Friday

February 24, 2017
Total # Posts: 2,591

**physics**

a longitudinal wave with a frequency of 3.0 Hz takes 1.7 s to travel the length of a 2.5-m slinky (see figure 16.3). Determine the wavelength of the wave.

*November 18, 2012*

**physics**

Suppose the sound is emitted uniformly in all directions by a public address system. The intensity at a location 22 m away from the sound source is 3.0 x 10-4 W/m2. What is the intensity at a spot that is 78 m away?

*November 18, 2012*

**physics**

light is an electromagnetic wave and travels at a speed of 3.00 x 108 m/s. the human eye is most sensitive to yellow-green light which has a wavelength of 5.45 x 10-7 m. what is the frequency of this light?

*November 18, 2012*

**physics**

at a distance of 3.8 m from a siren, the sound intensity is 3.6 x 10-2 W/m2. Assuming that the siren radiates sound uniformly in all directions, find the total power radiated.

*November 18, 2012*

**physics**

the distance between a loudspeaker and the left ear of a listener is 2.70 m a) calculate the time required for sound to travel this distance if the air temperature is 20oC. b) assuming that the sound frequency is 523 Hz, how many wavelengths of sound are contained in this ...

*November 18, 2012*

**physics**

From a vantage point very close to the track at a stock car race, you hear the sound emitted by a moving car. You detect a frequency that is 0.86 times as small as that emitted by the car when it is stationary. The speed of sound is 343 m/s. what is the speed of the car?

*November 18, 2012*

**math**

a particle starts at time t = 0 and moves along the x - axis so that its position at any time t is greater than or equal to zero is given x(t) = (t-1)^3(2t-3) A. Find the velocity of the particle at any time t greater than or equal to 0. B. For what values of t is the velocity...

*November 15, 2012*

**Math**

What is another way to write the expression 44n? 44÷n?

*November 14, 2012*

**Pre-Algebra**

A bag contains 10 white golf balls and 6 striped golf balls. A golfer wants to add 112 golf balls to the bag. He wants the ratio of white to striped golf balls to remain the same. How many of each should he add?

*November 14, 2012*

**math**

Write four million, four thousand, forty in standard form.

*November 14, 2012*

**math**

Order the following numbers from greatest to least. 2.071; 20.071; 20.71 Is this right 20.71; 20.071; 2.071

*November 13, 2012*

**Math**

Without multiply how many decimals places r in the product of 4.97 and 3.456?

*November 12, 2012*

**math**

Isn't 19 + 21 + 40 which is more than the amount of children in the class? Then you add 10 more that don't play it's 50. So how is the class total 38 as implied?

*November 10, 2012*

**math**

rene gave each of six people 1/10 of a veggie pizza. rene has 2/5 of the pizza left. explain how this is true

*November 8, 2012*

**science**

How much total work is done by 450-N girl who lifts a 52-N backpack 1.2m to her shoulders and then climbs a ladder 3.0m high?

*November 7, 2012*

**physics**

From the moment a 42 m/s fastball touches the catcher's mitt until its completely stopped takes 0.014 s. Calculate the average acceleration of the ball as it is being caught.

*November 6, 2012*

**math**

a pizza place sold worth 2000 of pizza on saturday. there were 29 small pizzas sold and medium pizzas sold

*November 5, 2012*

**physics**

A paperweight weighs 6.9N in air. When it is completely submerged in water it appears to weigh 4.3N. A) What is the volume of the paperweight? B) What is the density paperweight? The density of water is 1000kg/m3.

*November 4, 2012*

**physics**

A 2000 kg truck is at rest at a stop sign. A 1100kg car collides head-on with the truck. The car was moving at 15.0m/s before the collision if the collision was completely inelastic, what is the velocity of the car and the truck after the collision?

*November 4, 2012*

**physics**

A paperweight weighs 6.9N in air. When it is completely submerged in water it appears to weigh 4.3N. A) What is the volume of the paperweight? B) What is the density paperweight? The density of water is 1000kg/m3.

*November 4, 2012*

**physics**

A fulcrum is placed under the center of a uniform 4.00m long, 3.00kg board. Child A has a mass of 42 kg. This child sits on the left end of the board; Child B has a mass of 26kg. Child B sits on the right end of the board. Where should child C (mass 21 kg) sit in order to have...

*November 4, 2012*

**physics**

A paperweight weighs 6.9N in air. When it is completely submerged in water it appears to weigh 4.3N. A) What is the volume of the paperweight? B) What is the density paperweight? The density of water is 1000kg/m3.

*November 4, 2012*

**physics**

A 2000 kg truck is at rest at a stop sign. A 1100kg car collides head-on with the truck. The car was moving at 15.0m/s before the collision if the collision was completely inelastic, what is the velocity of the car and the truck after the collision?

