Friday

April 18, 2014

April 18, 2014

Total # Posts: 6,089

**physics**

Light with a frequency of 4.32 × 1015 Hz strikes a metal surface and ejects electrons that have a maximum kinetic energy of 5.8 eV. What is the work function (in eV) of the metal?

**Math- Calculus**

find the dimensions of a rectangle of maximum size that will fit into a half circle of radius 30 cm.

**algebra**

Will someone please help me slove this question. Completely factor the polonomial. 8x^3+16x^2+8x+16

** Math**

A company offers the following charges: $54 per thousand for orders of 62000 or less with the charge per thousand decreased by 38 cents for each thousand above 62000. Find the order which will make the company's revenue a maximum.

**math**

a driver comes to pick up members of your family (20 members) for a family reunion. the van holds 7 people not including the driver. assuming none of the babies will be riding (2 babies in the group of 20) how many different ways can 7 people be chosen to ride in the van?

**Math- Calculus**

A company offers the following charges: $54 per thousand for orders of 62000 or less with the charge per thousand decreased by 38 cents for each thousand above 62000. Find the order which will make the company's revenue a maximum.

**math**

how many different ways can 7 out of 18 people be picked to fit into a van

**math**

how many different ways can 7 out of 18 people be picked to fit into a van

**Math- Calculus**

A company needs to produce a cylindrical can to hold water. It must have a volume of 500ml. The side of the can will cost 40$/m^2 to produce and the top and bottom of the can will cost 50$/m^2 to produce. Find the most economical dimensions.

**Algebra (word problems)**

Studying help! Flights of leaping animals typically have parabolic paths. The figure illustrates a frog jump superimposed on a coordinate plane. The length of the leap is 9 feet, and the maximum height off the ground is 3a feet. Find a standard equation for the path of the fro...

**statistics**

the average proportion of red candies in a pakage is 20% and an 8 oz package contains about 250 candies.What is the probability that a randomly selected 8 oz bag contains less than 45 red candies?

**English**

Can someone check if this question is grammatically correct? Thank you very much in advance. What do you use the Internet for? What are the main advantages and disadvantages of using it? What are the most addictive things on the Internet? What are the positive and negative sid...

**Early childhood**

Can someone check if this is correct? Of all ages, ages four year olds need the most a) challenge and variety b) love and attention c) structure and discipline d) freedom and spontaneity I think it's a or d but I think a) challenge and variety more????

**Math**

Simplify the sum 4 5 ______ + ______ M+9 M^2 - 81

**Math**

3^x=10. Solve for x algebraically.

**math**

14.88

**pope**

Which of the following will help you produce clear and focused writing? A. Brainstorming before writing. B. A rubric that provides criteria. C. A solid thesis statement. D. The style of your paper.

**English**

Can someone check these sentences, please? Thank you. 1) Hi! I’m Mr Radcliffe. Today I would like to tell you about an unpleasant story which happened to me last Friday . 2) It was a beautiful day so I decided to invite our friends, Mr and Mrs Ghandon, to have dinner at o...

**Maths**

Let 3^a be the highest power of 3 that divides 1000! . What is a ?

**math**

arrange in descending order: 4/5, 6/20, 8/24 and 5/8.

**Algebra**

Consider all quadruples of real numbers (x_1,x_2,x_3,x_4), such that x_1\leq x_2 \leq x_3 \leq x_4 and each of the four numbers plus the product of the other three equals 130. If S is the sum of all possible values of x_4, what is S, rounded to the nearest integer?

**Algebra**

3 real numbers that form a geometric progression have sum equal to 175 and product equal to 17576. What is the sum of the largest and smallest numbers?

**English**

Can someone check of this email is grammatically correct? Thank you. How are things? 1) I’ve been on holiday in England and I’ve been attending an English summer course for two weeks. 2) I’ve met an interesting girl from London, Mary, at a party organized by the...

**Finance**

A firm's target capital structure consists of 40 percent debt, 5 percent preferred stock, and 55 percent common equity. The firm’s cost of debt is 10%, the cost of preferred stock is 11.26%, and the cost of equity is 14 %. What is the firm's weighted average cost ...

**College Algebra**

a box with an open top is constructed from a rectangular piece of cardboard with dimensions 14 inches by 18 inches by cutting out and discarding equal squares of side x at each corner and then folding up the sides as in the figure. The cost to create such a box is 2.50 per squ...

