Calculations Definition and 982 Threads

Homework Statement This is a general problem i have been having but if you are given the relative dielectric strength of a material, (take air, 1.00058986), i have then been told it can only handle a maximum of 3V/micro meter. i have then been given a question a asking what is the breakdown...

So I am trying to verify a couple of things on p59 of this document http://arxiv.org/PS_cache/gr-qc/pdf/9707/9707012v1.pdf How do we show eqn (3.16) implies (3.17)? I keep getting bogged down on the maths. Could someone outline the method?

Homework Statement I'm trying to show that not all (half) of the energy supplied by the power supply ends up in the capacitor when the capacitor is charged through a resistor. I've looked at some of the other threads on these sorts of topics and I'd thought I'd have a go at working through it...

I am an engineer but have a rather dumb question regarding superchargers for engines and probably compressors in general. Most specifications are give as XXcfm at XX psi. I am trying to understand if this truly means we are moving that amount of air at the rated psi or if that means that...

Homework Statement . Suppose a monatomic ideal gas is changed from state A to state D by one of the processes shown on the PV diagram below, in which each interval on the vertical (P) axis corresponds to 2 atm, and the values of the lines on the horizontal (V) axis equal 1 L, 2 L, and 4 L...

Hi, I am trying to calculate the amount of heat required to raise the temperature of a rubber sphere by 20 degree's Celcius within 10 seconds. The rubber sphere will be heated via radiation in a closed system. I have calculated the specific heat capactity, by using the formula q =...

Hey guys, something that puzzles me everytime I stumble across spinors is the following: I know that i can express Dirac spinors in terms of2-component Weyl spinors (dotted/undotted spinors). Now, if i do that, i can reexpress for instance the Lorentz or conformal algebra in terms of Weyl...

Homework Statement If the space station orbits the Earth 225 km above the surface , what are the satellites orbital speed and period ? The mass of the Earth is 5.97 E24 kg and the radius is 6.38 E6 m. Homework Equations The Attempt at a Solution I already have the speed ( v ) , I...

Homework Statement The polynomials are defined as follows H_n(x) for n = 0; 1; : : : as follows: first, set H_0(x) =1 and H_1(x) = -x; then, for n >= 2, H_n is defined by the recurrence H_n(x) = -xH_(n-1)(x) - (n - 1)H_(n-2)(x): (1) I have to use (1) to verify that H_2(x) = x^2 -1 and...

i am wondering when i read about planets or solar systems that are like 1million lightyears away, those that take into account length contraction, because if the light is traveling at the speed of light then the distance it has to go will contract. also another (possibly) stupid question...

Hey guys, not touched any mathematics in almost 5 years and I am just getting back into it, been going well so far but hit a hurdle with this, I presume its some gaps in my knowledge. So been at this for about an hour, got the first one, no clue on the second, can anyone offer assistance?K(-2...

I would be grateful for your help with a small project I am involved in at work. I would like to set up an excel spread sheet to calculate either the thickness of insulation required to reduce the temperature of say a furnace wall from the inside to the outside, or calculate the resultant...

Homework Statement When 50.0 mL of a 2.0 × 10-4 M Ag2CrO4 solution was added to 50.0 mL of a Na2CrO4 solution a ppt formed (Ag2Cro4). What was the initial concentration of this Na2CrO4 solution? Ksp Ag2CrO4 = 1.1 × 10-12Homework Equations Given A2 (aq) + B(aq) -> AB(s) Ksp = [A]n[B] The...

Hi, this contracted company that I am working with has this data. Basically they collect the number of transactions each day. Then they graph these transactions out by Week, always monday - sunday. The data is then stored in a table where the x-axis is the date of the monday the week started...

Homework Statement Considering a container of 3*10-2m3 filled with an unknown gas such that the pression is 15MPA (or 1.5*107Pa) and the temperature is 25°C. Determine the volume occupied by one atom of the gas and determine the average distance between its particles. Homework...

I am currently working on a project that cools water moving through a chilled aluminum block. I am not familiar with the math/physics involved and would like some direction or recommendations. My project is currently setup so that I suction 32oz of 70 degree F water out of tank1 and pump it...

