  # Topher

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Quark

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Metalergy
1. Hey, I know this is a little off topic but I'm having a little trouble finding the information .. everywhere I look the answer is just ''take it to a mechanic'' .. so here's the question, how do I do an oil change for a 1990 toyota celica manual and how much oil will I need to replace the drained oil? also what grade of oil is best for a car this old? before you ask yes I have the ability to jack the entire car up enough to get under it and all the tools I should need. Thanks for your help.
2. I don't get this part .. still .. it's the only part I'm not understanding right now I'm unsure of how you managed to get that answer can you please expand it so I can see what your doing at each point .. this is how my working goes when I do what you did .. lol ... 15000 x rev/min x 2pi rad/rev x 60s/1min = 15000 x 376.99rev rad/min rev min (divide number by 60 2 times to turn the minutes to seconds) 1570.7rad/s x s .. why do I end up with the extra second multiplied below the divide? .. and also why are you using those numbers to multiply .. are they from a formula/what do each of them stand for .. obviously15000rev/min is the change in speed but the other 2 I'm not understanding.. EDIT: the hyperlink was just your last posts first equation.
3. alpha = (11250r/s/s x 57.3)/80 = 8057.8125rad/s2 ... which means Torque = I x alpha = 11.5kg.m2 x 8057.8125rad/s2 = 92664.84375kg.m2 rad/s2 .. how do I change the units into just the N lol .. obviously done something wrong.. the acceleration in revolutions per second per second needed (on average) to achieve 15000 revolutions per minute in 80 seconds ... LOL how do I convert that to N?...
4. I multiplied by gravity to turn the units from kg.m to N.m .. obviously didn't need to do that :/ ... Ok so, alpha = change in w/change in time .. so alpha = (11250r x 57.3)/80 = 8057.8125 ... which means Torque = I x alpha = 11.5 x 8057.8125 = 92664.84375 .. is that correct? Just heading to work will look at the angular motion web sites you gave me when I get back, thanks for the help
5. Hey, I lost my book for the subject and test is on Monday, these are the problems I'm having trouble with, I need to know the formulas to use as they were in the book which I've since lost.. FIRST QUESTION What is the torque required to accelerate a turbine undergoing a dynamic balancing test from 0 to 15000 r/min in 80 seconds, it's mass moment of inertia is 11.5kg.m2 Torque = X (unknown) Time = 80 Acceleration = y (unknown) Mass moment of inertia = 11.5x9.8 = 112.7N.m2 15000x60 = 900000r/s (divide by time in seconds to find acceleration) 900000/80 = 11250r increase per second .. I can tell I'm lost SECOND QUESTION I can't find a question I copied down to cover this, so any help would be appreciated, I need to be able to do questions revolving around angular motion, all I remember is it's units, rad/s
6. In the first question .. no. In the second question of course, the air is ''allowed to cool''.
7. 1. 0.01kg of air is compressed in a cylinder so that the temperature of the air rises from 293K to 413k if the work done is 2000J, calculate the heat flow ... 2. if the air in the cylinder is now allowed to cool to 293K again, while the same cylinder volume is maintained, calculate the additional heat flow ... so for #1 known values are Delta T=120 M=0.1 Q=2000 ... #2 Delta T = -120 M=0.1 and volume stays constant ... also for all of the questions air: Cv=718J/kgK Cp=1005J/kgK R-287J/kgK I've managed to get myself stuck I don't know which formula is needed to solve this problem, or maybe it's just I don't know the symbol for heat flow, thanks for the help
8. Brilliant, thanks very much very helpful.
9. It's an assignment question, it asks, ''How to cut and/or machine bullet proof glass. For example a diameter 30mm hole through 30mm thick glass.'' I've not seen anything on tempered glass before only polycarbonate layered with normal glass, so I guess I want to know how would you make this cut into polycarbonate and glass layers? or would you make the cuts before lamination? And with what drill bit etc. EDIT: ''And with what drill bit etc.''
10. I can't find anywhere on the internet where they describe in detail how bullet proof glass is cut/machined .. specifically a diameter 30mm hole through a 30mm thick glass? any help greatly appreciated.
11. This is for an assignment, I have all the information I need now except for shrinkage rates, thank you everyone who's replied.
12. The metals, I'm more having difficulty with finding the sand compositions.
13. What type of sand is used to cast bronze, brass, steel and aluminium? also what are their shrinkage rates and melting points?
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