# Posts by J

Total # Posts: 1,010

**Calculus**

thankyou!

*May 9, 2012*

**Calculus**

Determine the vector u = AB and its magnitude, given A(3,7,-2) and B(9,1,5).

*May 9, 2012*

**Calculus**

thank you!

*May 9, 2012*

**Calculus**

Calculate the angle between u = [5,7,-1] and v = [8,7,8]

*May 9, 2012*

**Calculus**

thank you!

*May 9, 2012*

**Calculus**

Calculate the dot product of two vectors: m = [4,5,-1] and n = [6,-2,7]

*May 9, 2012*

**Calculus**

Find the total work done by a 15 N force in the direction of the vector [1,2,2], when it moves a particle from O[0,0,0] to P[1,-3,4] and then from P to A[7,2,5]. Distance is measured in metres.

*May 8, 2012*

**Calculus**

for this question, do i have to solve it? it just says interpret the results, does that mean only explain? im trying to solve it right now. i have: L1: [x,y,z]=[-1,1,0]+s[3,4,-2] L2: [x,y,z]=[5,9,-4]+t[2,3,1] First, cross product of the two directional vectors from both lines...

*May 7, 2012*

**Calculus**

Find the distance between the lines [x,y,z] = [-1,1,0] + s[3,4,-2] and [x,y,z] = [5,9,-4] + t[2,3,1]. Interpret the result.

*May 7, 2012*

**Calculus**

Isnt it 30 + 50 + 10 because 10* 1 is 10 so final is = 90

*May 7, 2012*

**Calculus**

could you help me calculate the second part also? thank you

*May 7, 2012*

**Calculus**

I don't understand it.. what is the final work done? Also, the arrows (< and >) are they actually supposed to be written as < and > or are they supposed to mean brackets ( ) or these brackets [] thank you

*May 7, 2012*

**Calculus**

Find the total work done by a 15 N force in the direction of the vector [1,2,2], when it moves a particle from O[0,0,0] to P[1,-3,4] and then from P to A[7,2,5]. Distance is measured in metres.

*May 7, 2012*

**Calculus**

We need the direction of their line of intersection? That's all the question mentioned... so is that still the correct answer? :/

*May 7, 2012*

**Calculus**

Find the vector equation of the line that passes through the point (2,-1,7) and is parallel to the line of intersection of the planes x + 2y - 3z = -6 and 3x - y + 2z = 4

*May 7, 2012*

**Calculus**

thank you :)

*May 7, 2012*

**Calculus**

Three forces of 5 N, 8 N, and 10 N act from the corner of a cube along its edges. Using Cartesian vectors, find the magnitude of the resultant force.

*May 7, 2012*

**Astronomy**

not sure

*May 7, 2012*

**cheistry**

For 6th grade its 3 questions and for 7th its 4 :D AND IM GUESSING FOR 8 ITS 5 :D XD

*May 6, 2012*

**Calculus**

Three forces of 5 N, 8 N, and 10 N act from the corner of a cube along its edges. Using Cartesian vectors, find the magnitude of the resultant force.

*May 6, 2012*

**Calculus**

Find the vector equation of the line that passes through the point (2,-1,7) and is parallel to the line of intersection of the planes x + 2y - 3z = -6 and 3x - y + 2z = 4

*May 6, 2012*

**Calculus**

how do i check that? that the components (z) match "automatically"

*May 6, 2012*

**Calculus**

is this a) First see that the two vectors are orthogonal: [4,8,-4].[-1,2,3]=-4+16-12=0 => orthogonal Next solve for s and t for each coordinate direction (x,y,z) 4+4t=1-s 7+8t=5+2s => s=-1, t=-1/2 and this b) Substitute into original equation: <4,7,-1>-<2,4,-2&...

*May 6, 2012*

**Calculus**

10. Consider the lines [x,y,z] = [4,7,-1] + t[4,8,-4] and [x,y,z] = [1,5,4] + s[-1,2,3]. a) Show that the lines intersect at the right angle. b) find the point of intersection. please and thanks!

