# Posts by Shelby

Total # Posts: 293

**Algebra**

An aircraft factory manufactures airplane engines. The unit cost C (the cost in dollars to make each airplane engine) depends on the number of engines made. If x engines are made, then the unit cost is given by the function =Cx+?0.2x248x21,748 . What is the minimum unit cost? ...

*March 17, 2017*

**Algebra**

Consider the following matrix. A = 7, -5 -4, 3 Choose the correct description of A Find A^?1 if it exists. Answer either Choice 1, or Choice 2: CHOICE 1: A is nonsingular; that is, it has an inverse. A^-1 = _________ or CHOICE 2 : A is singular; that is, it's inverse DOES ...

*March 17, 2017*

**Algebra**

The Peterson family takes their clothes to the local cleaners. The table below gives the number of coats, shirts, and dresses they had cleaned over the course of three months. They had no other items cleaned there. (January) 5 coats, 5 shirts, 6 dresses (February) 1 coat, 8 ...

*March 16, 2017*

**Math**

in a fifth grade class, 3/4 of the students like to go to the movies. of the students who like to go to the movies, 2/3 of them like action movies. of the students who like to go to action movies, 4/5 of them also like comedies. what fraction of the students in the class like ...

*January 27, 2017*

**science**

Sedimentary

*December 12, 2016*

**Physics**

1. The figure shows a 100-kg block being released from rest from a height of 1.0 m. It then takes 0.53 s for it to reach the floor. What is the mass m of the block on the left? There is no friction or mass in the pulley, and the connecting rope is very light. A) 16 kg B) 14 kg...

*December 11, 2016*

**Social Studies NEED HELP**

I agree with you

*December 11, 2016*

**Algebra!**

2y+x=$15 15*3=45

*December 11, 2016*

**math**

If you plug it in to a calculator you get 3.5 You didn't factor correctly (4t+7)(t+1)=4t^2+11t+7 -16t^2+48t+28 -16t^2-8t+56t+28 (16t+8)(-t+3.5) t=-1/2 t=3.5

*December 11, 2016*

**Physics**

Check my answers? 1.C, 2.B, 3.?, 4.E, 5.D, 6.A(angle A=45, B=30, 7.D, 8. To the left,? (block A is hanging off the left side, block C is on the right), 9.?

*December 11, 2016*

**Physics**

1. The figure shows a 100-kg block being released from rest from a height of 1.0 m. It then takes 0.53 s for it to reach the floor. What is the mass m of the block on the left? There is no friction or mass in the pulley, and the connecting rope is very light. A) 16 kg B) 14 kg...

*December 11, 2016*

**Science**

The earth needs to be at an angle to maintain life

*December 11, 2016*

**science**

What causes the current to move through a battery?

*November 19, 2016*

**Physics**

The captain of a plane wishes to proceed due west. The cruising speed of the plane is 255 m/s relative to the air. A weather report indicates that a 39.0-m/s wind is blowing from the south to the north. In what direction, measured with respect to due west, should the pilot ...

*September 12, 2016*

**Physics**

In the absence of air resistance, a projectile is launched from and returns to ground level. It follows a trajectory similar to that shown in Figure 3.10 and has a range of 29 m. Suppose the launch speed is doubled, and the projectile is fired at the same angle above the ...

*September 12, 2016*

**Physics**

A horizontal rifle is fired at a bull's-eye. The muzzle speed of the bullet is 640 m/s. The gun is pointed directly at the center of the bull's-eye, but the bullet strikes the target 0.028 m below the center. What is the horizontal distance between the end of the rifle...

*September 12, 2016*

**Physics**

A bird watcher meanders through the woods, walking 1.13 km due east, 1.01 km due south, and 3.95 km in a direction 49.8 ° north of west. The time required for this trip is 1.965 h. Determine the magnitudes of the bird watcher's (a) displacement and (b) average velocity.