I am having trouble explaining this picture and i am hoping someone online could answer it. I took a picture in a computer lab of 2 monitors, you can see the flurescent tube lightbulb reflection on both screens. the monitors are off.(they are the exact same brand no difference between them...

Homework Statement A satellite with a mass of 5.00 x 10^2kg is in a circular orbit, whose radius is 2(radius of the earth), around earth. Then it is moved to a circular orbit with a radius of 3(radius of the earth). a) Determine the satellite's gravitational potential energy from the...

Dear all, Recently, some young people and I started a project that may be called "Piecewise-linear ball complexes: calculations with GAP". As to me, my direct aim is to make calculations in some TQFT's (topological quantum field theories) naturally defined on PL ball complexes of any...

Homework Statement charge (q) in coulombs, can be calculated byt integrating the current (i) in amperes (A) with respect to time. determine the charge on a capacitor as a result of current flowing for 0.03 seconds if: a. the current is a constant 5mA (0.005A) b. the current is a function...

Homework Statement I uploaded a picture of the circuit diagram I'm using. Basically I'm having trouble with filling out the rest of the table. Homework Equations Ohm's law: V=IR series circuit: R(eq)= R1 + R2 + R3... parallel circuit: 1/R(eq)=1/R1 + 1/R2 + 1/R3 ... Kirchhoff's Law: series...

Hi I need to know how to calculate lift characteristics like cl ,cd and so on... how can we include the winglets in it?

A 20 000kg rocket exhausts gases at a constant 600kg per second at 300ms^-1 a) Calculate the momentum of the exhaust gases b) Deduce the thrust applied to the rocket engines Any help would be much appreciated

I need to calculate a number of things: 1. the torque of the wheels. 2. The peak power, i am assuming it means of the wheels 3. the work done. i know: total mass (car+wheel): 680kg. mass of wheel: 22.67kg there are 4 wheels. radius of each wheel = .203m time: 8s. acceleration: 26.82m/s^2...

Hi all, I'm trying to learn to do some basic calculations for welding, and I've been given the task in regards to finding out the weld sizes required for the loads being applied. I've got a 1.2m wide staircase, with 6 stairs, attaching to two angular beams on the outside. They will be...

Hi everyone, I am new here at Physics Forums and this is my first post. Earlier this evening, my dad and I were trying to figure out the initial velocity of our projectiles. We were successful in calculating the initial velocity in a vacuum, but we are perplexed as to how to calculate the...

Hi, I've been having a bit of trouble finding a summer IC that can perform the following calculation: V0 = V1 + V2 - (V3 + V4) I found the LM324 which includes that calculation in its documentation, but it requires V1 + V2 > V3 + V4 since it's only got V+ and GND inputs. This...

Homework Statement Suppose you put a coffee pot containing 300 g of water at 20 C on the stove. You then add 350 kJ of heat to the water, which heats the water to 100 C and the water starts to boil. After all the heat is added to the water, then how much water do you still have left? The heat...

This post is based on problem 1-11 in Taylor-Wheeler. The problem is very similar to the others in this section, which is mostly devoted to the invariance of the spacetime interval. The problems are structured so that three of the four required numbers can be determined. The missing number...

Hello all, I am having problems working out the weight I require for as braking system. I have a wind unit bringing me 1kw of power through a standard generator. However the wind I catching is far stronger than my generator can take, anything over a KW will kill my unit so I decided to make...

Homework Statement Problem #1 A ball is thrown horizontally from the roof of a building 56m tall and lands 45m from the base. What was the ball's initial speed. Problem #2 A ball thrown horizontally at 22.2m/s from the roof of a building lands 36.0 meters from the base of the building. How...

I don't have a question about a specific HW problem, just a general questions. When calculating complex power, I understand it's S = Veff*Ieff(conjugate). However, S can also be calculate as S = 1/2 * V * I. Why is this? I feel I'm missing something simple, but I'm pretty lost because...

I am doing a report on Bicycle Helmets and it's supposed to include calculations of some kind but as I am looking around and writing about it I'm not too sure what would be the best kinds of calculations to put into this that won't sound out of place. The report needs to tell about how it...

