For questions related to conversion of units.

learn more… | top users | synonyms

3
votes
5answers
528 views

Is there a basic “unit” of measurement in math

I am wondering if there is a basic unit in math. $$3\ cm \times 2\ cm = 6\ cm^2$$ The $cm$ is a unit of measurement, but what about: $$3\ cm \times 2 = 6\ cm$$ Should the $2$ have a unit of ...
0
votes
2answers
94 views

Converting squared or cubed units

At the moment I am going from square meters to square yards. One meter is $1.0936$ yards. So I figure $1\text{m}^2 = 1.0936 \text{yards}^2$ I know it isn't but I want to learn a good systematic ...
0
votes
2answers
72 views

How many inches are in 7.94 feet?

Question: the height on my land is 7.94 feet noted by a surveyor on a Certificate of Elevation form. In layman's terms, that is 7 feet and how many inches? or how much of an inch is it short of 8 ...
0
votes
1answer
52 views

If the cost per minute is $\$0.032$, is the cost per hour $\$1.92$ or $1.92$¢?

I hope someone can help me with this problem. The cost per minute to make a phone call is $0.032, I'm that multiplying this by 60 will get total cost per hour. ...
1
vote
1answer
18 views

How to normalise equations of the form $dy/dx=B$ and $d^2y/dx^2=A$?

So I am trying to normalise equations of the form, $$dy/dx=B \mbox{ and } d^{2}y/dx^{2}=A$$ If I define $y^{*}$ as; $$y^{*}=By \Rightarrow dy^{*}/dy=B $$ Is it also then true that, $$d(dy^{*})/dy = B ...
3
votes
2answers
927 views

Difference between “sq km” and “km sq”

If I have a square with side $2\ \text{km}$, what is its area: $2\ \text{sq km}$ or $4\ \text{km}^2$?
1
vote
2answers
68 views

Convert angles from the sexagecimal system to centesimal one

How do you convert angles from the sexagecimal system to centesimal one? For example 63 degrees 14 minutes 51 seconds reduced to centesimal ?? Here's how it's done but I don't understand the ...
0
votes
1answer
20 views

Find total yards with LXWXH?

I have a box I need to cover all 6 sides with a single layer fiberglass fabric. The fabric comes in 50" or 28" widths. The dimensions of the box are 34" long; 15" wide; 12" High. How do I determine ...
-1
votes
2answers
29 views

How can I Express It In DMS FORM? [closed]

This (below) 35.24 degree 160.11 degree -381.87 degree 280.99 degree -525.66 degree 85.372 degree
0
votes
1answer
49 views

sub-nanoseconds resolution

I found following statement in a higher engineering mathematics reference book, But couldn't understand how it has been determined ? I have two values as follows: nanoseconds - could be any 30 ...
-1
votes
2answers
48 views

How do I convert meters into feet and inches [closed]

I need to know the formula to convert meters into feet and inches. Example: $3.3\,\textrm{m} = 10'\,10''$
4
votes
4answers
6k views

Units of a log of a physical quantity

So I have never actually found a good answer or even a good resource which discusses this so I appeal to experts here at stack exchange because this problem came up again today. What happens to the ...
2
votes
1answer
19 views

Division of Compound Units

Why are compound units of speed,density etc. expressed in terms of a numerator and a denominator? For example, m/s, kg/m3 etc. I've always understood division as either the inverse of multiplication, ...
1
vote
1answer
36 views

Taylor's series and the function argument dimension

I've stumbled over an interesting question. In $\cos(x)$, $x$ is measured in, say, radians. When I expand cosine in Taylor's series, I have the terms with $x^3$, $x^5$ etc. so I am summing up ...
0
votes
1answer
11 views

How to determine a deficit of base 10 exponent from a minimum unit

I'm trying to determine if a number includes a portion in deficit of a base 10 exponent from a minimum unit. For example, given a minimum unit of $0.01$, $1$ would pass the test, but $1.001$ would ...
1
vote
1answer
119 views

What are the units of Singular Value Decomposition components?