*September 12, 2016*

**Physics**

A VW Beetle goes from 0 to 46.0 mi/h with an acceleration of +2.35 m/s2. (a) How much time does it take for the Beetle to reach this speed? (b) A top-fuel dragster can go from 0 to 46.0 mi/h in 0.750 s. Find the acceleration (in m/s2) of the dragster.

*September 12, 2016*

**Science**

It can be inferred from the passage that radioactive dating is important for estimating the age of A) all known meters B) all existing planets C) the earth D) the trees

*August 11, 2016*

**physics**

In a city grid, each block on the east-west streets is 180 meters long. Each block on the north-south streets is also 180 meters long. A walker walks 4 blocks north and then 3 blocks east. How much farther did the walker travel than the actual distance between the start and ...

*June 27, 2016*

**penn foster**

1. A 30 kg dog is receiving fluids at a rate of 40 mL/hour. It needs a drug added to 500 mL of fluids so that it receives 2 mg/kg each hour. The drug has a strength of 2%. What volume of drug will you add? A.15ml B.37.5ml C.12.5ml D.3ml

*May 25, 2016*

**Latin**

Translation Help: Where do Ablatives and Genitives fit into a Latin sentence? How do you tell if a prepositional phrase is with an Ablative or Accusative?

*May 22, 2016*

**Physics**

The figure (Figure 1) shows a model of a crane that may be mounted on a truck.A rigid uniform horizontal bar of mass m1 = 80.0 kg and length L = 5.30 m is supported by two vertical massless strings. String A is attached at a distance d = 1.90 m from the left end of the bar and...

*March 22, 2016*

**math**

A car traveled 63 miles on 3 gallons of gas. What proportion can you set up to determine how many miles, m, the car can travel on 7 gallons of gas?

*March 7, 2016*

**physics**

You throw a 0.15 kg ball straight upward from ground level with an initial speed of 15 m/s. (Yes, from ground level. This is to make the calculations easier. If it bothers you, imagine you are standing in a dugout.) Your friend throws a 0.09 kg lump of clay upward after it. ...

*February 28, 2016*

**MUSIC**

1. What is the difference between composition and improvisation? Choose the correct. A. Composition is the art of making music spontaneously, while improvisations are carefully planned. B. Improvisation is the art of making music spontaneously, while compositions are carefully...

*February 22, 2016*

**Algebra**

suck it

*November 17, 2015*

**phyics**

Suppose a runner completes one lap around a 400-m track in a time of 50 s. Calculate the average velocity of the runner. Express your answer in meters per second to the nearest integer.

*September 12, 2015*

**Math**

$9.67

*August 25, 2015*

**Politics**

The nerve center of the American Presidency is

*June 15, 2015*

**physics**

A flat (unbanked) curve on a highway has a radius of 220m. A car rounds the curve at a speed of 25m/s. What is the minimum coefficient of friction that will prevent sliding?

*March 28, 2015*

**english composition 2**

I am thinking its d

*March 5, 2015*

**Algebra**

Find the following sum: 9 + 10 + 11 + ... + 87

*January 29, 2015*

**Math**

You are buying a fence to enclose a garden that has an area of 360 square feet. x + 9 The bottom of garden x side of garden a) What is the width of the area to be enclosed? Answer in units of ft b) How much fencing do you need? Answer in units of ft

*January 28, 2015*

**Physics**

3.9x10^5 N/m^2

*November 22, 2014*

**Chemistry**

How many mL of 0.122 M Na2CO3 would be needed to precipitate all of the copper ions in 23.7 mL of 0.167 M CuSO4? How many grams of CuCO3 could be recovered?

*November 4, 2014*

**Math**

A kitchen floor measures 10ft by 12 ft. Calculate the minimum area and maximum area using the greatest possible error

*October 27, 2014*

**Algebra**

The cost for a student ticket to a basketball game is $1 and a non student ticket is $2. The total sales for the game were $460 with 360 tickets sold, how many student tickets were sold?

