Friday
November 21, 2014

Posts by DAVID


Total # Posts: 1,711

Biology
Which alga is most closely related to plants? A) Chara B) Kelp C) Ulva D) Diatom E) Euglena I think it's chara, because it is green algae, but I'm not sure. Can you explain to me why it is or not?
November 20, 2014

physics
A person is stranded and sitting 45m above the ground on the ledge of the cliff. of a safety rope is launched upward at an angle of 50 degrees above the horizontal at a distance of 60m away, what is the initial velocity of the rope so that it reaches the stranded person?
November 19, 2014

physica
help A thermally insulated vessel containing 100 grams of ice at 0 degrees Celsius . Water at 55 degrees celsius is poured and after some time , the system reaches the equilibrium at a temperature of 10 degrees Celsius. That amount of water in grams was placed . ( heat fusion...
November 17, 2014

Math
In a coordinate plane, Brittany labeled the coordinates for point m as (-31/2,2). Sade tells Brittany to reflect point m over the x axis to point r. What are the coordinate of point r?
November 16, 2014

physical
help the positions of two particles A and B are P1 (3,4) in meters and P2 ( -3, -4 ) meters respectively. Meters the position A with respect to B is:
November 14, 2014

physics
A space station shaped like a giant wheel has a radius of 1.00 x 10^2 m and a moment of inertia of 5.00 x 10^8 kgm^2. A crew of 150 lives on the rim, and the station is rotating so that the crew experiences an apparent acceleration of 1.0g. When 120 people move to the center ...
November 11, 2014

physics
a 2100 kg car starts from rest and accelerates at a rate of 2.6 m/s for 4 sec. assume that the force acting to accelerate the car is acting in the same direction as its motion. how much work has the car done? m=2100 kg w=fd v1=0 f=ma t=4 sec d=t+1/2at(squared) a=2.6 m/s2
November 11, 2014

Physics
A moving 4.5 kg block collides with a horizontal spring whose spring constant is 226 N/m (see figure). The block compresses the spring a maximum distance of 8.0 cm from its rest position. The coefficient of kinetic friction between the block and the horizontal surface is 0.47...
November 9, 2014

Engineering science
a roller of diameter 1.5 m has a mass of 450 kg; it is pulled by a handle attached to its centre. Find the minimum force to pull up a step which is 250 mm high if the roller handle makes an angle of 30o with the horizontal
November 9, 2014

math
Rounded to what? Currently it is rounded to the nearest thousandth. If you were to round it to the nearest hundredth it would be 0.08 and to the nearest tenth 0.1.
November 6, 2014

Intermediate Algebra
(-9)1/2 = -4.5 which is a real number. Unless you're talking about square roots?
November 6, 2014

chemistry
The trend for electron affinity on the periodic table is that it increases from the bottom left of the table to the top right. He>I>Te>Bi>Na Should be the order.
November 6, 2014

Science HELP
Due to the conservation of mass, the mass of the reactants is equal to the mass of the products. Mass(A) + Mass(B) = Mass Solid Product 10g + 17g = 27g Mass(beaker) = Mass(Beaker + product) - Mass (product) So Mass(Beaker) = 32g - 27g = 5g So your answer is "A. 5g."
November 6, 2014

Math
I'm not entirely sure what you are asking, but I'll give it a shot. (5x4) + (1x4) is NOT the same as 6x8. Lets look at it in detail: 6x8 = 48 5x4 = 20 and 1 x 4 = 4 20 + 4 = 24 which is not 48. The most you could do is some factoring, but you have to make sure your ...
November 6, 2014

Science HELP
Zn(s) + 2HCl(aq) ---> ZnCl2(aq) + H2(g) It is D, but don't forget to include the extra hydrogen atoms, or else the equation violates the law of conservation of mass. In this case, hydrogen gas (H2) is formed.
November 6, 2014

Science
Due to the conservation of mass, the mass of the reactants is equal to the mass of the products. Mass(A) + Mass(B) = Mass Solid Product 10g + 17g = 27g Mass(beaker) = Mass(Beaker + product) - Mass (product) So Mass(Beaker) = 32g - 27g = 5g So your answer is "A. 5g."
November 6, 2014

math
7 books to wrap, each 5/6 of a foot long. how long a roll needed 7x12 =84 5/6x7=35/42?
November 6, 2014

