# Posts by ANON

Total # Posts: 3,080

calculus
wait..dont u hve to integrate it?

calculus
for 0<=t<=21 the rate of change of the number of blakc flies on a coastal island at time t days is modeled by R(t)=3sqrt(t)cos(t/3) flies per day. There are 500 flies on the island at the time t=0. To the nearest whole #, what is the max # of flies for 0<=t<=21?

calculus
A. The cost of the timber lost = 1000 h The cost to have x firemen is x(25 h +20) The time to stop the fire is t= 3600/x C= 1000 h + x(25h + 20) B. Set h = t H = 3600/x C. Substitute for x in cost equation C= 1000 h + x(25h + 20) = 1000*3600/x + x(25*3600/x +20) = 3.6*10^6/x...

calculus
a) C=1000h+20x+25xh b) h=3600/x c) C=1000(3600/x)+20x+25x(3600/x) C=3600000/x+20x+90000 dc/dx=-3600000x^-2+20 -3600000x^-2+20=0 3600000x^-2=20 20x^2=3600000 x^2=180000 x=180000^1/2 (approx. 424.26) to justify it do d2c/dx^2 d2y/dx^2=7200000x^-3 sub in your answer 7200000*(...

calculus
Ok. Just do it the brute-force way. Initially, the area is 1/2 x 5 x 10 = 25 After one minute, the area is 1/2 x 6 x 7.5 = 22.5 After two minutes, the area is 1/2 x 7 x 5 = 17.5 You can see that the area is decreasing. In terms of derivatives, the rate of change is exactly ...

Forensics
A sample of light brown powder found in the kitchen of an alleged drug house gives a blue precipitate with cobalt thiocyanate. What is it? Is there enough evidence to prosecute?

Math-trig
The question in the textbook misses key information

Grammar
Thank you so much!! :D

Grammar
Am I using "into" properly in this sentence? Enrolling into college with an undecided major... I don't if I should use "to" or "into". Thanks :)

Grammar
Thanks :)

Grammar
Is this the right form of "to" in this sentence? I believe an education at XX College would give me the opportunity to hone my abilities and turn them into skills that can be translated to a successful career.

Chemistry
So it is a combination reaction, then?

Chemistry
What type of reaction occurs between zinc and Acetic acid? I think it is double replacement but I am not sure. Thank for the help :)

Grammar
Thank you :)

Grammar
I am writing an essay and for this sentence, I don't know if I have used the right tenses of "can" and "give". Please check to see if they are right :) "Using the insight gained from her road of life, she has given me the best life she can while ...

Chemistry
Go to back to H4P2

Chemistry
The data for everyone of us is different as you noticed formula is required

Chemistry
What is 4

Chemistry
He has got a point, though he did it a bit too aggressively. What he wants to know is, what are the formulas for working out these two questions? After all, a similar question could pop up in the final exam! To tell you the truth, i kinda miss how it was at the beginning of ...

math
9/20 7/10 4/5

Biology
bye boy. No one asked you to comment. I obviously could not find the answers to these question hence me posting them.

Biology
1. Two species live in the same area but breed in different parts of their habitat. These species are A) geographically isolated. B) ecologically isolated. C) artificially isolated. D) likely to produce hybrids. 2. A large population of animals is split in two by a physical ...

I used " nothing poeple " and " the girl that has no friends" answers and got a 100%. Thank you!

Grammar-clauses
I put the underlined parts of the sentences in parentheses. William Faulkner’s The Sound and the Fury is a novel (that uses the technique of stream of consciousness). independent clause adverbial clause adjectival clause (my answer) noun clause It takes effort to imagine...

English-Grammar
So the second one is a compound sentence?

English-Grammar
Although he was born in Scotland, he became a hero of the American Revolution. simple sentence compound sentence complex sentence (my answer) compound complex sentence His ship was badly managed, but Jones refused to give up. simple sentence (my answer) compound sentence ...

