Ratios Definition and 219 Threads

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...

Hi, I don't get the right answer for this question. I don't see where I'm going wrong. I use this equation to get the engine rpm for each gear ratio: engine speed (rpm) = gear ratio X final drive ratio X vehicle speed X 60 / (2*pi*rolling radius) So for first gear I get an engine rpm of...

I'm about to attempt this question but beforehand I was hoping if someone could just check if my diagram is correct on the basis of the question; A feed stream contains H2, CO and a trace of CH4. Pure CH3OH is produced by means of a reactor (CO + 2H2→CH3OH), separator and recycle with purge to...

I'm trying to determine how exactly gear ratio limits velocity. I know that a high torque configuration is generally regarded as low speed, but my calculations do not seem to support that. Basically, I've written a small problem where we have an input gear with constant torque and an output...

Hi, I am new here. I am just reading over my notes for stable and unstable nuclei and I came across this sentence: 'Large nuclei require a higher neutron proton ratio as this adds more nuclear attraction without adding repulsion'. I was wondering why the large ratio would reduce repulsion? Thank...

Homework Statement Prove that similar triangles have equal ratios (ratios of the sides) Homework Equations SSS, AAA, SAS, SSA The Attempt at a Solution I posted a rather messy and incorrect proof and problem statement prior to this and I wish to correct my mistakes now. The ratios of the...

1. Question from a textbook. I have written down the differential equations for part a) and shown part b), but I am unsure of how to tackle part c). 2. This is the Question from the book http://www.m-rossi.com/img/asp3012-1.png Any advice would be grateful. Thank you

Earlier this year I made (under a pseudonym) Freedom of Information requests to a number of British universities, asking for the numbers of applicants and offers for masters programs in physics. Perhaps the data will be of use to future applicants...

Hello, Can you tell me if there is anyway of calculating the top speed in each gear of a vehicle given its horsepower and gear ratios? Since Power = Force*Velocity Velocity = Power/Force Force = Drag Force + Rolling Resistance --> Velocity = Power / (Drag Force + Rolling Resistance) This...

Hello Ladies and Gents,I am look for some help with designing the gear trains for an orrery (a mechanical model of the solar system) I am planning. I need some advice on how to go about calculating the specification of the gears in the mechanism which I will machine. I will use cycloidal teeth I...

I'm confused as to how gear ratios work in bicycles. I'm given a problem which says that gear ratio = rfront/rear. It then says that the gear ratio changes from 4 to 0.7. Does this mean that the radii of the gears are changing? I'm unfamiliar with gears on a bicycle so I'm not sure if the radius...

Greetings, mechanical engineers of Physicsforums, I have been struggling with a particular problem calculating an ideal motor RPM for economical highway cruising. The motor I am looking at is the Subaru EE20 Diesel motor. Its torque curve can be found here...

Hi i have have a small question regrading to a NPN BJT transistor. the DC current gain (beta) is the ratio between Ic/Ib where Ic and Ib are the collector and base currents respectively. Ib is the input current, that's alright , but, i don't get why Ic considered as the output? in NPN BJT...

Comets have high Deuterium to Hydrogen ratios. They are enriched with extra neutrons. Comets periodically plunge close to the sun. And, the sun generates flares, which generate neutrons. Separately, I wonder if those neutrons come from fusion of solar corona gas, trapped on magnetic field...

I'm not stuck per say, but I need to know if I have the right idea for solving the rest of these questions. 1. Homework Statement For the following given trigonometric ratio and domain, determine the missing trigonometric ratio. Homework Equations cos\theta = -\frac{1}{2} ...

This might seem like a silly question, but why do we use division to compare two quantities, i.e., a ratio? I've always taken for granted that dividing two physical quantities tells how many of one quantity there is for the other quantity, but why exactly does this work? Why don't we define some...

Alright, so I bought some diced beef from the supermarket cos they were cheap and decided to just fry them on a non-stick fry pan with only salt and pepper and I didn't like the taste of it at all. Juices flowed all over the place and ended up boiling the meet instead of fry it... bleh. So I...

