Saturday

February 13, 2016
Total # Posts: 25,228

**Chemistry**

heat to warm copper= Ccopper * 50 *(39.3-10) heat to cool water= 4.18 * 200 * (40-39.3) set them equal and solve for Ccopper
*January 13, 2016*

**Physics**

radius = Rearth cos 41.9 omega =2 pi/(24 hrs * 1 hr/3600 s) v = r omega
*January 13, 2016*

**Math**

9. percent equivalent to 3 is... Is it 0.03%? No 3 * 100 = 300 percent
*January 13, 2016*

**Math NO !**

Oh, is 4 1/4 as a percent - 4.25%? 4.25 * 100 = 425 % More than 4 times is more than 400 percent more: 4. fraction equivalent to 0.75% is... Is it 3/4? NO!!! .75/100 = .0075
*January 13, 2016*

**math**

for the same numerator the bigger the bottom, the smaller the result surely 1/4 is less than 1/2 :)
*January 12, 2016*

**Physics**

think lifting a barbell work in = Force up * distance up That is also the increase on potential energy m g h when you drop it that same value in Joules becomes (1/2) m v^2
*January 12, 2016*

**Physics**

Conservation of energy work done = increase of energy or work done = increase in kinetic energy + increase on potential energy
*January 12, 2016*

**Math**

photo area = 88 in^2 outside dimension = 8+2x by 11+2x so we want (2x+8)(2x+11) - 88 = 42 4 x^2 + 38 x - 42 = 0 2 x^2 + 19 x - 21 = 0 (2x + 21)(x-1) = 0 x = 1 inch
*January 12, 2016*

**Math**

LOL check your physics question
*January 12, 2016*

**Math**

silver back got 1 and 2 however 3 when you multiply by negative, you reverse the arrow 3. -5 p > - 30 5 p < 30 p < 6 which is b
*January 12, 2016*

**Physics**

F cos 38 = m a easy way is for constant acceleration v average = (Vi+Vf)/2 so v average = (0 + 2.2)/2 = 1.1 m/s so time = t = 3.4/1.1 = 3.09 s a = change in v / time = 2.2 / 3.09 = .712 m/s^2 so F cos 38 = 12 * .712 F = 10.8 Newtons
*January 12, 2016*

**Math**

3 (3 + 7/8) = 9 + 21/8 =11 5/8 15 4/8 - 11 5/8 = 14 12/8 - 11 5/8 = 3 7/8 He could get one more if it were not for the saw cerfs :) ------------------ check note 3 7/8 = 4 - 1/8 4 (4-1/8) = 16 - 4/8 = 15 1/2 sure enough
*January 12, 2016*

**Math**

1.12 = 8 x x = .14 or 14 % extra
*January 12, 2016*

**Math**

yes
*January 12, 2016*

**math**

2 v + 3 (v-10) = 220 5 v - 30 = 220 5 v = 250 v = 50
*January 12, 2016*

**Math (Calculus - Limits)**

(x-8)(x+b) = x^2 + 2 x + c - 8 b = c and -8 x + b x = 2 x or b = 10 so c = -80
*January 12, 2016*

**Math**

I mean 30 + 12 + 30 + 12
*January 12, 2016*

**Math**

so 20 + 12 + 30 + 12 :)
*January 12, 2016*

**Math**

1.6 x x + .6 x I guess :)
*January 12, 2016*

**Physics help**

loss of potential energy = gain in kinetic energy from 38.7 to 25.6: m g (38.7 - 25.6) = (1/2) m v^2 v = sqrt (2 * 9.81 * 13.1) = 16 m/s 12 = sqrt (2 * 9.81 * distance down) 144 = 19.62 d d = 7.34 distance of fall so 38.7 - 7.34 = 31.3 meters high at 12 m/s v = sqrt (2 *9.81* ...
*January 12, 2016*

**physics**

m = F/a = 48/3 = 16 kg
*January 12, 2016*

**physics**

both horizontal and down are 10 * sqrt2 /2 Newtons because sin 45 = cos 45 = sqrt2 /2
*January 12, 2016*