*October 20, 2014*

**Algebra 1**

-5x-12<13 or -6x+8>50

*September 2, 2014*

**Algebra 2**

4x+5+2x=6(2+x

*September 2, 2014*

**physics**

A car with a mass of 2,000 kg has a kinetic energy of 900,000 J. How fast is it traveling?

*May 21, 2014*

**physics**

At the top of a hill, a roller coaster has 67,500 J of kinetic energy and 290,000 J of potential energy. Gradually, the roller coaster comes to a stop due to friction. If the roller coaster has 30,000 J of potential energy when it stops, how much heat energy is generated by ...

*May 21, 2014*

**math**

missing dimension, 14yd, v=489yd3

*April 2, 2014*

**west morgan**

find missing dimension cone, r=5in, v=487in3

*April 2, 2014*

**Calculus Rate of Change**

Find the average rate of change h(x)=2x^2-4 from x=2 to x=6 Simplify your answer as much as possible

*March 25, 2014*

**Trigonometry**

Graph the function y=2sin(x-2pi/3). To draw the graph, plot all x-intercepts, minima and maxima within on period. I need to graph at least 5 points. I have -pi, 0, pi, 2pi, 3pi, and 4pi along the x-axis

*March 24, 2014*

**Chemistry**

What is the molarity of an aqueous solution that is 6.44% glucose (C6H12O6) by mass? (Assume a density of 1.03 g/mL for the solution.)

*March 16, 2014*

**physics**

A 12.0 g bullet is fired into a 13.9kg wooden block that is hanging straight down, suspended by a 2.00 m length of light line. The bullet has a muzzle velocity of 94.2 m/s. When the bullet hits the block, the bullet stays in the block. The block swings outward so that the line...

*March 15, 2014*

**English**

A verb phrase that acts as a noun is called a? participial. adverbial. infinitive. gerund. Which of the following is the prepositional phrase in the sentence below? Applause came from the bleachers. A) Applause came B) came from C) from D) from the bleachers My answers: D. ...

*January 12, 2014*

**Physics**

When the end of a particular garden hose is held at a height of 1m, water flows out of it at 8 cm/s. What is the difference in fluid pressure between the end of the hose and a portion resting on the ground? Suppose I cover half of the area at the end with my thumb. What ...

*December 5, 2013*

**Physics**

Seawater has a density of about 1024 kg/m^3. In fresh water, the water line on a certain rectangular raft (8.8cm thick) moves 3.2 cm when a load of cargo is placed on it. How much will the same load of cargo move the water line in seawater? What is the pressure in fresh water ...

*December 5, 2013*

**Physics**

The gravitational acceleration on the surface of Mercury is 0.38 times that of Earth. Its radius is also about 0.38 times that of the Earth. What is the ratio of the density of Mars to that of Earth?

*December 5, 2013*

**Physics**

A particular asteroid has a circular orbit about the Sun with a radius of 450 million miles. How long does it take to go around the sun? Compare the prediction of Kepler's 2nd law to a direct computation with Newton's 2nd law. How much area does the line connecting the...

*December 5, 2013*

**Physics**

Placing a 215 g mass on a vertical spring causes a stretch of 5.1 cm. The mass is released at t=0 with y=0.15m (higher than the equilibrium hanging length) with a velocity of v=-1.3 m/s. What is the spring constant of the spring? What is the amplitude of the motion of the mass...

*December 5, 2013*

**Physics**

A particular piano wire has middle C (261.7 Hz) for its second harmonic. The wire's length is 2.7m. What is the speed of the wave in the wire? If the wire has 270 lbs of tension what is its linear density? What is the wavelength of this tone emitted into the air? Suppose ...

*December 5, 2013*

**biology**

Which provides more energy for the cell to perform its functions, cellular respiration or fermentation? Explain.

*December 3, 2013*

**econ/business**

Last month, Sue, of sue's sandwiches, sold $3000 worth of product(sandwiches and sodas) from her sidewalk cart to 300 customers. She spent $600 on the sandwich ingredients and buying the sodas wholesale. Her monthly costs are the following: Utilities = $60, salary =$1,500...