Algebra HELP!
Part A: Lets say the number any student chooses is 'x'. We need to perform operations to get to 'x-1'. There are many possibilities for this. For example, consider the following scenario where the student is 's' and the teacher is 't'. I'll ...
November 6, 2014

physics
A particle undergoes three successive displacement in a plane as follows 4m southwest, 5m east, 6m in a direction 60 degree north of east (a) draw an apropraite vector diagram to represcent the displacement (b) detarmine the displacement that would be required to bring the ...
November 4, 2014

physics
A hollow 0.358 kg sphere rolls without slipping down an inclined plane that makes an angle of 41.0o with the horizontal direction. The sphere is released from rest a distance 0.734 m from the lower end of the plane. a. How fast is the hollow sphere moving as it reaches the end...
November 3, 2014

physics
A hollow 0.358 kg sphere rolls without slipping down an inclined plane that makes an angle of 41.0o with the horizontal direction. The sphere is released from rest a distance 0.734 m from the lower end of the plane. a. How fast is the hollow sphere moving as it reaches the end...
November 3, 2014

Physics
Creating Z_0 boson via symmetric beams a. Z0 boson has a rest mass energy of 91.187 GeV. It is produced in collisions of positrons and electrons. e^- + e^+ to Z_0 How much kinetic energy must the positrons and electrons in symmetric colliding beams have to produce the Z0 boson...
October 30, 2014

Physics
Creating Z_0 boson via symmetric beams a. Z0 boson has a rest mass energy of 91.187 GeV. It is produced in collisions of positrons and electrons. e^- + e^+ to Z_0 How much kinetic energy must the positrons and electrons in symmetric colliding beams have to produce the Z0 boson...
October 30, 2014

Physics
A 0.250-kg ice puck, moving east with a speed of 5.26m/s , has a head-on collision with a 0.990-kg puck initially at rest. Assume that the collision is perfectly elastic.What is the speed of the 0.250-kg puck after the collision?
October 29, 2014

Chemistry
The reaction of iron and water vapor results in an equilibrium reaction, 3 Fe(s) + 4 H2O(g) ¡ê Fe3O4(s) + 4 H2(g) and an equilibrium constant of 4.6 at 850¡ÆC. What is the concentration of Hydrogen present at equilibrium if the reaction is initiated ...
October 28, 2014

physics
A figure skater is spinning with an angular velocity of +10 rad/s. She then comes to a stop over a brief period of time. During this time, her angular displacement is +5.8 rad. Determine (a) her average angular acceleration and (b) the time during which she comes to rest.
October 27, 2014

Biology
Compare ad contrast indirect versus direct values of biodiversity and provide two examples?
October 24, 2014

physics
A small pumpkin of mass 2.22 kg is dropped from rest from a height of 2.87 m. The pumpkin rebounds from the ground to a height of 1.12 m. a. With what speed does the pumpkin hit the ground? b. With what speed does the pumpkin leave the ground? c. What impulse was given to the ...
October 24, 2014

business math
The sweet candy shop buys 600 pounds of chocolate covered strawberries at $5.59 per pound. If a 10% spoilage rate is anticipated, at what price per pound should the strawberries be sold in order achieve a 60% markup based on cost?
October 20, 2014

Estimating decimal quotient
180.8/6=180/6=30 18.2/11=20/10=2 55/10.7=50/10=5 0.6/5=1.0/5=0.2 145/0.3=145/3=15 60/5.9=60/6=10 1.8/20=2.0/20=0.1
October 19, 2014

Estimating decimal quotient
Use compatible to find the following quotient 180.8 divided by 6 182divided by 11 55divided by 10.7 117.8divided by 0.12 0.6 divided by 5 145 divided by 0.3 60 divided by 5.9 1.8 divided by 20
October 19, 2014

Business Math
Jeanna wants to buy a new boat for her family. She has two payment options. The first option is to pay a cash payment of $7,200. The second option is to finance the boat with a three year installment loan. The loan requires a 10% down payment and 36 equal monthly payments of $...
October 19, 2014

Biology
Compare and contrast indirect versus direct values of biodiversity, and provide examples.
October 17, 2014

Math
Every item in the Just a Dollar store is priced at $1.00. When Mary Jo opens the store, there is $122.00 in the cash register. When she counts the money in the cash register at the end of the day, the total is $1,065.95. If the sales tax rate is 8.5%, how many items were sold ...
October 13, 2014