**Statistics**

0.833 grams per mm

**UMD**

A new car that is a gas- and electric-powered hybrid has recently hit the market. The distance traveled on one gallon of fuel follows an exponential distributed with a mean of 63 miles. One car is selected at random and is driven on one gallon of gas. What is the probability

**Plz help math**

n/(n-3)(n-2)

**Chemistry**

Thank you so much Dr.Bob222. You have my eternal gratitude.

**Chemistry**

Solid Na2SO4 is added to a solution which is 0.020 M in Pb(NO3)2 and 0.045 M in AgNO3. Assume the volume remains constant. Ksp = 2.0 10-8 for PbSO4 and Ksp = 1.2 10-5 for Ag2SO4. What is the concentration of the first ion precipitated when the second ion starts to precipitate?

**physics**

The effective value of g is inversely proportional to the SQUARE of the distance from the center of the earth. The radius of the Earth is 6378 km. At 5100 km altitude, you are 11,478 km from the center. g will lowered by a factor (6378/11478)^2 Credit to "drwl"

**physics**

Isn't "g" constantly -9.8 m/s/s, regardless of height?

**Math**

What do you mean by median? Do you mean average?

**Algebra**

Distribute the 0.03, 0.17y+0.03y+270=870 0.17y+0.03y = 600 0.20y=600 y= 3000

**English**

Could you please check the grammar in the following sentences? Thank you very much in advance. 1.I had just turned off the light to go to sleep and I was dozing off when I felt/experienced the greatest fear in my life 2.He had tried to get in touch with Sam when he arrived in ...

**Algebra**

What is the sum of all the possible values of a for which 25x^2 + (a-15)x + 9 has exactly one distinct real root?

**Algebra**

How many distinct prime factors does 100100 have?

**english**

what is girl in this sentence Sarah is a very smart young girl with a bright future. Is it a predicate nominative

**english**

The lake is finally smooth tonight after everyone rode jet skis and boats. is smooth the predicate adjective

**english**

what is girl in this sentence Sarah is a very smart young girl with a bright future.

**english**

what is smooth in this sentence The lake is finally smooth tonight after everyone rode jet skis and boats.

**english**

Is mommy the indirect object The girls baked mommy some brownies for Mothers day.

**english**

Is this a complete sentence or a fragment...... Smite a scorner, and the simple will beware.

**english**

Is this a question Smite a scorner, and the simple will beware.

**Calc**

could i get this step by step pls lim (20x + 400)/(x) as x->∞

**Physics**

A mass spectrometer is used to examine the isotopes of uranium. Ions emerge from the velocity selector at a speed of 3.00 x 10^5 m/s and enter a uniform magnetic field of 0.600 T directed perpendicularly to the velocity of the ions. What is the distance between the impact poin...

**Calculus**

A magic tank starts out 4 inches in length, 4 inches wide, and 12 inches deep. As the tank is filled, it magically expands proportionally keeping it rectangular form just big enough to hold the liquid. If the liquid is being pumped into the tank at 8 cubic inches per minute, w...

**Physics**

Every once in a while a bird will get hit by a baseball during a baseball game. The longest home runs in baseball land about 500 feet (which is 152.4 meters) from home plate. If these balls leave the bat at a 45 degree angle to maximize their distance, what is the minimum safe...

**Physics**

You are holding onto a 100 kg basket of fish hanging over the side of a boat. What is the minimum force in Newtons you need to exert to keep the basket from falling back down into the ocean?

**Calculus**

A train driver is driving along and he suddenly puts on the brakes. After he holds the brakes for t seconds, the train's sliding distance can be measured as d(t) = 30t - 0.6t^2 (in meters). When the train stops, how far did the train slide (in meters) after the train drive...

**Calculus**

Given f(x) = \frac{x^3-2x+5}{x+4} and f’(3) = \frac{a}{b}, where a and b are coprime positive integers, what is the value of a+b?

**Geometry**

7 points are placed in a regular hexagon with side length 20. Let m denote the distance between the two closest points. What is the maximum possible value of m?

**Geometry**

In distinct odd-town, the inhabitants want to number their houses with 3-digit positive integers that are odd, which have all distinct digits. What is the maximum number of houses in odd-town?

**Algebra**

In a certain positive fraction \frac{a}{b} , the numerator is 2 less than the denominator. If the numerator and denominator are interchanged, the fraction is increased by 1 \frac{1}{15} . Find a + b .

