Calculations Definition and 982 Threads

Homework Statement It is common to see birds of prey rising upward on thermals. The paths they take may be spiral-like. You can model the spiral motion as uniform circular motion combined with a constant upward velocity. Assume a bird completes a circle of radius 6.00m every 5.00s and rises...

Homework Statement Consider the matrix elements of \hat{x} in momentum space. That is, evaluate \langle p | \hat{x} | \psi(t) \rangle in terms of the momentum space wave equation \langle p | \psi(t) \rangle . Homework Equations \langle x | p \rangle = \frac{1}{\sqrt{2 \pi \hbar}}...

A submarine has run into trouble and is stuck at the bottom of the ocean. Several people are on board and must make their way to the surface without any diving gear. The air pressure aboard the submarine is 3.500 atm. The air temperature inside the submarine is 17.52 °C and you can take body...

I have a cantilever bracket, fixed at one end, free at the other. One vertical element AB, 330mm long with a fixing at either end to a wall. One horizontal element CD, 375mm long. CD is fixed at 90deg to AB, 130mm from the top. A constant, downward load W=30kg, is applied to the end of CD...

Homework Statement A hard rubber ball is bounced on the floor. Compare the ball's acceleration on the way down to its acceleration on its way back up. Homework Equations - [b]3. The Attempt at a Solution [/b First off, ignore air resistance. Lets assume that the person bouncing...

Hi all, I have a the following problem to solve fairly quickly, I need to calculate the required input torque to my gearbox and pump Gearbox output torque - 0.12348Nm Gearbox output speed - 80 rpm Gearbox input speed - 4 rpm Gearbox (compound gears) Gear A, driver = 100 teeth, Gear B...

I live in Dubai, and the water for my whole house is stored in a water tank on my roof. This is a problem as during the summer months the temperatures reach up to and a bit beyond 50 degrees in the day, this heats up the water in the tank a lot so we don't have any cold water during the later...

I have recently developed a multi-computer networked simulation of a turbofan jet engine test cell control room, including a real-time simulated jet engine "model", PLC control logic, video playback of a engine at various states, and a throttle for maneuvering. I currently calculate all...

I decided to write an arbitrary precision calculator but I'm having problems with division. It will multiply a thousand digit number by another thousand digit number in about a second but to get a division result to about 250 decimal places is taking around 20 seconds, I cannot figure out how...

I was toying with the idea of making an iron core electromagnet to retrieve a broken portion of my driveshaft from a recess in the end of the crankshaft on my boat motor. The mechanic at my work said I wouldn’t be able to do it, so I figured I would entertain the idea. The driveshaft is...

I have a physics assignment. Part of it is to calculate the speed throughout the rollercoaster and to not exceed 4.5g's of force. Anyway, I'm calculating the speed of the rollercoaster using the formula 0=g(h2-h1)+0.5(v2^2-v1^2)+μNd (I have already simplified to not include the mass...

I have been given a project at work to find the number of dozers needed to push a certain volume of material in a certain amount of time. My issue comes with the actual horsepower of the dozers. We run D10T, D11R, D11R CD, and D11T Cat "track-type tractors". So from what I am thinking, I want to...

Hi all, I have a peristaltic pump that i need to rotate at 26 rev/min. The gear arrangement attached to the pump is calculated at 13.1:1 therefore I am assuming an input speed of 340rev/min is required to produce a reduction in speed to the desired output of 26 rev/min. Gear A (1st...

Hello, Problem, let B={a_1,a_2,a_3} be a basis for C^3 defined by a_1=(1,0,-1) a_2=(1,1,1) a_3=(2,2,0) Find the dual basis of B. My Solution. Let W_1 be the subspace generated by a_2=(1,1,1) a_3=(2,2,0), let's find W*, where W* is the set of linear anihilator of W_1. Consider the system...

Homework Statement (old exam question attached) Homework Equations Complex power: S = VI* / 2 = P + jQ where P is the average power and Q is the reactive power Magnitude of complex power |S| = Vmax*Imax/2 V = ZI The Attempt at a Solution We can calculate θv - θi for each load by using...

I know it must relate to the velocity profile being a parabola shape and the max velocity being at the peak of the parabola - I wanted to know whether there are actual calculations I can do to show this? I only know the basics so as much details as possible would be great help...

