension. Of course people are not always mathematically similar in shape but never the less: ------ my answer is b

**Physics**

NONE !!!! work is force IN THE DIRECTION OF MOTION times distance

**Math help**

1. (Y+5)(Y-7)=0 if Y = -5 then you have (-5+5) (something) = 0 or 0 * something = 0 so 0 = 0 so Y = -5 IS A SOLUTION same deal for Y = 7 (something)( 7 - 7 ) = 0 sure enough y = 7 Is a solution so I claim in general if (something ) (a x + b) = 0 then x = -b/a IS a solution for...

**Chemistry**

Compare the physical and chemical properties of acids and bases.

**Algebra 2**

(5,10),(10,7)= y=(5/3)x-(17/3) m = (7-10)/(10-5) = -3/5 so your m = 5/3 y = (5/3) x + b x --> 15/2 y --> 17/2 so through (15/2 , 17/2) 17/2 = (5/3)(15/2) + b so 17/2 = 25/2 + b b = - 8/2 = -4 y = (5/3) x - 4 agree with your second answer this time

**Algebra 2**

(1,4),(6,-6)= y=(1/2)x-(3/4) m = (-6 -4)/(6-1) = -10/5 = -2 so your m = +1/2 check x ---> (1+6)/2 = 7/2 y ---> (4-6)/2 = -1 so (7/2 , 1) 1 = (1/2)(7/2) + b 4/4 = 7/4 + b b = -3/4 y = (1/2) x - 3/4 I like your first answer

**Algebra 2**

Perhaps I am not being clear. There is no reason the original pair of points would be on the perpendicular bisector of the line between them. In fact they better not be there.

**Algebra 2**

(-5,6),(1,8)= y=-3x+1 m = (8-6)/1+5) = 2/6 = 1/3 so yes, your slope is -3 y = -3 x + b now midpoint x --> (-5 + 1)/2 = -2 y --> (6+8)/2 = 7 so yes the middle is at (-2 , 7) 7 = -3(-2) + b 7 = 6 + b b = 1 so yes y = -3 x + 1 THe original points are NOT on the bisector.

**Math**

150 + 50 + 150 + 50 = 400 meters = 0.4 km .4 km/lap * n = 1 km n = 1/.4 = 2.5 laps

**algebra**

one gallon every 4/3 month so 3/4 mo/gal overcharge gallons = (3/4) gal/mo * t in months 5 = .75 t t = 6 2/3 months

**Pre-Calc Help please**

all logs base 5 64 is 4^3 log (4 x^2) = log 64 = log (4^3) so 4 x^2 = 4^3 x = 4

**health**

Now think about each of those. The only one that is hindered by exercise is the first, diabetes

**Math**

divide first row by 8 to get 1 in upper left 1 1/4 -17/2 add 7 times new first row to second to get 0 below the one 1 +1/4 -17/2 0 +3/4 -9/2 subtract 1/3 times row 2 from row 1 to get rid of that 1/4 in row 1 1 0 -7 0 3/4 -9/2 multiply second row by 4/3 to get 1 in 2,2 spot 1 ...

**Math**

-7 -6

**Math**

augmented matrix +8 +2 -68 -7 -1 +55 you have two rows, three columns now go to http://www.gregthatcher.com/Mathematics/GaussJordan.aspx

**Canals**

It makes New York bigger than Philadelphia :)

**Physics -- check answers please (new)**

Oh, and we disagree on 6

**Physics -- check answers please (new)**

1 c right 2 b right

**Physics -- check answers please**

you did not list them so I do not know what c and b are 6. If I add heat it will get hot I think, unless I subtract more heat :)

**Chemistry**

You are welcome :)

**Chemistry**

well, if I had one liter of the final stuff I would have 6 mols of H2SO4 in it so in 250 mL I need 6/4 or 1.5 mols H2SO4 so the real question is: What volume of 18M H2SO4 contains 1.5 mols of H2SO4 well there are 18 in a liter so I need 1.5/18 liter =.08333...... Liter which i...

**Typo**

3x=4y+5z=10 3x + 4y or 3x - 4y ???

**NEED HELP ASAP !!**

29,035 - (-1,349) = 29,035 + 1,349 =

**social studies**

New Orleans is a seaport and serves as the interface between shipping on the Mississippi River system(Including Missouri, Tennessee, Ohio rivers) and the rest of the world. When you cut a seaport off from the sea, it gets very poor as does the country behind it that depends on...

**social studies**

General Robert E. Lee.

**social studies**

It would be quite remarkable if they did.