English-Grammar
thanks :)

English-Grammar
After the war, American shipping became vulnerable to attacks by pirates. simple sentence (my answer) compound sentence complex sentence compound complex sentence

English-Grammar
John Paul Jones moved to America to avoid a trial that involved his handling of a mutiny. simple sentence compound sentence complex sentence (my answer) compound complex sentence

Chemistry
No, the solubility of PbCl2 would remain roughly unchanged.

Chemistry
if you want that question answered, post it separately.

physics
water is moving at a velocity of 2m/s through a hose with an internal diameter:1.60cm. What is the flow rate in liters per second?

math/algebra
A kicker punts a football from 3 feet above the ground with an initial velocity of 47 feet per second. Write an equation that gives the height (in feet) of the football as a function of the time (in seconds) since it was punted. Find the height (in feet) of the football 2 ...

Calculus
Let f be a continuous function on the interval [0,2] which satisfies integral of f(x)dx=5 when b is 2 and a is 0. Give this information compute the definite integral f(2y)dy when b is 1 and a is 0. Solve this

Calc-Derivative
Find the derivative of x^(1/x). Can someone show me steps for this problem...I go round in circles

Chemistry
The figure below is a heat curve for an unknown outerspace substance discovered by the Mars rover. By understanding the heat curve, scientists can make inferences about the composition of the planet. What is the temperature of fusion, Tfusion, and vaporization, Tvapor, for ...

Chemistry
What is true for water? A) In a phase diagram the solid-liquid coexistance line has a negative slope. B) In a phase diagram the solid-liquid coexistance line has a positive slope. C) The solid is more dense than the liquid. D) The solid is less dense than the liquid. E) The ...

English-Grammar
Thanks :)

English-Grammar
Which of the following is an example of an adverbial clause fragment? A.wherever there is a chance for a fabulous meal B.who described the book as a compelling masterpiece C.that the poet choose words carefully to convey a particular tone I think the answer is A, but I am not ...

Chemistry
Enthalpy of fusion 333.6 J/g 6010. J/mol Specific heat of solid H2O (ice) 2.087 J/(g·°C) 37.60 J/(mol·°C) Specific heat of liquid H2O (water) 4.184 J/(g·°C) 75.37 J/(mol·°C) Specific heat of gaseous H2O (steam) 2.000 J/(g·°...

Chemistry
To treat a burn on your hand, you decide to place an ice cube on the burned skin. The mass of the ice cube is 16.0 g, and its initial temperature is -11.4 °C. The water resulting from the melted ice reaches the temperature of your skin, 31.0 °C. How much heat is ...

Chemistry
On another planet, the isotopes of titanium have the following natural abundances. Isotope 46Ti Abundance 70.900% Mass(amu) 45.95263 Isotope 48Ti Abundance 10.000% Mass(amu) 47.94795 Isotope 50Ti Abundance 19.100% Mass(amu) 49.94479 What is the average atomic mass of titanium ...

Math
The Johnstown inclined plane in johnstown, pennsylvania, is a cable car that transports people up and down the side of a hill. during the cable car's climb, you move about 17 feet upward for every 25 feet you move forward. at the top of the incline, the horizontal distance...

physics
what even is this

Math

Chemistry
For the energy is it around 3.647x10^-19J? And how did you know that c=3*10^8m/s?

Chemistry
Is F=5.55*10^14Hz?

Chemistry Someone Check for me
What did you use for the freq?

Chemistry
What is the freq? You got C=2x10^8m/s but you don't have the freq.

Chemistry
Suppose that absorbances of several solutions were measured at 545 nm. What is the frequency of this wavelength? What is the energy of this wavelength? (h=6.626 times 10^-34J*S)

Chemistry
Ok. I thought 100mL/25mL=4mL. Thanks

Chemistry Need Some to Check
But when you times (100mL/25mL) you get 4mL. Then you times 4mL times 15.8 mg/L and it doesn't cancel out the mL.

Chemistry
Concentration 15.8 mg/L Final Volume 100.0 mL What is the concentration of phosphate in the original lake water sample if the unknown lake water sample in the option has been diluted by taking 25.0 mL of lake water and diluting it to the indicated final volume? •Chemistry...

