# Posts by JEFF

Total # Posts: 821

**physics**

a 600 kg hammer of pile driver is lifted 2 meters above a piling head. what is the change in potential energy if the hammer is released, what will its speed at the instant it strikes the piling?

**Math**

Fine the size of the following matrix and its additive inverse matrix. Identify if it is a square, column, or row matrix: [ 2 -3 7 1 0 4 ]

**math**

I think you would need one of the variables because all that is telling me is 180 = 1/2bh . Are there any other variables listed?

**math**

This is about direct variation. The area a painter can paint varies directly with the amount of time he works. One morninig, he painted 204 ft² between 8 a.m. and 12:15 PM. Write a direct variation equation to describe the area y covered in x hours. The forumlua for ...

**Trig**

Simplify: (cosx + cos2x + cos3x + cos4x + cos5x + cos6x) / (sinx + sin2x + sin3x + sin4x + sin5x + sin6x) into a single Cotangent function. Using the sum-to-products, I was able to get remove some of the addition in attempts to get full multiplication, but I could not get the ...

**math**

Find the maximum area of a rectangle inscribed between the x-axis and f(x)=-x^4+3

**science**

ice

**science**

jeff

**Math**

Find the periodic payment that will amount to the given sum under the given conditions: S=$150,000; interest is 6% compounded semiannually; payments are made at the end of each semiannual period for 11 years.

**math**

how would 3 neighbors divide a sharing a rectangle piece of land divide it into 24 equal pieces and what fraction of land would each get

**chemistry**

how many moles of sodium ions are present in 3.50 L of 0.400 M Na3PO4?

**math**

This pattern represents the SQUARE NUMBERS: 1,4,9,16,25,36...draw a picture or diagram to explain SQUARE NUMBERS.

**science**

How often do you water basil?

**spanish**

Help with spanish!!!! Have to put correct words in the banks. 2 of them will not be used.? Querida Beth: 1) (blank) esta todo bien y esperamos que 2) (blank) tambien lo este. 3) (blank) lo pensemos y lo conversemos, tu padre y yo no estamos contentos con tu viaje. 4) (blank) ...

**Chemistry**

When titrating an acid with a base, a dilute solution of the base is used. When titrating a base with an acid, a dilute solution of acid is used. Why are these titrations done with dilute solutions?

**Chemistry**

What volume of 0.5 N nitric acid would be required to completely neutralize 300 ml of 1.0 N sodium hydroxide?

**Chemistry**

If you had one gallon of concentrated hydrochloric acid (12 N) and added water to make dilute hydrochloric acid (6 N), how much dilute hydrochloric acid would you have?

**physics**

thank you !

**chem**

In the explosion of a hydrogen-filled balloon, 0.54 g of hydrogen reacted with 6.6 g of oxygen to form how many grams of water vapor?

**marketing**

Your team has been hired by ABC company’s senior management to conduct a research project. The company has 40 employees and has been in business for 25 years. The company offers sales & service on all sizes of new Xerox copiers. The company has been faced with decreasing ...

**chemistry**

Calculate the volume of 1.80 M \rm Na_3PO_4 in milliliters that contains 6.00 g of solute.

**college- Physics**

lulz

**math figuire**

Volts divided by the amount of resistance will give you the amps.

**Biochem**

The conc is 6.0M HCL

**Physics**

Two motorcycles are traveling due east with different velocities. However, 2.16 seconds later, they have the same velocity. During this 2.16-second interval, motorcycle A has an average acceleration of 1.30 m/s2 due east, while motorcycle B has an average acceleration of 19.4 ...

**Pre Calc**

From a committee of 6 people how many sub-committees of 3 can be formed, and with 7 people and with 8 people and with n people?

**Pre Calc**

How many triangle are determind by the vertices of a hexagon, heptagon, octagon, and n-gon?

**Math**

in salem, 42% of the registered voters are republicans and 44% are democrats. the other 217 are independents. how many registered voters are there in salem?

**math**

During a football game, two players try to tackle another play. One player applies a force of 50.0 N to the east. A second player applies a force of 120.0 N to the north. What is the total applied force? (Since force is a vector, you must give both the magnitude and direction...

**Chemistry**

A 4.50 g sample of LiCl at 250 C dissolves in 25.0 ml of water also at 25.0 C.? The final equilibrium temp of the resulting solution is 60.8 C. What is the enthalpy of solution, deltaHs, of LiCl expressed in kilojoules per mole.

**6th grade math**

Boy dis is 2 ez

**CHEMISTRY**

Explain why it is quantitatively not acceptable to titrate each of the vinegar samples with the NaOH titrant to the same dark pink endpoint?