Algebra
please help me im confused. Every item in the Just a Dollar store is priced at $1.00. When Mary Jo opens the store, there is $122.00 in the cash register. When she counts the money in the cash register at the end of the day, the total is $1,065.95. If the sales tax rate is 8.5...
October 13, 2014

physics
The weight of an astronaut plus his space suit on the Moon is only 270 N. A. How much do they weigh on Earth, in Newtons, assuming the acceleration due to gravity on the moon is 1.67m/s^2= 1584is this right? B. What is the mass of the astronaut and his space suit on the moon ...
October 9, 2014

physics,electrostatics
A 40uf parallel plate capacitor is charged to 12v. The capacitor is removed from the battery and the separation distance increased from 2mm to 3mm. What is the total charge on the capacitor? How much energy was stored in the capacitor when the distance was 2mm? By how much is ...
October 9, 2014

math
Hold on Sir... you have lots of questions going on here please wait a few min before a tutor gets to you Thanks :D
October 7, 2014

AP Calc
Find the equation of ALL horizontal tangents to the curve y^2=x^2+4/x, if any exists. My work: Derivative- First I multiply across and got x^2+4=xy^2 2x+0=(x)(2y(dy/dx)+(y^2) 2x-y^2=2xy(dy/dx) dy/dx=2x-y^2/2xy=x-y^2/xy I don't know what to do next... Can you help me? ...
October 6, 2014

AP Calc
Find the point on the curve x=4y-y^2 where the tangent to the curve is a vertical line. My work: Finding the derivative. 1=4(dy/dx)-2y(dy/dx) 1=dy/dx(4-2y) dy/dx=1/4-2y Therefore, y cannot equal +2 or -2 Right?
October 6, 2014

Math
The answer is -13.482 if you want it in Sig. Figs then the anser will be -13.4 Hope this helped :D
October 6, 2014

math
f(x)=(x-3)(x+2) If thats what you're looking fore :) To solve for x if you're going further Use T-Chart... answer then will be x=3 and x=-2
October 6, 2014

Math
1/5^9= 5.12 x 10^-7 Work backwards: 1/5 is the conjugate of 5 therefore, if 1/5 is raised to the 9th power the opposite of that is -9. 5^-9= 5.12 x 10^-7 your answer: B
October 6, 2014

Math
Find the point on the curve x=4y-y^2 where the tangent to the curve is a vertical line. My work: Finding the derivative. 1=4(dy/dx)-2y(dy/dx) 1=dy/dx(4-2y) dy/dx=1/4-2y Therefore, y cannot equal +2 or -2 Right?
October 6, 2014

Physical Education
Correct Carbohydrates are the main energy source to the human body :)
October 6, 2014

Physical Education
Carbohydrates are the main energy source for the brain. Without carbohydrates, the body could not function properly. Protein is the major structural component of cells and is responsible for the building and repair of body tissues. Protein is broken down into amino acids, ...
October 6, 2014

Math
Thanks I understand it now :D
October 6, 2014

Math
Find the coordinatesof the point on the curve xy=10 in the first quadrant such that the normal line passes through the orgin. My work: Okay i believe this is an inverse variation. Therefore, y=10/x? Origin is @ (0,0) and i'm stuck to move on...
October 6, 2014

Math- AP Calc
If 3x+xy+4y=8, what is the value of d^2y/dx^2 at the point (1,1)? My work: 3+(x)(dy/dx)+(y)+4(dy/dx)=0 dy/dx(x+4)=-3-y dy/dx=-3-y/x+4 2nd Dervative: (x+4)(0-dy/dx)-(-3-y)/(x+4)^2 (x+4)(-(-y-3/x+4))-(-3-y)/(x+4)^2 (x+4)(y+3)/(-x+4)+(y+3)/(x+4)^2 *Mult. everything by (-x+4) ...
October 6, 2014