**social studies**

Our own (Gloucester MA) General Butler mismanaged New Orleans :)

**4th grade math**

6/8 = 12/16 which is less than 15/16

**4th garde math**

3/5 = 36/60 4/12 = 20/50 so 3/5 is bigger

**Math typo**

.77 + .2 + .16 + .1 = more than 100% You have a typo I doubt if Europe has 77%

**math**

the corners

**Algebra**

B does 1/90 yards/min R does 1/75 yards/min B+R together do (1/90 + 1/75)yards per minute 1/90 + 1/75 = .0244 yards/min 1/.0244 = 40.9 minutes/yard

**basic algebra**

You are welcome :)

**basic algebra**

10 oz pot has 1 oz acid and 9 oz water x oz pot has .25 x oz acid and .75 x oz water so acid = 1 + .25 x water = 9 + .75 x total = 10 + x and (1 + .25 x) = .2 ( 10 + x) 1 + .25 x = 2 + .2 x .05 x = 1 x = 20 oz

**math**

use quadratic equation x = [ -4 +/- sqrt(16 - 24) ]/6 the solution is a complex number because b^2-4ac is negative. Given your last question, I do not think you have covered complex numbers. Perhaps you have a sign error.

**math**

(2x-1)(x+3)

**help**

Exactly how would we disallow workers from sending their money home? Like it or not, I think I might choose B.

**Algebra**

You are welcome :)

**Algebra**

v v+10 d = v*1 d = (v+10)*.5 so v = .5 v + 5 .5 v = 5 v = 10 d = v*1 = 10 miles

**Alegebra 2**

LOL - Yes, the reciprocals actually do add to 3

**Alegebra 2**

n and n+2 1/n + 1/(n+2) = 3 (n+2) + n = 3 n(n+2) = 3 n^2 + 6 n 2 n + 2 = 3 n^2 + 6 n 3 n^2 + 4 n - 2 = 0 n = [ -4 +/- sqrt (16 + 24) ]/6 n = [ -4 +/- 2 sqrt (10) ]/6 n = -2/3 +/- (1/3) sqrt 10 says positive so use + sign (sqrt 10 -2)/3 and (sqrt 10 -2)/3 + 6/3 = (4+sqrt 10)/3

**physics**

If the helicopter accelerates at 1 m/s^2 then the bananas accelerate at 1 m/s^2 unless the string breaks.

**Physics**

(1/2) m v^2 = 1.6*10^4 32 v^2 = 160 * 10^2 v^2 = 5 * 10^2 v = 10 sqrt 5 or about 22.4 m/s 22.4 m/s *3600 s/h * 1 km/1000 m = 80.5 km/h

**Math**

10 * 3 + 3 = 33

**math**

.8 * 360 = ?

**Physics**

average speed during stop = 15/2 = 7.5m/s time to stop = 7 m / 7.5 m/s = .933 s a = -15/.933 = -16.1 m/s^2 F = m a = 500(-16.1) = -8036 N a = same a = -16.1 v = Vi + a t 0 = 32 -16.1 t t = 32/16.1 = 1.99 s d = Vi t + (1/2)at^2 = 32(1.99) - 8(4) = 32 m d = Vi t - (16.1/2)t^2

**Algebra help PLEASE?**

(1/3)(pi*25)(20)

**Algebra help PLEASE?**

volume of cone = (1/3) area of base * height

**Math**

You are welcome :)

**Math**

http://www.jiskha.com/display.cgi?id=1393896576 that has the y axis intercept. for x axis what is x when y = 0? x = 2 so the two are (0, -2) (2, 0)

**stats**

binomial dist P(k wins in n trials) = C(n,k) p^k (1-p)^(n-k) C(10,1) = 10 because C(n,k) = n!/[k!(n-k)!] p = .1 1-p = .9 so P(10,1) = 10 *.1^1 *.9^9 = .387

**Math**

I just did that for you. http://www.jiskha.com/display.cgi?id=1393896576

**Science- Brady , Ms. Sue , Damon**

a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force. Would any of those balls go anywhere on any predictable path? Would their motion be random? Could you guess where a...

**Science- Brady , Ms. Sue , Damon**

I did not answer before because those games would be meaningless without inertia.

**Physics**

1 - .92 = .08 left PE = m g h PE2/PE1 = 1.21/1.45 = .8345 .8345^n = .08 n log .8345 = log .08 n = 13.96 or about 14

**Math**

divide both sides by 1.9 x - y = 2 or y = x - 2 start at (0,-2) go up to right with slope of 1

**math**

8 x = 10 x = 1.25 so 10 = 8 + 25% of 8 is that true? 8 + 8/4 = 8 + 2 = 10 sure enough 25% x (45) = 18 x = 18/45 = .4 so it is only 40 % of original which is a decrease of 100 - 40 = 60% decrease is that true? 60% of 45 = 27 is decrease 45 - 27 = 18 sure enough

**science**

a = F / m

**science**

F = G M m / r^2 = m a = m v^2/r in other words gravitational force equals mass times centripetal acceleration.

