Tuesday

December 6, 2016
Total # Posts: 338

**Physics**

A baseball coach shouts loudly at an umpire standing 3.6 meters away. If the sound power produced by the coach is 2.2×10−3 W, what is the intensity of the sound when it reaches the umpire? Answer in units of W/m2.

*October 21, 2012*

**Physics**

A harmonic wave in a wire has amplitude A = 7.6 mm, wavelength λ = 0.679 m and frequency f = 543 Hz. What is the propagation speed of the wave? Answer in units of m/s. The wire has linear mass density of 5.04 g/m. Determine the wire’s tension. Answer in units of N.

*October 21, 2012*

**Physics**

A harmonic wave is traveling along a rope. It is observed that the oscillator that gener- ates the wave completes 44.9 in 30.4 s. Also, a given maximum travels 436 cm along the rope in 9.4 s. What is the wavelength? Answer in units of cm

*October 21, 2012*

**Physics**

When a particular wire is vibrating with a frequency of 5.3 Hz, a transverse wave of wavelength 69.3 cm is produced. Determine the speed of wave pulses along the wire. Answer in units of m/s.

*October 21, 2012*

**Physics**

The time needed for a water wave to change from the equilibrium level to the crest is 0.4185 s. What fraction of a wavelength is this? What is the period of the wave? Answer in units of s. What is the frequency of the wave? Answer in units of Hz.

*October 21, 2012*

**Physics**

Beth, a construction worker, attempts to pull a stake out of the ground by pulling on a rope that is attached to the stake. The rope makes an angle of 60.9 ◦ with the horizontal. If Beth exerts a force of 116 N on the rope, what is the magnitude of the upward component ...

*October 21, 2012*

**physics**

A gazelle is running in a straight line (the x-axis). The graph in the figure (Figure 1) shows this animal's velocity as a function of time. During the first 12.0 , find the total distance moved

*October 9, 2012*

**o Chem**

The more nonpolar compound will have the higher retention time

*October 9, 2012*

**Physics**

A variable-length air column is placed just below a vibrating wire that is fixed at the both ends. The length of air column open at one end is gradually increased from zero until the first position of resonance is observed at 20 cm. The wire is 115.4 cm long and is vibrating ...

*October 5, 2012*

**Physics**

A length of organ pipe is closed at one end. If the speed of sound is 344 m/s, what length of pipe is needed to obtain a funda- mental frequency of 70 Hz? Answer in units of m.

*October 5, 2012*

**Physics**

The length of a string is 344 cm. The string is held fixed at each end. The string vibrates in two sections; i.e., the string has two antin- odes, and the string vibrates at 130 Hz. Find the wavelength. Answer in units of m. What is the fundamental frequency? Answer in units ...

*October 5, 2012*

**Physics**

To demonstrate standing waves, one end of a string is attached to a tuning fork with frequency 120 Hz. The other end of the string passes over a pulley and is connected to a suspended mass M, as shown. The value of M is such that the standing wave pattern has eight loops “...

*October 5, 2012*

**Physics**

Standing-wave vibrations are set up in a crystal goblet with four nodes and four antin- odes equally spaced around the 26.3 cm cir- cumference of its rim. If transverse waves move around the glass at 900 m/s, an opera singer would have to produce a high harmonic with what ...

*October 5, 2012*

**Physics**

The lowest A on a piano has a frequency of 27.5 Hz. Assume: The tension in the A piano wire (of length 0.51 m) is 305 N, and one-half wavelength occupies the wire. What is the mass of m the wire? Answer in units of kg.

*October 5, 2012*

**Physics**

A harmonic wave is traveling along a rope. It is observed that the oscillator that gener- ates the wave completes 38.9 in 27.4 s. Also, a given maximum travels 432 cm along the rope in 10.6 s. What is the wavelength? Answer in units of cm.

*October 5, 2012*

**Physics**

A variable-length air column is placed just below a vibrating wire that is fixed at the both ends. The length of air column open at one end is gradually increased from zero until the first position of resonance is observed at 20 cm. The wire is 115.4 cm long and is vibrating ...

*October 1, 2012*

**Physics**

explain Lambda? I was sick and missed class?

*October 1, 2012*

**Physics**

A length of organ pipe is closed at one end. If the speed of sound is 344 m/s, what length of pipe is needed to obtain a funda- mental frequency of 70 Hz? Answer in units of m.

*October 1, 2012*

**Physics**

A pipe that is open at both ends has a fundamental frequency of 330 Hz when the speed of sound in air is 333 m/s. What is the length of this pipe? Answer in units of cm. What is the second harmonic? What is the third harmonic? Answer in units of Hz. What is the fundamental ...

