In mathematics, a ratio indicates how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemons is eight to six (that is, 8∶6, which is equivalent to the ratio 4∶3). Similarly, the ratio of lemons to oranges is 6∶8 (or 3∶4) and the ratio of oranges to the total amount of fruit is 8∶14 (or 4∶7).
The numbers in a ratio may be quantities of any kind, such as counts of people or objects, or such as measurements of lengths, weights, time, etc. In most contexts, both numbers are restricted to be positive.
A ratio may be specified either by giving both constituting numbers, written as "a to b" or "a∶b", or by giving just the value of their quotient a/b. Equal quotients correspond to equal ratios.
Consequently, a ratio may be considered as an ordered pair of numbers, a fraction with the first number in the numerator and the second in the denominator, or as the value denoted by this fraction. Ratios of counts, given by (non-zero) natural numbers, are rational numbers, and may sometimes be natural numbers. When two quantities are measured with the same unit, as is often the case, their ratio is a dimensionless number. A quotient of two quantities that are measured with different units is called a rate.
1. Let’s say we have a solid wheel. The wheel can be modeled as a disk. Imagine that instead, the wheel is rotated at a location location 0.47R from the center of the wheel, so that the wheel rolled around a kind of loop. Essentially, the CM goes around the dashed line in the drawing. R is the...
Hi everyone. In a proof I'm working on, I have a ratio of two sums of functions in the following form:
\frac{f_1(x)+f_2(x)+...f_n(x)}{g_1(x)+g_2(x)+...+g_n(x)}
I want to prove this ratio is monotonically increasing in x. All of the functions f_i(x) and g_i(x) are positive and also...
i have been given ap project by my teachers to show the ratio between velocity and torque .
i.e i have to show the gear ratio in my project.
can some one tell me whether the ratio b/w torque and velocity remains constant if we use different number of gears .
also if some one can give me any...
Homework Statement
Use the ratio test to find the radius of convergence and the interval of convergence of the power series:
[[Shown in attachment]]
Homework Equations
an+1/an=k
Radius of convergence = 1/k
Interval of convergence: | x-a |∠ R
The Attempt at a Solution
I...
Hi all,
I always wondered if the combination of gears used to achieve a specific gear ratio mattered. Assuming the desired gear ratio is 3:1, would it matter if the gears used were 10x30 or 9X27?
Thanks in advance.
Homework Statement
A mineral slurry contains 3 components, solids, liquids and toluene.
The slurry has 20 wt% solids and 80 wt% liquid. In the liquid portion of the slurry the mole ratio of toluene to water is 1:5.67
Determine the composition of the slurry (solids, toluene and water) in...
http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Mathematics%20%289709%29/9709_w09_qp_31.pdfHomework Statement
6i
Homework Equations
r=a+λb
The Attempt at a Solution
first i find AB which is (2,2,-2)
the equation if line is then...
I have a linear recurrence sequence and am having a problem understanding what to do when the ratio does not seem to be the same between each of the terms, so
Terms;
4, 1.4, 2.44, 2.024... (n = 1,2,3...)
How do I find a the ratio of these terms, and if there is none, please advise how I...
How is charge/mass ratio derived in this example??
Hello, I know there are many ways to derive an expression for "q/m", but I am having some troubles with this one. We are given:
(1/2)mv^2 = qV (mass, velocity, charge, voltage)
qvB = (mv^2) / r (charge...
Homework Statement
Hey guys a problem similar to this is going to be on my exam on Thursday, and I'm a bit stuck.
A wire of length L and cross-sectional area A, has resistance R.
What will be the resistance Rstretched of the wire if it is stretched to twice its original length? Assume...
Homework Statement
A stationary detector measures the frequency of a sound source that first moves at constant velocity directly toward the detector and then (after passing the detector) directly away from it. The emitted frequency is f.
During the approach the detected frequency is f'app...
There is a certain equation relating both Mp (max. overshoot) and damping ration. Which is;
Mp = e(-ζ*pi)/(1-ζ2)1/2
What I get from that equation is for every system a certain damping ratio will result the system in a certain amount of max. overshoot.
That sounds ridiculous, because...
Homework Statement
Gerald stands on the roof looking up at the full moon, which has a mass of 7.39 x 10^22 kg. At this moment, Gerald is 3.77 x 10^8 m from the center of the moon. If the mass of the Earth is 5.96 x 10^24 kg, and the radius of the Earth is 6.39 x 10^6 m, what is the ratio of...
