Ratio Definition and 1000 Threads

Homework Statement A 72.8 kg ice skater is moving at 5.01 m/s when she grabs the loose end of a rope, the opposite end of which is tied to a pole. She then moves in a circle of radius 0.765 m around the pole. The acceleration of gravity is 9.8 m/s2 . Find the force exerted by the rope on...

What is the ratio of energy contained in photons vs energy contained in neutrions in the present universe? Also, how is that ratio changing with time? Thanks.

I'm unsure as to if I am using the correct terminology, but what I mean by this is log = logarithm in base 10. ln = logarithm in base e. logx = logarithm in base x. Upon some investigation, I found that log(a)/ln(a)=log(b)/ln(b) where a and b are constants, meaning that there is a ratio...

Homework Statement Designers of electrical circuits often take the maximum amplitude of the radiated electric field (at a large distance r) produced by an alternating current I0 flowing in a loop of area A cm2 to be given by E=\frac{2.6AI0f2}{r}\muVm-1 where f is the frequency in MHz...

Homework Statement I'm asked to specifically use the Ratio Test (formula below) to determine whether this series converges or diverges (if it converges, the value to which it converges is not needed.) \sum_{n=1}^{\infty}\frac{n}{(e^n)^2} Homework Equations Ratio Test: If a_n is a sequence...

Homework Statement Vectors A and B have the same magnitude. Given that the magnitude of A + B is 75 times greater than the magnitude of A - B, find the angle between them? Homework Equations We know that A=B, so: 2AB+2ABCos\theta=75(2AB-2ABCos\theta) Given that A=B...

Homework Statement assume summation of series An converges with all An>0. Prove summation of sqrt(An)/n converges Homework Equations The Attempt at a Solution I Tried using the ratio test which says if lim as n goes to infinity of |Bn+1/Bn|<1 then summation of Bn converges. I let Bn...

Homework Statement In each of the following the properties of a compound are given. In each case find A:B:C 1. 1/5 of A, 2/3 of B and the remainder of C. 2. 3/8 of A with B and C in the ratio 1:2. 3. A, B and C are mixed according to the ratios A:B= 2:5 and B:C=10:11. Homework...

Hello, I have some 10 signals in noisy and nonoise(noisy+good) situations. I just calculated the power of each signal in two cases and then used SNR formula for dB(10log noisy/nonoise). Now, I got noise levels in dB's. Here, i confused that these dB levels are referred to...

why does the hydration energy decrease as the size of the ion increases? I want a logical reason... I already know that it is because the charge to size ratio decreases...

From Todreas & Kazimi, Nuclear Systems I, Problem 2-3 1. Homework Statement Calculate the minimum critical power ratio for a typical 1000 MWe BWR operating at 100% power using the data in Tables 1 – 2, 1 – 3, and 2 – 3. Assume that: a) The axial linear power shape can be expressed as...

Considering a practical transformer, We can get a given voltage and corresponding current ratio by selecting a particular turns ratio. ie. V1/V2=N1/N2=i2/i1 Say that I want to make a 240V/60V. Now 240/60 volts ratio can be acheived by considering different no. of turns on primary(P) and...

I am having trouble with some of my homework. I am not quite sure how to find the damping ratio from a third order system when the transfer function (of s) is the only information supplied. Could anyone help me with this? I would like a method that would work with any nth order system...

Homework Statement x(t) is input into a perfect lowpass filter with frequency response H(ω), having a bandwidth of BHz and a passband gain of 1. For B = (2πT)-1 Hz, calculate the ratio of the output signal energy to the input signal energy. Homework Equations x(t) = Ae-|t|/T The...

Being a hobbiest programmer, I know enough about probability to get by. However, I've set myself an impossible (for me) calculation in my current personal project. I have a set of numbers. For this particular problem it is a set of four numbers {248, 184, 120, 56}, but I'll be repeating the...

Hi, I'm working on a project on dwarf spheroidal galaxies. Is there a way to get a mass-to-light ratio knowing the distance to the galaxy, its size, and maybe some other parameters like the absolute magnitude or velocity dispersion? In the end, I'm trying to figure out their masses using...

Hello, Quick question on how you would go about calculating this. A grade of steel has the following properties; Tensile strength = 300 N/mm^2 - (not relevant?) Youngs Modulus = 200 GPa Poisson Ratio = 0.3 The grade of steel is 2m long, with a 20mm cross sectional area. It is positioned...

