The fish Posted February 26, 2008 Posted February 26, 2008 A ball is dropped from a horizontal plane and rebounds successfully.The height above the plane is reached by the ball after the first impact with the plane is 4m. After each impact the ball rises to a height which is 3/4 of the height reached after the previous impact. Calculate the total distance traveled by the ball from the first impact until it comes to rest. Thanks It never comes to rest if taken literally. It's a declining series, so, where n=number of bounces, it's 7+ (3/4)^(n-2). Maybe. Haven't done them since October...
Chuck Posted February 26, 2008 Posted February 26, 2008 It never comes to rest if taken literally. Unfortunately I cannot use this as an answer. Fortunately I recognized the fact that it would never really reach zero before posting it on the forums.
Supergrunch Posted February 26, 2008 Posted February 26, 2008 Unfortunately I cannot use this as an answer. Fortunately I recognized the fact that it would never really reach zero before posting it on the forums. Treat it as a geometric series and take the sum to infinity.
chairdriver Posted February 27, 2008 Posted February 27, 2008 On average, 5% of passangers who have purchased a ticket for a plane flight do not turn up. 108 tickets are always sold. There is room for 104 passengers on the flight. [i've already calculated that there's a 0.373 chance the flight will be full, and people will have to be turned away] If a customer turns up, but there is no seat available, the airline pays compensation of £250. What is the expected amount of compensation per flight? [The answer in the back of the book is £85, but how do I get that answer?]
Mr_Odwin Posted February 29, 2008 Posted February 29, 2008 On average, 5% of passangers who have purchased a ticket for a plane flight do not turn up. 108 tickets are always sold. There is room for 104 passengers on the flight. [i've already calculated that there's a 0.373 chance the flight will be full, and people will have to be turned away] If a customer turns up, but there is no seat available, the airline pays compensation of £250. What is the expected amount of compensation per flight? [The answer in the back of the book is £85, but how do I get that answer?] Bit late and I always mess up on combinatoric stuff but I think it goes something like this (where aCb is "a choose b"): 108 tickets 104 seats compensation = £250 P(passenger no show) = 0.05 P(4 people turned away) = P(everyone shows up) = 108C108 * (0.95^108) = 0.0039278 P(3 people turned away) = P(everyone shows up, but one) = 108C107 * 0.05*(0.95^107) = 0.022326 P(2 people turned away) = P(everyone shows up, but two) = 108C106 * (0.05^2) * (0.95^106) = 0.062866561 P(1 person turned away) = P(everyone shows up, but three) = 108C105 * (0.05^3) * (0.95^105) = 0.116909745 So the probability of turning someone away is the sum of the above (0.206). The expected compensation is 1000*0.0039278 + 750*0.022326 + 500*0.062866561 + 250*0.1169097 = £81.33 Which is different to your book, so ... er ...
Eenuh Posted February 29, 2008 Posted February 29, 2008 Okay, this is a weird request, but I'm short on time and can't find what I'm looking for. For my After Effects animation, I am looking for a sound file of people talking, except you shouldn't be able to understand any words. You know, just mumbling, like you always have in films when there's a scene at a restaurant and you hear people in the background or something. There's only three people (gentlemen) in the scene. Sadly the only sound files I was able to find were of a ton of people in a restaurant. Anyone willing to help me out? ='3
Chuck Posted February 29, 2008 Posted February 29, 2008 Someone can record a voice clip on msn and you could save the file?
Shino Posted February 29, 2008 Posted February 29, 2008 Okay, this is a weird request, but I'm short on time and can't find what I'm looking for. For my After Effects animation, I am looking for a sound file of people talking, except you shouldn't be able to understand any words. You know, just mumbling, like you always have in films when there's a scene at a restaurant and you hear people in the background or something. There's only three people (gentlemen) in the scene. Sadly the only sound files I was able to find were of a ton of people in a restaurant. Anyone willing to help me out? ='3 Have you tried searching for the conversations in The Sims? They're basically what you described.
Eenuh Posted February 29, 2008 Posted February 29, 2008 Have you tried searching for the conversations in The Sims? They're basically what you described. Ah, that's actually a very good idea. Hadn't thought of that yet. Now just to find it somewhere. ^____^
Shino Posted February 29, 2008 Posted February 29, 2008 http://thesims.ea.com/us/getcool/graphics/index.html This is all I have found, sucky quality.