**algebra**

The perimeter of a rectangle is 128m the length is 4m more than twice the width

**12th grade maths**

i deposit 1,000 for 4 years a rate 2% nthe compounded annually how much money after 4years

**statistics**

which of the following statements are correct? a. a normal distribuiton is any distribution that is not unusual. b. the graph of a normal distribution is bell-shaped. c. if a population has a normal distribution, the mean and the median are not equal. d. the graph of a normal ...

**statistics**

indicate whether the given statement could apply to a data set consisting of 1,000 vlaues that are all differnt. a. the 29th percentile is greater thatn the 30th percentile b. the median is greater thatn the first quartile c. the third quartile is greater than the first ...

**12th grade**

The area of a circle is 28.26 square centimeters. What is its diameter (use 3.14 for ð)?

**physics**

A big yo-yo(radius .2m, mass 20kg) has a string wrapped about its circumference. If yo-yo falls, how far does it fall in 2 seconds? (The yo-yo is shaped like a disk)

**chemistry**

100 million automobiles contains 1.1 kg of CFC-12 and leaks 25% of its CFC-12(CF2Cl2) into the atmosphere per year, how much Chlorine in kilograms is added to the atmosphere each year due to auto air conditioners?

**economics**

By 2008 the US trade deficit was still very large (roughly 5% of gross income) and our net debt position was around $5 trillion (over 1/3 of gross income). Unfortunately, it also appears that we have fallen into a major recession of uncertain duration and depth. Discuss the ...

**Accounting**

Imagine you have been selected by your manager to present a training session to a group of new employees. The new hires do not have accounting backgrounds and have little or no work history in a responsibility center. The purpose of this training session is to explain the ...

**Physics**

A hunter aims directly at a target (on the same level) 125m away. If the bullet leaves the gun at a speed of 227 m/s, by how much will it miss the target? I'm not sure how to approach this problem. I know I need to find the horizontal distance traveled, probably by finding...

**Algebra 2**

I meant to type this one: If the sine of an acute angle is 0.8, what is the sine of twice that angle? 1.60 or .64? Thanks

**Algebra2**

I got it, .5

**Algebra2**

Help How do I figure out: (cos 40)(cos20) - (sin 40)(Sin 20) Thank you

**Right Hand Rule**

a) west b) zero deflection c) up d) down

**algebra 2**

I am taking an online class, and cant understand why when I calculate ona ti84 plus an answer I get decimal answer and my teachers answer is sq root, is there something I am not doing on my calculator? How do I convert. Example, teachers answer to the following was sin 315deg...

**algebra2**

Example, teachers answer to the following was sin 315deg = -sin 45deg = -sqrt2/2 I got a decimal answer.

**algebra2**

I am taking an online class, and cant understand why when I calculate ona ti84 plus an answer I get decimal answer and my teachers answer is sq root, is there something I am not doing on my calculator? How do I convert.

**Chemistry**

902 mL

**statistics**

The first class in a relative frequency table is 50–59 and the corresponding relative frequency is 0.2. What does the 0.2 value indicate?

**Science**

what is the relative location of the marine biome, specifically the ice cap biome?

**chemistry**

6) How many grams of copper (II) fluoride, CuF2, are needed to make 6.7 liters of a 1.2 M solution?

**calculus**

sum_(n=-1)^infinity(-1)^(n+1) (1/3)^n = 9/4~~2.25... How do you find that out? Is there a formula?

**chemistry**

Write a net equation for the reaction between aqueous solutions of HBr and NH3.

**Finance**

7.90%

**math**

Evaluate f(x)= 4x^2 - 2 for f(1/2)

**managerial economics**

a) Given total cost function as C=160+16Q+0.1Q(2){squared} and price equation P=96-0.4Q. Total Revenue function is R=PQ=96Q-0.4Q(2). The profit function is F=R-C=(96Q-0.4Q(2))-(160+16Q+0.1Q(2))=80Q-0.5Q(2)-160. Profit attains maximum when and is negative dF/dQ=0 and d(2)F/dQ(2...

**chemistry**

How many grams of oxygen are required to react with 0.128 lead(II) sulfide?

**algebra**

x – 2y = 6

**Chemistry**

This question is: How many orbitals are there in each of the following energy levels.. a) 1s b) 6p c) 10f d) 7d e) 5s Now.. do i use n^2 for the number of orbitals in each energy level? Ex. b) would be 36 OR can i state the number of orbitals in each sublevel using the shape? ...

**Chemistry**

Why do atoms display spectra?

**chemistry**

how did you get that?

**Calculus**

An isosceles triangle has a vertex at the origin. Determine the area of the largest such triangle that is bound by the function x^2 + 6y = 48. So, y=8 when x=0 making a vertical side equal to 8. I also determined that there is a zero at =/- the square root of 48, or ...