Homework Statement I understand that [Fe/H] ratios can be used to describe metallicity in a galaxy... but I'm having trouble understanding what [element/Fe] ratios should tell you. Anyone have an idea? Homework EquationsThe Attempt at a Solution

Hey guys, I've been doing a lot of research looking for a fluid that has a high expansion ratio that does not leave the liquid state. the idea is that the fluid could either: - using heat will expand and contract using hot and cold cycles - using electricity (not necessarily needing...

[Driary ratios of continents] Which continent is the driest continent? I think it should be Antartica, but I have found it is Australia. I think so because Antartica is also the largest desert in the World.

1. I need some help understanding ratios between 2 numbers/quantities og exponents: [b]2.Here is the problem, When you take the ratio between 100grams and 1000grams it is 100g/1000g = 0,10 and you can convert this to kilos 0,1kg/1kg = 0,10 and the ratio stays intact, that makes sense. But...

Why is division used for ratios? For example, if we have 1 dog for every 2 cats, then why can this relation be modeled by the division? Since the ratio can essentially have the value of 1/2 or 2, then what is the significance of these two distinct numbers in relation to the ratio? How does the...

Why can ratios be written as fractions? if there are 5 men in 20 people the ratio of men to total people is 5:20 which is 1:4. But when we write 1/4 it gives 0.25. And 0.25 means the magnitude of each part when 1 is divided into 4 equal parts. So how does ratio and fraction give a...

Homework Statement I need to know is how to figure out the ratio's in which the elements in period 2 combine with chlorine and oxygen i.e a method to solve the problem. I 'm currently in 10th grade. Thanks in advance I appreciate the help. Homework Equations None that I know of...

Hi,all. What changes the variations of compression rations in diesel and otto cycles which are always used in the engines. Are there any cycles used in automobile engines other than otto, diesel or seillinger?

I have to find both of the voltage ratios. This is just ugly algebra. Here is what I came up with, and was wondering if I was correct. Thanks

Homework Statement question attached Homework Equations The Attempt at a Solution i can't understand III i can't understand what he wants , if he wants the ratio , the ratio between AP and PB was 3/5 which is not the same as OA and OB (λ=3/8)

Why do trigonometric ratios have to be related to the angle between the base and hypotenuse of a right angle triangle? I am trying to understand why I can't use these ratios to any angle of a right angle triangle. I try to do that in the attached document. It seems to work for all ratios...

Homework Statement A noisy but slowly-shifting sensor signal is being filtered with a low-pass, finite impulse response filter. What is the mean delay and expected SNR boost (noise standard deviation of output compared to input) for two filter variations: N filter taps uniformly weighted...

I have three sizes of gears with 14, 34, and 84 teeth respectively. I need an exact 1:60 gear ratio. The problem I am finding is that 14:34 and 34:84 are very close to the same value. 14 and 84 is 1:6, but without a 1:10, that doesn't get me far. The closest I can get is 7:612...

Homework Statement Air is pumped into a bicycle tire. The 43 moles of air initially in the tire have a gauge pressure of 1 atm. How many moles of air must be pumped into the tire in order to raise the gauge pressure to 5 atm? Assume that the volume and temperature of the air inside the tire...

Hello there, This isn't specifically homework, it is study. I'm having a difficult time trying to understand how to calculate/estimate partial decay widths, \Gamma[\itex], and Branching Ratios. I haven't found very clear information online so far. Here's just an example below that I'd like...

If you are given a ratio, say apples to eggs and you were to increase the number of eggs but keep the number of apples the same, would you say that the ratio of apples to eggs is reduced, as when you divided apples by eggs, the number would be smaller if eggs are increased and apples remain...

The question: A perfect gas undergoes the following cyclic processes: State 1 to 2 cooling at constant pressure. State 2 to 3 heating at constant volume. State 3 to 1 adiabatic expansion. Deduce an expression for the thermal efficiency of the cycle in terms of r the...

I realize the answer depends how where in the atmosphere speed is increased more, and whether a higher orbit or lower orbit is desired, and the shape size and weight of the craft. But I'm just curious about typical ratios. About what fraction of the fuel goes to lifting the weight of the...

