Wednesday

February 22, 2017
Total # Posts: 105,442

**biology **

if you have 1.0*10^9 molecule in tube and perform a 10^-7 dilution, how many molecule will in the new tube?

*February 22, 2017*

**biology**

if you want to make 50 ml of a 1x TAE solution fro a 50X stock, how would you prepare it?

*February 22, 2017*

**Science**

How are the primary pigments related to the primary colors? The primary pigments are: A. Complementary to the primary colors B. Associated with the primary colors C. Unrelated to the primary colors

*February 22, 2017*

**Algebra**

Jameston High School has 2020 students. Its enrollment has been decreasing at a rate of 125 students per year. Townsville High School has 1075 students. Its enrollment has been increasing at a rate of 80 students per year. Assuming the enrollment rates continue: A. Write an ...

*February 22, 2017*

**math**

Of the following fractions: 9/19, 5/11, 7/15, and 11/23, which is the largest?

*February 21, 2017*

**Calculus**

What is y=-2/7x-1 in standard form?

*February 21, 2017*

**Calculus**

What is y=-18x+13 in standard form?

*February 21, 2017*

**Math**

A bicycle that usually sells for $230 is on sale for 15% off. Find the sale price. Is this correct 230/25=9.2 230-9.2=220.8

*February 21, 2017*

**Statistics **

Researchers recruited 20 volunteers- 8 men and 12 men omen- to take part in an experiment

*February 21, 2017*

**Math/velocity**

just kidding, I figured it out! It's -4, 0, and 4

*February 21, 2017*

**Math/velocity**

At time t seconds, the center of a bobbing cork is y=4sint centimeters above (or below) water level. What is the velocity of the cork at t = 0, ?/2, ?

*February 21, 2017*

**Math derivatives**

Let f(2)=3, g(2)=4, f'(2)=5, g'(2)=6, f'(3)=7, g'(3)=8, etc. find (f?g)?(2)

*February 21, 2017*

**Math**

A line segment has one endpoint of (-3,2) and an undefined slope. Find the coordinates of another possible endpoint.

*February 21, 2017*

**world**

The shares of a company

*February 21, 2017*

**Math**

A line segment has one endpoint of A (2, -1) and a slope of 3/4. Find the coordinates of another possible endpoint B.

*February 21, 2017*

**Algebra 1**

Oh sorry about that, the slope is 2/3 and also thanks for the help.

*February 21, 2017*

**Algebra 1**

1. yes 4/3 2. slope = -2 all right 3. You did not say what the slope is but the only choice with y intercept of 9 is C. The y axis intercept is the value of y when x=0

*February 21, 2017*

**Algebra 1**

1. Find the slope of a line that passes through (–2, –3), and (1, 1). A. 1/3 B. 1 C. 2 D. 4/3** 2. For the equation –4y = 8x, what is the constant of variation? A. -4 B. -2** C. 1 D. 2 3. What is an equation for the line with slope and y-intercept 9? A. y = 2/3x...

*February 21, 2017*

**Algebra 1**

Thanks for the help

*February 21, 2017*

**Algebra 1**

1. yes, y = 3 x so y = 30 when x = 10 2. slope = m = (1+3)/(3-1) = 2 so y = 2 x + b put a point in 1 = 2*3 + b b = -5 so y = 2 x - 5 agree

*February 21, 2017*

**Algebra 1**

1. Suppose y varies directly with x, and y = 24 when x = 8. What is the value of y when x = 10? A. 10 B. 30** C. 80 D. 240 2. What is an equation in slope-intercept form for the line that passes through the points (1, –3) and (3, 1)? A. y = 3x + 1 B. y = x – 3 C. y...

*February 21, 2017*

**Science**

potential energy + kinetic energy = constant at top, Pe = m g H and Ke = 0 on the way down (1/2) m v^2 + m g h = that original m g H

*February 21, 2017*

**math**

2(b+3b)=40 b = 5 so 5 and 15

*February 21, 2017*

**Math**

30*60 = 1800 seconds * 4 m/s = 4*1800 meters 2 pi r = 200 pi meters circumference 4 *1800/200 pi = 36/pi= 11.459 circles = 11 circles + .459 circle .459 * 360 = 165 degrees x = 100 cos 165 = -96.6 y = 100 sin 165 = +25.9

*February 21, 2017*

**language arts: plz help**

How mature Ms. Sue deleting my comment!!!! Such An Adult!!!!

*February 21, 2017*

**Math**

A recipe that makes eight servings calls for 2 cups of milk how many cups of milk will be needed for 36 servings

*February 21, 2017*

**physics**

work = pulling force in direction of motion * distance like period, the friction and all are irrelevant. work = 161 cos 35 * 13.5 If there are more parts like how fast does it go or something, the rest matters, but that is all you need to know for the question you asked.

