# Posts by Simon

Total # Posts: 169

**Linear Algebra**

Let v1= (1,1,2,1) v2= (0,1,3,3) v3= (1,-1,-4,-5) v4= (1,0,-2,-4) a) Let U=span{v1,v2,v3,v4}. Find the dimension of U b) Is span {v1,v2,v3,v4}=R4? c) Find a basis for U Very Much Appreciated!!!

*December 14, 2011*

**Linear Algebra**

A test Question: Find the parametric equations of the line through the origin that is orthogonal to the plane 2x+4y-z=0

*December 14, 2011*

**Electricity and Magnetism**

This was actually a test question: Additional Information: This question is based on the Hall effect in a wire. Question: I want you to build a magnetic feild sensor. You have all the properties of the materials and the dimentions of the sensor. a) derive a formula for a ...

*November 27, 2011*

**Linear Algebra**

Find the basis for the following vector space. Please state the dimension of the vector space. S consists of all x in R3 such that x is orthogonal to n=(2,3,2)

*November 20, 2011*

**linear math**

Let u=(2,0,k,-1) v=(-4,0,-3,2) and w= (0,1,0,0). Each answer must be justified(there is no answer where k=nothing) a) find all values of k, (if any) for which u is orthogonal to v b) Find all values of k (if any) for which the set {u,v,w} is linearly independent. Find all ...

*November 20, 2011*

**world history**

. With respect to human rights issues in Southeast Asia, which statement is most accurate? A. The leaders of the Khmer Rouge fled from Cambodia after 1979. B. Chinese merchants living in Cambodia and elsewhere have carried out vendettas against hill tribes. C. The Khmer Rouge ...

*November 15, 2011*

**Math**

The length and width of a rectangle are (x+4) cm and x cm respectively. Write down expressions for: A. The perimeter of the rectangle B. The length of the side of a square with the same perimeter If the sum of the areas of the square and the rectangle is 94 cm^2 , find x. ...

*October 23, 2011*

**Biology**

Why (in detail please) in the carboxypeptidase mechanism, the weak bonds between an enzyme and a substrate will stretch the peptide bond of the substrate which lowers the bond energy? I just want to know why in detail this happens... Thank you.

*October 9, 2011*

**maths**

no worry found the solution to be 200000((t-7/10)^2+1/100) first by multiplying out as above to get 200000t^2-280000t+100000 then taking out the factor of 200000 to get 200000(t^2-7/5t+1/2) then using the formula x^2+2px=(x+p)^2-p^2 to get 200000((t-7/10)^2-49/100+1/2) ...

*May 30, 2011*

**maths**

(400t-300)(400t-300)+(200t-100)(200t-100) complete the square showing all steps

*May 30, 2011*

**Social Studies**

why greater responsibility is placed on the husband in marriage

*May 18, 2011*

**Quantum Physics**

I don't understand why you've used 4 pi in your answer, i assume your rearranged the uncertainty principle equation for delta Px, but isnt the reduced plancks constant h/ 2pi instead of 4pi ?

*May 18, 2011*

**discreet math**

verify that f(n) = 1 + 2 + 4 + 8+..+ 2^n has order 2^n

*May 1, 2011*

**LIfe orientation**

I think the community will encountor many problems due to substance abuse

*April 26, 2011*

**Physics 30**

I see now that my question was already answered.

*January 25, 2011*

**Physics 30**

It takes a plane flying at 150 km/h 3.0 minutes to circle around a cloud at an altitude of 3000m. What is the diameter of the cloud?

*January 25, 2011*

**Physics HELP! QUICK!**

So does that mean you can just use friction force without resolving it into its components, and so what you use in you equation would be: M V^2/R = M g sin A - M g cosA*mu (This is what you did in the previous example) So did you basically just ignore the vertical component of...

*December 22, 2010*

**Physics HELP! QUICK!**

A banked circular highway curve is designed for traffic moving at 55 km/h. The radius of the curve is 220 m. Traffic is moving along the highway at 38 km/h on a rainy day. What is the minimum coefficient of friction between tires and road that will allow cars to take the turn ...

*December 22, 2010*

**English**

Hey "drwls" can you explain to me how you solved a previous physics question that you answered? It's for the following question below, and it's already posted on here. Unfortunately, it didn't allow me to post the link to it, so you may have to search for...

*December 22, 2010*

**English lit**

Alright thank's!