Good afternonn, these are the motor and circuit data: Motor power: 0.37kW, Nominal current: I= 0.8 A voltage: 415 V, cable length = 80m ambiant temperature: 50°C Maximum voltage drop percentage =415*4% =16.6V According to the Bahraini Regulations: - temprature factor= 0.89 - core...

Hi, When using data in calculations, errors can be introduced by the calculations themselves; A common example of this kind of data is the atomic mass of some element; The data might be reported by NIST as: 190.233(20), which indicates that the mean is 190.233, and the maximum likelihood...

Hello all, I have a few questions about calculating efficiency, torque and horsepower for a small pulse dc motor. The only parameters that I have are input voltage = 39Vdc, input current = 2A and rpm = 90,000 rpm. Are the above values obtainable with the given information? This is not a...

I have no idea how to calculate the bushing load which is stated in catalogues in unit N/mm^2 and KgF/cm^2. Anyone knows how?

Hi Guys, This is for my university project.I need to design a oil tank for the formula student car.The first stage is the analysis of the existing stock oil tank (Aprilia SXV 550 is the engine).I need to find out the heat lost/transferred from the of the existing oil tank.How can I calculate...

Hi Guys, This is for my university project.I need to design a oil tank for the formula student car.The first stage is the analysis of the existing stock oil tank (Aprilia SXV 550 is the engine).I need to find out the heat lost/transferred from the of the existing oil tank.How can I calculate...

Homework Statement Current, I, flows around symmetrical loop of thin wire. The loop comprises 2 halves (semicircle & triangle). Distance from vertex of triangle equals radius, a, of the semicircle. Find the mag' field at axis of loop (where axes coss) Homework Equations Could I use...

Hello, I am doing some calculations of the band structures of the surfaces of several materials. I would like to perform passivisation on these surfaces so as to remove any metallic surface states. Unfortunately, I was never great at chemistry and so it's not obvious to me how to choose what...

I know the formula T=F*D but having problems wrapping my head around this problem. I want to direct couple a stepper motor with a .5"D shaft to a .75"D ballscrew. The motor has 400 oz inch torque but since the motor shaft is .5"D or .25" radius How do I calculate the Torque at .25" radius? I...

Hello PF. I wanted to optimize time expenditure on some calculation that I'm doing. A natural way to do this can be by computing parts in parallel. Now when I say "parts" I don't mean that some computations are wholly independent of other computations. My situation is that I have a bunch of...

1) I'm not sure how to solve this question A 20MVA induction motor connected at 13.8kV draws a load current of 1.0 p.u, 0.85 power factor lag. Calculate the rated load current in Amps and the real power and reactive power drawn by the motor. Express these quantities in per unit form using...

I am trying to determine the expected heat exchange between flowing ground water in gravel/clay soil (that runs on top of blue clay) and glycol fluid in plastic pipe (1 1/4"). For my current interest, estimated ground water temperature of 60 degrees seems best. I am trying to determine the...

Hi all I am struggling to work symbolic math calculations with Fotran 95 in the Silverfrost ftn 95 plataform. Say you want to calculate c=a+b but without initializing "a" or "b" to get a value "c", but rather print out or obtain the actual generic expresion "a+b" I have tried to solve...

This isn't a homework question per se, but more of a coursework question. Specifically, I'm a bit at a loss as to how to go about learning a particular section of the coursework for a physical chemistry (i.e. thermochemistry) class I am taking. The section in question is that pertaining to...

I have been given a physics assignment which requires that I go over the physics of why 40km/h is a better speed to be followed in a school zone rather than 50km/h. (must include calculations for stopping distances etc.) I used the formula Vo ^ 2 / 2 x μ x g. It should give me the stopping...

Homework Statement I have a physics lad research that's due tomorrow, the overall process is to work out how much potential energy will be stored in a bow, and the efficiency of the bow. First of all, I have a graph, with the plots Force Vs. Displacement (of a weight 'm' on a string). We...

hi so i had to build a catapult and it's very small, but i need to find the total velocity of the ball upon impact and the maximum height reached. You might need to explain a little bit because I tend to not get things when they are vague so please post more than a formula. Please and thank you...

