CaptainBlood

I just got an answer from popovoleg that makes a lot of sense, that acceleration remains constant. In my original question I said that the other half the distance is traveled at a constant speed; I should have said that the rocket runs out of fuel at half the distance for the rocket motor. But I then get (1/2) aj * t^2 = (1/2) ar (t/2)^2 and the final answer comes out aj / ar = 1/4 which is not 8/9 so I'm still making a mistake somewhere. Ok, I did it, I just needed to use t1 for the first time which was at1 and t2 for the second so the equation I was missing is t1 + t2 and everything works out great.

Thanks for your answer, but after a lot of thinking I think I'm pretty sure that I will major in Biophysics. It's gonna take me to hell and back in terms of the workload and the complexity of the material; however, I have too many questions in regard to the universe and I love a challenge. I just hope that this major is not so hard that it will hurt my GPA and sequentially my chances to get into medical school. Did anyone major in physics or is in the process of going through it, if so please share some of your knowledge and advise it will be of great help.

On a horizontal test track two motors (jet and rocket) are tested. Starting from rest, the rocket motor was accelerated constantly for half the distance of the track and ran the other half at a constant speed. Next, a jet motor was started from rest and finished the whole track with constant acceleration for the entire distance. Both motors covered the same distance in the same time. Show that the ratio of the acceleration of the jet motor to rocket motor is given by: aj/ar = 8/9 I wrote two equations for the distance of each motor. For rocket: x = 1/8 ar*t^2 + v*t/2 and since v*t/2 = ar*t^2/4 we get x = 1/8 ar*t^2 + v*t^2/4 and for the jet motor: x = 1/2 aj*t^2 and set them equal to each-other and find that the ratio is aj/ar = 3/4 instead of 8/9. What am I doing wrong?

oxanes have oxygens inside the ring, not attached to the ring by single bonds

that's ok, but i'd just write: the indicator is used to tell when the solution is neutralized.

sorry, what i meant to say is hydroxides are strong bases and you need a molar equivalent of strong acids to neutralize the solution. So just figure out how many moles of base you got and then add half as many moles of sulforic acid. Sulforic acid is di protic which means it has two hydrogens so you need half as many moles of diprotic acid as you would monoprotic acid like hydrochloric acid.

any hydroxides are strong acids which dissociate completely in the solution so just figure out the exact molar equivalent of monoprotic acid to neutralize it or half molar eq of di protic acid like sulforic acid

I looked up 1,3 dioxane on line, just google it to see the structure, so you're no missing bonds, just hydrogen will attack the oxyden and make it a good leaving group, guess what happens then... then water attack the positive charge that was formed and another hydrogen will attach to the other oxygen, that one now leaves... so you only get the first molecule not formaldehyde... oh yeah ishouldn't say hydrogen attack anything since only oxygen attacks the hydrogens since it is negative...chao!

the first one has no real arrow pushing it's just a nitration through the arenium ion, first the 0N0 is attacked by the phynyl then arenium forma and then hydrogen is pulled of by the base in the second the base pulls off the tretiary hydrogen and the bromine comes off the third is all messed up and you're missing some bonds there, but the first molecule is likely to form rather than formaldehyde hope this helps

I'm torn between majoring in human biology or biophysics. I took all the prerequisites for medical school already, just finishing Organic and need two more semesters of Physics and I'm done with the prereqs, but i need to transfer and can't decide on what to major in. I know biology will better prepare me for medical school, and i like physics but physics is mostly math and physics and no medical school prep which could hurt my mcat score and might not give me a good prep for med school, so when I'm at med school i will have to work a lot harder than if i mojor in human bio that has physiology and other courses already in it. I know I don't want to major in chemistry even though i got all A's in my premed courses(except for B in inorganic chem 2 and C in molecular bio. But my GPA now is 3.43 and I don't know if i will make it to medical school and if I don't, then what am i gonna do with a biology degree. i heard it's hard to get a job with that i also thought about majoring in computational physics so in worst case scenario i get a lot of options like working as a physicist or a software engineer or on wall street, i heard they need computatinal physicists to write programs for buying and selling stocks. So it's really frustrating and I don't know what to do, sometimes i just go on this freaking researching spree about different majors when i should be studying, it sucks. Then I heard that one can only get financial aid for the first bachelors and not the second, then heard that financial aid is only for up to 100 units or so. Is that true? I'm also worried that computational physics or biophysics is a really hard major and will hurt my already crappy gpa (3.43), if someone can help with their advise I'll really appreciate it.

Great, that does the trick. Thanks man, you're a genius.

i solved v^2 = vo^2 + 2 ah for vo and got srt(2gh) then put that in to the equation y = vot + (1/2)at^2 for vo, and solved for h, but at the end I get h=1/2g(y/t - gt/2)^2 and not h=1/2g(2y/t - gt/4)^2, so I still don't see how I have to show the 2y/t - gt/4 part. How did he get 2 in the numerator of the first term and 4 instead of 2 in the second. That completely baffles me.

I think the equation to use is y = vt + (1/2)at^2 where v is the initial velocity y is the height, a is acceleration, and t is time, but we're not given initial velocity or the height that the ball reaches. What do I do? I think it has something to do with manipulating the above equation with v^2 = vo^2 + 2 ax where v is the final velocity and vo is the initial velocity, but I have no idea how

A person looks out of the window and sees a tennis ball that appears and disappears twice: first as it rises up past the top of the window and then again as it falls bellow the bottom of the window. The height of the base of the window to the top of the window is y. The total time he sees the ball is t. Show that the height (measured relative to the top of the window) that the ball reaches is given by h=1/2g(2y/t - gt/4)^2<br />How do you solve this? I tried it for an hour and can't figure it out.