# Posts by Robert

Total # Posts: 993

**Physics**

A car sits in the parking lot. Above is a cargo plane, flying horizontally at 61 m/s. At the exact moment the plane is 182 m directly above the car, a crate accidentally falls from its cargo doors. Relative to the car, where will the crate land? Enter m as unit and use g = 10...

**Physics**

Bert is standing on a ladder picking apples in his father's orchard. As he pulls each apple off the tree, he tosses it into a basket that sits on the ground 2.2 m below at a horizontal distance of 1.3 m from Bert. How fast must Bert throw the apples (horizontally) in order...

**Physics**

A ball rolls off the edge of a balcony at 8.0 m/s. Find its speed after 3.8 s in the air. Use g = 10. m/s2 and enter m/s as unit.

**Physics**

In her physics lab, Jessica rolls a 20-g marble down a ramp and off the table with a horizontal velocity of 1.10 m/s. The marble falls in a cup placed 0.44 m from the table's edge. Find the table's height. Use g = 10. m/s2. Enter m as unit.

**chinese grammar**

§Ú们礼»ª¦a©Ú绝¦oªºn¨D

**Science**

i belieeve you are working on penn foster :P if you are, you should email me and we can work together on it, im actually almost done with it. my email is rvargas @ live (dot) com. sorry, had to put it that way, cant post email addresses aparently :0

**Chemistry**

An aqueous solution of ethanol is 14.1M C2H5OH. The density of the solution is 0.853g/mL. What is molality of ethanol in the solution? What is mass % of ethanol in solution? I got the molality which is -21.7 ethanol, but I can't figure out how to get the mass % from the ...

**physics PLEASE HELP**

-2.793e-6

**English**

A restrictive clause is one that A. usually occurs at the beginning of a sentence. B. limits the meaning of the word it describes. C. should be set off by commas. D. functions as an adverb.

**algebra**

81x^5 - 3x^2

**Statistics**

Which of the following statements is not true about samples that can be treated as matched pairs data? I. Data collected on these samples is analyzed by calculating the differences between paired observations and using that data in one sample tests. II. Each value in the first...

**Statistics**

The game of chuck-a-luck consists of rolling 3 dice. The player picks a number, 1, 2, 3, 4, 5, or 6. Winning and losing depends on the number of times the number appears on the top of each die. If the number appears once then the winnings are equal to the bet. If the number ...

**maths**

Find the probability of drawing a diamond card in each of the consecutive draws from a well shuffled pack of cards,if the card drawn is not replaced after the first draw

**math**

Thank you ,I think I chose that answer but I did erase at one time and chose 4/5.Find out soon enough ,working on GED and it has been some years.

**math**

1/5

**math**

those were my choices

**math**

If I have 25 balls in a bowl 10 black,5 blue ,5 green ,5 red . what is the probability of me pulling out a red? 1/5 ,4/5,2/10,1/25 etc....

**Physics**

A shear force of 3.1 105 N is applied to an aluminum bar of length L = 19 cm, width w = 5.2 cm, and height h = 2.3 cm as shown in the figure below. What is the shear deformation Äx?____m

**Steve help pleaseeeee**

square root of 5

**Algebra 2 help please :)**

What is a cubic polynomial function in standard form with zeros 1, –2, and 2? Use synthetic division to find P(3) for P(x) = x^4 – 6x^3 – 4x^2 – 6x – 2. Divide 3x^3 + 3x^2 + 2x – 2 by x + 3 using long division. Divide using synthetic division. &#...

**Algebra 2 help :)**

Any number in the form of a+-bi , where a and b are real numbers and b not equal 0 is considered a pure imaginary number. TRUE OR FALSE The minimum value is the smallest y-value of a function. T RUE OR FALSE i2 = square root of -1. TRUE OR FALSE Complex numbers can be graphed ...

**Algebra 2 help!!!**

What value completes the square for the expression? x2 + 14x Use the quadratic formula to solve the equation. x2 – 7x – 6 = 0 Simplify the expression. (–2i)(8i) What are the solutions? 1/2x^2 + 2x + 3 =0 I need help

**Algebra 2**

Can you double check my answer The lengths of the sides of a rectangular window have the ratio 1.6 to 1. The area of the window is 2,560 square inches. What are the dimensions of the window? (1 point) 50.6 inches by 50.6 inches 40 inches by 64 inches 40 inches by 80 inches <...