Math
If 3x+xy+4y=8, what is the value of d^2y/dx^2 at the point (1,1)? My work: 3+(x)(dy/dx)+(y)+4(dy/dx)=0 dy/dx(x+4)=-3-y dy/dx=-3-y/x+4 2nd Dervative: (x+4)(0-dy/dx)-(-3-y)/(x+4)^2 (x+4)(-(-y-3/x+4))-(-3-y)/(x+4)^2 (x+4)(y+3)/(-x+4)+(y+3)/(x+4)^2 *Mult. everything by (-x+4) ...
October 6, 2014

geometry
Point C is in the interior of angle ABD. The measure of angle ABD is 40 degrees. The measure of angle DBC is 3x-5. If angle ABC is 22 degrees, what is "x"?
September 28, 2014

algebra
oh 65 and 66.
September 23, 2014

algebra
65 and 67?
September 23, 2014

algebra
its 65.5
September 23, 2014

algebra
the numbers on two consecutively numbered gym lockers have the sum of 131. what are the locker numbers?
September 23, 2014

math
-5 an 7/12 divided by 12 equals
September 23, 2014

Chemistry
Is it about 2 Zums?
September 22, 2014

Chemistry
8.5 Ed's = 10 Ebb's, 12 Ersk's = 100 Ed's and 5 Ebb's = 1 Zum. How many Zum's in approx. 1 Ersk? Starts out: 1 Ersk*__________ Ersk
September 22, 2014

Physics
The nozzle of a fountain jet sits in the center of a circular pool of radius 3.50 m. If the nozzle shoots water at an angle of 65 degrees. A) What is the maximum speed of the water at the nozzle that will allow it to land within the pool?
September 21, 2014

math
1) 4.1875 = 4 3 over 16 2) 4.5 = 4 1 over 2 3) 4.625 = 37 over 8 4) 4.75 = 19 over 4
September 21, 2014

Physics
is your d = square root of (60^2 + h basket^2) and for which question a,b or c
September 21, 2014

Physics
A Balloon carrying a basket is descending at a constant velocity of 20.0 m/s. A person in the basket throws a stone with an initial velocity of 15.0 m/s horizontally perpendicular to the path of descending balloon and 4.00 (s) later this person sees the stone strike the ground...
September 21, 2014

Pshyics
A meter stick has a mass of 0.12 kg and balances at its center. When a small chain is suspended from one end, the balance point moves 19.0 cm toward the end with the chain. Determine the mass of the chain.
September 21, 2014

Pre-Cal
Let x and y be real numbers such that x^2 + y^2 = 1. Find the maximum value of 2x - 5y.
September 20, 2014

Physics
A particle is moving at 0.75c relative to a lab on Earth. By what percentage is the Newtonian expression for its momentum in error, i.e., how wrong is the classical formula? (The percentage error is the difference between the erroneous and correct values, divided by the ...
September 20, 2014

Algebra 2
The line 4x + ky = -1 has a slope of 2/3. Find k. a. 3/2 b. 6 c. -3 d. -6
September 17, 2014

Math
You deposit $100 at the end of each quarter in a sinking fund earning 4% compounded quarterly. How many quarterly deposits must you make in order to reach your goal of saving $10,000? Round your answer off to the nearest whole number.
September 15, 2014

Chemistry
8-hydroxyquinoline (Q) can complex and precipitate many metals. A mixture of the aluminium and magnesium complexes weighed 1.0843g (MW=459.43; 312.61). When ignited, the mixture decomposed and left a residue of Al203 (MW 101.96) and MgO (MW 40.304) weighing 0.1344g. What is ...
August 24, 2014

computers
create a program that will input two quizzes and will compute for sum,difference,product,quotient and average using printf and scanf. create your own design.
August 21, 2014

Math
1165
August 20, 2014

MATH
The first month's dues will be used to rent a film about computer-related careers, to purchase a reference book, and to buy refreshments for the next meeting. If 1/2 of the money is spent on her film, 1/4 of the remainder is used for refreshments, and $7.50 is spent on the...
August 12, 2014

math
The answer is c
August 7, 2014

computers
when you connect to a remote VPN server with your laptop running windows 8 what key item is your computer allocated
August 7, 2014

math hw
42. Twenty minutes after a plane leaves the airport, it is reported to be 160 miles away. What average speed of the plane in the miles per hour?
August 5, 2014

math hw
An automobile party leaves at 7:55 A.M., and arrives at its destination 15 miles away at 8:15 A.M. What was the average rate on this trip (in M.P.H.)?
August 5, 2014

math hw
40. How far (in miles) does a car travel when its average rate is 35 miles per hour and it travels for 3 hours and 24 minutes?
August 5, 2014

math test review
18. In triangle ABC, m<C=2m<b,m<A=6m<B. what is the measure of <c? A.5 degrees B.15 degrees C.20 degrees D.30 degrees E.40 degrees
August 4, 2014