blender Posted March 1, 2008 Posted March 1, 2008 Bit late and I always mess up on combinatoric stuff but I think it goes something like this (where aCb is "a choose b"): The expected compensation is 1000*0.0039278 + 750*0.022326 + 500*0.062866561 + 250*0.1169097 = £81.33 Which is different to your book, so ... er ... I agree 81.33334902. chairdriver you need to tear the answer page out of the book and wipe your arse with it. It will be an idiotic rounding error in by the author
Eenuh Posted March 1, 2008 Posted March 1, 2008 http://thesims.ea.com/us/getcool/graphics/index.html This is all I have found, sucky quality. Ah, thanks! I tried opening one but since it's .exe files they don't work on my macbook, so I'll just have to check them on my pc tomorrow. =3
chairdriver Posted March 1, 2008 Posted March 1, 2008 I know why that's off; you had to approximate the value using the poisson distribution. Either way, I already handed it in (copyed off a friend :p)
Aimless Posted March 1, 2008 Posted March 1, 2008 For my After Effects animation, I am looking for a sound file of people talking, except you shouldn't be able to understand any words. You know, just mumbling, like you always have in films when there's a scene at a restaurant and you hear people in the background or something. How long does the sample have to be, roughly speaking? Or do you just need individual sounds to match to frames of animation? I came across a free sound archive a few months back and that has a lot of gibberish samples that are around 4-8 seconds, but they could be edited together to give the semblance of a conversation. Of course using Simlish would probably be a lot easier...
blender Posted March 1, 2008 Posted March 1, 2008 I know why that's off; you had to approximate the value using the poisson distribution. the poisson is a an approximation of the binomial.. given the very exact details of the question .. (e.g. always a certain number of tickets sold ), I'd say that it is more correct to use the binomial. EdIt: actually looking at their wording "average rate", it points to them wanting the poisson....
Guest Stefkov Posted March 5, 2008 Posted March 5, 2008 Anyone know how to do a Data Flow Diagram and the psuedo code to go with it when I want to, from a form, open a form and it's files, choose one of the items in the file and take it back to the form I started with? The actual coding for it is only opening the form, then whatever is in a text box in the opened form, when a button is pressed, will be taken back to the original form. It's not visible but it's taking back all the data, the only thing you can see is an ID number telling you it's that data... If you can understand that and help me by god I would be grateful. Anyone?
spirited away Posted March 13, 2008 Posted March 13, 2008 Ok then. Kinda confused by the vector stuff we're doing in maths, because i've missed a few lessons.l Probably easy, but I don't know what to do. Say i'm trying to find the vector for a diagonal line through a triangle OAB. O being the point on the bottom left, and A the top, B bottom right. R ius the mid-point on AB. If i'm trying to find vector of OR in terms of a and b. And we are given that a = OA, and b=OB, how do i go about it? Ok, so that may make little sense as i worded it so badly; but if anyone could help i'd be really grateful.
Ginger_Chris Posted March 13, 2008 Posted March 13, 2008 draw a graph, the x co-ord is exactly between the x co-ord of a and b. the y co-ord is exactly between the y co-ord of a and b. (a+b)/2 assuming O is origin. (you can easily modify it to O being the origin, work it out and replace the old axis)
Eenuh Posted March 14, 2008 Posted March 14, 2008 Hmmm, we (me and the rest of my group) need some inspiration. We have to find a subject to do a small paper on (minimum of ten pages) and a presentation. Thing is we have no clue what to do the paper on. The main subjects we have to focus on are Sociology and Visual Communications/Graphic design. We can discuss a sociologist, a subculture, a research, anything. But we're kinda stuck. All we can think of is your typical "How does media/advertising/whatever influence people/youth/kids?". So yeah, anyone have any good ideas? =P
Supergrunch Posted March 14, 2008 Posted March 14, 2008 How about the influence of scripts and fonts in advertising?
Sarka Posted March 14, 2008 Posted March 14, 2008 This is from a set of problems we were given by an exchange school. The maths teachers can't do it, so any maths enthusiasts - knock yourselves out! You are given a triangle ABC. The point M is the mid-point of BC. The length of MA is d. Prove that, given d < AB and d < AC, BC is always an even integer. Have fun!
MoogleViper Posted March 15, 2008 Posted March 15, 2008 This is from a set of problems we were given by an exchange school. The maths teachers can't do it, so any maths enthusiasts - knock yourselves out! You are given a triangle ABC. The point M is the mid-point of BC. The length of MA is d. Prove that, given d > AB and d > AC, BC is always an even integer. Have fun! That's not possible. If M is on BC and d is greater than AB and AC then ABC can't be a triangle. The furthest point from A has to be one of the corners. Unless I've read it wrong.
The fish Posted March 15, 2008 Posted March 15, 2008 This is from a set of problems we were given by an exchange school. The maths teachers can't do it, so any maths enthusiasts - knock yourselves out! You are given a triangle ABC. The point M is the mid-point of BC. The length of MA is d. Prove that, given d > AB and d > AC, BC is always an even integer. Have fun! I'm fairly sure that you can't prove that without some more information. However, I'm watching the rugby, so I'm not giving it my undivided attention
Sarka Posted March 15, 2008 Posted March 15, 2008 That's not possible. If M is on BC and d is greater than AB and AC then ABC can't be a triangle. The furthest point from A has to be one of the corners. Unless I've read it wrong. Oops... sorry. I put the wrong crocodile. Way to go, me... Also, I'm pretty sure it's posible. If I get a proof I'll post it here.
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