Homework Statement
Does anyone understand why density would increase when the poisson ratio is greater than 0.5 as indicated in this slide from my professor:
Does this density increase apply to a system undergoing tension or compression or both?
Hi guys, I am building my own automated Guided CART, using two car wiper motors as my mian motors connected to bicycle wheels, now i want to know how I am going to determine the weight limit that i can put on my vehicle? the power of the car wiper motors are not yet determined
Homework Statement
Please see the attached.
Q1.Why 0° is not a solution of the equation cosθ = 2sinθ - 1?
What's wrong with my steps?
Q2:http://www.wolframalpha.com/input/?i=cosx+%3D+2sinx+-+1
From the graph,the x-coordinate of the intersection point does NOT equal to the answer...
Hi there, I want to modify a equation which is written for Singal to Noise Ratio. Now I want to change for logical interference. But I could not find any reliable source of explanation, " what is the relation between SNR/SINR and interference(Logical/Physical)?"
Homework Statement
1. a) If we wish to record an ECG of amplitude 1mV in the presence of interference that causes a common-mode voltage of 100mV to appear on the inputs of the amplifier, then what common-mode rejection ratio (CMRR) do we need require if we need a signal to noise ratio better...
Homework Statement
S=1+(a/r)-(b/r^3)
Homework Equations
need to find r=sqrt(3b/a) and S=1+ sqrt((4a^3)/(27b))) from a derivation of the above formula in #1.
The Attempt at a Solution
0=(3b/r^4) - (a/r^2)
I've been trying to figure out how to get the signal to noise ratio of a completely multiple choice type exam. I can't do it and it's driving me nuts, so finally I found this website and decided I'd ask. :D
Say you let your students take a multiple choice test and you are able to get all...
Homework Statement
The two components of a double star are observed to move in circles of radii r1 and r2. What is the ratio of their masses? (Hint: Write down their accelerations in terms of the angular velocity of rotation, ω.)
Homework Equations
Newton's 2nd law? law of...
Homework Statement
Two capacitors connected in series store energy U. Now the two capacitors are connected in parallel to the same voltage source and have energy 5U. What is the ratio of the larger to small capacitor?Homework Equations
For series capacitors Ceq=C1C2/(C1+C2)
For parallel...
Homework Statement
I am reviewing some trig, and I forgot how to do this. Please let me figure this one simple thing out.
Here is the questions.
Find the exact trig ratios of 5∏/6
Ok, now look at my diagram below to see where I am having trouble with!
What simple process am...
Hello everyone!
I'm considering the problem of comparing the asymptotic behavior of two functions $f(x)$ and $g(x)$.
We can say that if $\lim _{x\rightarrow \infty} f(x) / g(x) = \infty$ then f is asymptotically greater than g. Similarly, if this limit is 0, then f is asymptotically less than...
You obtain an image of a 7 magnitude star in a 1 minute exposure. You found that the 7 magnitude star was detected at S/N = 10 in the image. The S/N was too low for your science and you decided to take another image. If you want to obtain a 1% photometric result on this star, what should be the...
Homework Statement
Show that
a_{n} = \frac{1 \cdot 3 \cdot 5 \cdot ... \cdot (2n - 1)}{2 \cdot 4 \cdot 6 \cdot ... \cdot 2n}
converges when n \rightarrow∞
and n is a natural number
Homework Equations
None that I can think of.The Attempt at a Solution
This was from an exam and I was pretty...
Is there anything wrong in saying there can be a charge to Planck Mass ratio?
I calculate it as
\frac{e}{M_p} \propto 1.861 721 726 984 943 \times 10^{-10} C/kg
But I find no references by any science that they have done this?
Homework Statement
In a bicycle, the ratio between the size of the wheel sprocket to the size of the crank sprocket is 2.5 which means...
An example of one of the answer choices is:
The rear wheel turns ___ times for every full rotation of the pedals.
Homework Equations
The...
A typical global concentration of hydroxii radicals (OH) is about 10^6 moleculues/cm^3. What is the mixing ratio corresponding to this concentration at sea level P = 10^5 Pa and T=298 K?
Using the previous equations derived earlier
ndOH= (P*Av/R*T)*COH
(ndOH*R*T/(P*Av) ) = COH
(10^6...
I am still trying to visualize horsepower and torque seen on the racetrack, and its hard. Obviously torque is a component of horsepower. Without enough torque, a car would take forever to reach its power-band. With a lot of torque, but merely no horsepower, a car would have a very steady...
(1) A mass of 3.0 kg is suspended from a vertical spring and produces a static deflection of 60 mm.
