Estimate Definition and 350 Threads

I am trying to estimate the amplitude of a real signal with a particular frequency and unknown phase. The signal is sampled at a frequency much higher than the Nyquist frequency for the signal. For simplicity, I take an FFT period which is a multiple of the signal period (which conveniently is a...

<< Mentor Note -- poster reminded to use the standard Template >> Question Three A pipe of outside diameter 200 mm is lagged with an insulating material of thermal conductivity 0.06 W m-1 K-1 and thickness 75 mm. The pipe carries a process fluid at a temperature of 300 °C and the average...

I came across this book 'Street fighting Mathematics, The art of educated guessing and opportunistic problem solving' , by Sanjoy Mahaan, published by MIT press. The book talks about how we can guess some property of the solutions of a number of physics and math problems without actually solving...

Homework Statement Make a very rough estimate of the probability that two high energy photons with an invariant mass of 126GeV are decay products of the Higgs. Use information found elsewhere (so I need to find this info preferably on the internet). Homework EquationsThe Attempt at a Solution...

one side of a right triangle is known to be 12 cm long and the opposite angle is measured as 30°, with a possible error of ±1°. (a) Use differentials to estimate the error in computing the length of the hypotenuse.

..."supervolcano" will cause? Immediate area affected, ash patterns, etc?

Homework Statement Suppose that a heated gas comprised of electrons glows bright orange when it is in use. Estimate the average speed of the electrons in the gas. Model this gas as an ideal gas. Homework Equations None. I have no clue. This is a "review" question on a chapter titled "Current...

Hi guys, I am just wondering if it is possible to calculate/estimate the location of measurement point on a rigid body? For example, let's say we have a rigid body that is in motion. We attach a sensor, say an accelerometer on the surface of the rigid body. Now can we estimate the location of...

Homework Statement Liquid ammonia is heated as it flows at a mean velocity of 2 m s–1 through a circular pipe. The pipe, which has an internal diameter of 75 mm, is at a uniform temperature of 27°C, and the ammonia at a section 1.2 m from the inlet to the pipe has a temperature of –23°C. Use...

Hey guys, Do you have ideas on the current dollar amount spent on nuclear fusion research since it's Rutherfordian inception?

Homework Statement Show that the time of matter-radiation equality, t_{eq} can be written: $$ t_{eq} =\frac{a_{eq}^{\frac{3}{2}}}{H_{0}\sqrt{\Omega_{m}}} \int_{0}^{1} \frac{x}{\sqrt{x+1}} dx $$ Homework Equations $$ t = \int_{0}^{t} dt = \int_{0}^{a} \frac{1}{H(a)} \frac{da}{a} $$ [Given]...

I have constructed a torsional balance, which basically consists of a torsional spring, and a damper. I model this as a spring mass damper system. And it is used to measure thrust of some propulsion system. This is how the system looks like. I am just very eager to find out, how to model the...

Hi, I recently came across a blog on schlieren visualization (http://ottobelden.blogspot.in/2010/07/homemade-schlieren-photography-setup.html). I replicated it with the following: Convex lens (130 mm dia and 350 mm focal length), LED light source (5 mm white LED) and smartphone camera (Moto G4...

Homework Statement If a ball is thrown into the air with a velocity of 48 ft/s, its height in feet t seconds later is given by y = 48t − 16t2. (a) Find the average velocity for the time period beginning when t = 2 and lasting for each of the following. (i) 0.5 seconds (ii) 0.1 seconds...

Homework Statement 3. (I) Estimate the pressure exerted on a floor by (a) one pointed chair leg (66 kg on all four legs) of 2 area  0.020 cm , and (b) a 1300-kg elephant standing on one foot   2 area  800 cm . Homework Equations P=F/A=W/A The Attempt at a Solution I know the solution...

i know that the total energy density of a blackbody radiation is E= 4 segma/C * T^4 so how i can use this to find the number of the CMB photons in 0.25 litre?

Homework Statement a) Estimate the radiation pressure due to a 100 W bulb at a distance of .08 m from the center of the bulb. b) Estimate the force exerted on your fingertip if you place it at this point. (Assume an area of .0001 m2 for the fingertip.) Homework Equations F=PradA The Attempt...