Chemistry
Water treatment plans must reduce phosphate levels to 3.2 micromoles PO4^3-/L before the water is considered drinkable. If water from Lake A is determined to have a phosphate concentration of 0.419 mg PO4^3-/L, does it meet this allowable standard for drinking water?

Chemistry
Don't you have times 100/25 by 1000mL/1L to get it to mg/L?

Chemistry
Concentration 15.8 mg/L Final Volume 100.0 mL What is the concentration of phosphate in the original lake water sample if the unknown lake water sample in the option has been diluted by taking 25.0 mL of lake water and diluting it to the indicated final volume?

Chemistry
The quantity of antimony in an ore can be determined by an oxidation-reduction titration with an oxidizing agent. The ore is dissolved in hot, concentrated acid and passed over a reducing agent so that all the antimony is in the form Sb3 (aq). The Sb3 (aq) is completely ...

Math
The grade of a highway up a hill is 50%. How much change in horizontal distance is there if the vertical height of the hill is 175 feet?

Calculus
Evaluate Integral of (lnx)^4/x dx when b is E and a is 1

Math
OMG, thank you!

Calculus
Evaluate integral of x times square root of (2x-1)dx

Calculus
Evaluate integral of x times the square root of (x-4) dx I got u-(8u^(3/2) over 3) Can anyone check this for me?

Chemistry
Balance the following equation for a half reaction that occurs in acidic solution. Use e– as the symbol for an electron. Mo^3+ -> MoO2^2+

Chemistry
The quantity of antimony in an ore can be determined by an oxidation-reduction titration with an oxidizing agent. The ore is dissolved in hot, concentrated acid and passed over a reducing agent so that all the antimony is in the form Sb3 (aq). The Sb3 (aq) is completely ...

Chemistry
Classify each of the following as a redox reaction or a non-redox reaction. Zn+CuCl2 -> ZnCl2+Cu HCl+NaOH -> H2O+NaCl 2CO+O2 -> 2CO2 SO3+H2O -> H2SO4

Chemistry
Can someone check my answers? What is the oxidation state of each element in K2Cr2O7? K +1 Cr +6 O -2 What is the oxidation state of each element in SO32–? S +4 O -6

sat essay
Assignment: Should heroes be defined as people who say what they think when we ourselves lack the courage to say it? Plan and write an essay in which you develop your point of view on this issue. Support your position with reasoning and examples taken from your reading, ...

SAT Essay
Assignment: Should heroes be defined as people who say what they think when we ourselves lack the courage to say it? Plan and write an essay in which you develop your point of view on this issue. Support your position with reasoning and examples taken from your reading, ...

Lang Arts
4 is c. You made me get it wrong... -_-

Physics
Which requires more energy: to raise 1 kg of liquid water from 0 to 100 degrees (Celsius) or to turn that water to steam after it hits 100 degrees? Assume the specific heat capacity of water is approximately independent of temperature.

math
44% of adults say cashews are their favorite kind of nut. You randomly select 12 people and ask each to name their favorite nut. Find the probability that the number who say cashews are their favorite nut (a) exactly three, (b) at least four, and (c) at most two.

Chemistry
How do you prepare 600.0mL of 0.48M Al(NO3)3*9H2O? Is this correct? 1. Measure out 71g of solution 2. Put approx. 300.0mL of water into container 3. Add the 71g of solution to the water and mix 4. Add more water until 600.0mL of solution is obtained 5. Mix •Chemistry - ...

Chemistry HELP
Isn't the total mass of the Al(NO3)3*9H2O around 247.18 g/mol?

Chemistry
How do you prepare 600.0mL of 0.48M Al(NO3)3*9H2O? Is this correct? 1. Measure out 71g of solution 2. Put approx. 300.0mL of water into container 3. Add the 71g of solution to the water and mix 4. Add more water until 600.0mL of solution is obtained 5. Mix

Chemistry
The moles of C is 3.227. The moles of F is 3.224. Therefore the empirical formula is CF. How would I find the empirical mass? Your explanation is confusing.

