Saturday

September 20, 2014

September 20, 2014

Total # Posts: 1,090

**Mechanics**

Typically, a tennis ball hit during a serve travels away at about 51 m/s. If the ball is at rest mid-air when struck, and it has a mass of 0.058 kg, what is the change in its momentum on leaving the racket? Show the solution and answer.
*September 19, 2013*

**Mechanics**

A 1000-kg car whose motor delivers a maximum power of 40.0 hp to its wheel can maintain a steady speed of 130 km/h on a horizontal roadway. How large is the friction force that impedes its motion at this speed? Show the solution and answer
*September 15, 2013*

**algebra b**

the cumulative number of car accidents from 2000-2010 can be modeled by the quadratic expression, C=-33x^2+792x+8,877, where x=1corresponds to 2000, x=2 corresponds to 2001, and so on untill x=11 corresponds to 2010 a)find the number of cumulative car accidents in 2005? b)use ...
*September 14, 2013*

**algebra b**

the height h in feet of a ball after t seconds is given by h=176t-16t^2. how long did it take to hit the ground
*September 14, 2013*

**algebra b**

I'm sorry sue the area is 84 square feet
*September 14, 2013*

**algebra b**

the length of a rectangular banner is 5 feet longer than the width. If the width is 84 square feet, find the dimensions
*September 14, 2013*

**Mechanics**

a driver of a 1200-kg car notices that the car slows from 20 m/s to 15 m/s as it coasts a distance of 130 m along level ground. How large a force opposes the motion? Show the solution
*September 14, 2013*

**Physics**

An AC voltage with 169 peak volts is applied across a 506 ohm resistor. To the nearest tenth of a watt, what is the average power?
*September 4, 2013*

**physics**

You are on an archaeological dig and discover a strange artifact. It is a utensil that appears to be carved out of an elephant's tusk You analyze it and discover that it has 0.625 the amount of carbon-14 you would find in a living specimen. 1.How many half-lives has the ...
*August 15, 2013*

**math**

13/28 x 100% =46.4%(corr. to 3 sig. fig.) (we usually correct to 3 significant figure if we see long decimals)
*August 14, 2013*

**Math**

I assume you and your friends share the pizza equally and no other people are going to share the pizza. Each one will get = 3 1/8 divided by 5 = 5/8
*August 14, 2013*

**physics**

Charge A has a charge of +2C. Charge B has a charge of -3C and is located 1 meter to the right of A. Charge C is located 1 meter to the right of Charge B and has a charge of -1C. If a fourth charge (Charge D) is placed 4 meters to the right of Charge B, how much charge must it...
*August 8, 2013*

**Introduction to Physical Science**

When a cannon with a longer barrel is fired, the force of expanding gases acts on the cannonball for a longer distance. What effect does this have on the velocity of the emerging cannonball? (Do you see why long-range cannons have such long barrels?)
*August 4, 2013*

**physics**

An iorn rod (a=11.8 x 10^-6 C^-1) has a length of 1000 meters(or 1 km) at 0 degrees Celsius. If the rod must expand 10 cm to bridge a gap, to what temperature must the rod be heated?
*August 1, 2013*

**Physics**

An iorn rod (a=11.8 x 10^-6C^-1) has a length of 1000 meters(or 1 km) at 0 degrees Celsius. If the rod must expand 10 cm to bridge a gap, to what temperature must the rod be heated?
*July 31, 2013*

**Physics**

thanks simon76 :)
*July 27, 2013*

**Physics**

Anyone have any idea for q2_2_1 Q2_2_3 Q2_2_5 Appreciate your help. Thanks :)
*July 27, 2013*

**Physics**

2_1_3 is wrong
*July 27, 2013*

**Physics**

Q2_2_5 is incorrect
*July 27, 2013*

**Physics**

A boat is constructed in the shape of a rectangular cube. The base of the boat is 2m by 3m and the side of the boat is 2m high. The boat has a total mass of 4500kg. Hint-The density of the water is 1000kg/m^3. a. What is the buoyant force on the boat? Explain answer. b. ...
*July 25, 2013*