*February 21, 2017*

**physics**

mass does not matter, call it m normal force = m g cos 44 max friction force up slope = .27 m g cos 44 gravity force down slope = m g sin 44 so m g sin 44 - .27 m g cos 44 = m a (sin 44 - .27 cos 44) 9.81 = a

*February 21, 2017*

**Hala -- Physics**

Hala - acceleration = total change in velocity/time, not average a = 10 /2 = 5 m/s^2 what is in your mind I think is total distance = average speed *time

*February 21, 2017*

**Math**

2 x + 5 x = 63 7 x = 63 x = 9 2x = 18 5x = 45 ================== add to check 18 + 45 = 63, whew !

*February 21, 2017*

**Differential equation, calculus**

dt/dr = k/r^2 dt = k dr/r^2 try t = k (-1/r) + c I do not know where you got the other.

*February 21, 2017*

**physics**

Ac = 1.5 g = approximately 15 m/s^2 Ac = omega^2 r so omega^2 = 15/8 omega = 1.37 radiaans/second 2 pi radian /rev so .218 revs/sec times 60 s/min = 13 revs/min

*February 21, 2017*

**no idea**

Need better description of how boxes interact. (one on top of other? one hanging vertically from pulley? whatever)

*February 21, 2017*

**physics**

moving at 2.5 m/s relative to ground t = 35 m/2.5 m/s moving at (v-1) m/s same t 35 = (v-1) t solve for v

*February 21, 2017*

**math**

480000(.15)(.5)= 36,000

*February 21, 2017*

**Physics**

k = m g/.15 omega = 2 pi/T = sqrt (k/m) 2 pi/T = sqrt (9.81/.15)

*February 21, 2017*

**Math**

A wire is stretched from the top of a two feet tall anchor to the top of a 45 foot tall antena. If the wire is straight and has a slope of 3/5, then what is the length of the wire in feet?

*February 20, 2017*

**Algebra**

there are three nickels three dimes and four quarters in your pocket. you randomly pick three coin and place them on the counter. the first two coin are a dimes, and the third is quarter Probatitly of what happening?

*February 20, 2017*

**English**

I know that when we are writing essays, we cannot use the words we, you, etc. Is it okay if we use the words they, them, their?

*February 20, 2017*

**English**

what is passive voice

*February 20, 2017*

**math**

20 men dig a trench in 12 days,how many men would be needed to do it in 10 days

*February 20, 2017*

**math**

You are welcome.

*February 20, 2017*

**math**

15 y > -99/13 note < to > when multiply by negative 9 y > -99/(15*13)

*February 20, 2017*

**algebra**

A car cost $25,750.00 and depreciates in 20% per year how much will the car be worth in 5 years

*February 20, 2017*

**Algebra 1**

a^n /a^m = a^(n-m)

*February 20, 2017*

**Algebra 1**

say (2 *10^5) / (1*10^3) that is (2/1) (10^5/10^3) = 2 * 10^(5-3) <<<---important = 2 * 10^2 ================ check 2* 100000 /1000 = 2 * 100 :)

*February 20, 2017*

**Algebra 1**

(9*10*2)^3 = 9^3 *10^6 so (4/3) pi 9^3 * 10^6 about 4 * 81*9 * 10^6 about 2.9*10^9 the top one

*February 20, 2017*

**Math**

r = .05/4 = .0125 every quarter year multiply by 1.0125 7 years = 28 quarter years so 16,000 * 1.0125^28 = $ 22,655.88

*February 20, 2017*

**chem**

22.5 grams of lithium reacts with 33.5 grams of aqueous aluminum sulfate

*February 20, 2017*

**Algebra Word Problem**

n (n+2) (n+4) n(n+4) = 9 +12(n+2) n^2 + 4 n = 9 + 12 n + 24 n^2 - 8 n - 33 = 0 (n-11)(n+3) = 0 n = 11 n+2 = 13 n+4 = 15

*February 20, 2017*

**math (precalc)**

(x-5)(x-5)(x-3+4i)(x-3-4i) = 0 (x^2-10x+25)(x^2-6x+25) multiply that out

*February 20, 2017*

**physics**

I do not understand your second problem.

*February 20, 2017*

**physics**

average speed during stop = 25/2 = 12.5 m/s time to stop, t = 125/12.5 = 10 s v = Vi + a t 0 = 25 + a(10) a = -2.5 m/s^2 F = m a F = -2.5 m F = -mu m g F = -mu m (9.81) so mu(9.81)=2.5 mu = 2.5/9.81

*February 20, 2017*

**physics1**

What is the magnitude of your total displacement if you have traveled due west with a speed of 23 m/s for 125 s , then due south at 12 m/s for 255 s ? Express your answer using two significant figures. What is the direction of your total displacement in part A.