*May 6, 2012*

**Calculus**

thank you!

*May 5, 2012*

**Calculus**

Does the line [x,y,z] = [-2,6,5] + t[3,2,-1] lie in the plane 3x - 4y + z + 25 = 0 ? Please show work.

*May 5, 2012*

**Calculus**

Explain why a line in three-space cannot be represented by a scalar equation.

*May 5, 2012*

**Calculus**

thank you :)

*May 5, 2012*

**Calculus**

Determine an equation for the line parallel to 2x + 6y + 4z = 1 and contains the point P(3, 2, 1).

*May 5, 2012*

**Calculus**

So the final answer for this one would be [x,y,z]=[6,10,1]+1[3,4,-1]=[9,14,0] ? Thank you!

*May 5, 2012*

**Calculus**

Where does the line [x, y, z] = [6, 10, 1] + t[3, 4, -1] meet the xy-plane?

*May 5, 2012*

**Calculus**

thank you! :)

*May 5, 2012*

**Calculus**

Could you please help me with this question though, I don't understand this one: Explain why a line in three-space cannot be represented by a scalar equation. thank you!

*May 5, 2012*

**Calculus**

Thank you! everything is clear :)

*May 5, 2012*

**Calculus**

I don't understand it still.. So is a) parallel and b) coincidental? Please help! :(

*May 5, 2012*

**Calculus**

Determine if the planes in each pair are parallel and distinct or coincident. a) 5x - 2y + 4z = 7 5x - 2y + 4z = -3 b) 7x - 3y - z = 9 21x - 9y - 3z = 27

*May 5, 2012*

**Calculus**

Explain why a line in three-space cannot be represented by a scalar equation.

*May 5, 2012*

**Calculus**

Hi bobpursley, I got 2 answers for a) but I'm not sure which one is correct, could you please help me determine which is correct? the first answer I got is posted in this question, the second answer I got is this one for part a) could you please help me for a) I got this ...

*May 4, 2012*

**Calculus**

1. a) Write the vector and parametric equations of the line through the points A(6, -1, 5) and B(-2, -3, 6). b) Find another point on the line in (a). ----- This is what I got for a) r = 6i-j+5k + t(-8i-2j+k) x = 6-8t y = -1-2t z = 5+t I need help with b)

*May 4, 2012*

**Calculus grade 12**

thank you :)

*May 4, 2012*

**Calculus grade 12**

Explain why three directional vectors of the plane cannot me mutually perpendicular .

*May 4, 2012*

**Calculus grade 12**

Determine an equation for the line parallel to 2x + 6y + 4z = 1 and contains the point P(3, 2, 1).

*May 4, 2012*

**Calculus grade 12**

Explain why three directional vectors of the plane cannot me mutually perpendicular .

*May 3, 2012*

**Calculus grade 12**

Determine an equation for the line parallel to 2x + 6y + 4z = 1 and contains the point P(3, 2, 1).

*May 3, 2012*

**Calculus grade 12**

thank you :)

*May 3, 2012*

**Calculus grade 12**

Determine an equation for the plane that contains the points A(6, 2, 3), B(5, 1, -3), and C(5, 7, -2).

*May 3, 2012*

**Calculus grade 12**

Steve, for a) I got this instead: vector equation: [x, y, z] = [6, -1, 5] + t[-8, -2, 1] parametric equation: x=6+t(-2) x=6-2t y=-1+t(-3) y=-1-3t z=5+6t is that correct? ...

*May 3, 2012*

**Calculus grade 12**

Can you please do b) Steve? Thank you.

*May 3, 2012*

**Calculus grade 12**

1. a) Write the vector and parametric equations of the line through the points A(6, -1, 5) and B(-2, -3, 6). b) Find another point on the line in (a).

*May 3, 2012*

**African American Lit**

Would the last stanza be an example of Naturalism? "Maud, who went to college, Is a thin brown mouse. She is living all alone In this old house."