**Math**

xx 1 2 3 4 5 6 ------------- 1| 1 2 3 4 5 6 2| 2 4 6 8 10 12 3| 3 6 9 12 15 18 4| 4 8 12 16 20 24 5| 5 10 15 20 25 30 6| 6 12 18 24 30 36 well Leah's number must happen 3 times for every 2 of Sam's for example 2 happens twice (Sam) 4 happens 3 times (Leah) is there a ...
*January 12, 2016*

**math**

radius pond = 13 yds radius outside walk = 13+2 = 15 yds area of walk = pi (15^2-13^2) Got it now ?
*January 12, 2016*

**math help please**

5 (36-15)
*January 12, 2016*

**Algebra**

m + (m-15) = 44 ?? 2 m = 59 m = 29.5 s = m-15 = 14.5
*January 12, 2016*

**math help please**

20 + 5 + 20 + 5
*January 12, 2016*

**physics**

LOL - I guess unless the string breaks they better have the same acceleration force of m1 down slope = 3.7 g sin 30 = 1.85 g force of m2 the other way = 2.3 g net force = (2.3 -1.85)g = .45 * 9.81 = 4.41 N block 2 wins and heads straight down, block 1 heads up slope a = 4.41...
*January 12, 2016*

**Algebra II**

well, I suppose I would check -125^4/3 -125^1/3 = -5 then(-5)^4 = 625 so it looks like you are right to me
*January 12, 2016*

**Calculus AB**

Ah, so you have heard the words "mean value theorem" now let's see what the slope is from x = 1 to x = 2 y(2) = |(-2)(6)| = 12 y(1) = |(-5)(3)| = 15 so slope = -3/1 = -3 Mean value theorem says slope must be 3 at least once between = 1 and x = 2 lets look at ...
*January 12, 2016*

**Calculus AB**

Here you go http://www.sosmath.com/calculus/diff/der11/der11.html (mean value theorem)
*January 12, 2016*

**Calculus AB**

DRAW A GRAPH !!! somehow a smooth curve has to get from 4 at -3 back to 4 at +4 It could be a horizontal line, but that is a trivial case It could start up, but then would have to come down. SO HAS TO HAVE SLOPE of ZERO in here at least once if it started down, it has to come ...
*January 12, 2016*

**us history. Plz help!**

Well where is Louisiana and the Mississippi valley on your map ?
*January 12, 2016*

**us history. Plz help!**

3 is wrong. The United States did not exist when France was fighting England and us in the north east. I suspect they mean Louisiana purchase 5 wrong remember slavery etc at the time period 7 - I do not remember, assume you are right 9 I guess 11 no 12 - need for strong ...
*January 12, 2016*

**math help**

45 min + 30 min = 75 min = 1 hour and 15 min = 1.25 hr 9 - 1.25 = 7.75 which is 7:45 am
*January 12, 2016*

**Math**

2.5 gal (4 qt/gal) = 10 qt
*January 12, 2016*

**math help**

70/2
*January 12, 2016*

**math**

3 * 5.5 = 16.5 = 17
*January 12, 2016*

**math**

if n is 12 then n+6 is 18
*January 12, 2016*

**Conversion**

if it is 10 seconds I suspect 110 yards :) 1760 yd/mi 3600 s/h 110 yd/10 s (1 mi/1760 yd)(3600s/h) = 22.3 mi/h
*January 12, 2016*

**PHYSICS 1**

if your angles are math convention, counterclockwise from x axis and not compass angles from north then just use what Steve gave you for A Ax = 145 cos 190 Ay = 145 sin 190 etc
*January 12, 2016*

**math**

4.5 / 60
*January 12, 2016*

**6 is right**

You got one, enough already
*January 12, 2016*

**Random selections?**

4 C Hey have you just picked random answers?
*January 12, 2016*

**Math**

3D wrong, solution is y = 0 but what about 0 x = 0 in 2C ?
*January 12, 2016*

**Math**

2. Same mistake 5 x = + 40
*January 12, 2016*

**Math**

1) no 16 - 9 = +7
*January 12, 2016*

**Please try to do these before asking**

We are here to help, not to do your work for you. Try first
*January 12, 2016*

**math**

I just answered this http://www.jiskha.com/display.cgi?id=1452632926
*January 12, 2016*