*February 20, 2017*

**History**

Who does Robespierre round up and execute

*February 20, 2017*

**History**

What was the name of the new freedom of the press newspaper created by Jean Paul Marat

*February 20, 2017*

**History**

When does the Terror end and who seizes control of france? July 27 1794 and Napolean

*February 20, 2017*

**Physics**

which of the following is NOT true about the path of a cannon ball launched horizontally from the earth's surface if air resistance is neglected? a. the cannnonball has a uniform horizontal velocity b.the total velocity of the cannon ball increases as a function of time c....

*February 20, 2017*

**Physics**

What happens to the location of the image when the radius of curvature changes? I think it moves farther away when the curvature increases.

*February 20, 2017*

**math**

x is distance between d is how close the close one is I assume they are on exactly the same bearing , not just the same side, or the problem is meaningless. People who write math books do not navigate. tan 42 = 48.8/d tan 35 = 48.8/(d+x) so d = 48.8/tan42 so d = 54.2 and 54.2...

*February 20, 2017*

**math**

tan 46 = h/400

*February 20, 2017*

**Math**

you must find the other side of rectangle using Pythagorean theorem where 5 is the hypotenuse and 3 is one of the legs. you will find out that the other leg is 3 cm. then find the area of the triangle 1/2bh using 4 as the height and 3 as the base.

*February 20, 2017*

**mathmatics**

A man has Rs 10000. he lost 2/5 of his money and he spent 1/4 of the reamainder. find the reamaining money with him now.

*February 20, 2017*

**Science **

density of wood that is 20 cm below water and 60 cm above water

*February 20, 2017*

**psychology**

Dr. Zimand is studying testosterone levels and their influence on aggression in adult males. It is likely that Dr. Zimand specializes in the ____________ approach to psychology.

*February 20, 2017*

**Chemistry**

Recall the reactions for this lab: S2O82- + 2I- ? 2SO42- + I2 (slow) Reaction 1 The one that delays the solution turning blue: I2 + 2S2O32- ? 2I- + S4O62- (fast) Reaction 2 b. All the S2O32 is consumed when the color change occurs. Therefore, ?[S2O32] = c. Use the ...

*February 19, 2017*

**Chemistry**

. A student mixed the following reactants, using the general procedure for the experiment: 10.0 mL of 0.10 M KI, 10.0 mL of 0.0010 M Na2S2O3, 20.0 mL of 0.040 M K2S2O8, and 10.0 mL of 0.10M HCl. It took about 75 seconds for the mixture to turn blue. a. By using the dilution ...

*February 19, 2017*

**Math 104**

There are 5 cyclists in a race. There will be a first-place and a second-place prize awarded. In how many different ways can the 2 prizes be awarded?

*February 19, 2017*

**chem**

0.210 mole of Na2CO3 in 200.0 mL of solution

*February 19, 2017*

**physics**

how is energy conserved ith a spring and box on a ramp. does 1/2kx^2 still equal gpe? what if the spring displacement is the same but the angle of the ramp changes, causing the gpe to change. how is energy conserved since the gpe is lower than before but the spring pe is the ...

*February 19, 2017*

**addition vectors (physics)**

east components (+ x axis) 75 cos 25 - 75 cos 65 north components (+ y axis) 75 sin 25 - 75 sin 65 - 75 so I get east = +36.3 km north = -111 km distance = sqrt(36.3^2 +111^2) tan angle south of east =111/36.3

*February 19, 2017*

**Physics**

You have typed this all wrong but look at the question above this one to see how to do it.

*February 19, 2017*

**MATH**

What is the percentage of sugar in the syrup made of 10 kg of water and 15 kg of sugar?

*February 19, 2017*

**Algebra**

150g of sugar was used to make a bottle of 8% syrup. How much water was used to make this bottle of syrup? How much syrup is there in this bottle?

*February 19, 2017*

**Geo**

(SAT Prep) The perimeter of pentagon ABCDE is 30 in, AB = 7 in, BC = CD = 6 in, DE = 5 in. How many sides of the pentagon have equal length?

*February 19, 2017*

**Geo**

(SAT Prep) The diagonals BF and CE divide the hexagon ABCDEF into two equilateral triangles and a square. Find the perimeter of the hexagon if BF = 3 cm.