**Algebra**

How many distinct prime factors does 100100 have?

**Calculus**

Given f(x) = x^4 + 6x^3 - 15x + 7, evaluate \displaystyle \lim_{h \to 0} \frac{f(1+h) - f(1-h)}{h}.

**Calculus**

a and b are integers that satisfy: \displaystyle \lim_{x \to 1} \frac{x-1}{x^2-ax+b} = -\frac{1}{3}. What is the value of a+b?

**Physics**

You launch a model rocket up into the sky. Right after launch the rocket is accelerating upwards at 10~m/s^2. What is the magnitude of the net force in Newtons on the rocket if the rocket has a mass of 0.1 kg?

**Algebra**

Joe picks 2 distinct numbers from the set of the first 14 positive integers S = \{1,2,3,\ldots,14\}. The probability that the sum of the 2 numbers is divisible by 3 can be expressed as \frac{a}{b}, where a and b are coprime positive integers. What is the value of a+b?

**Trigonometry**

ABC is a non-degenerate triangle such that 2\sin \angle B \cdot \cos \angle C + \sin \angle C = \sin \angle A + \sin \angle B, what is the value of \lfloor 100 \frac {AC}{AB} \rfloor ?

**Algebra**

If f(x) = 2x + 5 and g(x) = 8-3x^2, what is the value of f(g(4)) - g(f(4))?

**Algebra**

How many ordered pairs of solutions (a, b) are there to \frac{a}{b} - \frac{b}{a} - \frac{2}{a} - \frac{2}{b} = 0, where a and b are integers from -100 \leq a,b \leq 100?

**Algebra**

What is the sum of all the possible values of a for which 25x^2 + (a-15)x + 9 has exactly one distinct real root?

**Algebra**

Consider all three-digit numbers that are greater than the sum of the squares of their digits by exactly 543. What are the last three digits of the sum of these numbers?

**Algebra**

Find the largest possible real value of \sqrt{(x-20)(y-x)} + \sqrt{(140-y)(20-x)} + \sqrt{(x-y)(y-140)} subject to -40\leq x \leq 100 and -20\leq y \leq 200.

**Algebra**

Let \phi(n) be the Euler Phi Function. If 1 \leq n \leq 1000, what is the smallest integer value of n that minimizes \frac{\phi(n)}{n}?

**Algebra**

Suppose f(x) and g(x) are non-zero polynomials with real coefficients, such that f(g(x))=f(x)\cdot g(x). If g(2)=37, what is g(3)?

**Algebra**

Given the system of equations \begin{cases} x(x+y) &=& 9 \\ y(x+y) &=& 16 \end{cases} the value of xy can be written as \frac{a}{b} where a and b are positive coprime integers. Find a+b.

**Geometry**

Let S = \{ 1, 2, 3, \ldots 12\} and T_1, T_2, \ldots T_a be subsets of S such that T_i \not \subset T_j \, \forall i \neq j . What is the maximum possible value of a?

**Geometry**

Determine the largest positive integer N, such that given any N-gon (not necessarily convex), there exists a line (infinitely extended in both directions) that contains exactly 1 edge of the N-gon. The figure in blue is an example of a 20-gon that doesn't satisfy the condi...

**Geometry**

Six standard six-sided die are rolled. Let p be the probability that the dice can be arranged in a row such that for 1\leq k \leq 6 the sum of the first k dice is not a multiple of 3. Then p can be expressed as \frac{a}{b} where a and b are coprime positive integers. What is t...

**Math**

72 strips of wood. 8 divide 4 equal 2, and it 1 inch wide. so 36 wide. so there 36 times 2 which is 72

**Physic**

An aluminum ring of radius 5.00 cm and resistance 2.00 10-4 Ω is placed around the top of a long air-core solenoid with 997 turns per meter and a smaller radius of 3.00 cm, as in the figure below. If the current in the solenoid is increasing at a constant rate of 267 A/s,...

**Physic**

A pickup truck has a width of 78.9 in. If it is traveling north at 36 m/s through a magnetic field with vertical component of 33 µT, what magnitude emf is induced between the driver and passenger sides of the truck?

**Math**

you multiply each number by three and it will be your denominator

**science**

cell membrane

**English**

I urgently need to prepare these sentences for tomorrow. Could you please have a look at them? 1.If they told me to clean my room, I would. 2.You’d better take the keys in case I might still be out when you come back. 3. Would all this have happened if he hadn’t acte...