**Physics**

A ball is rolled off a table that is 0.481 m above the floor. The ball is rolling with a velocity if 1.8 m/s as it goes off the edge of the table. At the exact instant the first ball rolls off the table a second ball is dropped from the same height. A.) How long does it take ...
*July 22, 2013*

**physics**

an automobile is travelling towards you at a speed 25.0m/s. When you measure the frequency of its horn, you obtain a value of 26Hz. If the actual frequency of the horn is known to be 240Hz, calculate speed of sound in air? answer is 325m/s
*July 17, 2013*

**Physics**

The femur of a human leg (mass 10 kg, length 0.9 m) is in traction, as shown in the figure below. The center of gravity of the leg is one-third of the distance from the pelvis to the bottom of the foot. Two objects, with masses m1 and m2, are hung using pulleys to provide ...
*July 15, 2013*

**Physics**

49, 24
*July 14, 2013*

**physics**

If a cyclist traveling at 14.0m/s skids to a stop in 5.60 s, determine the skidding distance assume uniform acceleration? Answer is 39.2m
*July 3, 2013*

**physics**

Approaching a flashing pedestrian activated traffic light, a driver must slow down to a speed of 30km/h. If the cross walk is 150m away and the vehicle's initial speed us 59km/h, what must be the magnitude of the car's acceleration to reach the speed limit? Answer is 0...
*July 3, 2013*

**chemistry**

the heat of vaporization for water is 540 cal/g. how many kilocalories are needed to change 22g of liquid water to steam at 100*c?
*June 18, 2013*

**Chemistry**

Nope that's how they are given. That's why I was having trouble with them.
*June 11, 2013*

**Chemistry**

calculate the rate constant at 225C for a reaction that has a rate constant of 8.1X10^-4 at 95c and an activation enegry of 93.0 kj/mol
*June 8, 2013*

**Chemistry**

1. The following data was collected for the reaction between hydrogen and nitrogen monoxide. The time recorded corresponds to a N2 concentration change of 5.3 x 10-4 M. 2H2(g) + 2NO(g) 2H2O(g) + N2(g) Trial [H2], M [NO], M Time, s 1 0.01 0.02 74 2 0.02 0.02 37 3 0.01 ...
*June 4, 2013*

**Chemistry**

I just wanted to see if my answers made sense. 1. What effect would each of the following have on your calculated value of Kf (too high, too low, or no effect)? In each case explain your answer. a) There was a small bubble in the thermometer, causing all the temperature ...
*June 2, 2013*

**Engineering**

Q1_1_2. My answer is -4*rho*A*g*L
*May 23, 2013*

**statistics**

well i guess you cannot stop cheating only but one should not ignore those who are studying hard with just one aim to learn so its ok this world is full of cheaters or copycats no originality no creativity but you should also keep in mind that still there are some good ...
*May 18, 2013*

**Calculus**

if the surface area of a sphere is given by the formula SA=4pir^2, find the rate of increase of the surface area if the radius is 4 cm and is increasing at the rate of 0.5 cm/min.
*May 5, 2013*

**Calculus I**

find the antiderivative of f(x)=(x^2)/(x^3+5) with explanation
*May 5, 2013*

**Math**

Reiny was close, I would adjust the possible combination to 10^4 = 10,000 So 36/10,000 = 9/2,500
*May 1, 2013*

**math**

Jim draws a sketch of his bedroom wall to scale. The actual wall is 10 feet long and 8 feet high. The drawing is one- sixth the length and width of the actual wall. What are the dimensions of the drawing in inches?
*May 1, 2013*

**Literature ?! Check my answers?**

Yep you are right Alyssa! CCB! THANKS
*April 17, 2013*

**math**

l&k are two lines given by the following equations l: 3x-5y+4=0 k:5x+3y+2=0 could anyone please help
*April 13, 2013*

