# Posts by David

Total # Posts: 2,289

**physics**

A heavy table of mass M is vibrationally isolated by being hung from the ceiling by springs, so that its frequency of vertical oscillation is \omega_0 (take \omega_0 to be 2\pi/sec, a typical value). Assume now that the ceiling vibrates vertically with amplitude A at frequency...

**Math**

1) Prove that for every x>=0 and 0<a<1 x^a-ax<=1-a 2)prove that for 0<=x<=1: x^m*(1-x)^n<= (m^m*n^n)/((m+n)^(m+n)) can someone please guide/help me in about how to solve and or approch these questions? (I know I have already posted it before but i think it...

**Math**

1) Proove that for every x>=0 and 0<a<1 x^a-ax<=1-a 2)prove that for 0<=x<=1: x^m*(1-x)^n<= (m^m*n^n)/((m+n)^(m+n)) can someone please guide/help me in about how to solve and or approch these questions?

**Science**

Yes, the answers are: 1.C 2.B 3.B 4.D

**programming**

It is a computer course for physicists. Therfore i do not study programming as my main course. also i have missed a few lessons, therfore i do not even know where to begin.

**programming**

– Define a structure called Object which includes three doubles specifying the object’s mass, volume and density. – Create an array of 10 Objects. – Define the function void scanobjectsdata(struct Object objects[], int size) that scans from the input and ...

**AP Calc**

Find the value of c which satisfies Rolle’s Theorem for the function f(x)=sin(x²) on (0,√π).

**Physics**

A 283 g air track glider moving at 0.69 m/s on a 2.4 m long air track collides elastically with a 467 g glider at rest in the middle of the horizontal track. The end of the track over which the struck glider moves is not frictionless, and the glider moves with a coefficient of...

**Physics**

A 283 g air track glider moving at 0.69 m/s on a 2.4 m long air track collides elastically with a 467 g glider at rest in the middle of the horizontal track. The end of the track over which the struck glider moves is not frictionless, and the glider moves with a coefficient of...

**Calculus**

Thanks!

**Calculus**

This is a calculus homework question but in reality the problem here is understanding the algebra. Find the Critical Numbers of f(x) = x^(3/5)(4-x) The product rule gives -x^(3/5) + (12-3x)/(5x^(2/5) My booklet explains that simplifying this gives you 12-8x / (5x^(2/5). How ...

**Calculus**

in the equation a/(1-r)

**Calculus**

so a is the first term in the series and r is the term that is being reused over and over again ?

**Calculus**

So this one is confusing me: limit of n as it approaches infinity of (n{SIGMA}i=1) (1/(2^i) *the n is on top of the sigma notation and i=1 is at the bottom. I understand that 'i' would equal (n(n+1))/2 however the algebra from there confuses me.

**Calculus**

I am trying to solve the following L'hopital's limits question below: lim x -> 0 from the positive direction of ( 5^(sin(x)) - 1 )/ (x)

**Calculus**

L'hopital's question below: lim x -> 0 from the positive direction of ( 5^(sin(x)) - 1 )/ (x)

**AP Chemistry**

What percent (by mass) of granulated sugar is fructose, and what percent of it is sucrose? Background: We are doing a colligative properties lab in my class where we are to add 20 grams, 40 grams, 60 grams, and 80 grams of sugar to 100 grams of water, and use the change in the...

**AP Chemistry**

What is the Van't Hoff Factor of MgSO4*7H2O? We're doing a colligative properties lab at my school where we dissolve various amounts of MgSO4 in 100 grams of water. What value/range of values should I expect the Van't Hoff Factor to be?

**Physics**

You have a brass ring of inside diameter 10.00 cm that is at 20.0oC. You want to slip this ring over an aluminum rod that is at 20.0oC and has a diameter of 10.01 cm. a. To what temperature do you have to heat the ring to slip it over the rod? b. Once you have the ring over ...

**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?

**Math**

23 multiplied by 12= 276 276-15= 261 The answer is 261

**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?

**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...

**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?

**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:

**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 ...

**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

**PLEASE HELP ASAP Language Arts**

I believe it's A correct me if I'm wrong though.*

**PLEASE HELP ASAP Language Arts**

I believe it's B correct me if I'm wrong though.

**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...

**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

**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.

**Intermediate Algebra**

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

**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.

**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."

**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 ...

**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.

**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."

**math**

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

**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 ...

**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 ...

**sixth grade math**

A person on a moving sidewalk travels 28 feet in 7 seconds. The moving sidewalk has a length of 200 feet. How long will it take to move from one end to the other?

**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...

**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...

**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...

**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...

**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?

**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 ...

**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.

**Biology**

Compare ad contrast indirect versus direct values of biodiversity and provide two examples?

**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 ...

**physics**

vf1= ((m1-m2)/(m1+m2))(v1) vf2= ((2m1)/(m1+m2))(v1)

**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?

**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

**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

**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 $...

**Biology**

Compare and contrast indirect versus direct values of biodiversity, and provide examples.

**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 ...

**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...

**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 ...

**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 ...

**science**

planetary accretion

**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

**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? ...

**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?

**Math**

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

**math**

f(x)=(x-3)(x+2) If that's 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

**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

**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?

**Physical Education**

Correct Carbohydrates are the main energy source to the human body :)

**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, ...

**Math**

Thanks I understand it now :D

**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...

**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) ...

**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) ...

**math**

How do you do this problem f(x)=3x6+2x3-176;c=-2

**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"?

**algebra**

oh 65 and 66.

**algebra**

65 and 67?

**algebra**

its 65.5

**algebra**

the numbers on two consecutively numbered gym lockers have the sum of 131. what are the locker numbers?

**math**

-5 an 7/12 divided by 12 equals

**Chemistry**

Is it about 2 Zums?

**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

**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?

**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

**Physics**

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

**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...

**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.

**Pre-Cal**

Let x and y be real numbers such that x^2 + y^2 = 1. Find the maximum value of 2x - 5y.

**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 ...

**Algebra 2**

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

**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.

**physics**

your mom

**math**

I DO NOT FREAKING KNOW

**5th grade math**

289 x 7=2023

**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 ...

**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.

**Math**

1165

**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...