*November 20, 2013*

**math**

Question 3 Terry invests $3,000, at 10% interest, compounded semiannually for 12 years. Use the compound interest formula to calculate the compound amount for his investment. a. $9,675.30 b. $6,760.00 c. $6,663.28 d. $9,860.00

*October 31, 2013*

**Statistics**

A university has 1,000 computers available for students to use. Each computer has a 250-gigabyte hard drive. The university wants to estimate the space occupied on the hard drives. A random sample of 100 computers showed a mean of 115 gigabytes used with a standard deviation ...

*October 27, 2013*

**algebra**

1 hour=360 seconds (60*60) 1 kilometer=1000 meters to convert kilometers/hour to meters/second you can just do 1(kilometer)/1(hour)=1000(meters)/360(seconds) seeing as how you want your final answer in hours well convert the 89.44m/s train into km/h 89.44*1000/360=?km/h then ...

*October 20, 2013*

**science**

Explain the following statement: "scientific knowledge is the result of a great deal of debate and confirmation within the science community."

*October 18, 2013*

**Physics**

A dock worker applies a constant horizontal force of 80.0N to a block of ice on a smooth horizontal floor. The frictional force is negligible. The block starts from rest and moves 10.0m in the first 6.00s. What is the mass of the block of ice?

*October 2, 2013*

**budgeting**

its not b

*August 29, 2013*

**math**

a rectangle with a perimeter 70 feet can have an area of 150 ft^2. use A(x) to demonstrate this fact algebraically and graphically.

*August 15, 2013*

**Math**

What descriptive statistical information is needed in order to determine if a current temperature of 75-degree is a departure from the average temperature of 65 for that date of the year in that particular location, if the record low is 35 and record high is 90 for that date?

*June 11, 2013*

**chemistry**

If 15 grams of table salt is used how many moles of sodium sulfate are produced

*May 14, 2013*

**math**

can you help with this one Find the area of the regular polygon. Round your answer to the nearest tenth. the individual sides are 10 the radius is 13.07

*May 4, 2013*

**math**

The area of a parallelogram is 420 centimeters squared and the height is 35 cm. Find the corresponding base. Be sure to show all work and label your answer

*May 4, 2013*

**physics**

What wavelength of sound would a bat need to detect a 1cm diameter mosquito? Also, if it took 0.3 seconds for sound to return to a moth how far away would the moth be?

*April 11, 2013*

**Alg 3**

Put the following equations in standard form. State the center and the radius. x^2-5x+y^2+4y=-3 I get how to end up with (-2.5,2), what is the radius?

*April 3, 2013*

**Geometry: Student Correction (Stuck)**

she sucks

*March 29, 2013*

**Chemistry**

h2, i2 = 11.4 hi = 22.8

*March 16, 2013*

**MATH**

Radical equation, with a graphing calculator to the nearest thousandth?? 1 over /pi x-3+ sq2over/ 2.7x = 1.8??

*March 11, 2013*

**Physics**

I came here earlier with this question: "A force of 20 N acts toward the west. Another force acts at the same point so that the resultant of the two forces is zero. What is the magnitude and direction of the second force?" I was wondering if someone could explain to ...

*March 5, 2013*

**Physics**

A force of 20 N acts toward the west. Another force acts at the same point so that the resultant of the two forces is zero. What is the magnitude and direction of the second force?