*December 3, 2010*

**English lit**

Who would have thought...eheh last week I had a literature exam about ''The Necklace''. Thanks for the good, tragic, idea. By curiosity, why would the father kill himself? If other people have more ideas, be free to post. Thanks all.

*December 3, 2010*

**English lit**

Thank's for pointing that out Writeacher. I approve that Ms Sue's classic story is more in the spirit of Christmas, but I'm more in search of a story with a suprising ending. When you read the end, you're like : wow, who would have thought that...

*December 3, 2010*

**English lit**

So, for my english class, I'll have to write a Short story ( Exposition Rising Action Climax Falling action Resolution ) I'd like the story to be around the theme of christmas or horror during x-mas. So I need you guys to help inventing a story with a surprising ending...

*December 3, 2010*

**Math**

Reiny is right.

*December 3, 2010*

**earth**

? = 8 :D

*December 3, 2010*

**physics**

Also how did you just substitute mg in for the Normal Force. Cause when I solved for the normal force from the vertical components I got: FNcos A + mu*FNsin A = mg FN = mg / (cos A + mu*sin A) And I basically just substituted that into: FNsin A - mu*FNcos A = m*v^2/R I solved ...

*October 5, 2010*

**physics**

I know its been a while, but I'm just wondering how drwls solved the question without resolving friction into its x-component because isn't the centripetal acceleration directed horizontally instead of parallel to the incline and wouldn't the friction force be ...

*October 5, 2010*

**Statistics**

0.0213

*August 29, 2010*

**Biology**

thanks !

*June 3, 2010*

**Biology**

prokaryotes are not found in following kingdoms, except: (a) Monera (b) Protoctista (c) Animalia (d) All of these Help please!

*June 3, 2010*

**Biology**

prokaryotes are not found in following kingdoms, except: (a) Monera (b) Protoctista (c) Animalia (d) All of these Help please!

*June 3, 2010*

**Chemistry**

Opps... spelled Chemistry wrong.

*May 12, 2010*

**Chesitry**

Calculate the energy needed to melt 50.0 L of nitrogen (N2).

*May 12, 2010*

**Algebra**

(2*x)(4*y)=192

*May 11, 2010*

**math**

In a test, the average was 74 points/100 points. After the test, three of students relocate. Then the average was 75 points/100. The circumstances of the students were 6:5:3. How many points did the three students have? I know the answere is 45, 75 and 90, but can you write ...

*May 11, 2010*

**math**

In a test, the average was 74 points/100 points. After the test, three of students relocate. Then the average was 75 points/100. The circumstances of the students were 6:5:3. How many points did the three students have? I know the answere is 45, 75 and 90, but can you write ...

*May 11, 2010*

**algebra**

The countries "Drømmeland", "Erkerivalia" and "Fantasia" had a competition. Please tell me how maney gold medals the won each with these sentences. 1. They won 17 medals in all 2 "Erkerivalia" won three times more medals than &...

*May 11, 2010*

**sicence**

If you place a metal ring in a region in which a magnetic field is rapidly alternating, the ring may become hot your touch, why? be as specific as you can

*May 2, 2010*

**Math**

Barter question: name will give for a 1 marble 2 paper clips m 2 marker 1 pencil r 5 notepads 4 markers l 1 pencil 5 paper clips g 3 erasers 5 notepads Question how does a get erasers?

*April 26, 2010*

**math**

Logarithm!!! Select all of the following that are true statements: (a) log(2x) = log(2) + log(x) (b) log(3x) = 3 log(x) (c) log(12y) = 2 log(2) + log(3y) (d) log(5y) = log(20y) – log(4) (e) log(x) = log(5x) – log(5) (f) ln(25) = 2ln(5) (g) ln(1) = log(1) (h) ln(e) = ...

*April 16, 2010*

**life orientation**

Genetically modified foods

*April 13, 2010*

**Stonehenge**

Q: How big is Stonehenge? Q: Are some stones on top of other stone? And how were they stacked? Q: How did the stones get there? Q: Did people ever live there? Q: Are the stones heavy? Q: Where is stonehenge?

*March 31, 2010*

**Stonehenge**

What do people do at Stonehenge?

*March 31, 2010*

**chemistry**

This is super confusing complex brain killing A column packing for chromatography consists of a mixture of two types of particles. Assume that the particles in the batch being sampled are spherical with a radius of 0.5 mm. 36% of the particles appeared to be pink and are known...