Homework Statement At the given 10 Hz frequency calculate the magnitude of the voltage across a: (1)4.7kohm resistor (2)100nF capacitor Homework Equations Vr/v=R/z=R/sqrtR^2+(1/wC) Vc/v=(1/wC)/z=(1/wC)//sqrtR^2+(1/wC) The Attempt at a Solution (1)4.7/sqrt(4.7^2+2*PI*4.7^2)...

For my investigation regarding the aerodynamic forces on a spherical projectile, I really need to know the theoretical ratio of rotational kinetic energy to linear kinetic energy of a spherical projectile (assuming the only spin is forward spin and there is no Magnus effect). Can someone please...

Homework Statement Determine divergence/convergence of this series: \sum\frac{(2n)!}{(n!)^{2}} * (\frac{1}{4})^{n} Homework Equations ratio test? The Attempt at a Solution I attempted to use the ratio test and the resulting limit was 1, which means the ratio test is inconclusive. So far, I...

Homework Statement Electric and magnetic fields in many materials can be analyzed using the same relationships as for fields in vacuum, only substituting relative values of the permittivity and the permeability, ε = κε0 and μ = κmμ0, for their vacuum values, where κ is the dielectric...

Homework Statement Test for convergence and divergence. Homework Equations \sum_{i=1}^{n} \frac{n!}{3^n} \sum_{i=1}^{n} \frac{1}{{(log (n))}^{1/n}} The Attempt at a Solution For the first one I get \frac{(n+1)}{3} After applying the ratios. Taking the limit as n approaches infinity, it is...

The sqeuence of ratios of a fabinacci number F_n+1/F_n on looking at this. F_2/F_1 =1/1 =1 F_3/F_2 =2/1 =2 F_4/F_3 =3/2 =1.5 F_5/F_4 = 5/3 = 1.667 Why would F_n+1 = at F_4 =3 with also F_3=2 I think i understand the squence is fabin accie on the denominater but on the...

The Supergolden ratio is the solution of x3=x2+1. \psi = \left({{\sqrt{31}}\over{2\ \times 3^{{{3}\over{2}}}}} {{29}\over{54}} \right)^{{{1}\over{3}}} {{1}\over{9\,\left({{\sqrt{31}}\over{2\ \times3^{ {{3}\over{2}}}}} {{29}\over{54}}\right)^{{{1}\over{3}}}}} {{1}\over{ 3}}\approx...

1. \sin \theta = \cos \theta \theta=\frac{\pi}{4} 2. \sin \theta = \tan \theta \theta = 0 3. \cos \theta = \tan \theta \theta =\arcsin (\varphi -1) 4. \sin \theta = \csc \theta \theta = \frac{\pi}{2} 5. \sin \theta =\sec \theta \theta does not exist. 6. \sin \theta =\cot...

Homework Statement The weight of an object of mass 1kg at the surface of Mars is about 4N. The radius of Mars is about half the radius of Earth. Estimate the ratio: mass of Mars/Mass of Earth Homework Equations The Attempt at a Solution The answer is 0.1 but I don’t see...

Homework Statement If the work put in is 3000j, calculate the useful energy output. [PLAIN]http://www.mkwebman.com/question Load = 1962N Homework Equations VR = Distance covered by effort / Distance covered by load MA = load/effort Efficiency = MA / VR Efficiency = useful...

What is Image Rejection Ratio (IRR) and How to calculate an Image Rejection Ratio (IRR)?

Homework Statement Here is the objective: To experiment with the resultant of two gravitational forces. In particular, you will find the equilibrium position for a test mass located on a line between two point masses. Here are the instructions: (1) Drag the test mass (red disk) to an...

Homework Statement Copper forms two oxides. For the same amount of copper, twice as much oxygen was used to form the first oxide than to form the second one. What is the ratio of the valencies of copper in the first and second oxides? (This is not my homework question. I am solving a book...

Homework Statement The temperature of a fixed mass of gas drops from 127 C to 27 oC under constant pressure. Find the ratio of the new volume to the original volume. C. 3:4 D. 4:3 E. 1:1 A and B arent here because i have gotten them wrong. Homework Equations Ideal gas law: PV=...

Two carts each 12 cm long travel toward each other on a frictionless air glider track. The first cart on the left has an initial velocity of 18 cm/s toward the other cart that is stationary. The carts then collide. The cart on the left has a new velocity of -4cm/s and the stationary cart now has...

I am working on a project that will use cylindrical neo magnets. Is there an ideal height to diameter ratio for neo magnets?