*May 2, 2012*

**African American Lit**

For what I am trying to understand I am using these definitions: Realism- a faithful reproduction of reality and promotes awareness Naturalism- a harsher treatment of reality and realism Modernism- connecting realism and naturalism to today.

*May 2, 2012*

**African American Lit**

How is the poem 'Sadie and Maud' by Gwendolyn Brooks synonymous to Realism, Naturalism and Modernism?

*May 2, 2012*

**PHYSICS**

A catapult launches a rocket at an angle of 56.9° above the horizontal with an initial speed of 100 m/s. The rocket engine immediately starts a burn, and for 3.25 s the rocket moves along its initial line of motion with an acceleration of 28.1 m/s2. Then its engine fails, ...

*April 25, 2012*

**Chemistry**

I still don't understand what to do after setting the K= pO2^(3/2). What do you substitute into the O2?

*April 6, 2012*

**algebra**

Participants in a psychology experiment were able to memorize an average of M words in t minutes, where M = −0.001t3 + 0.1t2. Use the following graph.Estimate the number of words memorized after 14 min. m 20 / 18 / 16 / 14 / 12 / 10 / 8 / 6 / 4 / 2/02468101214161820t

*April 5, 2012*

**math**

Determine the water level inside a tank that has a diameter of 40 feet and contains 180,000 gallons of water?

*March 26, 2012*

**RUBY MS**

what is 8.3% of 132,000,000

*March 23, 2012*

**Physics**

A 83-kg fisherman in a 122-kg boat throws a package of mass m = 15 kg horizontally toward the right with a speed of vi = 4.7 m/s as in the figure below. Neglecting water resistance, and assuming the boat is at rest before the package is thrown, find the velocity of the boat ...

*March 19, 2012*

**Physics**

An object has a kinetic energy of 244 J and a momentum of magnitude 24.9 kg · m/s. (a) Find the speed of the object. (b) Find the mass of the object.

*March 19, 2012*

**Chemistry**

my deltaGf was dGf=290.4kJ/mol i got K=1.69e18 as my answer and it was correct. still getting the equation wrong though :/

*March 14, 2012*

**math**

nicks class has 30 students. 2/5 of his class sings in the school chorus. how many students sing in the chorus?

*March 13, 2012*

**physics**

hb h

*March 12, 2012*

**english 11**

Its right

*March 9, 2012*

**Finance**

Suppose your bank account will be worth $4,200.00 in one year. The interest rate (discount rate) that the bank pays is 5%. What is the present value of your bank account today?

*March 7, 2012*

**Finance**

Suppose your bank account will be worth $4,200.00 in one year. The interest rate (discount rate) that the bank pays is 5%. What is the present value of your bank account today?

*March 7, 2012*

**chemistry**

Constitutional isomers have the same molecular formula but different atom connectivity. Conformational isomers have the same molecular formula and the same atom connectivity but different spatial arrangements due to rotation about single bonds. The answer is true.

*March 4, 2012*

**Physical Chemistry**

Calculate the value of the change in enthalpy(H) when the temperature of 1 mole of a monatomic gas is increased from 25C to 300C.

*March 4, 2012*

**algebra**

how to make a 4x4 magic sqaure which equals 18

*February 27, 2012*

**Physics**

The string of a conical pendulum is 54.5 cm long and the mass of the bob is 0.22 kg. a) Find the angle between the string and the horizontal when the tension in the string is three times the weight of the bob. b)Under those conditions, what is the period of the pendulum?

*February 26, 2012*

**Physics**

A mass m1 on a horizontal shelf is attached by a thin string that passes over a frictionless pulley to a 2.5 kg mass (m2) that hangs over the side of the shelf 1.2 m above the ground. The system is released from rest at t = 0 and the 2.5 kg mass strikes the ground at t = 0.82 ...

*February 26, 2012*

**physics**

,bjj

*February 23, 2012*

**chemistry**

12.2

*February 22, 2012*

**Physics**

(b) What is the acceleration of the ball if an upward force of 64 N is applied?