**physics**

A string under a tension of 43.0 N is used to whirl a rock in a horizontal circle of radius 2.45 m at a speed of 20.9 m/s on a frictionless surface as shown in the figure below. As the string is pulled in, the speed of the rock increases. When the string is 1.00 m long and the...

**Government**

In which type of colony did strict governors anger the colonists? A. the royal colonies B. the proprietary colonies C. the charter colonies D. the informed colonies

**SCIENCE **

when a diorite partially melts, which element(1)............ decreases in the melt as a(2).......... magma forms. I have few options to choose from a)iron b)andesite c)rhyolite d)potassium f)basalt No one has

**maths**

Find the largest possible value of sqrt[(x-20)(y-x)] + sqrt[(140-y)(20-x)] + sqrt[(x-y)(y-140)] if -40<=x<=100 and -20<=y<=200

**Probability**

The probability that it will take 5 or more flips of a fair coin before it lands on heads can be written as a/b , where a and b are coprime positive integers. Find a+b

**Chemistry**

I was given extra credit to find who Le Châtelier's High School Principal was. Not his PrincipLE, but his PrincipAL. My chemistry teacher told us only one student of his out of all these years came with the answer. Think outside of the box. Thanks.

**SCIENCE**

when a diorite partially melts, which element(1)............ decreases in the melt as a(2).......... magma forms. I have few options to choose from a)iron b)andesite c)rhyolite d)potassium f)basalt

**Math**

the median was 142 I forgot a number 142 is also on my list. thank you so much for your help

**Math **

Dr. Jane I came up with this: 127,128,129,139,139,139,141,143,144,145,146,147,148,152 Does this seem to work?

**math**

make up a set of 15 numbers with the following landmarks: maximum: 152 Range: 25 Mode: 139 Median: 142

**Geometry**

What is the minimum distance between any point on the circle x^2 + y^2 = 25 and the line y = -\frac{3}{4}x + \frac{75}{4} ?

**Geometry**

In the 2001 population census, information was collected about the number of people in each household, which is denoted by X. It is given that P(X=1) = 0.25, P(X=2) = 0.32, P(X=3) = 0.18, P(X=4) = 0.15, P(X=5) = 0.07, P(X=6) = 0.02 and P(X\geq 7) = 0.01. If R is the probabilit...

**Geometry**

Martin's iPod has 24 songs on it. He wants to make a playlist consisting of three songs to dance to. Let N be the number of different playlists Martin can make. What are the last 3 digits of N?

**Calculus**

Evaluate \displaystyle \int_1^{10} \left(\sqrt{x} + 1\right)^3 dx - \int_1^{10} \left(\sqrt{x} - 1\right)^3 dx .

**Trigonometry**

If g(t) = 5t+1 and h(n) = 2(n - 7), what is the value of h(g(3))?

**Algebra**

Find the smallest positive integer N such that 13^N \equiv 1 \pmod{2013}.

**Physics**

You launch a model rocket up into the sky. Right after launch the rocket is accelerating upwards at 10~m/s^2. What is the magnitude of the net force in Newtons on the rocket if the rocket has a mass of 0.1 kg?

**Calulus**

Given \displaystyle \int_0^{\frac{3\pi}{2}} x^2\cos x \, dx = a - \frac{b\pi^2}{c}, where a, b and c are positive integers and b and c are coprime, what is the value of a + b + c?

**chemistry help !!!!!!!!!!!!!!!!**

a)A N6+ ion in its ground state absorbs an X-ray photon of energy 2.0000 keV. Explain what happens to the ion and why. b)Explain why the nitrogen ion N6+ is a hydrogen-like ion. Assuming the ion is for the major stable isotope 14N, state which sub-atomic particles it contains ...

**SCIENCE**

when a diorite partially melts, which element(1)............ decreases in the melt as a(2).......... magma forms. I have few options to choose from a)iron b)andesite c)rhyolite d)potassium f)basalt

**Geometry**

Given a 100 by 100 square grid, what is the most number of 1 by 51 rectangles that we can cut out of it?

**Geometry**

ABCDE is a regular pentagon. FAD is an equilateral triangle, such that points F and E are on the same side of line AD. What is the measure (in degrees) of \angle FAB?

**Geometry**

How many perfect squares less than 1000 end with the digit 6?

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