What is performance: Definition and 258 Discussions

I have the equations to determine the rise time, peak time, percent overshoot, and settling time for a generic second-order system with no zeros in the system. Given a unit step input for the open-loop transfer function G(s)=(s+1)/(s2+2s+1) how do I analytically determine the performance...

I have the equations to determine the rise time, peak time, percent overshoot, and settling time for a generic second-order system with no zeros in the system. Given a unit step input for the open-loop transfer function G(s)=(s+1)/(s2+2s+1) how do I analytically determine the performance...

I would like to know what effect does tire width and tire diameter has on performance or overall efficiency of a vehicle.

Homework Statement I have access to a test facility for window type air conditioners that has a small room that is used to simulate the outdoors. I need to use the facility to test the effect of temperature on the performance of one of our window type AC units. The performance must e done as a...

So if there were say 10 teams that were randomly matched into alliances of 3 v 3 with a score given for eatch match. How can I given a sufficiently large data set determine how much each team affect the score that there alliance achieves?

Hi, I'm trying to put a long open-ended debate to rest. For those who don't know, the EGR, Exhaust Gas Recirculation, system takes some of the exhaust gas and reintroduces it into the intake manifold. From what I understand, at 1600°C NOx is formed because air molecules, nitrogen N2 and...

Hey every body, I need to ask you about the difference between off design performance of gas turbine engine and the design point performance of gas turbine engine ? Thanks.

Hello, my question is about air in engine cooling systems. Coolant is formulated to resist boiling, and furthermore kept under pressure to increase its boiling point. I think this is to control its phase. In other words we must prevent coolant from boiling (vaporizing) because vapor does...

This is all in relation to a 90 degree v8 I am looking for the highest frequency/note/tone/pitch I can get. I very much enjoy the higher, crisper, cleaner sound the european v8 makes. I hate with a passion the rumble of the harley/dumptruck American v8. I have heard flowmasters on these cars. I...

Hello everyone! It's my first post here. So, I'll try to be as descriptive as possible. And I do apologize for a relatively long introduction part of my post which is NOT aimed at teaching smbd the basic aerodynamics but is here to help me better explain my point. Judging from the...

I'm just wrapping up my last semester at community college before heading to university, and while I'm likely to get A's in Calc 3, O.D.E. and Prob/Stats, this will not be the case in Physics II. I had the same instructor for both courses, each time was his first time teaching that course (he...

I am studying performance analysis and character instance gets brought up a lot. I am unclear to what this means. It also talks about functions of instance characteristics. Can someone elaborate?

Homework Statement The COP for heat pumps and refrigerators achieved in the industry is almost 50% of the Carnot limit. Make estimates for the following case: For refrigerator to achieve -10°C in the freezer area with an external temperature of 25°C Homework Equations COP for...

I have used a multitude of inverters within the past couple of years. I've experienced the good and the bad. I've found that the higher dollar inverters seem to work better, but don't know why. I used a 2KW Samtec Pure Sine wave inverter to power a 1500 watt load without any issues. I tried...

I haven't taken the chemistry GRE exam yet, and I certainty don't plan on doing poorly, but part of me wonders if I did do poorly how if would affect my applications. A majority of the places I am applying to do not require it (but "strongly recommend" it). So if you get in the 50th...

Hi Folks; I am developing a series of pump performance curves for pulp slurries. I am running a closed-loop Lab-Scale pipeline facility. My question is about measuring head vs. flow rate at constant RPMs. I did it for pure water by continuously feeding the system with water, and gradually...

Hello, I am new to the physical therapy field and I have a huge interesting in performance testing, especially VO2 testing. I am currently working on a project involving such testing. I was wondering if anyone knows the effects of unloading during VO2 max testing. For example, if a user...

why the mechanical efficiency and brake thermal efficiency curve increases as load increases and reaches a maximum value and then again decreases( in contand speed test)

Having a boyfriend/girlfriend obviously takes a lot of time. Do you think that one should have a boyfriend/girlfriend while still in college, and do you think having one would lower one's performance (grades)? Do you have any experience to share on the topic? thanks

I've got a few questions. First of all I've heard a lot that willpower is the cause of sometimes superhuman efforts like keeping awake for several days in a row, walking beyond one's physical capability, performing even when under severe resistance or extreme pain etc. What I first of all...

I've been interested in 3D printers for a while but am not good enough with computers to do my own home designs. I read an article about new software that, along with being easy to make designs into code, can also turn a 2D picture into a 3D object...

I watched some performances of midsummer nights dream on utube sort of expecting to hear this meter, but instead the actors seem to only adhere to the periods and commas in the text. The rest of the vatiation seems to just depend on the actor. I was told that one of the reasons for iambic...

I am building a water rocket for my physics class and I want to make my calculations as precise as possible. I want to calculate throttle, velocity, acceleration, momentum, and max height. With that said, what should I take into account? Gravity, wind velocity, shape of cone of the rocket...

Hi, I came across an engine performance graph as attached. I have basically two questions looking at that: 1.To do any engine testing we keep some parameter constant - May be throttle position or applied load (torque) or speed or power. What is kept constant for this test? 2.In the...

Peltier Project: 50% PWM --> alternate circuit switching for increased performance? Hi all, I have a project where I am making a drink cooler device using four peltier devices which can draw up to 30amps or 24 volts each. we are considering battery power (pretty ridiculous but anyway..) and...