*February 20, 2012*

**math**

a shot is released at a height of 1.89m, with a speed of 13m/s and at an angle of 34 degrees. Calculate the maximum height reached and the time at which this occurs, the range and the time of flight, and the optimum projection angle.

*February 16, 2012*

**biomechanics**

a shot is released at a height of 1.89m, with a speed of 13m/s and at an angle of 34 degrees. Calculate the maximum height reached and the time at which this occurs, the range and the time of flight, and the optimum projection angle.

*February 16, 2012*

**physics**

A tiger leaps horizontally from a 15.0 m high rock with a speed of 7.10 m/s. How far (in meters) from the base of the rock will it land? so using the equation h=1/2 gt^2 and i put in 15 for h and g is 9.8 so i solve for t. is this right and when do i use the 7.10 m/s

*February 14, 2012*

**physics**

so does that mean vf is zero, vi is 29.69848481, and g is 9.8

*February 14, 2012*

**physics**

A golfer drives a ball with a velocity of 42 m/s at an angle of 45 degrees above the horizontal. What is the maximum height (in meters) of the ball above the level fairway?

*February 14, 2012*

**physics**

so h is 15, g is 9.8 15= 4.9t^2 then take the square root of 3.061. then do i multiply by 15?

*February 14, 2012*

**physics**

is g negative or positive, because that is what i did and the answer is still wrong!

*February 14, 2012*

**goverment**

Federal regulatory agencies have responsibility primarily in the area of

*February 13, 2012*

**Physics**

A circular automobile racetrack is banked at an angle theta such that no friction between road and tires is required when a car travels at 28.0 m/s. If the radius of the track is 390 m, determine theta .

*February 11, 2012*

**calculus**

Parametrize the curve of intersection of x = -y^2 - z^2 and z = y.

*February 8, 2012*

**Chemistry**

What is the empirical formula if given c-.1929 h-.01079 o-.08566 cl-.1898

*January 30, 2012*

**chem**

D is the correct answer!!!

*January 30, 2012*

**Geometry Question (multiple choice)!**

Geometry unit 10, Lesson12 1.C 2.D 3.A 4.A 5.D 6.A 7.A 8.A 9.B

*January 10, 2012*

**chemistry**

The electrochemical cell described by the balanced chemical equation has a standard emf (electromotive force) of -4.05 V. Calculate the maximum electrical work (kJ) the cell has done if 6.8500 mol of F2(g) (Molar Mass - 38.00 g/mol) forms. Round your answer to 3 significant ...

*December 4, 2011*

**Chemistry**

Thank you so much :)

*December 3, 2011*

**Chemistry**

If the initial concentration of NH3(g) is 4.643 mol/L, calculate the % of NH3(g) left over after the reaction reaches equilibrium according to the balanced equation. The value of Kc at 773.0 K is 16.70. The initial concentration of the reaction products is 0 mol/L. 2NH3(g) = ...

*December 3, 2011*

**Algebra II**

^^^

*November 22, 2011*

**Physics 1**

12000j

*October 20, 2011*

**math**

112-49=63 63/(7+7) = 63/14 =4.5 4.5+ (8-2)^2 4.5+ 6^2 40.5 jeeze this was easy,how old are you, 3??

*October 19, 2011*

**physics**

you can use the max height for parabloic path equation.look it up on google you lazy bum!

*October 19, 2011*

**physics**

the answer is dragonballs....simple as that.

*October 19, 2011*

**Science**

When plants die, what happen to carbon dioxide? They would be more co2 or less?

*October 18, 2011*

**Math**

Round 50.4 square miles to the nearest Square mile

*October 13, 2011*

**Science (Chemistry**

ad

*October 11, 2011*

**Math**

Construct a grouped frequency distribution for the following 28 scores using a class width of 4: 64 63 58 46 52 62 47 49 56 47 43 41 45 51 60 62 51 61 50 55 56 53 54 58 48 48 58 46

*October 10, 2011*