Homework Help

Yo, i am a 15-year-old student. One day I saw this in my assignment. A car of mass 1500 kg accelerates from rest at 5.00 m/s2 for 5.00 s on a straight road. Find teh minimum power needed for the engine to achieve this task. The answer they gave was Power = work done/time = 1/2 mv2 / t =1/2 m(u+at)2 / t =1/2(1500)(0+5x5)^2 / 5 =93750 =93.8W But my answer was Since m=1500 kg u=0 a=5.00 m/s2 t=5.00s F=ma=1500x 5.00 = 7500N v=u +at =5.00 x 5 =25m/s P=Fv ==> 7500x25 = 187500 = 187.5 kW Not only the answer is wrong, 187500 is twice as 93750. What happened? Please enlighten…

hey guys im having trouble working out this question. be great if ya can help. The position of a golfball is given by r = ((3t^2)i^ + (2t^2-1/6gt^3)J^)m. Calculate its velocity and its acceleration at time t = 1s (assume that g = 10ms^-2 i^ = i hat J^ = j hat

Today my teacher told us things about naming the acids but I get confused. 'Acid - an electrolyte which ionizes in water to give H+ (aq) as the only cation' quote from my notes. What does ionizes mean in here ? So it is an electrolyte? what's that? Can you explain to me , please. cheers

Hey all, i can do part (a) (or at least i think i can, i get: 9.4eV but for part (b), i can't find a formula to use. any ideas guys/gals? and for part © i caluclated that you would need to give ~28eV worth of energy to the an elecron to excite it to the first excited state. i am unsure whether this is said to be 'easy'.... do you think 'easy' involves cmplicated equipment or me poking it with my finger? sorry bout the 1000 questions Sarah

Hi Not sure if anyone can help me here. I'm doing a 3D project based on physics and dynamics. I wanted to know if anyone on here has, or could take, some photos of a double-pan beam balance. It could be a harvard trip balance, or an old one. From pictures on the internet, I am unable to see the underside of the pans and how they connect. I am setting this up in 3D and need to see all the components so I can model them, texture them, and then rig them and use rigid body dynamics so the balance will react similar to how it does in real life. Here is a link to a low quality image I found if you are not sure what model I mean. http://www.morrisonlabs.com/images/b…

Hi, Could you tell me what is meant by 'as respiratory substrate to release energy for metabolism' in the function part of Carbohydrates? And what is hydrolysis? Couldn't figure it out. thanks

I have this question for school but I have no Idea how to answer it...Please Help.... Draw Curves showing how the relative amounts of a radioactive parent and a stable daughter can yeild an absolute date for a rock sample.

Hi. I have to write a proposal for an experiment I will be doing. I need to prepare some tissue samples to run a SDS-PAGE. I would like to know how do I know what pH to make my extraction buffer for tissues like beef, turkey, soybeans....etc.

Hi , Nice to meet you all. I have a few questions on Chemistry. 1. What are transition elements? Are they metals or non-metals? 2. Can elements be ion and molecule? Are there any difference? 3. What 'element' can form an ionic bond and covalent bond? 4. What are the differences between conductor and electrolyte, insulate and non-electrolyte? 5.What is the difference between mass(i.e. a.m.u) and weight(kg)? Thanks in advance. I really want to know the answers

Anyone here be able to link me to some tuts on balancing chemical equations? i googled for about 5 minutes and came up with nothing.

Yo, I am a 16-year-old student who struggles with probability. Pardon my grammar. A bag contains 8 green and 4 red balls. 6 balls are drawn at random in succession from the bag without replacement. What is the probability that the colours appear alternately? Does this question require a probability tree? Do tell me if it does, because we have to choose 6 balls and I think it is too complicated for one. So on seeing that it is "without replacement", I just did this. G R G R G R => 8/12 x 4/11 x 7/10 x 3/9 x 6/8 x 2/7 = 2/165 R G R G R G => 4/12 x 8/11 x 3/10 x 7/9 x 2/8 x 6/7 =2/165 And then I add them up because they are mutually exclusive events. …

I hate my health class.. These questions are NOT found in my book. Argh. 1. The first stage of alcoholism is characterized by a) malnutrition b) defensive behavior c) rationalization of drinking behavior d) reverse alcohol tolerance 2. A major factor in traffic accidents, homicides, and suicides for 16 to 24-year-olds is a) alcohol use b) smoking cigarettes c) affiliation with gangs d) psychological disorders My guess: C and D are obviously jokes. In small towns, there are no gangs or "mental disorders" that's just ridiculous. I'm guessing it's A but I'm not *100%* sure. 3. Becaue alcohol dilates blood vessels, a person who goes outside in …