Greetings, I’m looking at the output of an electronic 3-phase meter. I have 2 “snapshots” from the meter. In one snapshot I can make sense of most of the data presented. The output gives me Va, Vb, Vc, Ia, Ib, Ic, and their angles, a single power factor, watts, VA, and VAR. When I...

Can someone please guide me (with an example if possible) on Cable Sizing Calculations. I want to learn the step by step procedure alongwith calculations that are performed during the preparation of Cable Sizing Documents. Thanks in advance!

looking to find out what it take to retro-fit a small elementry school ( 3,000sqft) with new base board heater or small boiler. to calculate the different fuels (electric vs natural gas) and amounts used? In NW: older rates (just for calculations) electric is $.0463/kWh vs 1st 2,000...

After measurements, the following values and their uncertainties were recorded: x = 8.3 ± 0.1 and y = 2.72 ± 0.07 Find the following values of Z a) Z = x + y b) Z = x - y c) Z = xy d) Z = x/y e) Z = y/[(x)^0.5] (this is y divided by the square root of x) f) Z = exp(y)...

I'm so very confused on how to go about these problems. Define a TM that for every n duplicates a string of the form 1^n, creating 1^n 0 1^n. Does the machine calculate any function? We're using the notion that a string of n+1 n's represents n. Basically, I've surmised that I need a...

Hi everyone, I am in the process of putting together a water feature and am having trouble selecting the correct pump for the job. The pump will be required to pump water to a vertical distance of approx 7.4 meters. A submersible pump would be best. The pipe coming up from the pump is 12mm in...

Hi I am new to the design game as it where and I have scoured books and the internet looking for calcs, examples, help with a design I am putting together which involves raising and lowering a heavy object using a lead screw. I know its not strictly CNC stuff but I believe someone may be able...

Homework Statement Determine the number of moles of Nitrogen atoms in a sample of C7H5(NO2)3 that has the same number of oxygen atoms as 12.6 grams of sugar. Homework Equations Mole calculationsThe Attempt at a Solution First find the amount of moles of Oxygen in sugar. Multiply 12.6g by...

I have been searching for a long time and can't figure this out. The formulas I find are way over my head. Anyhow, I am trying to find how much flow would go through 2 different sized pipes. One is 3/8" ID and the other is 1/2" ID. The 3/8" uses 26psi and the 1/2" uses 17psi. All I want...

Homework Statement We have to prove the speed of sound using a ultra-sound emitter, connected to EasySense software which records the speed for it to travel to surface and back. Known data - Speed of sound is 337 metres a second at 20 degrees celcius. Also, the distance covered is, 3.4m or...

Hello yall I am new here. I am a first year student in engineering. I'm writing up a lab now and I am supposed to be showing the error. the error usually accurs when adding subtracting muliplying of dividing variables. Only I am a little clueless here. please help.

Would the approach taken to measurements and calculations be the same for the many different branches of science (Physics, Biology, Chemistry, and Earth science) that exist? Defend your answer by giving one example for reach branch of science listed. If someone could briefly answer this...

Homework Statement Suppose that 500g of water vapor condense to make a cloud about the size of an average room. If we assume that the latent heat of condensation is 600cal/g, how much heat would be released to the air? If the total mass of air before condensation is 100kg, how much warmer...

Would like to know how to calculate which hydraulic motor to turn a 2-1/2 dia shaft at a length of 30",with 15 mounted rotating chewing disks for a shredder machine. We are shredding soils and clay at about 40 yds/hr. we are also using a No. 80 drive chain on 12 to 19 tooth sprocket too...

Hey guys, I understand that if you lift an object a short distance in the air that it takes work because you are moving against the the weight of the object through a distance. So the equation in my mind is W=mgdcos\Theta where \Theta=0. But what I can't figure out is what if I lift the object...

I have a qualitative understanding of a heat engine; that being that when heat moves through a heat engine from a source to a sink, an amount of energy that passes through the heat engine will be absorbed, until no heat gradient exists between the source and the sink The attachment is a...

me again... what are next to next leading order calculations in the standard model?