Homework Statement 4 ounces of substance for a 10% solution for 1 gallon of water Homework Equations The Attempt at a Solution 42.68 ounces of substance per gallon? to make a 10% solution in water?

I was pondering over this problem about ratios and wondered what does 3/2 (oranges:apples say) actually means. I then understood after giving some thought that you DIVIDE the oranges with the no. of apples so that you get an idea about how many oranges correspond to 1 apple i.e. how much of one...

The current input of a system is 250mA. If the current ratio of the system is 15dB, determine: (i) the current output and (ii) the current ratio expressed in nepers I have the answer to the questions which are (i) 1.406 A (ii) 1.7272 Np I am just struggling with the complexity of the...

Homework Statement Why does the ratio: \frac{σ(e^- + e^+ \rightarrow μ^- + μ^+) }{σ(e^- + e^+ \rightarrow τ^- + τ^+)} tend to unity at high energies and would you expect the same for: \frac{σ(e^- + e^+ \rightarrow μ^- + μ^+) }{σ(e^- + e^+ \rightarrow e^- + e^+)} The attempt at...

can you explain to me what my trigonometry book say "the value of each ratio is determined only by the angle $\theta$ and not by the particular point $P(x,y)$ on the terminal side; that is , the value of the ratio is a function of the angle $\theta$." what does "determined only by angle...

Homework Statement Three equal masses are attached to the ends and midpoint of a light uniform rod, which lies on a smooth horizontal plane. One of the end masses is struck by an impulsive force perpendicular to the direction of the rod. Find the ratios of velocities of the three masses...

First time posting. Homework Statement Gears A and B, of Masses 4kg and 10kg, respectively, are rotating about their mass centers. The radius of gyration about the axis of rotation is 100mm for A and 300mm for B. A constant couple of C=0.75Nm acts on gear A. Neglecting friction, compute: -...

Homework Statement Assuming the person weighs 980 N on the surface of the Earth, how would you use ratios to obtain the weight of a person at 128 000 km above the surface of the Earth. Homework Equations Fg is proportional to 1/d2 The Attempt at a Solution The answer in the...

Homework Statement (see attachment)Homework Equations The Attempt at a Solution If a force a F acts on the farther end of the wrench, the torque due to it Fl where l is the length of wrench. The work done by this torque for one full turn is Fl*(2##\pi##) For wrench A, l=10 cm, and for wrench B...

Homework Statement A 6.2*10^2-kg satellite above Earth's surface experiences a gravitational field strength of magnitude 4.5-N/kg. Knowing the gravitational field strength at Earth's surface and Earth's radius, how far above Earth's surface is the satellite? (Use ratio and proportion.)...

Hi, Would a clump of gas in space have some diatomic molecules in it as well? If it does, how do we find the ratio? I know that hydrogen gas at room temperature on Earth is diatomic. So I guess the state of the gas molecules change like this. Diatomic molecules -> Monatomic ground state ->...

Hi hi hi, So guys I'm just having a little trouble with this question.. Compute the ratio between the luminosity from part B to the mass from part A. How does that ratio compare with the Sun's ratio of luminosity to mass? So for part A I got 1Msun and part B I got 1000Lsun So to compute the...

Video help -- Fully Expand and Animorphic aspect ratios? I converted a lot off my DVDs that are of 1970's TV show Land Of The Lost to avi files so I can watch them on my pc. There is one setting for Aspec Ratio I do not get I know if I pick 16:9 this is for Wide Screen. And I know if I...

Hi all, I have a question regarding to the branching ratio of neutral D-meson decay. Give three decays: 1. D --> negative kaon + positive pion 2. D --> positive pion + negative pion 3. D --> positive kaon + negative pion The one with highest branching ratio is 1. due to its non-cross...

proportional ratios with exponents - Need Help! A walker's speed, v, is proportional to the ratio of his leg length, L, and the period of the repeating motion of his legs, T, that is, v ∝ L/T. If the period is measured to be proportional to Lp, where p = 4/5, what power of L must the speed be...