Hi.. I having trouble answering this question. Any input would be greatly appreciated =) Explain why the size of red blood cells stored in 0.15M urea would differ significantly from cells stored in the same concentration 0.15M of Na Cl? (Hint: work out the osmolarity and tonicity of the 2 solutions and compare each solution to the intracellular fluid of the erythrocyte(Red blood cells) This is what I done so far... not sure whether it's right or not. Osmolarity Urea: 0.15 x 1000 = 150mOsM Salt [Na Cl]: 0.15 x 2 (the sodium and the chloride ions dissociate and 2 particles formed) x 1000 = 300 mOsM Tonicity Urea: cell bigger (swell) and becomes normal…

Can anyone give me a definition of Elements, Ion and molecule? Are they related? thanks

I have a math project which consists of building a bridge, and I have to make a complete report of how I carefully planned how wires, poles, etc. would be able to handle the weight. So I need to know how to calculate how much force a metal wire can handle according to whatever parameter (ray? material? length?) is involved. I'm talking about the pulling force on the end of the wire when the other end is attached. Thanks.

1. A condition in which fats build up in the liver and cannot be broken down. 2. A condition in which liver tissue is destroyed and replaced with useless scar tissue. I know that the two answers for above is fatty liver and cirrhosis. But I don't know which is which. It's so confusing. 3. Physical and mental impairment resulting from alcohol use. --> is this intoxication? 4. The KIDNEY oxidize(s) alcohol to form water, carbon dioxide, and energy. --> I'm pretty sure this is false because I think it's liver that does this. Help! I appreciate this greatly.

I was wondering if someone could help me with this word problem. I am terrible with word problems.....I need you to explain it in steps and tell me why you are doing what you are doing. I greatly appreciate it. Tom and Huck start a business painting fences. They paint Aunt polly's fence and find that they can paint a 200 square foot fence in 40 minutes if they work together/ If huck works 4 times faster than tom, how long would it take each of them to paint a 500 square ft fence working alone?

Okay, I have a question that I need to get my mind straight to this. I'm still kinda confused about it. Check this out, these a-m letters are supposed to fix the word equations (or "balances?"), these in pencil I wrote from the whiteboard. These in black, I put it in what was missing, led to my belief/thought on this. I'm not sure if these are correct.....and plus, check this out on a), it was written by a teacher (i put / on number 2, btw, cuz me and teacher were discussing on it on somethin)...the teacher says his on a) is 100% right and i'm not sure.....because i think Nsmall2+2Hsmall2>2NHsmall2 was supposed to be like Nsmall2+Hsmall2>2NHsmall2.......the compound…

Was wondering if anyone could tell me how I'd go about integrating: Int[(r(z))^2 dz] on the interval [1,h] where r(z) is an arbitrary function of z. help is appreciated:)

Hi. I was wondering if any of you could tell me the term used to keep cells alive but stop them growing when they are removed from the host (by altering the growth medium). This is in relation to Dolly the Sheep if that helps at all. Any help would be greatly appreciated! Thanks

Hullo, I am a 16-year-old. This is a question in my assignment. A student said that a piece of paper would fall on the ground when released because the atmospheric pressure forced the paper to fall down. Use the kinetic theory to determine whether the above statement is true. So my answer is (Pardon my grammar. i know it's bad) The above statement is false. The volume of fixed mass of air on the upper and lower sufaces of the paper is the same. This means that the number of air molecules moving around per unit volume of space is the same on the top of and below the paper. The frequency of collision between air molecules and the two surfaces of the piece of pa…

Hi, I'm really stuck on my biology homework. I need to find any plant (excluding a cactus), a picture of it and list at least 6 adaptations of it. Can anybody help?

hello... please help me with this question. thanks. A small block of mass 2 kg is held against the side of a larger block of mass 10 kg which sits on a frictionless floor. The small block does not touch the floor and does not slip down as the blocks move across the floor. The coefficient of static friction between the two blocks is 0.4. The smallest acceleration the two blocks can have is a) 2.5 m/s2 b)4.9 m/s2 c) 5.4 m/s2 d) 9.8 m/s2

I'm starting a Complex Analysis class at my high school and I'm having trouble proving this delta-epsilon limit: [math]\lim_{z \to 0} \frac{\overline{z}^2}{z}=0[/math] any suggestions?

I`m trying to prove the following: An algebraically closed field is of infinite extension over its prime subfield. I'm not sure I translated it correctly. What I mean is: Let K be an algebraically closed field and k its prime subfield. Then the degree of the extension K/k is infinite, i.e. [K:k] is not finite. I have in my mind an example like C/Q (the complex and rational number fields). I know it's true in this case, because Q has transcendental numbers. So I tried to prove k must have a transcendental element, since if the extension were finite, it would be algebraic. But I`m not sure this would work, because not all infinite extensions are algebraic. In a…