**Intermediate Algebra**

b = 5 + h b (h/2) = 33 b h = 66 (5+h)h = 66 h^2 + 5 h - 66 = 0 (h - 6)(h+11) = 0 h = 6 b = 11

**Physic**

weight = 2 kg * g accelerating at a down T = string tension 2 g - T = 2 a or T = 2(g-a) block mass m slope = 20 deg I think (don't have your font) mus = .73 and muk = .53 Normal force = m g cos 20 friction force = mu m g cos 20 weight component down slope = m g sin 20 T -m...

**Math**

sin^2 + cos^2 = 1 so sin^2 = 1 - cos^2 so here 1 - cos^2 - cos^2 = .......

**math**

tan 65 = h/25 yes

**math**

24/10 - (1 3/10) 24/10 - 13/10 ???? = 11/10 = 1 1/10

**Physics**

F * 4 = 56 F = 56/4 = 14 N

**Physics -- check answers please**

I agree with all six

**Science**

grass for the horse that turns the treadmill. corn to make ethanol .... I will be at this all night, have to stop.

**Science**

windmill in the back yard for electricity and water well pump solar panels for hot water and electricity and heat stationary bikes hooked up to alternators to run battery chargers for your computers and some lights and maybe TV stream in back yard diverted to run over water mi...

**Physics**

m g h + (1/2) m v^2

**Pre-Calculus**

Go back and check your volleyball question. I just saw it and you missed the angle of launch in your equations.

**Pre-Calculus**

Hey Alexis, between the two of us we have been doing an awful lot of problems for you. Many of them are the same old, same old. It is time for you to try and post what you did.

**Pre-Calculus**

I got ( +36 , 24 , 39 )

**Science -Check Answers-**

You are welcome :)

**Science -Check Answers-**

first is ok second no by conservation of momentum the velocity will remain the same until an outside force ACCELERATES it F = m A

**math**

4 y = -x + 5 y = (-1/4) x + 5/4 so m, slope = -1/4 y = -(1/4) x + b 9 = -(1/4)(6) + b 36 = - 6 + 4 b 4 b = 42 b = 10.5 so y = (-1/4)x + 10.5

**math**

12/8 = 3/2 = 1.5 9 = 1.5 w = 3 w/2 w = 18/3 = 6 feet 6 ft (12 in/ft) = 72 inches

**Pre-Calculus**

t = x - 6 y = 2 (x-6) - 4 y = 2 x -16

**Pre-Calculus**

Oh, I see from your other questions you are not using vector notation x = 0 + t = t y = 4 + 6 t

**Pre-Calculus**

y = 6 x + 4 through point (0,4) slope = 6 well (0,4) + (1,6) t should work

**Pre-Calculus**

That is the resultant, but you need the opposite to that so move it around 180 to cancel it

**Math**

y(t) = -16 t^2 + 32 sin 35 t + 4.5 x = 32 cos 35

**Physics**

three masses m .18 m and m - .18 m = .82 m ----------------------- momentum = m Va forever so m Va = .82 m (0) + .18 m (v) v is relative to ground or Va = .18 v throw speed relative to moving cart = v - Va = .82 v v = Va/.18 = 5.56 Va new speed of baggage relative to ground = ...

**Math**

what you have is .7 , .75 , .4 , .5 , .67 so 2/5 , 1/2 , 2/3 , 7/10 , 3/4

**Alegbra**

.05 x + .08(5000-x) = 331

**math101**

I will assume you mean (1/4) x - 18 = (1/2) x - 6 then -18 + 6 = (2/4) x - (1/4)x -12 = x/4 x = - 48 If I misinterpreted, please repeat using parentheses to show what is numerator and what is denominator.

**math**

By the way, we know any angle greater than 45 degrees will cause a crash without doing any arithmetic. At 45 degrees the tree is 65 feet high.

**math**

yes, 65 tan 50 is 77.5 so crash

**Chemistry 2**

20 at t = 0 5 at t = 40 A = C e^kt 5 = 20 e^40 k .25 = e^40 k ln .25 = 40 k -1.39 = 40 k k = - .03466 so A = 20 e^-.03466 t when A = 10, we have not only the blank filled but the half life .5 = e^-.03466 t ln .5 = -.6931 = -.03466t t = 20 I think you can do it now

**Physics**

If it is at rest plane angle T from horizontal force down plane = m g sin T force up plane = mu m g cos T no acceleration so mu m g cos T = m g sin T or mu = tan T

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