math
That was by mistake, I didn't know and typed in again.
August 4, 2014

math
1. If b is positive integer less than 200, then how many integer pairs (a,b) satisfy the equation a/b= 2/9?
August 4, 2014

math
1. If b is a positive integer than 200, then how many integer pairs (a,b) satisfy the equation a/b= 2/9
August 4, 2014

math test review
16. If the base of a right triangle is 8 (square root)2 and the hypotenuse is 18, what is the area of the triangle? A.14 B.14 square root 2 C.56 square root 2 D.64 E.64 square 2
August 4, 2014

math hw
In set of 30 different positive integers, every number is even and/or a multiple of 3. If 22 of these numbers are even and 15 are multiple of 3, then how many of these numbers are multiple of 6?
August 4, 2014

math hw
2. If a^2-b^2=20 and a+b=2, what is the value of a-b? I added the a^2-b^2+20 and a+b+20, but i couldn't get the answer to equal a-b.
August 4, 2014

math hw
71
August 4, 2014

math hw
10.Thirty students in a chemistry class took a test on which the overall average score was 78. If the average score for 15 of those students was 85, what was the average score for the remaining members of the class? I know that "average" means dividing, but i'm ...
August 4, 2014

math
9. In Mr.chin's math class there were g girls and b boys. The number pf girls was 5 less than twice the number of boys. What is the value of g in terms of b? this is what I have so far: 2n-5
August 4, 2014

Chemistry
2Na + 2H2O------> 2NaOH + H2 H=-386kJ If 5g of sodium is added to 200g of water in an open container: (A) How much heat is absorbed/released int he reaction? (B)What volume in formed at 22C and 102kPa? (C) If boiling point elevation constant is 0.52K molal what is the ...
August 3, 2014

maths
The Park's are buying new carpet for their house.They need about 1,175 square feet of carpet.The carpet they buy is sold by the square yard. Estimate the number of square yards of carpet the Parks need for their house. Show your work.
August 2, 2014

Astronaut launches bowling ball
A 100 kg astronaut carries a launcher loaded with a 10 kg bowling ball; the launcher and the astronaut’s spacesuit have negligible mass. The astronaut discovers that firing the launcher results in the ball moving away from her at a relative speed of 50 m/s. The astronaut ...
July 28, 2014

English
She waited patiently for her turn on line at the New Age bookstore. adjective adverb noun verb
July 6, 2014

Physics
. A stone is dropped from the top of a building that is 500m high. Disregarding air resistance how long does it take the stone to reach the ground?
June 25, 2014

math
20
June 8, 2014

math
Charlie must choose a number between and that is a multiple of , , and . Write all the numbers that he could choose. If there is more than one number, separate them with commas
May 28, 2014

Physics
A 69.5kg football player is gliding across very smooth ice at 2.15m/s . He throws a 0.470kg football straight forward. A) What is the player's speed afterward if the ball is thrown at 16.0m/s relative to the ground? B) What is the player's speed afterward if the ball ...
May 27, 2014

Math please check my answer?
1)6x+11y=30 A) x-intercept= (-24,0);y intercept =(0,19) B)x-intercept=(0,1/5);y intercept=(11/30,0)<<<< C)x-intercept= (5,0);y intercept=(0,30/11) D)x-intercept= (24,0);y intercept=(0,19)
May 22, 2014

Math please check my answers?
1) The linear function f(x) contains the points (-10, -29) and (-2, 83). If g(x) = 25x - 50, which statement is true? A. The functions f(x) and g(x) both have positive slopes. <<< B. The functions f(x) and g(x) both have negative slopes. C. The function f(x) has a ...
May 22, 2014

Algebra please check my answers
Are 1 and 2 correct?
May 21, 2014

Algebra please check my answers
Thanks! Are the others correct?
May 21, 2014

Algebra please check my answers
1) The linear function f(x) contains the points (-10, -29) and (-2, 83). If g(x) = 25x - 50, which statement is true? A. The functions f(x) and g(x) both have positive slopes. <<< B. The functions f(x) and g(x) both have negative slopes. C. The function f(x) has a ...
May 21, 2014

Algebra
The table below represents the function f(x). (-6, 12),(-5,-8),(-4,-4), (-3,0),(-2,4),(-1,8),(0,12). If g(x) is a linear function that has a slope of -3 and a y-intercept of -9, which statement is true? A) The x-intercept of f(x) is less than the x-intercept of g(x). <<&...
May 21, 2014

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