Homework Help

During high tide the water depth in a harbour is 22 m and during low tide it is 10m(Assume a 12h cycle). Calculate the times at which the water level is at 18m during the first 24 hours. My solution: I found the cos equation: H(t)=-6cos(π/6t)+16 then.. Let π/6t=Θ 18=-6cosΘ+16 18-16=-6cosΘ Θ=1.230959417 Let Θ=π/6t π/6t=1.230959417 Then I don't know what's next....

for the titration of 25.0mL of 0.20M hydrofluoric acid with 0.20M NaOH, determine the volume of base added when pH is 2.85?

I have a huge assignment to complete and I don't understand these questions can someone Please help me out!

a parallel plate capacitor has plates of dimensions 20cm by 20cm seperated by 2mm. The dielectric constant of the material between the plates is 5 and the plates are connected to a voltage source of 500V. calculate (a) the capacitance, (b) the charge on either plate, © the energy density, and(d) the total energy stored in the capacitor.

what this equation means h=hf+x*hfg what is the physical meaning of dryness fraction.

If you place a DNA of a mouse, mRNA of a rabbit, ribosomes of a hydra and tRNA of a human in a test tube, and place it in optimal conditions for translation to occur, which imitate the conditions inside cell cytoplasm, you will get a polypeptyde chain of which animal: mouse, rabbit, hydra or human?

how do you calculate specific heat capacity? if you can work an example that would be great!

I have started this thread to help cloudzell91 with an idea for a thesis project. He needs more than one to present to his adviser. The original idea came from one of the Knuth "Fundamental Algorithms" volumes, as I recall. I do not have a copy to verify my memory and extract a quote. However, the quote said something to the effect that programming languages cannot modify their own syntax, as spoken languages can. That peaked my curiosity and started me on a lifelong quest to satisfy my curiosity about how it may be done. Several years later, I worked for Datapoint, a minicomputer manufacturer, who had developed a scripting language called CHAINPLUS, which had fun…

Hello, my teacher gave me this question and seems like none of my classmates know the answer. I understand that first I have to find a compund that reacts with HCL to find the first letter "A" but how do I do that? Thank you in advance for the ones willing to help me Compound X was treated with Hydrochloric acid to give compound A, a primary substituted compound. Compound A was then treated with aqueous sodium hydroxide to give compound B and sodium chloride as products. Compound B was oxidized to compound C which was further oxidized to compound D. Compound D was found to have a formula of C3H6O2 and had a pH <7. Compounds B & D reacted with one another in the…

Hello. I have got homework for tomorrow and I have some difficulties doing it, can you please help me doing it? Thanks BTW, its not necessery to do the essay so I will do it on my own.

Lions and tigers are two closely related species which evolved from a common ancestor. Explain how moving to different habitats has resulted in the formation of these two different species.

in case of turbine it is said the work is done by the system and for compressor it is said that the work is done on the system.in case of turbine steam moves the blades and in case of compressor air moves the piston.then where is the difference in regard to work done or work by???

Hi!!! Which is the parametrization of z= y^2-x^2 , and f(x,y)=(-x,-y,z) ???

a math problem goes like this a gas initially at p1=512 kpa and v1=142 litre undergoes a process to p2=172 kpa and v2=274 litre durig which enthalpy decreases 65.4 kj.specific heats are constant,Cv=3.175 kj/kg-k.determine dU,Cp and R. here my question is 1) I cant understand which thermodynamic process is this,isothermal,polytropic or adiabetic.and why??

Hii!!! I hope someone can help me with the following exercise...!!! Let G=(V,E) be a directed graph with weight w: E->R, n=|V|. Let m( c )=1/k*sum(w(e_{i}), i=1,k) be the mean weight of a circle. Let m*=min(m( c )), the minimum of the mean weights of the circles of G. Is it correct to say that, since the minimum of the mean weight is 0 and not negative, there are no circles with negative weight? Or is there an other explanation that if m*=0 there are no circles with negative weight..??? And also, how could I explain that δ(s,v)=min(δ_{k}(s,v), o<=k<=n-1), where δ(s,v) is the weight of the lightest path from s to v, and δ_{k}(s,v) is the weight of the light…

octane is burnt with 80% air if it is theoritical air ,the equation wiill be C8H18+a(O2+3.76N2)------>xCO2+yH2O+a*(3.76N2) and form that equation we can find the coefficient a,x,y. for x=8; 2y=18, so y=9; 2a=2x+y, so 2a=2*8+9, a=12.5 but when it comes to less than theoritical air there should be co present ,shouldn't it? then what will be the equation c8h8+a(o2+3.76n2)----->xco2+yh2o+a*(3.76n2)+co if i give some coefficient to co my question is how i can find the value coefficient of co here ?