**HELP ! Algebra**

Solve the quadratic equation by completing the square. (-x^2 + 6x + 10 = 0)

**HELP !!! Algebra 2**

15. What is the solution of the linear-quadratic system of equations? {y = x^2 + 5x - 3} {y - x = 2}

**Math for Steve or someone good at math**

Okay im not sure if anyone was even right but i dont feel like checking a million times, i got a 3/5 following one of them. The answers are: B 10% increase D 12% decrease A 20% increase D 8% decrease B increase was about 1.1% Please do not listen to the trolls, they just want ...

**Math for Steve**

If you could see WARNING!, Jman, and Emily both replied within 4 minutes. Thats how you can tell they are lying. Josslyn was correct, the other people are the type of people that are banned from the site. (other person* because it was one guy making the names).

**Statistics**

@John I have come from a year later to reply to your concern, to uproot this tyranny that is Math Guru. No longer shall we sit wondering what the other half of the question is. No longer must we be given a formula and have to solve it out. NO LONGER MUST WE SIT THROUGH THIS. ...

**Statistics**

I got only love for John. The answer is fate

**physics**

Since the masses stick together, there is conservation of momentum but no conservation of energy. Let x be the new velocity. Hence, 0.5*0.4 + 0.8*(-0.20) = (0.5+0.8)*x X = (0.2-0.16)/1.3 = 0.0307 m/s KE = 0.5*1.3*0.0307^2 = 0.000615 J.

**Science**

While traveling along a highway a driver slows from 24 m/s to 15 m/s in 12 seconds. What is the automobile's acceleration? How would I show the work and find this answer?

**Algebra 2**

3. Identify the vertex and the axis of symmetry of the graph of the function y = 3(x + 2)2 – 3. (1 point) A- vertex: (2, –3); axis of symmetry: x = 2 B- vertex: (–2, –3); axis of symmetry: x = –2 C- vertex: (2, 3); axis of symmetry: x = 2 D- vertex...

**chemistry**

how many milliliters of 0.250 M KMnO4 are needed to react with 3.55 grams of iron(II)sulfate, FeSO4? the reaction is as follows: 10FeSO4(aq)+2KMnO4(aq)+8H2SO4(aq)¨ 5Fe2(SO4)3(aq)+2MnSO4(aq)+K2SO4(aq)+8H2O(l)

**chemistry**

WHAT IS THE VOLUME IN MILLILITERS OF 0.100 SULFURIC ACID CONTAINING 0.949 GRAMS H2SO4

**Algebra 2 Helpp :(**

QUESTIONS (vvv) (1) Solve the system by subsitution 2x + y = -11 3 - 4y = 11 (2) Solve the system by elimination 2x + 6 = -12 5x - 5y = 10 (3) What is the solution of the following system? -3x - 2y = -12 9x + 6y = -9 (4) What is the solution of the following system? x - y = 11...

**Algebra 2 Please Help**

22. The graph of g(x) is f(x) translated to the left 8 units and up 2 units. What is the function rule for g(x) given f(x) = x²? (2 points)

**Algebra 2 Please Help**

Please show your work on how you got the answer please and thank you :)

**Algebra 2 Please Help**

21. A candle is 17 in. tall after burning for 3 hours. After 5 hours, it is 15 in. tall. Write a linear equation to model the relationship between height h of the candle and time t. Predict how tall the candle will be after burning 8 hours. (2 points)

**Ratios of Similar Figures**

is number 5 c?

**nutrition**

Jonathan, a two-and-a-half-year-old, lives with his mother and brothers at his grandmother's house in Chicago. His mother, Anita, works at a pharmacy to support the family. Jonathan spends his days at home with his grandmother. While Anita works, his grandmother brings the...

**History**

ccbdb

**Microeconomics - University of Boston**

4. If Cassandra bought 16 cotton blouses last year when her income was $40,000 and she buys 24 cotton blouses this year when her income is $50,000, then what is her income elasticity of demand? Interpret what the income elasticity of demand you just calculated means to you. ...

**Microeconomics**

4a. In the market for hand-made guitars, when the price of guitars is $800, annual revenues are $640,000. When the price falls to $700, annual revenues decline to $630,000. Over this range of guitar prices, is the demand for hand-made guitars elastic, unit-elastic, or ...

**Microeconomics**

The producer of X is contemplating a price change and has asked for your advice. After some empirical investigation, you conclude that the price elasticity of demand for X is 1.25. As an economist, what would you advise the producer to do in order to raise total revenue? Would...