*November 4, 2012*

**physics**

A uniform, horizontal beam is 5.00m long and has a weight of 200N. The beam is hinged at one end to a wall. A 600N weight is attached to the order end of the beam. The beam is supported by cable at the end opposite the wall. The cable attaches to the wall directly above the ...

*November 4, 2012*

**physics**

A pendulum has a length of 1.35m. What mass should be placed on a spring with a spring constant of 10.0N/m to have oscillations with the same period as the pendulum.

*November 4, 2012*

**physics**

A duck is floating on water with 26% of its total volume submerged below the surface. If the duck has a mass of 2.6kg, what is the duck’s total volume? You must show all necessary work, the density of water is 1000kg/m3.

*November 4, 2012*

**physics**

A 3.0 kg sphere moving to the right at 2.0m/s undergoes an elastic head-on collision with a 2.0kg sphere. The 2.0kg sphere is initially at rest. What is the speed of each sphere after the collision?

*November 4, 2012*

**math**

According to a national study, 45% of american adults have hypertension, 20% have hypotension, and 35% have normal blood pressure. A sample of 150 adults was taken and the following data were collected. Hypertensive: 54, Normal: 69, Hypotensive: 27. Test at the 5% level ...

*November 3, 2012*

**SCIENCE**

Identify the primary biological foundations of psychology linked to behavior.

*October 29, 2012*

**math**

Chelsea left the White House and traveled toward the capital at an average speed of 34 kn/h. Jasmine left at the same time and traveled in the opposite direction with an average speed of 65km/h. Find the number of hours Jasmine needs to travel before they are 59.4 km/hr

*October 25, 2012*

**Statistics**

In practical use, oral contraceptives have a 5% chance of failing. If a doctor has 10 patients using oral contraceptives, what is the probability that at least 1 will get pregnant?

*October 23, 2012*

**Algebra 1**

C is more than half of n

*October 23, 2012*

**geometry**

Determine the measure of angle B of triangle ABC given the following information A= 42 deg c = 12 C = 96 deg

*October 21, 2012*

**trigonometry**

Determine the area of triangle ABC, given the following information c = 40m b = 20m A = 48deg

*October 21, 2012*

**science- physics**

A rotating wheel requires 4.17 s to rotate through 37 rev. Its angular speed at the end of the 4.17 s interval is 104 rad/s. What is its constant angular acceleration? Assume the angular acceleration has the same sign as the angular velocity.

*October 19, 2012*

**math**

Question Part Points Submissions Used Verify that the function satisfies the three hypotheses of Rolle's Theorem on the given interval. Then find all numbers c that satisfy the conclusion of Rolle's Theorem. (Enter your answers as a comma-separated list.) f(x) = cos ...

*October 17, 2012*

**math x**

5(1 – 3m) = 30 – 2(4m + 7)

*October 17, 2012*

**world geography**

thank u amanda ;)

*October 17, 2012*

**world geography**

The statement, "People celebrate their birthdays on January 1st" is an example of what type of region? o climate o cultural o physical o political

*October 17, 2012*

**world geo**

honestly i dnt kno but culture economic physical political is one of the answers

*October 17, 2012*

**world geo**

The statement, "Paraguay is one of two landlocked South American nations" describes what type of region? o cultural o economic o physical o political

*October 17, 2012*

**statistics**

what was the answer???

*October 14, 2012*

**Chemistry**

I need to find the average molar mass of an unknown element. The atomic mass is 120; the mass numbers of isotopes are 295, 296, 297, 298 and 299; the percent of each isotope is 2.356%, 4.325%, 15.652%, 48.452% and 29.215%. The mass of the neutron is 1.67262164x10^-24g and the ...

*October 14, 2012*

**Chemistry**

I need to find the average molar mass of an unknown element. The atomic mass is 120; the mass numbers of isotopes are 295, 296, 297, 298 and 299; the percent of each isotope is 2.356%, 4.325%, 15.652%, 48.452% and 29.215%. The mass of the neutron is 1.67262164x10^-24g and the ...

*October 13, 2012*

**math**

James is 15 years older than Sue. In 12 years James will twice Sue's age. How old are James and Sue?

*October 11, 2012*

**Math**

Find the derivatives of the function g(t)= cosh^3 t.

*October 9, 2012*

**chemistry**

A home swimming pool is disinfected by the daily addition of 0.50 gal (1 gal = 3.785 L) of a "chlorine" solution–NaOCl in NaOH(aq). To maintain the proper acidity in the pool, the NaOH(aq) in the "chlorine" solution must be neutralized. By experiment ...