*March 4, 2013*

**physical chemistry**

This question is about a lab called Heats of Ionic Reaction in my Physical Chemistry class. I need to know why there should be a large percentage error in deltaH4

*March 4, 2013*

**math**

27-^(2/3)

*March 2, 2013*

**math**

81-^3/4 cubed of 81-square root of 3 over 4 which is cubed

*March 2, 2013*

**math**

square root of 45 simplfy by factoring

*March 2, 2013*

**math**

a+9b=23 a+2b=2

*February 16, 2013*

**math**

why do i find this confusiong a+8b=11 a+2b=-1

*February 16, 2013*

**math**

find the ordered pair of a+8b=9 a+3b=-1

*February 16, 2013*

**chemistry**

help please, have no clue how to solve this. (a) you are given a mixture containing two compounds, A and B. both compounds have a solubility of 1g/100mL of solvent at 20 deg C and 16g/100mL of solvent at 100 deg C. The sample is composed of 3.5 g of A and 10 g of B. at 100 deg...

*February 11, 2013*

**Math precal**

Show that ab= 1/2 [(a+b)^2 - (a^2+b^2)] Show how's its done i want to learn thank u

*January 10, 2013*

**geometry**

a tree grew at a 3 degree slant from the vertical. at a point 60 feet from the tree, the angle of elevation to the top of the tree is 14 degrees. find the height of the tree to the nearest tenth of a foot.

*December 11, 2012*

**geometry**

an A-frame house is 45 feet high and 32 feet wide. find the measure of the angle that the roof makes with the floor. Round to the nearest degree.

*December 11, 2012*

**Geometry**

A 38 foot tree casts a 16 foot shadow what is the angle of elavation of the sun to the nearest degree?

*December 11, 2012*

**Physics**

A truck is moving 40 m/s when it encounters a ramp inclined by 30% above the horizontal. Gravel provides a frictional force to slow the truck and has a coefficient of friction(.5). How far along the ramp would the truck travel before coming to a stop?

*December 9, 2012*

**calculus**

a lighthouse is 1 km from the shoreline and revolves at 10 pi radians a minute what is the speed of the light as it sweeps across the shore as it lights up at sand at 2 km from the light house

*December 6, 2012*

**Chemistry**

How much heat, in Kj, is required to melt 11.0g of ice, at -13.0 degrees C, and vaporize the H20, and rise the temperature of the steam to 114 degrees C. Need help. Anyone, please!

*November 19, 2012*

**math**

765 876

*November 15, 2012*

**PHYSICS HELP!**

A typical propeller of a turbine used to generate electricity from the wind consists of three blades as in the figure below. Each blade has a length of L = 33 m and a mass of m = 415 kg. The propeller rotates at the rate of 21 rev/min. 120degree angle between blades a) Convert...

*October 31, 2012*

**Calculus**

A farmer has 120 meters of wire fencing to make enclosures for his pigs and cows. The rectangular enclosure he is considering will have one side up against a barn (in the center of one side that is 150 meters long, so the enclosure won't require fencing along that edge) ...

*October 30, 2012*

**College Chemistry**

Two moles of Mg and five moles of O2 are placed in a reaction vessel, and then the Mg is ignited to produce Mg (F.W.= 40.31 g/mole). What is the actual mole ratio, the calculated mole ratio, how many moles of MgO are formed, and what is the weight of MgO formed?

*October 21, 2012*

**Chemistry**

The solution CrCl3 is not colored. What does this suggest about its electron configuration?

*October 13, 2012*

**Math**

128=x+16 128= number of total students. X= the number of boys so, 16+X because there are 16 more girls than boys... so subract 16 from 128 which equals 112 so the number of boys is 112 and the number of girls is 112+16

*October 13, 2012*

**Literature**

How was Opheila mistreated by male characters in Hamlet.

*October 13, 2012*

**math**

Jon begins jogging at a steady 3m/sec down the middle of lane one of a public track. Laura starts even with him in the center of lane two but moves 4m/sec. At the instant they begin, Ellie is located 100 meters down he track in lane four, and is heading towards them in his ...

*October 2, 2012*

**Chemistry**

can u explain that a little more because i still don't understand

*September 23, 2012*

**Chemistry**

The density of dry air measured at 25 degrees Celsius is 1.19x10 to the negative 3rd power. What is the volume of 50.0g of air?

*September 23, 2012*