*October 1, 2012*

**Physics**

The length of a string is 344 cm. The string is held fixed at each end. The string vibrates in two sections; i.e., the string has two antin- odes, and the string vibrates at 130 Hz. Find the wavelength answer in m What is the fundamental frequency? Answer in units of Hz.

*October 1, 2012*

**Physics**

To demonstrate standing waves, one end of a string is attached to a tuning fork with frequency 120 Hz. The other end of the string passes over a pulley and is connected to a suspended mass M, as shown. The value of M is such that the standing wave pattern has eight loops “...

*October 1, 2012*

**Physics**

A harmonic wave is traveling along a rope. It is observed that the oscillator that gener- ates the wave completes 38.9 in 27.4 s. Also, a given maximum travels 432 cm along the rope in 10.6 s. What is the wavelength? Answer in units of cm.

*October 1, 2012*

**Physics**

The lowest A on a piano has a frequency of 27.5 Hz. Assume: The tension in the A piano wire (of length 0.51 m) is 305 N, and one-half wavelength occupies the wire. What is the mass of m the wire? Answer in units of kg.

*October 1, 2012*

**Math**

actually it is 1.25-.86

*September 30, 2012*

**Math**

How do i figure out this question? There are two roads, one has a grade of 20% the other has an elevation of 15 degrees. Which road would be steeper?

*September 16, 2012*

**Math**

One road has a grade of 20% and the other has an elevation of 15 degrees. Which road would be steeper? How do i figure this out?

*September 13, 2012*

**math**

thank you

*September 13, 2012*

**math**

A trucker is looking on a map of two roads he could take to get to Nelson. One has a grade of 20% and the other has an elevation of 15 degrees. Which road would be steeper? How do I figure this out?

*September 13, 2012*

**physics**

Two point charges are placed along a horizontal axis with the following values and positions: +3 µC at x = 0 cm and - 12 µC at x = 35 cm. At what point (the coordinate) along the x axis is the electric field zero? Expess the answer (in cm) with one decimal place.

*September 11, 2012*

**Physics**

40 mph

*September 6, 2012*

**com/155**

what objecets,people,subject or concepts are you going to compare and or contrast?

*August 16, 2012*

**math**

what is (24 divide by 4)+(3 times 6 +4)

*August 15, 2012*

**Physics**

An ac generator supplies an rms voltage of 5.00 {\rm V} to an RL circuit. At a frequency of 21.0{\rm kHz} the rms current in the circuit is 45.0 {\rm mA}; at a frequency of 26.0{\rm kHz} the rms current is 40.0 {\rm mA}. Find value of L an R ?

*July 30, 2012*

**com/155**

Review the steps in the prewriting phase of essay writing. How important do you think prewriting is to the success of an essay? Can you skip the prewriting phase? Why or why not?

*July 26, 2012*

**geometry**

i got 56√90 but that's not one of the answer. The answers are 84√5 cm^3 168√10 cm^3 336√5 cm^3

*July 25, 2012*

**geometry**

Find the volume of a rectangular solid with the following dimensions: 2√3 cm x 7√5 cm x 4√6 cm.

*July 25, 2012*

**compostition**

I need a topic to Write a 150- to 200-word paragraph to explain how purpose, audience, tone, and content impact academic writing. Be sure to use the three components of a good paragraph covered in this weekâ??s readings. Underline the topic sentence and bold the ...

*July 22, 2012*

**chemistry**

How many moles of Ca(NO3)2 are needed to make 0.250 liters of a 0.200 M Calcium nitrate solution?

*April 29, 2012*

**algebra**

Joseph always throws change into a can and takes it out every two weeks. This time it is all nickels and dimes. There are six times as many dimes as nickels, and the value of the dimes is $4.95 more than the value of the nickels. How many nickels and dimes does Joseph have. (...

*April 22, 2012*

**calculus**

Let f be the function given by: f(x)=1/5x^5/2+x^-1/2, for all x in [1,4]. Find the length of the graph of f.

*April 9, 2012*

**Math**

A wire is stretched from the top of a 12-foot pole to a stake in the ground and then to the base of the pole. If a total of 20 feet of wire is needed, how far is the stake from the pole (the answer is NOT 16)

*April 3, 2012*

**9th grade math**

37 and 15

*April 3, 2012*

**algebra**

A man invested half of his money at 5%, one-third of his money at 4%, and the rest of his money at 5.5%. If his total investment income was $570, how much had he invested? and please show me the solution to solve this problem. thanx sorry bobpursly I cant understand your ...