Hi!!! I need some help at the following exercise... Let G=(V,E) be a directed graph, where V={a,b,c,d,e}, E={(a,b),(a,e),(b,c),(c,d),(d,e),(e,c)} and their weights 1,2,2,-1,-1,3 respectively. Show where the Dijkstra's algorithm fails. What I've done so far is: At the beginning the distances are d[a]=0, d=d[c]=d[d]=d[e]=infinity a gets extracted first, after the edges (a,b) and (a,e) are relaxed, and the distances are d=1, d[e]=2. b is extracted next, after the edge (b,c) is relaxed, and d[c]=3 then c is extracted,after the edge (c,d) is relaxed and d[d]=2 At this step I have difficulties... Now d[d]=d[e]... How do I continue??

1, Prove the following: (i) [latex]if, ax = a[/latex] for some number [latex]a \neq 0, then, x = 1.[/latex] (ii) [latex]x^2 - y^2 = (x-y)(x+y)[/latex] My Answer: (i) if [latex]ax = a, a \neq 0[/latex] [latex]ax * a^{-1} = a * a^{-1}[/latex] [latex]x * a * a^{-1} = a * a^{-1} = 1[/latex] [latex]x * 1 = x = 1[/latex] (ii) let [latex]y = x +k[/latex] then [latex]x^2 - y^2 = x^2 - (x+k)^2[/latex] [latex]= x^2 - (x^2 + 2xk + k^2)[/latex] [latex]= x^2 - x^2 -2xk - k^2[/latex] [latex]= -2xk -k^ = -k(2x+k)[/latex] then [latex](x-y)(x+y) = (x - (x+k))(x + x +k)[/latex] [latex]= (x-x-k) (2x +k)[/latex] [latex]= (0-k)(2x+k) = -k(2x +k)[/latex] Thus, [late…

1. The problem statement, all variables and given/known data find dy/dx for the function xy^2+xlnx=4y for x>o 2. Relevant equations xy^2+xlnx=4y 3. The attempt at a solution I found the dy/dx to be "(y^2+lnx+1)/(4-x)=dx/dy" What is it asking me to do with the x>0? Do they want me to plug in a value greater than 0 for x and solve for y? or what?

I'm taking an online course so there is no teacher to check my work. Thanks in advance! ps. don't worry about #4.

which of the following mostly accurately describes why a plastic, air-filled ball expands in the sun? a) when they heat up the air molecules expand b) when they heat up molecules making up air expand c) when they heat up, the distance between the air molecules expands. d) when they heat up the distance between the molecules making up the air expands.

what is "equivalent molecular mass " means and how to determine it from mole fraction ????

Please forgive me for my ignorance but my studies with regards to NMR was lifetimes ago! I work with Polyurethane systems and my question with regards to these is the following: If the polyurethane material is cured out (like a hard plastic like PE or ABS rigid) would there be any detectable signal in a NMR test and/or in a MRI instrument? My thought is that as long as the polyurethane is 100% reactive it is solid and kind of in a pseudo frozen state, a state in which the electrons are not readily manipulated by the magnetic field for alignment as well as less susceptible for RF deflection. I could imagine that if a unreactive material is used like a plasticizer it wil…

Are my calculations to graph this function [f(x)=(-5x^2+3x)/(2x^2-5)]correct? Can you please check them over and see if I have done this wrong?

The problem statement, all variables and given/known data Find the critical point of f(x)=(-5x^2+3x)/(2x^2-5), and show whether this point is a max/min. Relevant equations f(x)=(-5x^2+3x)/(2x^2-5) The attempt at a solution When I tried solving for the derivative of; f(x)=(-5x^2+3x)/(2x^2-5), I got (-6x^2+50x-15)/2x^2-5)^2. then I set it equal to 0 and I got 0=-6x^2+50x-15 Now from here do I use the quadratic formula to solve for x? I tried that and I am getting x=(25+sqrt535)/6 and x=(25-sqrt535)/6. Have I done it right so far? When I try to plug in the x-values into the original eq to get y my calc says error... What do I do now?