**Business Statistics**

That does not help at all.
*April 7, 2013*

**Business Statistics**

Suppose that in the past, 94% of all Hispanic grocery shoppers were women. Perhaps due to changing cultural values, we believe that more Hispanic men are now grocery shopping. We randomly sample 689 Hispanic grocery shoppers from around the United States and 606 are women. ...
*April 7, 2013*

**Trigonometry**

Every point (x,y) on the curve y = \log_{2}{3x} is transferred to a new point by the following translation (x',y') =(x+m,y+n), where m and n are integers. The set of (x',y') form the curve y = \log_{2}{(12x-96)} . What is the value of m + n ?
*March 27, 2013*

**Trigonometry**

Given \tan \theta = -\frac{4}{3}, where \frac{\pi}{2} < \theta < \pi, what is the value of \frac{1}{\sin \theta + \cos \theta}?
*March 27, 2013*

**Geometry**

The vertices of a regular 10-gon are labeled V_1, V_2, \ldots V_n, which is a permutation of \{ 1, 2, \ldots, 10\}. Define a neighboring sum to be the sum of 3 consecutive vertices V_i, V_{i+1} and V_{i+2} [where V_{11}=V_1, V_{12}=V_2]. For each permutation \sigma, let N_\...
*March 27, 2013*

**Geometry**

ABCD is a trapezoid with AB < CD and AB parallel to CD. \Gamma is a circle inscribed in ABCD, such that \Gamma is tangent to all four sides. If AD = BC = 25 and the area of ABCD is 600, what is the radius of \Gamma?
*March 27, 2013*

**Geometry**

Two points are chosen uniformly at random on the unit circle and joined to make a chord C_1. This process is repeated 3 more times to get chords C_2, C_3, C_4. The probability that no pair of chords intersect can be expressed as \frac{a}{b} where a and b are coprime positive ...
*March 26, 2013*

**Geometry**

Two points are chosen uniformly at random on the unit circle and joined to make a chord C_1. This process is repeated 3 more times to get chords C_2, C_3, C_4. The probability that no pair of chords intersect can be expressed as \frac{a}{b} where a and b are coprime positive ...
*March 26, 2013*

**Geometry**

When writing a math expression, any time there is an open bracket "(", it is eventually followed by a closed bracket ")". When we have a complicated expression, there may be several brackets nested amongst each other, such as in the expression (x+1)*((x-2...
*March 26, 2013*

**Science**

Please help me with matching the stages of the meiosis to its proper description. Sentences: 1. Members of each homologous pair separate from each other (chromatids) still remain together). 2. Homologous chromosomes pair up with each other and chromosomes 'cross over' ...
*March 25, 2013*

**geochemistry**

@DrBob222: I know how to do redox problems. It's just that this problem has a specific answer with the coefficients being 5,4=>2,4,1,3. Where no protons remain in the final answer
*March 14, 2013*

**geochemistry**

Been trying to balance this equation for a while, but can't get the right answer. any help would be apperciated! CH2O (aq) + NO3 - ---> N2 + HCO3 - + CO2(g)
*March 14, 2013*

**Math problem solving**

in 5 years time i will be 3 times as old as my son. in 14 years time, the sum of our ages will be 62. find the sum of our ages today
*March 7, 2013*

**compound interest**

1. If you were to place $15,000 in the bank at 3% interest, how much would you have in the bank after one year if the interest were compounded quarterly?
*March 7, 2013*

**Fiance**

Use your knowledge of income statements to fill in the missing items: Sales Cost of goods sold $575,000 Gross profit $1,600,000 General and administrative expense $200,000 Selling and marketing expense $ Depreciation $50,000 Operating income $ Interest $100,000 Income before ...
*March 3, 2013*

**Finance**

Use the “balance sheet equation” to determine owners’ equity if liabilities are $5 million and assets are $10 million. Assets = Liabilities + Owners’ equity
*March 2, 2013*

**math**

the factor of part b. would end up being 3x^2(23-3pi). because you would have to bring down the area of part a. which would be 69x^2 with the 9pix^2 not 84, therefore, giving the factored solution of 3x^2(23-3pi). 3 is the gcf because 69 cannot and 9 cannot be multiplyed to ...
*March 1, 2013*