Chemistry
For n I got 26.18 mols. For the mass I got 31 because it was CF.

Chemistry
A 0.02882 g sample of gas occupies 10.0-mL at 288.5 K and 1.10 atm. Upon further analysis, the compound is found to be 38.734% C and 61.266% F. What is the molecular formula of the compound? What is the geometry shape around each carbon atom? Polar or Nonpolar?

English-Grammar
The underlined words (I put them in parantheses) are an example of a(n) ___________. (When the earth, moon, and sun are in line), an eclipse occurs. A. adverbial clause B. adjectival clause C. noun clause My answer is C.

Grammar
In case anyone was wondering, the other answers are 1. A 2. B 3. B and then yes 4. Is A

Grammar
Thanks :)

Grammar
Which of the sentences below displays the correct punctuation? A.The patient looked at the doctor as though he had never seen her before. B.Even though Laura is very young she is already a skilled chess player. C.Carlos asked me to buy the gift, since I am more aware of our ...

physics HELPP!!!!!!!
Two astronaut, as shown in the figure, each having a mass of 88.0 kg, are connected by a 10.00 m rope of negligible mass. They are isolated in space, moving in circles around the point halfway between them at a speed of 6.00 m/s. By pulling on the rope, the astronauts shorten...

Grammar
Thanks :)

Grammar
"that"?

Grammar
Which of the following is a complex sentence? A.After the class, we all went to Alec's house. B.Alec's brother John was home, but his sister Cynthia wasn't. C. Alec suggested we all go to the neighborhood pool. I'm thinking the answer is A, but I'm not too ...

physics HELPP!!!!!!!
A beam resting on two pivots has a length of L = 9.00 m and mass M =89.0 kg. The pivot under the left end exerts a normal force n1 on the beam, and the second pivot placed a distance 4.00 m from the left end exerts a normal force n2. A woman of mass m= 48.0 kg steps onto the ...

physics HELPP!!!!!!!
A 6.00 kg mass is connected by a light cord to a 1.00 kg mass on a smooth surface as shown in the figure. The pulley rotates about a frictionless axle and has a moment of inertia of 0.400 k∙m2 and a radius of 0.700 m. Assuming that the cord does not slip on the pulley, ...

Math
Please help! Economy drapes for a certain size window cost \$90. They have shallow pleats, and the width of the fabric is 2 times the window width. Luxury drapes of the same fabric for the same size window have deeper pleats. The width of the fabric is 3 times the window width...

Math
Letter 'C' on this question confuses me, please help! Holly has joined a video rental club. After paying \$6 a year to join, she then has to pay only \$1.25 for each new release she rents. a. Write an equation in intercept form to represent Holly’s cost for movie ...

statistics
fck u boi

Math
Freshman math question, super confused! Today while Don was swimming, he started wondering how many lengths he would have to swim in order to swim different distances. At one end of the pool, he stopped, gasping for breath, and asked the lifeguard. She told him that 1 length ...

math
Yes it is 88.9%!

Math for Steve or someone good at math
The answers in order are: B D A D D

physics
A 1,660 kg car is parked on a hill with a slope of 8.0°. Its brakes and transmission are locked in position to keep the car from rolling. The coefficient of static friction of the rubber tires on the asphalt road is 0.14. What is the force of static friction between the ...

physics
A sled whose total mass with cargo is 30.0 kg rests on ice. The coefficient of static friction is 0.20, and the coefficient of kinetic friction is 0.15. The sled is attached to a rope, horizontally, in which the tension force is slowly increased. How much tension force applied...

calculus
Just take tbe derivative of the functions, set that to zero and solve for x. Take those values you got and the interval values and test them in the ORIGINAL function ( f(x) not the derivative! )and see which is the biggest value (absolute max) and the smallest value (absolute ...

Physics
she could have meant 14.1... just saying

Math
Thanks alot to "Miss Sue". I like how you show us how to do it, not just give the answers. Very helpful.

math
I am lol