*February 25, 2012*

**algebra**

A man invested half of his money at 5%, one-third of his money at 4%, and the rest of his money at 5.5%. If his total investment income was $570, how much had he invested? and please show me the solution to solve this problem. thanx

*February 25, 2012*

**government **

Which institution developed outside the limits of the written Constitution of the United States?

*February 10, 2012*

**math**

add 3yds, 16 inches,+ 6yds, 54 inches

*January 31, 2012*

**algebra**

the number of people the school can hold is at most 200. how can i present this in inequality is this correct x=<200

*January 29, 2012*

**physics**

In an historical movie, two knights on horseback start from rest 90.6 m apart and ride directly toward each other to do battle. Sir George's acceleration has a magnitude of 0.340 m/s2, while Sir Alfred's has a magnitude of 0.346 m/s2. Relative to Sir George's ...

*December 13, 2011*

**Math**

Calculate the number of sides of a regular polygon whose interior angles are each 156 degrees.

*December 4, 2011*

**trig**

Try to draw an image of the ladder leaning against the wall. The diagram will look like a right abgled triangle. Now let the distance of the ladders base to the wall = x Cos 71 = x / 30 x = 30Cos71 x = 9.8

*December 3, 2011*

**math**

express as a single log: 1/2 log x + 3 log y - 4 log x =

*November 5, 2011*

**AP Physics**

Use the momentum conservation formula: m₁∆v₁ + m₂∆v₂ = m₁∆v₁' + m₂∆v₂' The initial velocity of the second ball is 0, since it starts from rest, and the final velocity of the first ball is 0 since ...

*October 18, 2011*

**Genetics**

1) The F2 progeny from a cross exhibits a modified dihybrid ratio of 9:7 instead of 9:3:3:1. What phenotype ratio would be expected from a testcross of the F1 progeny? 2) In Drosophila, mutants a through g all have a white eye phenotype. The following data shows the results of...

*September 16, 2011*

**math help**

On a drive through Allegheny County Natalie drove due west for 9 miles, then turned left and proceeded to drive due south. After traveling 12 miles south, what was the straight line distance between where Natalie started and where she ended her drive?

*August 29, 2011*

**algebra**

55gj

*August 22, 2011*

**physics**

A 500g block is released from rest and slides down a frictionless track that begins 2m above the horizontal. At the bottom of the track, where the surface is horizontal, the block strikes and sticks to a light spring with a spring constant of 20.0N/m. Find the maximum distance...

*August 10, 2011*

**algebra**

A certain number decreased by 2

*July 28, 2011*

**govt**

I think pardoning a former senator

*July 14, 2011*

**govt**

Which act is an example of governor's use of legislative powers? a firing a parks commissioner b rejecting part of a recycling bill c pardoning a former senator d assessing flood-control efforts

*July 14, 2011*

**govt**

is it c

*July 14, 2011*

**govt**

In 21 states voters may propose and pass laws without the legislature a.by direct initiative b by indirect initiative c by optional referendum d by mandatory referendum

*July 14, 2011*

**exp of math**

add and simplify 96/125 + 83/125 + 2/15 =

*July 14, 2011*

**math**

A man is 67 7/18 taller than his son his son is 65 ¾ tall how much taller is the man?

*July 14, 2011*

**algebra 2**

Solve the problem. The profit made when t units are sold, t>, is given by P²-36t+320. Determine the number of units to be sold in order for P>0 (a profit is made). The future value of $6000 invested for 5 years at rate r, compounded annually, is given by S=6000(1+r...

*July 6, 2011*

**algebra 2**

Solve the problem. The profit made when t units are sold, t>, is given by P²-36t+320. Determine the number of units to be sold in order for P>0 (a profit is made). The future value of $6000 invested for 5 years at rate r, compounded annually, is given by S=6000(1+r...

*July 6, 2011*

**college algebra**

8 nickels 9 dimes

*June 23, 2011*

**daycare**

You've decided to operate a day care home. Which one of the following factors is the most important in helping you make your decision? A. Your family is willing to share their living space with the children in the program. B. Your home seems to be large enough. C. You find...

*June 7, 2011*

**Math**

2.9

*May 29, 2011*

**geometry**

How do you go about drawing a 1/4 mile running track?

*May 18, 2011*

**math**

solve the equation for x. write the solution set x2-100x=0

*May 18, 2011*

**math**

solve the equation for x. write the solution set . -x2 + 12x = 0

*May 18, 2011*

**math**

Solve the equation for x. Write the solution set -x(x + 8) = 0

*May 17, 2011*

**math**

Solve the equation for x. Write the solution set -4x + x2 – 9x + 6x = 0

*May 17, 2011*

**intergrated math**

Solve the equation for x. Write the solution set 3x2 + 5x2 – x – 7x2 = 0

*May 17, 2011*

**intergrated math**

Solve the equation for x. Write the solution set. 1. x(x – 2) = 0

*May 17, 2011*

**Physics**

How do you get these answers?