I have a symmetric variance/covariance matrix $A$ which is of size (27 x 27). I know that it's rank deficient (rank = 21). I also know that the units of $A$ are $m^2$. I am trying to use Singular ...
0
votes
1answer
28 views

I have trouble understanding simple equality passage

I don't know why I always have trouble with these things, there is something that must do 'click' in my head. Knowing that 1000000 cm³ = 1 m³, how do you get that ...
3
votes
3answers
79 views

Why radian is dimensionless?

Can't understand why we say that radians are dimensionless. Actually, I understand why this is happening: theta = arc len / r ...
15
votes
8answers
3k views

Why do we require radians in calculus?

I think this is just something I've grown used to but can't remember any proof. When differentiating and integrating with trigonometric functions, we require angles to be taken in radians. Why does ...
0
votes
3answers
39 views

Significance of squared in meters per second squared [closed]

What exactly is the difference between $3 \mathrm m/\mathrm s^2$ and $3 \mathrm m/\mathrm s$? According to Wikipedia... An object experiences a constant acceleration of one metre per second ...
0
votes
1answer
26 views

How many gallons are used in the U.S. each day and if this gasoline were used to fill a cubical tank how big would one side be?

The question I am trying to solve is: Part I) How many gallons of gasoline are used in the U.S. in one day assuming there are $2$ cars for every $3$ people and each car is driven $10,000$ miles a ...
-2
votes
1answer
54 views

Why is the cos, sin definition of the unit circle true?

So imagine we have a unit circle and there a point $M$ on it. Then the $x$ coordinate of $M$ is $\cos(\theta) $ ($\theta$ is the angle ${IOM}$ as you know) and its $y$ coordinate is $\sin(\theta)$. ...
0
votes
2answers
77 views

Two dimensional integral gives a volume, but what if I don't deal with distances and volumes?

I have I believe a simple question which relates to two-dimensional integral. I have been reading enough (and watch video tutorials) on the technique to hopefully understand it well. Every tutorial ...
3
votes
7answers
160 views

Software for unit aware calculations?

When doing engineering calculations it is great convenience to do have software that keeps track of units. Example when calculate something trivial as stress: $\sigma = \frac FA$ And be able to ...
1
vote
1answer
18 views

cross-products versus units of measure

If I draw 2 perpendicular line segments on the ground, 3 meters and 4 meters, how far into the sky does their cross-product extend? What if instead the line lengths are 300 cm and 400 cm? Can ...
1
vote
1answer
51 views

Angular speed to linear speed: Arbitrarily discarding Radians units?

I asked this question long ago, but wanted to see if I can get some new perspectives this time. Why is the radians implicitly cancelled? Somehow, the feet just trumps the numerator unit. For all ...
1
vote
2answers
75 views

Square Root Yields Different Result After Unit Conversion [duplicate]

This is boggling my mind. The square root of 100 seconds is 10 seconds The square root of ...
0
votes
0answers
2k views

How to find out the depth of a cuboid

A water tank in the form of a cuboid is 15m long,10m wide. What will be depth of this tank, if it contains a maximum of ...
1
vote
1answer
104 views

Radian, an arbitrary unit too?

I just browsed through various sources fore questions related to the advantage of use of radians compared to other measurement units. The question I started the investigation for, however, stands as I ...
0
votes
2answers
45 views

How to change to same units

Could anyone help me change it into same units/ values? I need to have them all in "years" Demand(D): Every month there is 5000 food: Therefore, $D= 5000 * 12 = 60000$ food per year Production(P): ...
0
votes
1answer
31 views

D=P/gv^3 what units is the D

(Sorry for my bad english) I got a task to do: In the research, scientists noticed that the necessary power P is obtained from P=Dgv^3, where D is constant, g is the earth's standard acceleration ...
1
vote
2answers
22 views

What is the length of the bar needed to represent 75 kilometers( in centimeters)?