*March 28, 2010*

**statistics**

A column packing for chromatography consists of a mixture of two types of particles. Assume that the particles in the batch being sampled are spherical with a radius of 0.5 mm. 36% of the particles appeared to be pink and are known to have a polymeric stationary phase attached...

*March 28, 2010*

**Math**

Prove that cos2x=(1-tan^2x)/(1+tan^2x) I can't find any identities that can help me with this. I'm really confused

*November 8, 2009*

**math**

Haha, I just noticed she asked you to do your own question.

*September 16, 2009*

**math**

The question is incomplete.

*September 16, 2009*

**math**

38.9 + 5.58 + 7 + 15.8 Significant digits will round to the whole number due to the 7.

*September 16, 2009*

**math156**

bobpursley, it's a matter of parenthesis.

*September 15, 2009*

**math156**

x/3 = x + 10/6 x/3 - x = 10/6 x(1/3 - 1) = 10/6 x = (10/6)/(1/3-1)

*September 15, 2009*

**sensory organs**

External

*August 24, 2009*

**science**

Vocal Sounds

*June 30, 2009*

**Social Studies**

Why is the First Amendment to the U.S. Constitution so important to us?

*February 26, 2009*

**Chemistry**

Based on the balanced equation Al2S3 + 6H2O → 2Al(OH)3 + 3H2S calculate the number of excess reagent units remaining when 4 Al2S3 formula units and 30 H2O molecules react? Molar Mass (g/mol) Al2S3 150.16 H2O 18.015 Al(OH)3 75.361 H2S 34.082 Avogadro's No. 6.022×...

*February 20, 2009*

**physics**

solve for H: V=LWH

*January 26, 2009*

**Leadership**

Deliverable Length: 1000-1200 words You are excited about your new position as compliance officer at ECG because this is your first role as a member of a senior executive team. You have the enviable opportunity to be a critical part of ECG’s growth as the leader who will ...

*January 4, 2009*

**Marketing class**

What is the importance of international trade to a country's economy. Advantages of owning an international business?

*May 31, 2008*

**Economics**

it did not help at all. Thanks though.

*May 31, 2008*

**Lemon**

Lime

*May 28, 2008*

**math**

Given A = {1, 2, 3, 4} B = {2, 5, 10, 17}, a E A and b E B The mapping rule for f maps 1 to 2, 2 to 5, 3 to 10 and 4 to 17 (b) Write the mapping rule in the format of the listing method. Display the mapping using the listing format. (c) Write the mapping rule in the format of ...

*October 9, 2007*

**math**

Given A = {1, 2, 3, 4} B = {2, 5, 10, 17}, a E A and b E B The mapping rule for f maps 1 to 2, 2 to 5, 3 to 10 and 4 to 17. (A) Write the mapping rule in the format of the listing method. Display the mapping using the listing format. (B) Write the mapping rule in the format of...

*October 9, 2007*

**Algebra**

law of indices

*September 26, 2007*

**Arts/social science**

What is the relevance of academic study of the Bible today,especially in African context? Define Ethics and show how it relates to Epistemology. Here are previous answers to these very same questions: http://www.jiskha.com/display.cgi?id=1187166711 http://www.jiskha.com/...

*August 20, 2007*

**University of Botswana**

Define Ethics and show how it relates to Metaphysics and Epistemology. Check these sites. http://en.wikipedia.org/wiki/Ethics http://en.wikipedia.org/wiki/Epistemology http://en.wikipedia.org/wiki/Metaphysics Why are we here on Earth? What is our Purpose? How do we relate to ...

*August 15, 2007*

**University of Botswana**

What is the relevance of the academic study of the Bible today,especially in African context. One of the controversies concerns the actual location of the kingdom of Sheba; some scholars say it was in Ethiopia (Africa) and others claim it was in Yemen (Asia). The location of ...

*August 15, 2007*

**math**

can anyone help please, i need a simple formula for working out taxes.if i had any number i need to know what the base was before 16% tax was added. i know the formula if the tax was 17.5%,what ever the total is if you divide that by 47 then x that by 7 that will give you the ...

*April 15, 2007*

**maths**

can any one tell me a way of working out a percentage from a total for tax purposes. Example; if i have a total of 78 and the tax was 17.5% it would be 78 divide 47 x 7 =11.61 can anyone tell me how to work it out if the tax was 16% thanks "78 divide 47 x 7 =11.61 "...

*April 8, 2007*