**Math**

2 L + 2 w = 30 L = 4 w ======================== 2(4 w) + 2 w = 30 10 w = 30 w = 3 so L = 12 and A = 3 * 12 cm^2
*January 12, 2016*

**Language Arts - Please Help!**

1. I would pick B. It follows line by line the poem. 6. It says rhythym, not rhyme 7. I have no idea. 9. the second half can stand independently.
*January 12, 2016*

**Grade 5 math**

16 * 75 = ??? cm divide cm by 100 to get meters
*January 12, 2016*

**msth**

10 x + y x = 3+5 = 8 8 = 2 y so y = 4 80 + 4 = 84
*January 12, 2016*

**Math**

yes, you are welcome.
*January 12, 2016*

**Math**

2.6 + 6.03 + 2.6
*January 12, 2016*

**Algebra**

I do not see your answers.
*January 12, 2016*

**maths**

LOL you need more than that side side side? side angle side? angle side angle? or something
*January 12, 2016*

**Math**

1. yes 2. yes 3. no 9-12 = ? 4. five less is x-5 it can be equal to 9 or x-5 = 9 or it can be greater than 9 or x-5>9 so x - 5 >/= 9 which I believe is A
*January 12, 2016*

**Algebra**

y = (-3/4) x + 2 y = (+3/4) x + 2 slopes are -3/4 and +3/4 if they were the same, then parallel if one were - 1/the other, then perpendicular so neither
*January 12, 2016*

**math**

45 x = 100 + 25 x
*January 12, 2016*

**SS HELP!**

Which answer uses the word "Rights".
*January 12, 2016*

**SS HELP!**

1. No 2. yes 3. yes 4. I am not familiar with Georgia constitution but wonder if the conduct negotiations with Germany
*January 12, 2016*

**History**

neither
*January 12, 2016*

**History**

The assumption that "Most people know ... " is a hint of bias of course.
*January 12, 2016*

**History**

No, but we do not see what is in the article you read.
*January 12, 2016*

**Math**

yes
*January 12, 2016*

**Social studies**

Look at a globe or map !!!!!
*January 12, 2016*

**Social studies**

I would not pick d. That covers all of Europe and Africa :)
*January 12, 2016*

**Social studies**

For example: Israel, Jordan, and Lebanon. Saudi Arabia, Iraq,Iran Egypt, Turkey. ============================= find them :) by the way I am sure that they are all south of the arctic and north of the south pole, but that does not locate them satisfactorily.
*January 12, 2016*

**Math**

13891885.31 approximately
*January 12, 2016*

**Math**

220/8 = 27.5 225/5 = 45 do the others the same way and see which is the most words/minute
*January 12, 2016*

**Math**

Which ratio is equivalent to 4/16 A. 2:4•• B. 6 to 20 C. 8:32 D. 12 to 64 ===================== no 2/4 = 1/2 4/16 = 1/4 the only one with a denominator four times the numerator is 8/32 C.
*January 12, 2016*

**I am not sure**

I guess I would start with a Google search, maybe on napkin dye safety or just paper dye safety or something. I am not sure they are any more dangerous though.
*January 12, 2016*

**Wait a minute**

What am I thinking? The RANGE is the amount in the account. The DOMAIN is the date :)
*January 12, 2016*

**Algebra 2**

However it would not include 51.473 so 100 * entry is integer
*January 12, 2016*

**Algebra 2**

Why would it be integers? $ 51.47 for example I suppose it could be negative if your bank has some sort of policy covering your bad checks.
*January 12, 2016*

**math**

2 x^2 = 100^2 ? x^2 = 5,000 x = 70.7 feet if you want the sides of a square with 100 ft diagonal
*January 12, 2016*

**I do not understand**

Is this the diagonals of a square or something and you want the sides?
*January 12, 2016*