*October 9, 2012*

**Chemistry**

the half-life of cobalt-60 is 5.20 years.. how many milligrams of a 2.000-mg sample remains after 6.55 years

*October 8, 2012*

**Math**

Come up with an expression for a function f such that the domain of f is all real numbers, lim (f(x) = 3) as x approaches 2 and f(2) = 3.

*October 8, 2012*

**Free Fall**

The acceleration due to gravity on planet X is one fifth that on the surface of the earth. If it takes 3.9 s for an object to fall a certain distance from rest on earth, how long would it take to fall the same distance on planet X?

*October 4, 2012*

**Economics**

There are two types of consumers of potatoes: 10 are rich and 50 are poor. Every rich consumer has a demand of 0 for a price of $500/ton; and his/her demand decreases by 1 ton each time the price increases by $1/ton. Every poor consumer has a demand of 0 for a price of $280/...

*October 2, 2012*

**social sciences**

The market supply for potatoes in New York is 2,000 tons for a price of $200 a ton, and 5,000 tons for a price of $500 a ton. Between these two prices market supply is a straight line. What is the equation of the supply curve?

*October 2, 2012*

**chem**

Which of the following solutions has the highest concentration of Cl- ions? 500 mL of 0.10 M NaCl 100 mL of 0.20 M MgCl2 200 mL of 0.10 M FeCl3 400 mL of 0.30 M NH4Cl 200 mL of 0.20 M KCl

*October 1, 2012*

**chemistry**

NO ITS RIGHT

*October 1, 2012*

**chemistry**

it said that was wrong

*October 1, 2012*

**physics**

46.8

*September 30, 2012*

**physics**

Three vectors are shown in Fig. 3-32 (A = 60.0 , B = 56.0°). Their magnitudes are given in arbitrary units. Determine the sum of the three vectors. (a) Give the resultant in terms of components. (b) What is the magnitude of the resultant? What is the resultant's angle ...

*September 30, 2012*

**physics**

i don't get what theta is or arcsin

*September 30, 2012*

**physics**

You are given a vector in the xy plane that has a magnitude of 85.0 units and a y component of -60.0 units. What are the two possibilities for its x component?

*September 30, 2012*

**physics**

An airplane is traveling 675 km/h in a direction 42.5° west of north (a) Find the components of the velocity vector in the northerly and westerly directions. b) How far north and how far west has the plane traveled after 3.00 h?

*September 30, 2012*

**physics**

Vector V1 is 8.98 units long and points along the negative x axis. Vector V2 is 4.00 units long and points at +50.0° to the +x axis. a) What are the x and y components of each vector? (b) Determine the sum V1 + V2.

*September 30, 2012*

**physics**

A delivery truck travels 15 blocks north, 21 blocks east and 18 blocks south. What is its final displacement from the origin? Assume the blocks are equal length. magnitude and direction

*September 30, 2012*

**physics**

A car is driven 105 km west and then 65 km southwest. What is the displacement of the car from the point of origin (magnitude and direction)?

*September 30, 2012*

**STATISTICS**

The height of PU men are normally distributed with mean 65 in. and standard deviation 5.3 in. find the probability of finding: a. A men selected is at least 75 in. tall? b. A man selected is no less than 58 in. tall?

*September 30, 2012*

**algebra**

(2x+3)^2 is 25x right?

*September 29, 2012*

**College algebra**

(2x-3)(x^2-3x+5)

*September 29, 2012*

**College algebra**

How do I solve this?(7x+5y)^2

*September 29, 2012*

**college algebra**

(x+5y)(7x+3y)How do I solve this. I know I have to somehow combine the x and y but can't remember.

*September 29, 2012*

**college algebra**

how do I solve this: (17x^3-5x^2+4x-3)-(5x^3-9x^2-8x+11) and putting the resulting polynomial in standard form?

*September 29, 2012*

**math**

I copied it from the page I got it from - hummm? so 3,000,000 cant be a 6 digit # can it? Maybe its 300,000

*September 25, 2012*

**math**

it is a 6 digit number. there is no repetition of digits. It is divisible by 5 and is more than 3000,000. The digit in the hundreds place is 3 more than the digit in the ones place. The digit in the ten thousands place is 3 times the digit in the hundred thousands place. The ...

*September 25, 2012*

**college physics**

A new planet has been discovered that has a mass one-tenth that of Earth and a radius that is one-sixth that of Earth. Determine the free fall acceleration on the surface of this planet. Express your answer in the appropriate mks units.

*September 24, 2012*

**college physics**

Although astronauts appear weightless, they are not. They only appear weightless because they are in free fall. If a 79 kg astronaut is orbiting Earth with an orbital radius of 5.31×107 m, determine how much the astronaut would weigh. Earth's mass is 5.974 1024 kg.