Before I Start here is a disclaimer - I am not a professional CAD or Mechanical Engineer to know much about this. Also, All information I have is from the internet and have NO practical knowledge. Here we go then. I am currently working on building a High Performance Free Flow Exhaust...

Ok, I am going to start this out by saying I know little about rocket engines, but I sure wish I knew more. When looking at things like specific impulse, thrust to weight ratio, actual exhaust velocity, etc; what type of rockets are the best choice/most used? Ie, solid, liquid bipropellant...

Hi guys, My professor recently asked a challenging question - he says it's been asked on an interview and he wanted to pose it as a homework. Attached is the graph of sorting algorithm performance. The interviewer asks: "Tell me everything you can about this algorithm just by looking at...

I am currently majoring in mechanical engineering at Texas A&M after having completed my associates degree in automotive technology (4.0gpa) while i'v been fixing cars at Firestone Autocare. Its odd that i rarely find anyone who knows a thing about the physics of energy efficiency and the...

Today I totally bombed my physics (Mock college entrance) exam. I mis read questions, pressed the wrong button on the calculator etc.. This has always happened to me. Whenever I do an exam I both figuratively and literally crumble to pieces. (dry skin) Does anyone have any tips for...

Hi, I am new to this forum to ask for advice: I have shown experimentally that a very well known material offers great advantages when used as substitute for another material in a range of devices. It is not obvious to use this material and because it requires some very specific knowledge...

Hi all, I'm a 3rd year undergrad at a top 20 university, not known for its math program, finishing up my degree in applied math and I've come to the conclusion that I behind in mathematical experience and ability when compared to other 3rd years undergrads at top math universities. The point...

i want to model air flow in the inlet manifold using CFD ,how do i predict how flow variations and other parameters affect engine performance ? i know how it affects but how do i show it virtually

There are always people arguing here about IQ and "geniuses" etc.. So I've came up with a relatively interesting question on this debate. The people who made history.. Glaois, Newton, Einstein, Niels Bohr, Riemann, etc.. Were "geniuses" the ones getting 95+ on their test, or were they the...

Okay, this is a long post so buckle up (not sure if this counts as Homework Help or not - technically it WAS homework, but now it's basically exam revision). I was wondering if anyone would mind helping me with a few physics problems I have? It was originally for a mastering physics...

Homework Statement I'm looking at an Ethernet direct link network with media access control between two computers. What effect will changing the packet size have on the Ethernet performance? The Attempt at a Solution I think if the packet size is increased then the number of collisions is...

Hi Physics Guys, I'm not a physics guy myself but some google searching lead me to this site so I signed up so I could ask a question. I'm into amateur motor sport and I'm currently driving a 1999 Subaru WRX. Anyway I'm always looking out for anything that will increase it's performance...

Dear all, I am trying to understand what is the difference between a transmitter and receiver antenna. If I recall correctly an antenna is a dipole so you can always use it to either transmit or either receive. All the antennas that are used for transmitting purposes come with some...

Say fired from this gun; it's a gun i made from Pimp My Gun, but it's not real. however I'm curious of what is it's performance; Muzzle Speed, Muzzle Velocity, Recoil, and Effective Range at 50" of barrel. using normal and +P+ ammunition Infinite Conundrum .338 lapua Magnum x98 Telescopic Sight...

what is the performance difference of MUX 4-to-1 by using NAND universal gate between conventional logic gates?...anyone

Hey Everyone! I'm looking for a good tool to do some high performance computing and analysis for my research. I've been going back and forth about using Excel as my primary tool as it is pretty straight forward so that I can share my data and results with others. Does anyone have any thought...

Hi, I'm confused about something. Why is it that in magazines and videos it seems as though adding more transistors to a CPU will make it faster? Is it a numbers thing (like, instead of marking amps on signs, they show volts)? I mean, I understand that you can do multithreading, multiple...

This seems to be a high interest topic and nobady else started it so I will. If previous discussion is evidence of a future trend please put on your asbestos underwear before you post. Before you start throwing knives, I will concede that there have been serious mistakes and defective...

I recently updated my Radeon HD 5870 (crossfire) drivers to the latest version, how do I benefit from this? Does it improve performance in any way? I also updated my creative soundblaster x-fi drivers, what did that do?

I am looking for a help in finding out the recommended programming language for real time (30 frames/ sec) particle simulation. This simulation involves a lot of calculations and Physics (fluids,...). I do have a little experience with C++ and I want to concentrate a good part of my time on...

Homework Statement Consider a household refrigerator that uses HFC-134a as the refrigerant, operating between the pressures of 1.0 bar and 10 bars. Determine the enthalpy at each ofthe points 1, 2, 3, and 4, and calculate the coefficient of performance. Compare to the COP of a Carnot...

I performed an improvisation with nay (reed flute):

In this project I'm tasked to do several things: (1) Find the area at each station in the turbojet and calculate the thrust, \dot{m}_{fuel} by calculating all relevant parameters at each station. On-Design Values M_0=0.8 \pi_c=15.472 M_2=0.5 \dot{m}_{corr,2}=35...

in defining cell you can use '#' but i read some where use this operator slowing your computation but i think mcnp at first chage your code and transform this oprator by use of (':' & ' ') and build new code then start to computation to prevent it , are you know about this subject?

I am currently in 10th grade, and this first semester has not been good. My weighted GPA totaled to about a 3.0. I'm taking English Honors, Chemistry Honors (weighted), PE, AP European History (weighted), Algebra 2--Trig. Honors, and Spanish 3. I understand the subject when the teacher is...