*May 13, 2011*

**Calculus**

Find the centroid of the region bounded by the curve sin x on the interval (0, pi) and the x-axis. Please help

*May 12, 2011*

**Math**

A bag contains forty coins, all of them either 2c or 5c coins. Let there be x 2c coins and y 5c coins. If the value of money in the bag is $1.55, find the number of each kind.

*May 12, 2011*

**Science**

What time of reactions is Silver + gold(III)> silver nitrate + gold

*April 20, 2011*

**us history**

list two reasons that stereotypes creted by propaganda may gave affected the deciosion to drop the atomic bomb on japan

*April 19, 2011*

**us history**

Explain why the U.S. supported a policy of the open door?

*April 18, 2011*

**Physics**

A motorboat travels at a speed of 40 km/h relative to the surface of the water. If it travels upstream against a current of 12 km/h what is the boats speed relative to the shore?

*April 15, 2011*

**Algebra**

Name the property shown by the following statement: 9x+0=9x?

*April 8, 2011*

**math**

because he wanted a potatoes chip

*April 2, 2011*

**Analytic Goemetry**

Find the equation of the parabola with axis parallel to the x-axis and passing through (3/2,1),(5,0) and (-1,2).

*March 23, 2011*

**Analytic Goemetry**

Find the equation of the parabola whose axis is horizontal, vertex on the y-axis and which passes through (2,4) and (8,-2).

*March 23, 2011*

**calculus SIMPSON RULE**

Use Simpson's Rule and all the data in the following table to estimate the value of the integral . x -16 -15 -14 -13 -12 -11 -10 y -8 9 4 9 -5 -9 3

*March 14, 2011*

**college math**

A business associate who owes you 3600 dollars offers to pay you 3360 now, or else pay you three yearly installments of 1200 each, with the first installment paid now. Assume that the interest rate will be 7 percent (compounded continuously). Find the total of 3 installments?

*March 14, 2011*

**college math**

Find the approximate (with an integral estimate) present and future values of a constant income stream of 2500 dollars per year over a period of 40 years, assume a 5 percent annual interest rate compounded continuously. Find current and future value?

*March 14, 2011*

**college math**

You won the lottery. They will pay you 1 million dollars a year for 20 years. Assuming 10 percent interest compounded continuously, approximate the present value of your winnings by assuming the money is paid to you continuously over the period of each of the 20 years and in ...

*March 14, 2011*

**math college**

A bank account earns 10 percent interest compounded continously. What annual amount of money must parents deposit each year in order to save 110000 dollars in 9 years for a child's college expenses? Assume the annual amount is added continuously over the period of each year.

*March 14, 2011*

**math**

(a). Determine the DFS tree of K3,3. (b). Determine the BFS tree of K3,3.

*March 14, 2011*

**math**

(a). For any connected graph G, all internal nodes of the BFS tree on G have the same number of children. (b). For any connected graph G, the DFS tree on G and the BFS tree on G have the same number of edges.

*March 14, 2011*

**math**

Problem A: Let T be a balanced 5-ary tree with 81 nodes. (a). How many internal nodes does T have? (b). How many edges does the tree T have? (c). What is the height of T?

*March 14, 2011*

**math**

A bank account earns 10 percent interest compounded continously. What annual amount of money must parents deposit each year in order to save 110000 dollars in 9 years for a child's college expenses? Assume the annual amount is added continuously over the period of each year.

*March 14, 2011*

**Physical science**

(A) A red light source and a green light source shine on a white screen. What color will the screen be? Explain your answer (B) if a blue object is aced in front of the screen, what color will it be? Explain your answer

*March 14, 2011*

**Physical science**

Two hunting forks are struck at the same time. One tuning fork has a frequency of 20 Hz while the second fork has a frequency of 226 Hz. How many beats will result?

*March 14, 2011*

**Physical science**

A player uses a hockey stick to increase the speed of a 0.200 kg hockey puck by 6 m/s in 2 seconds. How much did the hockey puck accelerate? How much force was exerted on the puck? How much force did the puck exert on the hockey stick?

*March 14, 2011*

**physics**

Determine the resulting temperature when 150g of ice at 0°C is mixed with 300g of water at 50°C

*March 9, 2011*

**physics**

How much heat is absorbed by an electric refrigerator in charging 2 Kg of water at 15°C to ice at 0°C?

*March 9, 2011*