*February 19, 2017*

**Maths,**

(2/5)s + (1/4)s = (8/20 +5/20)s = (13/20)s so (7/20)s = 2.10

*February 19, 2017*

**Algebra I**

3 c + 5 b = 31 c = 3 b - 1 ====================== 3 (3b-1) + 5 b = 31 9 b - 3 + 5 b = 31 14 b = 34

*February 19, 2017*

**your turn**

This is so similar to ones I have shown you how to do that you should be able to do it.

*February 19, 2017*

**Physics**

By the way, I am assuming that either way the man goes up into the container. If not then he has to move his own mass up, not only the wheelbarrow.

*February 19, 2017*

**Physics**

It does? Not in my shipyard :) Block and tackle tends to have higher frictional losses than a wheelbarrow. All methods do the same amount of "useful" work. That is the weight times 4 meters up. With your simple machines, wheels up ramps, blocks and tackles, you ...

*February 19, 2017*

**Physics**

primarily friction loss, bearings heat up on axle where wheelbarrow wheel turns.

*February 19, 2017*

**chemistry**

.43 L (1.25 mol/L) = .525 mols needed .525 mols (1 Liter/3.9 mol) = 0.135 Liters

*February 19, 2017*

**chemistry**

.17 *1.1 = .187 mols CaCl2 = 111 grams/mol (40 + 2*35.5 ) .187 mol (111 g/mol) = 20.8 grams

*February 19, 2017*

**Chemistry**

N = 14 g/mol H = 1 g/mol NH3 = 14+3 = 17 g/mol 3.68 g * 14/17 = 3.03 grams of N needed by the way check grams of H 3.68 *3/17 = .65, just enough hydrogen:)

*February 19, 2017*

**Chemistry**

Hello, I really don't understand how to find the grams of moles in some of these reactions. If someone could help I would appreciate it. 1) Balance the following chemical reaction and determine the number of moles of HI produced when 2.33 moles of H2(g) are consumed in the...

*February 19, 2017*

**Algebra**

James has a 6-ft board that is 24 in. wide. He wants to cut it into five pieces to make a small bookshelf with two shelves. The front and back will not be covered. What should be the dimensions of the bookshelf to maximize the volume and use all of the 6-ft board?

*February 18, 2017*

**Algebra**

A page should have perimeter of 42 inches. The printing area within the page would be determined by top and bottom margins of 1 inch from each side, and the left and right margins of 1.5 inches from each side. What should be the overall dimensions of the page in order to ...

*February 18, 2017*

**Math**

The cost of renting a car is given by the formula C= 50n +0.15d, where C is the cost in dollars, n is the number of days rental, and d is the distance driven in miles. How much would it cost to rent a car for a 15- day road trip, and drive 475 miles each day? My Answer: 8 ...

*February 18, 2017*

**Math**

-1/8(x+35)= -7 How do I solve this??? I am confused

*February 18, 2017*

**Math**

I don't think so since the answer is nothing to the choices A. $144 B. $199 C. $251 D. $277

*February 18, 2017*

**Math**

Karen spents 450 dollars on monthly bills. Of this total amount, 12% is for phone service,1/10 is for Internet service, and 2/9 is for utilities. If the rest of the total amount is for food, how much does Karen have for food? I said $130 since I subtract all

*February 18, 2017*

**english**

I worded the sentence to how I thought it should look like. So I'm guessing it's wrong? Do I put a comma before the h?

*February 18, 2017*

**english**

More states have, “… embraced laws requiring waiting periods for abortion…” however this is unfair to the women going through this. Would I capitlize the however or leave this sentence how it is

*February 18, 2017*

**Algebra I**

4 p = 2 m -2 so m = 2 p + 1 3 p + 9 m = 54 3 p + 9 (2 p + 1) = 54 etc

*February 18, 2017*

**electronic**

Determine the power dissipated in each of the resistors and the power entering the source. Express your powers in Watts. Remember that the power entering a two-terminal device is the product of the voltage across the device and the current through it in the associated ...

*February 18, 2017*

**Psychology**

s

*February 17, 2017*

**grammar simple, compound/complex**

1. We like stories which have unusual endings. <-- compound 2. The novel that was written is about dragons. <-- complex 3. The main character Adela is interesting; she is a warrior. <-- Compound 4. Dragons are ruining the small village in the story. <--- simple 5. ...

*February 17, 2017*

**english 2**

In this scene the Sergeant compares Macbeth and Banquo to â€œAs sparrows eagles, or the hare the lion.â€ Knowing that the eagle and the lion are predators and the sparrow and the hare are prey, what does Shakespeare reveal about the characters ...

*February 17, 2017*

**Ethics**

Please assume that, in the process of assisted reproductive technology (ART), more human embryos were created than are needed by the donors for the purposes of their assisted reproduction. Under these circumstances, which of the following is most likely to conclude that it is ...

*February 17, 2017*