I assume this is a simple summation of the normal components of the vector fields at the given points multiplied by dA which in this case would be 1/4. This is not being accepted as the correct answer. Not sure where I am going wrong. My textbook doesn't discuss estimating surface integrals...

Hello! (Wave) Let $u(x)$ be a solution of the problem $$Lu=-1 \text{ in } \Omega , u|_{\partial{\Omega}}=2, (c(x) \leq 0)$$ I want to determine the constants $c_1,c_2$ such that $c_1 \leq u(x) \leq c_2 (1)$. Also I want to improve the estimate $(1)$ when it is furthermore given that $c(x)...

Homework Statement Estimate the E-field required to ionize Hydrogen in a time comparable to the time taken for the electron to orbit the nucleus. (n=1 ground state) (hint: relate the required E field to the energy of a charged particle) Homework Equations F = mv^2/r (rotational) F = Ze^2/Kr^2...

Homework Statement Question: A student used a digital stopwatch three time 10 oscillations of a pendulum. The timings were 13.52s, 13.64s and 13.58s a) Calculate i the average time for 10 oscillations, ii the time period of the oscillations. b) Estimate the accuracy of the timings, giving a...

Hello all, I've been tasked with developing a model for dose received from the Chernobyl Accident. I'm struggling a little to find dose estimates from which I can extrapolate back to find the initial dose received. Does anyone have any references that they can point me towards? I believe there...

Data Data obtained from a survey conducted by a tyre manufacturing company, using a sample of 60 tyres of a certain category, on the distance tyres ran before they became unsuitable for further use. Problem i. What is the modal class ii. Taking the mid value of the modal class as the...

The supply current was sampled 1024 times over a very short time interval. The data so obtained is given in column B of the accompanying Excel worksheet1. This worksheet has been set up to give a graph showing the spectral components of the data. Question 3 i) Obtain the Fourier Transform for...

I am doing a nonlinear least squares estimation on a function of 14 variables (meaning that, to estimate ##y=f(x)##, I minimize ##\Sigma_i(y_i-(\hat x_i))^2## ). I do this using the quasi-Newton algorithm in MATLAB. This also gives the Hessian (matrix of second derivatives) at the minimizing...

Hi all, Do any has an idea how to give a rough estimation for this process's cross section: g g -> H -> h h, (h -> b b~), ( h -> b b~) ? where h is SM Higgs and H is a heavy Higgs boson with BR (H > hh) ~ Gamma (H > hh) ~ 10^-3 GeV and sigma (g g > H ) ~ 10 pb .. When I calculated it by...

Homework Statement Suppose that ##Y \sim N_n\left(X\beta,\sigma^2I\right)##, where the density function of ##Y## is $$\frac{1}{\left(2\pi\sigma^2\right)^{\frac{n}{2}}}e^{-\frac{1}{2\sigma^2}(Y-X\beta)^T(Y-X\beta)},$$ and ##X## is an ##n\times p## matrix of rank ##p##. Let ##\hat{\beta}## be the...

Hey all I have one last question for you. I just need clarification on point estimate and margin of error as I have to find both in a problem. Let's say the endpoints are 5.9 and 8.1. When I do a margin of error problem, I subtract the mean of 7 from 8.1 right? When I do point estimate do I add...

Homework Statement Experimental data for the heat capacity of N2 as a function of temperature are provided. Estimate the frequency of vibration of the N2 molecule. Homework Equations Energy of harmonic oscillator = (n+1/2)ħω C=7/2kB Average molecular energy = C*T But this is an expression...

I'd like to know if it's possible to roughly estimate a light source wattage remotely, knowing the distance and perhaps estimating that at such a distance it's still above the minimum human recognizable threshold at night (in a light polluted area). Maybe using a DSLR camera could help by...

Homework Statement Suppose that a 15 M(solar masses) star finally runs out of nuclear fuel in its core and undergoes a Type II supernova explosion. You are going to analyse the energy budget, calculating all the quantities in Joules. a) Estimate the amount of gravitational energy that would be...

Homework Statement Consider a closed rectangular box with a square base of side 3cm and height 5cm. If the side is measured with an error at most 0.02cm and the height is measured with an error at most 0.01cm, use differentials to estimate the maximum possible error in computing the volume of...

