Wednesday

February 10, 2016
Total # Posts: 1,020

**physics**

Consider the window (of area 0.68 m2) of an airplane. If the pressure inside the plane is atmospheric pressure, while the pressure outside is 31 % of Patm, find the force on the window. Ignore the velocity of the airplane (i.e., ignore Bernoulli’s effect).
*October 28, 2011*

**Physics**

If the pressure outside a window drops by 9.1%, while the pressure inside does not change, what is the force on the window? Assume that the area of the window is 2.3 m2.
*October 28, 2011*

**Physics**

Correction h + (d^2)/4h
*October 17, 2011*

**Physics**

h + (d^2)/h
*October 17, 2011*

**ALGEBRA-Help please**

Find the solution to the following system of two linear equations, if it has a solution. x+3y=4, 3x+9y=12
*October 13, 2011*

**Math**

I dont think I follow....
*October 13, 2011*

**Math**

1) Find the solution to the following system of two linear equations, if it has a solution. 2x-y=3, -x+y=1 2Find the solution to the following system of two linear equations, if it has a solution. 2x+y=4, x+3/2y=3
*October 13, 2011*

**math**

When is an exact number needed and when is an estimate okay?
*October 10, 2011*

**World History**

Everybody is saying the answer is Traditional Brahman elites,but that is so wrong. I ahve my history book here in front of me, and it says the answer is The Buddhist clergy .
*October 10, 2011*

**physics**

A military gun is mounted on a railroad car (m = 1590 kg) as shown in Figure P7.34. There is no frictional force on the car, the track is horizontal, and the car is initially at rest. The gun then fires a shell of mass 26 kg with a velocity of 280 m/s at an angle of 28° ...
*October 2, 2011*

**physics**

How long does it take an automobile traveling 62.0 km/h to become even with a car that is traveling in another lane at 37.5 km/h if the cars' front bumpers are initially 138 m apart? in seconds
*September 29, 2011*

**Calculus**

Let A be the region bounded by the curves y = x^2-6x + 8 and y = 0. Find the volume obtained when A is revolved around the Y-AXIS
*September 26, 2011*

**Calculus**

Let A be the region bounded by the curves y = x^2-6x + 8 and y = 0. Find the volume obtained when A is revolved around the Y-AXIS
*September 26, 2011*

**Science**

Why does a toy car go faster and further when it is added weight onto it and is put on a ramp at 45 degrees?
*September 25, 2011*

**biology**

Lack of iron in the photic zone of the open ocean restricts the size of plankton populations. Iron is what kind of factor for marine plankton?
*September 22, 2011*

**Math word problem**

A carpenter wants to put four shelves on an 8-foot wall so that the five spaces created decrease by 6 inches as we move up the wall. If the thickness of each shelf is 3/4 inch, how far will the bottom shelf be from the floor?
*September 21, 2011*

**chemistry**

An unknown rectangular substance measures 3.6 cm high, 4.21 cm long, and 1.17 cm wide. If the mass is 21.3g, what is this substance’s density?
*September 16, 2011*

**Biochemistry**

What is the pH after 5 mL of 0.1M NaOH has been added to 25 mL of 0.2M acetic acid?
*September 8, 2011*

**math**

Brandon’s rentals charges $ 25 per hour to rent a Windsufer and a wet suit. Wendy’s charges $20 per hour plus $15 extra for a wet suit. Find the number of hours for which the total charges for both would be the same.
*September 8, 2011*

**science**

The radius of the Iron atom is 124 pm. How many of these will span a distance of 50.5 m..
*September 5, 2011*

**math**

a person can copy the final exam in 28 minutes using a new copy machine. using an old copy machine, it takes 70 minutes. if both machines are used, how long will it take to complete the job
*August 2, 2011*

**Physics-Need Help fast!**

Two converging lenses, each of focal length 15.1 cm, are placed 40.2 cm apart, and an object is placed 30.0 cm in front of the first lens. Where is the final image formed? The image is located... What is the magnification of the system? M =
*August 1, 2011*

**Physics-Need Help fast!**

Part 1 A 3m long pipe is in a room where the temperature is 20 degrees C. What is the frequency of the first harmonic if the pipe is closed at one end? Part 2 sound traveling in air at 23 degrees C enters a cold front where the air temp is 2 degrees C. If the sound frequency ...
*July 27, 2011*

**Math**

Find a polynomial of minimum degree with zeros -3, -2 and 1 (of multiplicity 2)
*July 16, 2011*