*September 24, 2012*

**college physics**

new planet is discovered orbiting a distant star. Observations have confirmed that the planet has a circular orbit with a radius of 21 AU and takes 118 days to orbit the star. Determine the mass of the star. State your answer with appropriate mks units. [NOTE: AU stands for &...

*September 24, 2012*

**economic**

its is B?

*September 22, 2012*

**economic**

In a free market, which of the following is an accurate statement regarding price? A) Prices tend to increase. B) The price of a good or service helps to quantify its value to consumers. C) None of these statements are accurate. D) Sellers offer misleading information to beef ...

*September 22, 2012*

**economic**

it is true?

*September 22, 2012*

**economic**

A price set above equilibrium price creates a shortage. True or False

*September 22, 2012*

**economic**

it is true?

*September 22, 2012*

**economic**

In microeconomics, little emphasis is given to how prices are established and why they change. True or False?

*September 22, 2012*

**economic**

Store managers must consider which of the following trait? A) Cultural style B) Age groups C) Income level D) All are correct

*September 22, 2012*

**business law**

B. Telephones S.'s store and orders certain goods that S. delivers to B. Neither party says anything about the price or payment terms. B. does not pay S. Is S. entitled to be paid by B.? Why?

*September 21, 2012*

**business law**

A music club sends you an advertisement. You select ten "free" downloads and agree to become a member. When you get your free downloads, you decide to resign. Does the music club have any rights against you? Why?

*September 21, 2012*

**Physics**

A speedy tortoise can run at 0.09 m/s, and a hare can run 20 times as fast. In a race, they start at the same time, but the hare stops to rest for 2.4 min, so the tortoise wins by a shell (20 cm). How long does the race take? Answer in units of s What is the length of the race...

*September 19, 2012*

**physics**

FFFFFFFFFFUUUUUUUUUUUUUUUUU

*September 18, 2012*

**math**

A vampire could have the ability to infect an entire planet if he bit 2 people each day. Those 2 people would bite 2 people the next day, and then all of those vampires would each bite 2 people the next day, and so forth... How would I solve this to find out how many people ...

*September 17, 2012*

**Differential Equations**

A tank originally contains 5 lb of salt dissolved in 200 gal of water: Starting at time t=0, a salt solution containing 0.10 lb/gal is to be pumped into the tank at a constant rate and the well-stirred mixture is to flow out of the tank at the same rate. a)The pumping is to be...

*September 17, 2012*

**Statistics**

2

*September 16, 2012*

**Physical Science**

waves moving on a lake have a speed of 2.0 m/s and a distant of 1.5m between adjacent crest. what is the frequency of the waves? find the period of the wave motion?

*September 13, 2012*

**Physics**

A car traveling at a constant speed of 39.6 m/s passes a trooper hidden behind a billboard. One second later the trooper starts the car with a constant acceleration of 2.25 m/s^2 . How long after the trooper starts the chase does he overtake the speeding car? Answer in units of s

*September 9, 2012*

**Physics**

An airplane moves at 300 mi/hr relative to the air. It must fly from city A to city B, 600 miles due east. One day the wind is blowing at 100 mi/hr in a direction of 30 degrees north of east. Draw a diagram. b. What will the velocity of the plane relative to the ground (value ...

*September 9, 2012*

**College Physics**

A 6107 kg elevator is moving 4.6 m/s up. The tension in the elevator cable is 66,512.6 N. Determine the acceleration of the elevator (state the appropriate mks units).

*September 9, 2012*

**Diff Eq**

If y(t)=3e^(t^2)is known to be the solution of the initial value problem y'+p(t)y=0, y(0)=y_0, what must the function p(t) and the constant y_0 be?

*September 7, 2012*

**Math**

Jim is paid overtime when he works more than 40 hours of per week. Write an expression for the number of hours he works overtime when he works h hours. Find the number of hours Jim works overtime when he works 40, 44, 48, and 52 hours

*September 6, 2012*

**spanish**

what is the spanish word for "see you soon"

*September 4, 2012*

**physics**

A small rock is thrown vertically upward with a speed of 13.0from the edge of the roof of a 37.0 tall building. The rock doesn't hit the building on its way back down and lands in the street below. Air resistance can be neglected. A) What is the speed of the rock just ...

*September 3, 2012*

**math**

sorry i forgot to say that i don't need the answer... i need an equation or expression that models this situation.

*September 3, 2012*

**math**

a man who is 5 feet tall stands 15 feet from a lamppost that is 27 feet high. how far away from the man is the tip of his shadow?

*September 3, 2012*