**Math**

(3/7)(3/3) = 9/21 sure enough :)
*January 12, 2016*

**Math**

Cute problem :)
*January 12, 2016*

**Math**

log 2 (-3sin x) -log2 (cos^2) x =1 log 2 [ -3 sin x/cos^2 x = 1 -3 sin x / cos^2 x = 2^1 = 2 sin x/cos^2 x = -2/3 well the sin must be negative so x is between pi and 2 pi well try sin x/(1 - sin^2 x ) = -2/3 let z = sin x z/(1-z^2) = -2/3 3 z = -2 + 2 z^2 2 z^2 - 3 z - 2 = 0...
*January 12, 2016*

**Math**

5h - 9 = -16 + 6h subtract 5 h from both sides - 9 = - 16 + 1 h add 16 to both sides 7 = h the end
*January 12, 2016*

**Social studies**

LOL - I would have picked A. Jews, Christians of all sorts in Syria and Lebanon and Armenia (if any survive) and Egypt .... But probably C is the expected answer.
*January 12, 2016*

**of**

1 12/60 hours = 1.2 hours 50 km/h * 1.2 h = 60 km
*January 12, 2016*

**math**

so A total = 32 x^2 sqrt 3/.75 so 32 x^2 sqrt 3/.75 = 19200 sqrt 3 x^2 = 450 x = 21.2 check my arithmetic
*January 12, 2016*

**math**

If you draw it you can see that An = An-1 * .25 or a , .25 a , .25^2 a etc we have a sum of a geometric series here with r = .25 see http://www.mathsisfun.com/algebra/sequences-sums-geometric.html the first term a is area of triangle with 8 x sides a = 2 * 4x * 4x sqrt 3 = 32 ...
*January 12, 2016*

**machanics**

G m M/r^2 = m v^2/r so G M/r = v^2 M = (4/3)rho r^3 G(4/3) rho r^2 = v^2 T = 2 pi r/v v^2 = (2 pi)^2 r^2/T^2 so G(4/3) rho = (2 pi/T)^2
*January 12, 2016*

**Physics**

450 * 2 = 900 Joules
*January 12, 2016*

**Physics**

Depends if they are vertical and symmetric about the cg if so 100/8
*January 12, 2016*

**Physics**

F = .5 m g = .5 * 35 * 9.81 Newtons
*January 12, 2016*

**Physics**

PE = 31 * 9.81 * 1.92 Joules at bottom (1/2) m v^2 = PE suspect C wants work done which is the same as the PE again
*January 11, 2016*

**yes**

If the tree were INCREASING there would be less CO2 released to the atmosphere. So you are right.
*January 11, 2016*

**math**

300/330 = .91 1 - .91 = .09 .09 * 100 = 9 %
*January 11, 2016*

**Physics**

with F = m a f cos 38 = .788 F again a = change in velocity/time = 2.2/time but time = distance/average speed = 3.4 /1.1 = 3.09 seconds so a = 2.2/3.09 = .712 m/s^2 so .788 F = 12 * .712 F = 10.8 Newtons (remarkable)
*January 11, 2016*

**Physics**

You can do it with work if you wish or you can do it with F = m a with work work done = Force in direction of motion * distance Force in direction of motion = F cos 38 = .788 F work done = .788 F * 3.4 meters = 2.68 F Joules that is the increase in kinetic energy (1/2) m v^2...
*January 11, 2016*

**so what is the question**

Are you doing geometric sequences? Fractals ? whatever ?
*January 11, 2016*

**us history**

If you go east from Florida you go to Africa.
*January 11, 2016*

**Math watch addition**

45 min for lunch so 6 hrs and 85 minutes I hour = 60 minutes so you have 7 hours 20 minutes I think 25 minutes
*January 11, 2016*

**Math**

driving 6.5 hr gas 1/6 hr lunch 3/4 hr sum = 7.41666666... hr = 7 hours + .416666.. * 60 min = 7 hours and 25 minutes so that is 5 hours to noon + 2 hours 25 minutes before noon sounds like 9:35 am
*January 11, 2016*