**Math**

Given the function f(x) = 7 - 6x, evaluate f(x+h)-f(x)/h
*July 16, 2011*

**Math Calculus**

Reiny, Before you do equals to zero, how did you get 0.04x^3 + 55x^2 - 1380 = 0? I set 0.04x + 55 - 1380/x^2 = 0 and I got x=-137.317, or x=-5.204,, or x=4.921 if i plus in to the originals i have to plus each x's? and the minimum average is the smallest number from the ...
*July 8, 2011*

**Math Calculus**

no i don't see any negative sign in my homework question... first I did C*bar(x)/x = 0.02x^3+55x^2+1380/(x) = 0.02x^2 + 55 x + 1380/x then I differentiate it C*bar*'(x) = 0.4x - 1380/x^2 +55 then I set it equal to zero which gives me x = -137.317 or x=-5.104 and 4.921 ...
*July 8, 2011*

**Math Calculus**

Let C(x) = 0.02x^3 + 55x^2 + 1380. Find the minimum average cost for this commodity. I got to the point where I got x=-1374.98, x=-5.018, x=5 but what do I have to do again after this? Because I am missing some steps after I find x. Do i have to plug all the X's to the ...
*July 8, 2011*

**Math Calculus**

sorry actually i got that part which is part a. What I need is part (b). Find the delta(v)
*July 8, 2011*

**Math Calculus**

Thank you soo muccchh
*July 8, 2011*

**Math Calculus**

A sphere is initially measured as having a radius of 4 inches. A subsequent measurement shows that the radius is really 3.99. Find (a) the actual difference in volume between the initial measurement and the correction, and (b) the difference as estimated through differentials...
*July 8, 2011*

**Math Calculus**

Thank you very much for your help :)
*July 8, 2011*

**calculus**

thank you very much
*July 8, 2011*

**calculus**

A rectangular aquarium is to be built with an open top (no material needed) and a square base. You have 60 square feet of material to build it with. (We are assuming that the sides and bottom are perfectly flat). What is the maximum volume that this aquarium might have? Note-...
*July 8, 2011*

**Internet- Virtual Communities**

I need help on explaining how cyber bullying relates to virtual communities for a paper that I need to write.
*July 6, 2011*

**chemistry**

what is an ionic compound that forms an acid-base neutralization reaction?
*July 5, 2011*

**science **

A patient presents with angina pectoris due to inadequate blood supply. Which diagnosis best describes this condition?
*July 4, 2011*

**alga br e**

How many ft of fencing is needed to enclose a square with 33ft sides
*July 3, 2011*

**Science **

A chemist is studying the following equilibrium: 2Pb(NO3)2 (s) ! 2PbO (s) + 4NO2 (g) + O2 (g) He starts out with 10 g of Pb(NO3)2 and, at equilibrium, has 2.02 g of PbO. The concentrations of NO2 and O2 at equilibrium are 0.25 M and 0.019 M, respectively. What is the value of ...
*June 30, 2011*

**Science **

Three acids solutions have the following pH: Solution A: pH = 2 Solution B: pH = 5 Solution C: pH = 3 Which solution is made with the acid that has the smallest ionization constant?
*June 30, 2011*

**Physics**

A 3 kg block is being pulled by a string at a constant speed on a surface with a coefficient of kinetic friction of 0.3. If the string is at an angle of 30 degrees with the horizontal, what is the magnitude of the force necessary to pull the block?
*June 30, 2011*

**math**

ohh that makes sence! thank you!!
*June 28, 2011*

**math**

-1/7 divided by -4
*June 28, 2011*

**math**

how to solve it
*June 28, 2011*

**math**

3+5x+(-3)
*June 28, 2011*

**accounting**

What kinds of problems could be created in a financial report is not reliable, relevant, consistent or comparable?
*June 27, 2011*

**Chemistry**

what is my percent yield if i had 1.46 grams of copper to start with and ended with 2. 47 grams of copper?
*June 14, 2011*

**calculus**

Sketch the region bounded by the curves y = x^2, y = x^4. 1) Find the area of the region enclosed by the two curves; 2) Find the volume of the solid obtained by rotating the above region about the x-axis; 3) Find the volume of the solid obtained by rotating the above region ...
*June 9, 2011*

**Managerial Economics**

Assume the only choice variable is total benefit function is B(x) = 170x-x², and cost function is C(x) = 100-10x + 2x². a. What are the marginal benefit and marginal cost functions? b. Set up the net benefit function and then determine the level x that maximises net ...
*May 25, 2011*

**Math**

t - (-4) = 18
*May 23, 2011*

**math**

What are five points in which the x-coordinate and the y-coordinate are opposites?
*May 22, 2011*