1. Question The speed of an electron is known to be between 6.0×10^6 m/s and 6.7×10^6 m/s . Estimate the uncertainty in its position. Homework Equations ΔpΔx ≥ h/2π (mΔv) Δx ≥ h/2π (Since Δp= mΔv) Δx≥ h/2π(mΔv) h= 6.63*10-34 J*s c= 3.0*108 mass of electron= 9.11*10-31 The Attempt at a...

Homework Statement A star experiences a sudden increase in pressure to a new value P'. Taking the average density as ρ and the radius R, estimate the time scale of expansion of the star. (Ignore gravity altogether). Homework Equations The only thing I can see in my notes that may (or may not)...

Homework Statement In a mathematics-based investigation, I am trying to estimate the stress through a voussoir (member) of an arch bridge. However, these members have non-uniform cross-sections. I don't need to know how to exactly calculate the stress in each part of the member, only the total...

Homework Statement Estimate the vapor pressure of mercury at 25 ∘C (use data from Appendix D from the textbook). Homework Equations Using the appendix I can find ΔG, ΔH, and ΔS. The Attempt at a Solution I have no idea where to start. I think that maybe vapor pressure would be found when...

As we all know, the LIGO collaboration published a paper recently on the first direct observation of a binary merging black hole system. From the observed signal, they were able to infer the black holes' masses and their distance from Earth. However, the fact that they can estimate masses and...

Hi. I'm a computer science student developing a kalman filter for autonomous sailboat, but I severely lack knowledge of the physics behind sailboats. I have a wind sensor giving data about wind speed and wind velocity, problem is the data is unreliable. So i thought that i could estimate what...

Homework Statement [/B] The area of a triangle is (1/2)absin(c) where a and b are the lengths of the two sides of the triangle and c is the angle between. In surveying some land, a, b, and c are measured to be 150ft, 200ft, and 60 degrees. By how much could your area calculation be in error if...

Homework Statement Hi, I need to get an estimate of the branching ratios of the processes [/B] t ---> b + W ---> b + c anti-s t ---> b + W ---> b + anti-tau nu(tau) without doing the calculations, just a qualitative estimation. I know I have to take into account the way W decays...

How do I estimate the height of the tall building spiderman swings to at 0:48? I need it for a physics assignment. What does you're intuition tell you? (I've never lived in a city full of buildings). Is there a way to estimate it using physics? I'm not sure that building actually exists.

I am trying to figure out whether I can use a small Minn Kota trolling motor as an electric generator. If I add a 10" prop the max energy from the water passing the prop should be about 700W and if the prop is 50% efficient, it should put half of that on the shaft. I expect the prop to turn...

When a nucleus gamma decays, the gamma has its intrinsic spin of ##1\hbar##, but it can also carry away a significant amount of angular momentum in addition to that. Quadrupole radiation is very common, and in exceptional cases you can even get gammas with 5 or ##10\hbar##. Now suppose I do the...

Homework Statement I am given a table of ~3000 measurements for the number of decays from some radioactive substance within some period T. I want to estimate the mean number of decays per period. Homework Equations Poisson distribution How to calculate mean. The Attempt at a Solution My...

Homework Statement The half life of U-238 is approximately 4.4 billion years, while U-235 is approximately 700,000,000. A Uranium ore has 0.75% U-235. Assuming there was an even amount of both types of Uranium when the Earth was formed, estimate the age of the Earth. Homework Equations N =...

Homework Statement Estimate the diffraction angle. The spectrometer is made from rolling up a 30cm long piece of cardboard into a tube. Duct tape is placed over one end, and a thin slit is made. The other end has a diffraction grating held in place. I look through the diffraction grating and...

Scientists usually conduct a variety of in vitro and in vivo studies on rodent and their cell cultures and they show the concentration of a particular drug is effective against the disorder for both in vitro and in vivo for the rodents. My question is how do they translate that to a dose for the...

If R = [−3, 1] × [−2, 0], Use a Riemann sum with m = 4, n = 2 to estimate the value of ∫∫R(y2 − 2x2) dA. Take the sample points to be the upper left corners of the squares. So far, I found the indefinite integral of the function to be y3/3 - 2x3/3 Not sure where to go from here

Homework Statement...

Not sure if this is the right place, but I'm hoping to ask two questions: 1. I shine a laser pointer at a mirror at night, and the reflecting beam glaces off of my eye. Obviously it's quite bright, and I want to know if this has caused any serious damage. Of course I shut my eye, but apparently...