In a bar graph, 1 centimeter represents 30 kilometers. What is the length of the bar needed to represent 75 kilometers( in centimeters)?
1
vote
1answer
27 views

Conversion Question

A heavy rain fell on a city for 26 minutes, at a rate of 3.9mm/hr. If the area of the city is 244km^2, how many gallons of water fell on the city that day?
0
votes
1answer
60 views

Rates of Change Question with Mixed Units

I have come across the following question in a past exam paper of a module that I will be teaching this semester. The volume $V$ of m$^3$ of earth removed from a pit after $t$ hours is given by ...
1
vote
1answer
482 views

Units in definite integral

I've been given a problem in my electrical engineering class which is confusing me. I'm given $i(t) = 5\sin(6 \pi t/\mathrm s)\, \mathrm{mA}$ (mA is mC/s) and I need to find the total charge ...
7
votes
4answers
230 views

Is there an established notation, either modern or historical, for any unit of measure which is then further subdivided into 360 degrees or parts?

This question about notation is simple as dirt, but would be useful for me regardless, because of some work that I'm doing in music theory. Basically, while there's a notation for subdividing the ...
0
votes
1answer
58 views

convert from one time scale to another

i would like to exactly to convert given scale of time into years and month,suppose we have time $T = 2.35$ years clearly it is more then $2$ year,but what about $0.35$?in which scale it is given? ...
3
votes
0answers
59 views

What could volume * mass be called? [closed]

I need a denotation for a rather unusual unit. $$ \frac{m}{V} $$ is called density. So what could $$ m \cdot V $$ possibly be called, or is there maybe already a denotation for it? I'd furthermore ...
5
votes
2answers
515 views

Arbitrarily discarding/cancelling Radians units when plugging angular speed into linear speed formula?

Why is the radians implicitly cancelled? Somehow, the feet just trumps the numerator unit. For all other cases, you need to introduce the unit conversion fraction, and cancel explicitly. Is it ...
-4
votes
2answers
386 views

Calculating distance, time, given lightyears, speed. [closed]

A lightyear is defined as the distance that light travels in a year (i) calculate, in meters, the distance of $1$ light year, give your answer In standard form( speed of light=$3\times10^8$ m/s, ...
1
vote
2answers
58 views

Units in this problem: velocity or distance?

I know this is slightly off-topic here, but it's really bothering me. My class was given the following immensely simple problem today: A bird flies due south at a constant speed of ...
1
vote
1answer
61 views

The question is how many ounces (dry material) to add to one gallon of water?

The question is how many ounces (dry material) to add to one gallon of water? Formula given was 45.5g/100ml 45.5 grams (dry)= powdered sodium carbonate 100 ml (fluid)= water
1
vote
1answer
34 views

problem with units when calculating with angles

I have this formula to calculate the refraction of a star in the sky (the difference between where the star appears and where it really is.) $z_0 = z + 60''\times \tan z$ where $z_0$ is the ...
2
votes
2answers
60 views

Can minutes be used to measure the length?

I am using an Old American maths textbook and it uses US customary units. For the length, they use minutes (like $6'$ for the altitude of a triangle). How is this related to foot which is the unit of ...
0
votes
1answer
281 views

Is there a “metric system” equivalent for measuring time? [closed]

Just as in the metric system it's easy to convert from one unit of measurement to another using base 10, is there any calendaring system that measures time in an equivalent way? In other words, is ...
3
votes
1answer
171 views

Can you calculate an area of a curve using a string?

Take a look at this curve. Imagine that I have drawn this on a paper, and that I want to find the area of it. (The thickness of the line is assumed to be constant). Assume that I use a string to ...
1
vote
1answer
782 views

convert joules to watts

I am investigating the changes in heat fluxes from a given body of water where the measurements are shown in units of W/m2. There are alternative methods for determining the heat fluxes from a given ...
0
votes
3answers
246 views

converting units - Joules to gcm

I have a rather basic mathematical question regarding converting units. I have read some papers that measure a given variable in Joules per meter square (Jm^{-2}) and others that measure the variable ...
1
vote
2answers
189 views

Is there a limit to how exact $\pi$ can be calculated? [duplicate]

Possible Duplicate: Do We Need the Digits of $\pi$? Working out digits of Pi. What are the limitations? Faster computers More accurate measuring devices
0
votes
1answer
44 views

Is there a common notation for a group formed by appending a unit (eg. seconds) to some group?

Assume $(G,+)$ is an (abelian) group. And we have some unit $u$ (not the unit from ring theory, but some measurement unit like meters, seconds, etc.). Then with $G_u = \{k\ u \mid k \in G\}$ and ...