I am doing the following practice problem in prep for an exam: sum from n=0 to infinity: (3^n)/(n+1)^n The book says to use the ratio test on it, which I did, but would the root test also apply to this?

Homework Statement Determine whether 1/n! diverges or converges. So far, we have only learned the comparison tests, p-series, geometric series, divergence test, and integral test, so I can only use these tests to prove it. Homework Equations N/a The Attempt at a Solution I...

Hi all, Speed is a ratio of the distance traveled per unit time. But what then is work done and moments? For example, work done is force multiplied by the distance traveled in the direction of the force. But how would you explain the rationale of multiplying these two quantities? As...

Homework Statement question A ciclindrical metal specimen 10 mm in diameter is stressed elastically in tension. A force of 15000 N produces a reduction in diameter of 0.007 mm. Compute Poisson ratio if its elastic modulus is 100 GPa Homework Equations E=stress/strain The...

question A ciclindrical metal specimen 10 mm in diameter is stressed elastically in tension. A force of 15000 N produces a reduction in diameter of 0.007 mm. Compute Poisson ratio if its elastic modulus is 100 GPa my attempt D original = 0.01m change in D = 0.000007m F=15000N E=...

Hi all, this is my first post. I find a lot of conflicting definitions of damping factor, damping coefficient, and damping ratio on the internet, and in some textbooks, when related to RLC circuits. Sometimes I see the neper frequency described as the damping factor or damping coefficient...

Homework Statement To start, I did find a few very similar or equal topics, but I could not gather enough information. And, the pi symbols are intended to be pi symbols with negative superscripts (couldn't get it to work/finalize). --- The charge-to-mass ratio of a \pi- particle is known to...

Homework Statement Show that the volume of an upright cylinder that can be inscribe in an upright cone is 4/9 times the volume of cone Homework Equations volume of cone volume of cylinder differentiation ?? similarity of triangle The Attempt at a Solution I draw the picture of...

I don't really know how to approach this problem... A satellite is in a circular orbit around its parent body. The ratio of the satellite's kinetic energy to its potential energy, K/Ug, is a constant independent of the masses of the satellite and parent, and of the radius and velocity of the...

\begin{array}{l} \\ \mathop {\lim }\limits_{n \to \infty } \left| {\frac{{{x^{n + 1}}\left( {\frac{1}{{{{\left( { - 3} \right)}^{n + 1}}}} - 1} \right)}}{{{x^n}\left( {\frac{1}{{{{\left( { - 3} \right)}^n}}} - 1} \right)}}} \right| = \mathop {\lim }\limits_{n \to \infty } \left| {\left(...

We have 2 solenoids : S1 and S2 The coils are wind up as close as they can get and both have length L. They are both made from the same material and have the same length. They are both connected to a DV source. S2 has a wire with a double diameter The ratio between B1 and B2 then is? I...

Homework Statement Suppose that an electron is a small spherical shell of mass m with a charge e spread over its surface. Show that the ratio of the magnetic moment to angular momentum of such an electron should be e/2m whether the electron is a) moving in a circular orbit or b) spinning...

Homework Statement 1962N Load 5 m from effort (hydraulic ram) and fulcrum 1m from effort. Calculate the Velocity ratio, if work input is 3000j calculate work output. Homework Equations VR = distance moved by effort / distance moved by load effort = 11772N MA = load / effort =...

The ship is twice as old as the boiler was when the ship was as old as the boiler is. What is the ratio of their ages? I do believe I have solved this (without Googling) and have uploaded my answer online with a timestamp of 10:35PM 4/27/2011 (i.e. before I posted this). Let me know...

Homework Statement 1. A photocpier increases the paper with the ratio 4:5, what % is the paper increased 2. An alloay has a copper, alloy and lead with the ratio 5:7:3, what % is the alloy to lead 2. The attempt at a solution 1. Difference in equation = 5 - 4 = 1...

Homework Statement For copper we find that J=\sigmaE , where \sigma has the value 5.8x10^7 mksc units. If an alternating electric field represented by E0ei\omegat exists within the copper. Find the ratio of the conduction to the displacement current density at a frequency of 1megacycle/sec...

Homework Statement Ice cube at 0 degree is mixed with steam at 100 degree, both become water at 50 degree. Find the ratio of mass of the ice : mass of steam Homework Equations Q=ml Q=mcdT The Attempt at a Solution I tried this way : let the ratio of ice to steam = a:b a x...