I tried posing my question by using some Latex features here, but I could work faster by using Word coupled with what I could use from Latex here. When I tried putting the material here from Word, it didn't work out, so I'm attaching a pdf of my question. The reference to IMO is the...

Hi Folks, Not the best at this so hoping somebidy can help me. I have a 67.4 litre vessel and I'm filling it with SF6 to 6Bar. Can I work out how much SF6 I'm using in litres? Is this a dumb question? should nI be asking what weight I'm using. I've been asked to supply usage in litres.

Homework Statement A duct of length 5 m at 38 Degrees inclination to horizon with a cross section dimensions of 0.3 m X 0.4 m is carrying 2 kg/s of a heavy gas at 10C and 1.2 bars and delivers the gas flow at 50C at the end of the duct to a horizontal pipe section. i) Calculate changes to...

Hi, ok, so the task is to define the thickness of th weld, the so-called a-dimension. If the welds were either vertical or horizontal, I'd have no problem, but they're not. So do I divide the force into components or perhaps the welds? What about how to calculate the moment caused by the force...

Hello, I need to find the bending moment and forces at the mid point cross-sections of two separate beams connected together. One is a horizontal beam connected to the top of a vertical beam that sort of look like this: H======== H H H H There is a UDL of 10kn/m on the top member, with the...

HI i am a student from Singapore , and i was told to calculate the amount of hot water needed to supply to a house. The design brief stated 1)Deliver 15 gallons of water at average 110°F (43°C) temperature within 10 minutes; 16 water draws during 1 week 2)Dishwasher: Successfully wash five...

Homework Statement In a high school project we have been given the assignment to design the mechanism to transform the a rotary motion into the oscillating of a wiper blade. I'm a bit confused as to how to go about the problem.. I have been given that there is a closing force between the...

Homework Statement Hello everybody, I have a problem dealing with complex circuits, especially those that have extra symbols (transistors, earth, V_in, V_out). Hopefully somebody can give me helping hand. Thanks a bunch. This is the link to the problem which is on page 11 (the first one)...

Homework Statement Basically, I need to understand how to calculate Irms and I*rms given a Vrms and an impedance Z. Example question: Given Vrms = 120 V at an angle of 30° and an impedance of Z = 10 Ω, find Irms and I*rms. Homework Equations How exactly do I solve for Irms and...

In the diagram attached, the 3 resonance structures of arenium ion bonded to H electrophile are shown.I labelled the carbon atoms in one of the structures for convenience. From the diagram, the A and B carbons, and D and E carbons, have a double bond between them for two of the resonance...

I'm trying to find the equation of a parabola that goes through any three given points in the x-y plane denoted by (a,b), (c,d), and (e,f), which would be considered givens in these calculations. I need the form of the equation y = Ax^2 + Bx + C where A, B, and C are unknown. I have gotten as...

Hi guys, I just wanted to know when to use ωxr and when to use rxω when we're making vector based calculations. I realized that when reversed te calculations tend to differ a lot. Thanks for the help in advance!

hi, not sure if I am posting in the right section, had a good look through the search option but cannot find what I am looking for, probably because I am being stupid.. im working on some simple beam calculations, I am a studying architecture, however I am trying to get my head round load...

What is the equation I should be using for the following question: At 298K a cell reaction has a standard emf of +0.17V. The equilibrium constant for the cell reaction is 5.5 X 10^5. What is the value of n for the cell reaction. Grateful for anyone's help!

Homework Statement Using matrix algebra calculate the voltage expected across each resister in the circuit diagram. Only need the simultaneous equations. The Attempt at a Solution -15=6800(I_b-I_a )+2200(I_b-I_c) 15=2200(I_c-I_b )+8200(I_c-I_d) -25=8200(I_d-I_c )+4700I_d Thanks for any help.

Homework Statement A lamborghini's breaking speed is 6.7 times that of its acceleration. The total time taken to go from 0 to 100 and back to 0 is 13.7 seconds. What is the displacement of the car? Homework Equations Unsure at the moment The Attempt at a Solution So, you divide...

(i) Obtain the scale factor a(t) and redshift z when the energy density of matter and radiation were equal. (ii) Next use the a(t) relation for a matter-only universe to estimate the time of matter-radiation equality. (iii) Repeat (ii) but using the a(t) relation for a radiation-only universe...