**Statistics**

Really, you will go to this length to cheat? This is a part of an online exam, please do not answer
*March 1, 2013*

**StatIstics**

The answer is....Do your homework and stop cheating, this is a part of an online exam, please do not answer
*March 1, 2013*

**Physics**

A block weighing 5.7 N requires a force of 2 N to push it along at constant velocity. What is the coefficient of friction for the surface?
*February 19, 2013*

**Entropy question**

What is the absolute entropy of 2.5 mol of gaseous methane at 1.3 bar and 298 K?
*February 10, 2013*

**Science**

If the adverage weight of a human body is 75kg and given the mass of the earth is 5976 x 10^21kg, how many people will it take to exceed the weight of the earth? At the present growth of 1.14%, when will the present population of 6.8 x 10^9 grow to that number?
*February 6, 2013*

**physical science**

In terms of energy, the general chemical equation AB+CD+energy = AD+CB represents a (an)_________ reaction.
*January 29, 2013*

**English**

What elements of the Restoration comedy are seen in The Importance of Being Earnest?
*January 22, 2013*

**Penn Foster**

im sorry ive been trying to find the answer for this but its deff. not A i just got it wrong.
*January 22, 2013*

**U Hart**

The 50 kg cylinder shown, which was initially at rest, rolls without slipping. when the speed of A is 20 cm\s, the speed of point B is most nearly
*January 14, 2013*

**chemistry**

Use the reaction shown to calculate the mass of iron that must be used to obtain 0.500 L of hydrogen at STP: 3Fe(s) + 4H2O(l) pr029-1.jpg Fe3O4(s) + 4H2(g
*January 13, 2013*

**Principles of Finance**

Determine the size of the M1 money supply using the following information. Currency $700 billion Money market mutual funds $2,000 billion Demand deposits $300 billion Other checkable deposits $300 billion Traveler’s checks $10 billion
*January 13, 2013*

**physics**

A van traveling down a slope with a uniform acceleration of 2.15 meters/second2 attains a speed of 20.00 meters/second after 7.00 seconds. What is the initial velocity of the van?
*December 18, 2012*

**Trig**

15^(-x-3)=-17^(-3x) using a log base 10
*December 12, 2012*

**John**

Is the following simple, compound, comples, or compound complex sentences? The shopping mall has a store that sells nothing but clocks. The governor chose the best people whom we could find for the committee; Mr. Dobbs was appointed committee chairman.
*December 11, 2012*

**physics**

An attack helicopter is equipped with a 20- mm cannon that fires 105 g shells in the forward direction with a muzzle speed of 669 m/s. The fully loaded helicopter has a mass of 4260 kg. A burst of 133 shells is fired in a 5.41s interval. What is the resulting average force on ...
*December 10, 2012*

**Physics**

A(n) 20.5 g bullet is shot into a(n) 6254 g wooden block standing on a frictionless surface.The block, with the bullet in it, acquires a speed of 1.64 m/s. Calculate the speed of the bullet before striking the block. Thank you
*December 10, 2012*

**Physics**

A(n) 20.5 g bullet is shot into a(n) 6254 g wooden block standing on a frictionless surface.The block, with the bullet in it, acquires a speed of 1.64 m/s. Calculate the speed of the bullet before striking the block. Thank you
*December 10, 2012*

**Physics**

A(n) 20.5 g bullet is shot into a(n) 6254 g wooden block standing on a frictionless surface.The block, with the bullet in it, acquires a speed of 1.64 m/s. Calculate the speed of the bullet before striking the block. Thank you
*December 10, 2012*

**Physics**

Before the force is applied (t < 0 on the graph), the particle moves along the X axis with velocity V1 = -6.6 m/s. Find the velocity V2 of the particle after force stops acting on it. (t > 9s)
*December 10, 2012*

