Homework Help

So suppose f(x) = 4x - 5. Solve f(f(x)) = 23 for x. I have no idea how to solve what I think is a function of a function, as I am new to this type of "basic" algebra problem. Not a homework problem just trying to learn new things from some things I found online.

14.3g of an oxide of copper contained 12.7g of copper calculate the empirical formula of this oxide relative formula masses Cu= 63.5 O=16 please help this is what I done 12.7/63.5= 0.2 I am not sure about the rest

________ the amount of GABA _________ seizure activity and/or anxiety.

The density of two liquids (A and B) is given as 1000 kg/m3 and 600 kg/m3, respectively. The two liquids are mixed in a certain proportion and the density of the resulting liquid is 850 kg/m3. How much of liquid B (in grams) does 1 kg of the mixture contain? Assume the volume of the two liquids is additive when mixed.

Hey chemistry experts, i need help with a problem. This is not homework, this is just for self studying purposes and i even have the solutions but i still cant make it. Available are 0.10 M solution of HCl, HAc (Acetic acid), NH3 and NAOH. One wants to make a buffer solution with pH = 4.0 and with a pH = 9.0. Neither of these two buffers may be prepared by combining the solutions of acetic acid and NH3. a) Explain the solutions of the buffer with a pH of 4.0 and calculate the volume ratio of these solutions in order to achieve the goal. -> CH3COOH + NaOH -> <- NaCH3COO + H2O K = 0.1 x 55.56 = 555.6 0.1 x 0.1 pK = -log (555.6…

If a ball is thrown upward at an angle of 30 with the horizontal and lands on the top edge of a building that is 20 meters away, the top edge is 5 meters above the throwing point, what is the initial speed of the ball in meters/second? Help me with initial steps.

Hello, I was wondering if someone could help me out with this question. "If the gene for polyphenoloxidase is "old" in evolutionary terms, what do we expect to see when looking at activity in other plant species?" From my limited knowledge on evolution, I want to say that that there would be more variance in the polyphenoloxidase genes in different species due to a longer period of time as well as more random mutations. Does this make sense or does anyone else have a clue at what they are specifically asking? Thank you!!!

Hello again everyone! So this post is less dramatic and doomsday-ish then all my others have been as it pertains to chemistry at least. Lab 1 was Monday for me, our aim was to use the Thomas-Hoover Apparatus to discover the melting point of our unknowns. So I wanted to first state that I understand how to perform the lab, as a small group we did well on the lab experiment (except for one minor error which happened on our first trial but that was quickly adjusted). I just wanted to post to get more insightful opinions on how I can formulate my ideas on why things went the way they did. The chemicals we used for my group were: biphenyl [Melting Point] 69-72 …

The question: Four 60W, 240V light bulbs are connected in parallel. If these lights were to be placed in series, what voltage and power rating would each have to be in order to produce the same amount of power? I know I'm meant to explain what I've tried but the confusing thing is that if 60W light bulbs are placed in series, each one would have 60v thus 1A will flow through so the power would be the same as the parallel circuit? Thanks for the help!

I am having trouble with this question in physics: An acoustic signal is composed of the first three harmonics of a wave of fundamental frequency 300 Hz. If these harmonics are described, in order, by cosine waves with amplitudes of 0.210, 0.340, and 0.170, what is the total amplitude of the signal at time 0.689 seconds? Assume the waves have phase angles θn = 0. I understand that I should use the formula (sorry is formatting is not correct) F(t)=A1cos(2pif1t-THETAn)+A2cos(4pif1t-THETAn)+...... I have subbed in 0.210 for A1, 0.340 for A2, 0.170 for A3, 300 Hz for f1, and 0.689s for t to get an answer of -0.0149. When I put in the answer is says it is wrong.…

Hey, I am very confused with calculations and I guess I am mixing molecular mass with molar concentration. I just want straight answer for two questions about how to make calculations: 1. I have a liquid with molecular weight = 40 and I want to prepare 15ml of 100mM stock. It is not a powder like for example NaCl. 2. I have 50ug of lyophylized chemical and molecular weight = 500 and I want to use it all (50ug) to prepare 500mM of stock. Thanks a lot. B19