**Calculus**

The radius of a tank can not exceed 5m, and the height can not exceed 12 m. Is it possible to construct a tank with a volume of 900m^3? If it is possible, determine the minimum amount of material required to make the tank. When i solve it, the radius exceeds the restrictions...

**physics**

Evidence suggests that there are trillions of dollars' worth of minerals and metals buried in Near Earth Asteroids (the ones that come close to the Earth, not the ones in the asteroid belt between Mars and Jupiter). Many scientists think an asteroid mining mission is ...

**Chemistry**

I've been asked to find the IUPAC name for polyvinyl acetate. when i type it in google i keep getting butan-2-yl acetate. but isn't the IUPAC name for acetate ethanoate ..? so would the proper IUPAC name for PVA be butan-2-yl ethanoate?

**Physics**

What is the equation for work?

**Middle school Math**

Graph 3y-4=11 by finding intercept(s) How do you do this... Thanks

**Math**

Stop cheating. gtfo. (Like Kevin, there is no doubt in my mind that you will be victorious.)

**Chemistry**

I'm doing an intro to organic chem, and i'm looking at the functional groups of organic compounds. More specifically, I am looking at melting/boiling points. I keep reading that one has a greater m/b pt. than another, but another one has a greater m/b pt. that one but ...

**French**

I need help with grammar, can someone check it out for me? 1. Une valeur mobilière est un fongibles, un instrument négociable représentant une valeur financière. Les deux types de valeurs mobilières sont les actions et les obligations. 2. Une...

**electric potential**

Given a square of side length a = 6 cm. We place a charged particle at each corner, three of them carry +7 nC of charge and one carries the same amount of negative charge. What is the electric potential at the center of the square? Choose V = 0 V for a position very far from ...

**Chemistry**

What are the products when you add water to 2-methyl-2-pentene?

**calculus**

dh/dx x = 7 , h (x) = (x^-1/2 + 8x)(4 - x^-1)

**Personal Finance**

The Lees, a family of two adults and two dependent children under age 16, had a gross annual income of $68,000 for 2007. Determine their standard deductions, exemption, and child tax credit amounts, as well as their marginal and average tax rates assuming their filing status ...

**10th grade**

I need to unscramble the letters to this word from the renaissance. The letters are NWIHZGLCIRULI

**science**

An athlete throws a basketball through a hoop. The ball leaves his hands at a height of 2.5 m with a speed of 9.0 m/s. Calculate the speed of the ball when it “swishes” through the hoop. The hoop is at a height of 3.0 m and it is 5.0 m along the court from the ...

**Math**

Yes. X=2-2t y=3t

**Physics**

Two events that are simultaneous in one frame of reference will be: A) simultaneous in all frames of reference B) simultaneous in another frame that is moving in the opposite direction C) simultaneous in another frame of reference that is moving in the same direction D) ...

**Math**

If the digits 1 through 9 are written in order, it is possible to place plus and minus signs between the numbers or to use no operation symbol at all to obtain a total of 100. For example,1 + 2 + 3 + -4 + 5 + 6 + 78 + 9 = 100 Can you obtain a total of 100 using fewer plus or ...

**Algebra**

Let U = {u, n, i, t, e} A = {n, i, t} B = {n, e} C = {u, n, i, t, e} D = {u, e} Find each of the following: (a) A ¡ä B (b) C ¡å D (c) ¡D¡ (d) ¡A ¡å D¡ (e) B ¡ä ¡C¡ (f) (B ¡ä C) ¡...

**Algebra**

Given the following function rules and domains, find the associated ranges. (a) f(x) = 2x +3, Domain = {0, 1, 2} (b) f(x) = 0, Domain = {0, 1, 2} (c) f(x) = 2x + x2, Domain = {1, 0, 2}

**Algebra**

16

**statistics**

Question 1 Question 1 1. Question 1 text The head of the History Department wants to compare the averages of 2 different instructorâ€™s to see if they differ. A sample of 15 students in Instructor Aâ€™s class has average of 74 with a standard ...

**math**

estimate 4/5of 49

**math**

6/11x32 by using estimating product

**math**

2/3x35 by using estimating product

**math**

3/4x35 by using estimating product

**math**

7/8x30 by using estimating product

**math**

5/8x41 by using estimating product

**math**

2/9x26 by using estimating product

**math**

2/9x26 by using estimating product

**math**

3/7x29 by using estimating product

**math**

1/2x17 by using estimating product

**math**

1/5x26 by using estimating product

**math**

3/8x17 by using estimating product

**math**

5/8x19 by using estimating product

**math**

4/7x20 by using estimating product

**math**

what is 1/5x24 by using estimating product