**Math**

Expand (2x+5y)^6
*May 12, 2011*

**Math**

The square root of 27b 11 squared ( square root 27^11)
*May 4, 2011*

**Algebra II**

(6x4 +4x3 - 2x2 +5) - (3x4 - 2x3 +x+4)
*April 13, 2011*

**Essay titles**

If you are writing an essay, and in the title of your essay, you have the title of a novel, does the title of the novel have to be italicized? For example, if you were writing an essay (MLA format)titled A New Perspective on The Scarlet Letter, would The Scarlet Letter need to...
*April 13, 2011*

**physics**

f a typical family of four uses electric energy at an average rate of 458 W, how many kWh would their electric bill be for one month? Answer in kW
*April 5, 2011*

**Math**

explain what the values of m and b in your equation tell about the relationship between number of containers to be recycled and attendance at the school event
*April 4, 2011*

**geometry**

A right circular cylinder has an altitude of 11 feet and a radius of 5 feet. What is the lateral area, in square feet, of the cylinder, to the nearest tenth?
*April 3, 2011*

**Human Growth and Development**

Sorry. I posted them and I don't know why it didn't show up but here they are again! #1. b #2. b Thank you!
*April 2, 2011*

**Math**

the height of a new home is going to be 74 feet. if the height of the home in a scale drawing is 9.25 inches, what is the scale used?
*March 31, 2011*

**Communications **

Explain the impact and use of jealousy in interpersonal relationships.
*March 30, 2011*

**Math**

The following data show the number of Chinese citizens who immigrated to the U.S. Use the data to predict how many Chinese immigrated to the U.S. during the 1990. Decade No. of Chinese Immigrants 1950s 10,000 1960s 35,000 1970s 124,000 1980s 389,000
*March 29, 2011*

**PHYSICS**

A nuclear reactor contains nuclei that fission when bombarded by slow neutrons. The fission reaction produces fast neutrons which need to be moderated (i.e. slowed down) in collisions before they can cause further fissions. In this problem we consider a reactor which uses ...
*March 28, 2011*

**Math**

A company contributes $170 per month into a retirement fund paying 4.20% compounded monthly and employees are permitted to invest up to $ 2,800 per year into another retirement fund which pays 4.20% compounded annually. How large can the combined retirement fund be worth in 29...
*March 28, 2011*

**chemistry**

What is the percent yield of the mass of water that will be produced when 5.0 grams of H2 is reacted with excess O2 if 40. g of water are actually recovered?
*March 27, 2011*

**chemistry**

how do you calculate the mass of water that will be produced when 5.0 grams of H2 is reacted with excess O2?
*March 27, 2011*

**Math**

A company contributes $170 per month into a retirement fund paying 4.20% compounded monthly and employees are permitted to invest up to $ 2,800 per year into another retirement fund which pays 4.20% compounded annually. How large can the combined retirement fund be worth in 29...
*March 27, 2011*

**Math**

How much did you invest at 9% compounded bi-weekly if 10 years later the investment is worth $54,000?
*March 26, 2011*

**6th grade math**

I am still stumped on this question... What should I divide 216 by?
*March 24, 2011*

**Money**

77 nickels 385 pennies No other possibilities with one type of coin
*March 23, 2011*

**Math**

i want to spend 62¢ by only using 4 coins which are 25¢, 10¢, 5¢, 1¢ what are 2 ways I can spend it?
*March 21, 2011*

**Physics please help!!**

Water is flowing in a straight horizontal pipe of variable cross section. Where the cross-sectional area of the pipe is 3.50·10-2 m2, the pressure is 5.30·105 Pa and the velocity is 0.310 m/s. In a constricted region where the area is 12.90·10-4 m2, what ...
*March 20, 2011*

**science**

If latitude were the only control of temperature, the isotherms would run straight across the maps from east to west. Describe one region of the world where this hypothetical isotherm pattern is actually observed and Why.
*March 19, 2011*

**Physics please help!!**

Suppose you pour water into a container until it reaches a depth of 30.2 cm. Next, you carefully pour in a 14.8 cm thickness of olive oil so that it floats on top of the water. What is the pressure at the bottom of the container? Assume 1000 kg/m3 and 901 kg/m3 for the density...
*March 16, 2011*

**math**

what is the difference of 8 and the quotion of 5
*March 16, 2011*

**Physics**

Top and Bottom??
*March 15, 2011*

**Physics**

I'm confused about what A should be then? Is that what I'm solving for? I thought I was solving for pressure?
*March 15, 2011*

**Physics**

A water tower is filled with fresh water to a depth of 6.38 m. What is the water pressure at a depth of 3.96 m?
*March 15, 2011*