1. Question: Rachel walks 2.80 Km to a gym at 6.00 Km/h. Upon reaching, she walks back the same distance at 7.70 Km/h as the gym was closed. Find her average velocity. Attempt: I find the total time by: (2.8/6)+(2.8/7.7) ~=0.830 h. Divide 5.6 by this to get approximately 6.74 Km/h. First thing I am confused by is, why is the average velocity simply not zero since her displacement over the entire time period is zero? (I actually calculated this since the back of the book gave a finite answer) Second can someone please confirm this answer? The back of the book says 3.27 Km/h but I don't know how that would be achieved. 2. Question: A car moves 0 to 900 m, starting and en…

Hey, I am to complete a project that involves doing an experiment 'to determine the impact of each additive, the effects on samples of a garden soil of adding 20% by mass of (a) sand, (b) potting compost, and © clay on the rate of drainage of soil'. My question is: does one add the additive that would equates to 20% of the mass of the garden soil i.e. adding 20g of sand to 100g of garden soil or does remove 20% of the garden soil and replace it with the additive i.e. 20g of sand mixed with 80g of garden soil. Thanks in advance for any help!

Hello, Actually this is not a homework. I'm a teacher and I'm gonna have a class in Monday and I need an excel spreadsheet of the ENTIRE PERIODIC TABLE OF ELEMENTS (With the electronegativity, Boiling Point, Melting point, etc.). I don't have time to do it because I'm doing other researches for my other classes. So please help me!

PLEASE KINDLY HELP ME SOLVE THIS QUESTIONS BELOW THANKS. 2003.pdf

Does environment that having delta wave frequency able to help human to fall asleep faster? Another question will be is brain wave a transverse wave or longitudinal wave?

Hello, For my homework (prior to work in the laboratorium) I need to find out which proteins have a natural affinity with Ni2+. I've tried googling it but unfortunately I didn't find the answer... Thanks!

1. How come children suffering from "SCID" shows impaired growth even though there is NO infection? 2. Detailed explanation why conjugate vaccines stimulate B- and T-cell response? Would really appreciate your help.

My 13 year old nephew has asked me to help with his science homework on electricity, which I'm not familiar with. Can you explain what I need to know. It would have helped if i knew what book he was working from but doesn't have one apparently. Click image to enlarge.

micro RNA in stress signal and human disease

Hello everyone, I am working my way through an old Morrison and Boyd 3rd edition Organic Chemistry book. I was unable to find a solutions manual, so I thought this the best way to pose questions that I wasn't 100 percent sure about or could use a little more clarification on. Thanks in advance for the help anyone passes along through my, probable, multiple questions. The first question I had was from one that had the answer in the book: What is the Lowry-Bronsted acid in (a) HCl dissolved in water; (b) HCl (unionized) dissolved in benzene? © Which solution is the more strongly acidic? I got (a) and (b), but I said that (a) was more acidic than (b) because th…

Hello all, I have been stuck in this question for at least 3 hours, and i would like to get some tips on how to solve it. First, please check the drawing in the files to understand the water-barometer. The question is as followed: "The water-barometer is very sensitive for temperature changes in the flask. For the increase Δh in water level per degree of increase in temperature, the following formula can roughly be applied: Δh / ΔT = p / (T * ρwater * g) T is the absolute temperature and p the pressure inside the flask. The atmospherical pressure (outside the flask) is equal to 10^5 Pa. Now roughly calculate the increase of the water level in cm when the…

Hi all, I was wondering what the test is for negative non-metal ions? Also, what is the test that uses sodium hydroxide solution for positive metal ions? Is it a flame test? Thanks in advance for any replies

Hello! I have this question in my textbook, in which I know the answer, yet I cannot figure out how to obtain it: The air has helium 0,0007% (m/m). Convert this concentration into ppm. The answer should be 0,7ppm. Thank you for reading this!

How to solve this?