**Chemistry**

How many moles of Br2 are present in 500mL of vapor when Br2(l) and Br2(g) are in equilibrium at 33 degrees celcius? (Pvap Br2 at 33C = 299 mm Hg)
*December 7, 2012*

**calculus**

find the limit u-> sqr(u^4 + 3u+ 6)
*December 3, 2012*

**Chem**

A And B are my main problems
*December 3, 2012*

**Chem**

Methane and Hydrogen Sulfide react at 960 degree Celsius and come to the following equilibrium CH4(g)+2H2S(g) <-> CS2(g)+ 4H2(g) At Equilibrium the concentration measured as [Ch4]= 5.56M [H2s]= 11.12 [CS2]= 2.44M [H2] 1.76, A) Write the equilibrium constant expression ...
*December 3, 2012*

**College Algebra**

log(xy^12)
*December 1, 2012*

**math**

Solve the equtions b = 1.2g and b= 2(g-50) to get 150 boys.
*November 30, 2012*

**Calculus**

It took me your trig substitution followed by a u substitution to get 93squrt(x^2+9)/9x+C
*November 30, 2012*

**QBASIC, Computers question 2 **

Why do I keep getting a Type Mismatch error on this line? Also, when i click "View" to view my output screen its blank, so nothing is printing.... can so please help me resolve this? PRINT USING D$; NAM$; VehicleType$; DaysHeld; Miles; Charge My Code: '...
*November 29, 2012*

**QBASIC, Computers**

Yes, It doesnt print anything to the output screen and I get a syntax error on the READ line.... READ EmployeeNam(N), Salary(N)
*November 29, 2012*

**QBASIC, Computers**

The following is a list of salaries of the six employees in a certain company: Name Salary T. Angel $43,000 F. Smith $31,000 K. Johnston $22,000 P. Miner $18,000 C. Altman $27,000 A. Lu $19,000 Read a single dimension array for name and another array for Salary. Calculate and ...
*November 29, 2012*

**stats**

what is the distinction between repeated measurements and matched items?
*November 27, 2012*

**physics**

What is the speed of sound in a medium where a 100-kHz frequency produces a 5.96-cm wavelength?
*November 27, 2012*

**physics**

What is the sound intensity level in decibels of ultrasound of intensity 10^5 W/m2, used to pulverize tissue during surgery
*November 27, 2012*

**physics**

What sound intensity level in dB is produced by earphones that create an intensity of 4.00¡¿10^-2 W/m^2?
*November 27, 2012*

**physics**

What is the intensity in watts per meter squared of 85.0 db sound?
*November 27, 2012*

**Social studies**

what was the formal name for our country?
*November 27, 2012*

**physics**

The pendulum on a cuckoo clock is 5.00 cm long. (a) Determine the period of this pendulum. (b) What is its frequency?
*November 20, 2012*

**physics**

What mass on a spring with a spring constant of 120 N/m will oscillate with a period of 1.0 s?
*November 20, 2012*

**physics**

A force of 85 N is required to compress the spring by 0.0200 m. How much force is needed to compress the spring by 0.0600 N? 3.
*November 20, 2012*

**physics**

A 4.5-kg block is hung from a spring causing the spring to elongate 12 cm. With what period will the spring oscillate if the spring was stretched 15 cm and released?
*November 20, 2012*

**Science**

What is the Frosted Eflin's role in the food chain?
*November 18, 2012*

**science**

A bullet with a mass of 7.11 g and a speed of 774 m/s penetrates a tree horizontally to a depth of 1.85 cm. Assume that a constant frictional force stops the bullet. Calculate the magnitude of this frictional force. Try energy considerations. Answer in units of N
*November 16, 2012*

**science**

An outfielder throws a 1.88 kg baseball at a speed of 57 m/s and an initial angle of 10.2. What is the kinetic energy of the ball at the highest point of its motion? Answer in units of J
*November 16, 2012*

**science**

It takes 3.38 J of work to stretch a Hooke’s-law spring 5.63 cm from its unstressed length. How much the extra work is required to stretch it an additional 4.22 cm? Answer in units of J
*November 16, 2012*

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