**Physics please help!!**

So F1/2.15E-5=1072N/2.4E-3 F1= 2.15E-5*(1072/2.4E-3) F1=9.63E10 N I think I did this right but the answer comes up wrong when I submit it
*March 15, 2011*

**Physics please help!!**

Is the 1072N=F2?
*March 15, 2011*

**Physics please help!!**

Piston 1 has a diameter of 0.524cm Piston 2 has a diameter of 5.64 cm. In the absence of friction, determine the force required on piston 1 necessary to support an object, m, with weight 1072 N. (Neglect the height difference between the bottom of the two pistons, and assume ...
*March 15, 2011*

**Physics**

The four tires of an automobile are inflated to a gauge pressure of 1.84E+5 Pa. Each tire has an area of 0.0237 m2 in contact with the ground. Determine the weight of the automobile.
*March 15, 2011*

**Physics please help!!**

A 73.5 kg person sits on a 3.20 kg chair. Each leg of the chair makes contact with the floor in a circle that is 1.74 cm in diameter. Calculate the pressure exerted on the floor by each leg of the chair, assuming the weight is evenly distributed.
*March 15, 2011*

**Physics please help!!**

The mass of a star is 1.49·1031 kg and it performs one rotation in 26.1 days. Find its new period (in /days) if the diameter suddenly shrinks to 0.59 times its present size. Assume a uniform mass distribution before and after.
*March 14, 2011*

**Stats**

if 5% of all calculators are defective, find the mean, variance, and standard deviation of a lot of 400 calculators. round your final answer to two decimal places if necessary.
*March 13, 2011*

**Physics please help!!**

A 1.94 kg solid sphere (radius = 0.105 m) is released from rest at the top of a ramp and allowed to roll without slipping. The ramp is 0.710 m high and 5.17 m long. When the sphere reaches the bottom of the ramp, what is its total kinetic energy?
*March 13, 2011*

**Physics**

After you pick up a spare, your bowling ball rolls without slipping back toward the ball rack with a linear speed of v = 3.41 m/s To reach the rack, the ball rolls up a ramp that rises through a vertical distance of h = 0.529 m. What is the linear speed of the ball when it ...
*March 13, 2011*

**Physics please help!!**

A 12.1 g CD with a radius of 6.16 cm rotates with an angular speed of 31.1 rad/s. What is its kinetic energy?
*March 13, 2011*

**Physics please help!!**

A 12.1 g CD with a radius of 6.16 cm rotates with an angular speed of 31.1 rad/s. What is its kinetic energy?
*March 10, 2011*

**Physics please help!!**

A 12.1 g CD with a radius of 6.16 cm rotates with an angular speed of 31.1 rad/s. What is its kinetic energy?
*March 10, 2011*

**Physics please help!!**

How much work must be done to accelerate a baton from rest to an angular speed of 7.27 rad/s about its center? Consider the baton to be a uniform rod of length 0.529 m and mass 0.478 kg
*March 10, 2011*

**Math**

Converting 60 percent into A fraction in simplest form
*March 7, 2011*

**Physics**

I'm still confused on how the find the center of the student's mass though????
*March 4, 2011*

**Physics**

To determine the location of his center of mass, a physics student lies on a lightweight plank supported by two scales L = 2.40 m apart If the left scale reads 278 N, and the right scale reads 116 N, calculate the student's mass. Calculate the distance from the student'...
*March 4, 2011*

**Physics please help!!**

A school yard teeter totter with a total length of 5.46 m and a mass of 35.9 kg is pivoted at its center. A 17.7 kg child sits on one end of the teeter totter. Where should a parent push with a force of 272 N in order to hold the teeter totter level?
*March 4, 2011*

**geometry**

bisects and is perpendicular to line segments and . = 96 inches, and line segment = 52 inches. What is the length of ?
*March 3, 2011*

**PHYSICS tension & angle**

A van accelerates down a hill (Fig. P4.71), going from rest to 30.0 m/s in 6.70 s. During the acceleration, a toy (m = 0.250 kg) hangs by a string from the van's ceiling. The acceleration is such that the string remains perpendicular to the ceiling. Find theta Find tension...
*March 3, 2011*

**physics**

Two blocks, A and B (with mass 50 kg and 100 kg, respectively), are connected by a string, as shown in Figure P5.64. The pulley is frictionless and of negligible mass. The coefficient of kinetic friction between block A and the incline is µk = 0.25. Determine the change ...
*March 3, 2011*

**Statistics**

A random variable X is normally distributed with ì = 60. Convert the value of X to a z-score, if the standard deviation is as given. X = 60; ó = 7 A) 7 B) 1 C) 60/70 D) 0
*March 2, 2011*