The system is also subjected to viscous damping of 36 N s/m.
Calculate the value of the:
(a) natural frequency
i. In Hz
ii. And rad/s
(b) damping ratio...
So harmonic series diverges because of the integral test but if I try it on ratio test
= (1 / ( x+1 )) / (1 / x)
= x / (x + 1) and this is less than 1 so shouldn't it converge?
Homework Statement
I have a sequence an+1=sqrt(2+an) ,with a0 = sqrt(2)
which leades to nested radicals.
I am asked to show that for n approaching infinity:
1) the sequence converges to 2, and that
2) lim {(an+1 -2) / (an -2)} = 1/4
The Attempt at a Solution
1)I have proven the...
I understood that for a direct proportion such as "if 6 mangoes cost $12, then how many dollars worth are 12 mangoes?", we have to first divide 12 by 6 to get the no. of divisions of 6 in 12 i.e. precisely 2 and then as 1 division is worth $12 we multiply the two divisions with $12 and that's...
Hi all,
I've been having a discussion about doing calculations on data which is supposedly Gaussian.
And (Of course) there is a problem: Once operations are performed on the measurements -- such as taking a ratio of one kind of measurement to another; the result is often no longer a Gaussian; In...
Hi,
I recently got an opportunity to work on a clutch assembly. The clutch is an old model one which has six helical springs that keep pressing the pressure plate, clutch plate and engine flywheel against each other. The cross section is:
To give a brief working principle, when the...
Let X be standard normal and Y uniform [0,1]
find the distribution of Z=X/Y.
i think i managed to deal with this problem up to the integral stage:
P(X/Y< t ) = P(X<Y*t )
thought of :
1.
F_{z}(t) = \int^{1}_{0}\int^{yt}_{0}f(x,y)dxdy
2.
F_{z}(t) = \int^{yt}_{0}f(x)dx
maybe is neither one of...
Homework Statement
It's desired to build a capacitor which has two concentric spheres separated by a dielectric of high permittivity, low loss, and high dielectric strength. Calculate the ratio of sphere b's radius to sphere a's radius which produces the lowest electric field between the...
Homework Statement
There are two tanks with water, there are standing very close to each other. Tank 1 is having a temperature of 0 degrees and tank 2 is having a temperature of 10 degrees. The heatflow between the two is Q1. Then tank two is getting a temperature of 100 degrees. That heatflow...
Hi,
It is well known that a sphere has the lowest surface to volume ratio. However, a related question is: What is the shape that gives the lowest surface to volume ratio if you do not include the "top" in the surface. That is, what is the maximal volume of an uncovered vessel of a fixed...
(Plse bear with me: until i learn how to fly this thing, / must stand for radical)
If the side ratio for a 30:40:90 deg right triangle are 1 : /3 : 2
then, is the following true:
one may multiply this ratio by 1,2,3 or 5,6,7,8,9 or 10 and the pythagorean identity obtains but NOT by 4
If so...
Gas turbine fuel/air ratio & cooling, help please!
Hello Dear Colleagues,
I am doing a gas turbine project and I wonder why we use cooling air instead of decreasing the fuel/air ratio after getting the following results from my gas turbine thermodynamic model.
I have a mechanism in my model...
I just built a transformer to the specs of the original.
The transformer has a turns ratio of 1:16. Input to primary is 12V.
The problem I am having is a very low voltage at the secondary side. The no load voltage was the highest (40V) that I have got out of it so far.
The primary coil...
An angle -- why an angle is the ratio of two sides of a triangle?
Perhaps I should have already learned this, but I just can't seem to grasp why an angle is the ratio of two sides of a triangle, or the length of a circular arc by its radius.Why is this so?
The problem is :-
Integral of (1+x^4) / ( 1 + x^6) . dx
I have reduced it to a form of
Integral of 2.sqrt(tantheta) / ( 1 + tan^3 theta ) over dtheta where x^2 = tantheta.
However I cannot reduce it further. How do I proceed ? In general, how do I proceed given a problem of the form...
Homework Statement
Hi, this is a stats question, hope I'm asking it in the right place.
I am estimating an animal populations health based on it's weight to length ratio, I have a population ratio (10grams/cm) from 5 years ago and a sample estimate made from recently gathered data.
I am...
Homework Statement
The points P and Q divide a given interval AB internally and externally respectively in the ratio 1:λ. The point X lies on the circle with diameter PQ. Prove that AX:XB=1:λ
Homework Equations
None
The Attempt at a Solution
Basically, if we define the centre of PQ and the...