**Physics**

In Case A the mass of each block is 4.8 kg. In Case B the mass of block 1 (the block behind) is 9.6 kg, and the mass of block 2 is 4.8 kg. No frictional force acts on block 1 in either Case A or Case B. However, a kinetic frictional force of 9.4 N does act on block 2 in both ...

**chemistry**

in an experiment, 2.50g of salicylic acid is reacted with 10.31g of methanol. the yield of methyl salicylate, C8H8O3, is 1.27g. what is the percentage yield?

**chemistry**

if a reaction vessel contains 11.5g NH3, 12.0g O2, and 10.5g CH4, what is the maximum mass in grams of hydrogen cyanide that could be made?

**chemistry**

in a reaction of 3Cu(s)+ 8HNO3(aq)¨ 3Cu(NO3)2(aq) +2NO(g) + 4H2O(l). if 5.58 grams of Cu(no3)2 is made how many grams of nitrogen monoxide is present

**chemistry**

copper metal reacts with nitric acid. assume that the reaction is 3Cu(s) + 8HNO3(aq) ——> 3Cu(NO3)2(aq) + 2NO(g) + 4H2O(l). if 5.58 grams of Cu(NO3)2 is obtained, how many grams of nitrogen monoxide would have formed

**Science**

In the early 20th century, some scientists were reluctant to accept the conclusion that DNA could be the genetic material because it is so_________________.

**IMPERIALISM AND THE PROGRESSIVE ERA**

Ivy L. Lee

**Biology**

A bacterium that synthesizes an enzyme that neutralizes an environment toxin would probably use a(n) _____________ operon to regulate production of the enzyme.

**world history**

you should email me, im also in Penn Foster lol we could cut work in half if we work on this crap together.. rvargas1020 @ live . com

**science**

200g of steam at 110°C is condensed, and the resulting water is frozen into ice at 0°C. How much heat was removed?

**english 4**

Please explain to me how to determine the answer im looking for

**english 4**

if i knew i would not ask

**english 4**

The two waiters exchanged a look whose meaning was clear to me. what type of clause or phase is used?

**english4**

can you explain to me how to determine what type of verbal it is my choices are Participle, Gerund, and infinitive

**english4**

What do you think Ms. Sue

**english4**

Well as the verbal i chose "to be moved" im not sure what type of verbal it is!

**english4**

He will not allow the table to be moved. identify the Verbal in the sentence and type of verbal

**english4**

what type of clause or phrase is used in the sentence: we hit a snag while rowing to shore

**math**

Average Growth Rate(2000-2009)of China - GDP: 10.9 Population: 0.8 Per Capita GDP: 10.1 Ethiopia - GDP: 7.5 Population: 2.8 Per Capita GDP: 4.7 How fast does total output(GDP)have to grow in order to raise per capita GDP in Instructions: Enter your responses to one decimal ...

**Physics**

Max Height = 1,306M Range = 3,840M Hangtime/Total Time = 32 seconds Time to reach max height = 16 seconds

**English**

What are the nouns and verbs in the sentence. Life is full of choices, so I must learn to make good ones.

**Biochemistry**

Acetylcholinesterase catalyzes the hydrolysis of the neurotransmitter acetylcholine: Acetylcholine + H2O actetate + choline The KM of acetylcholinesterase for its substrate acetylcholine is 9 x 10-5 M. In a reaction mixture containing 5 nanomoles/ml of ...

**Linear Algebra**

awesome, thanks a lot Steve, that link will come in handy!

**Linear Algebra**

Solve the following system using Gauss's algorithm (a) x1 + 2x2 + 4x3 + 6x4 = 3 2x1 + x2 + 3x3 = -6 -2x1 + x2 + 6x3 + 4x4 = -11 2x1 + x2 + x3 = 0 so the matrix will be: 1 2 4 6 3 2 1 3 0 -6 -2 1 6 4 -11 2 1 1 0 0

**Math**

Staring from the pit, Helen made three laps around a circular track at 40 seconds per lap. She than made a 30-second pit stop and two and a half laps before running off the track and getting stuck in the mud for the remainder of the race. Graph Helen's distance from the ...

**Calculus**

Calculate the following integral and determine whether it's convergent, or divergent. integral at [-3,0] x dx / sqr(9 - x^2)

**calculus**

Thanks Reiny and Steve. Now to pass the exam!

**calculus**

Calculate the following integral: ∫ dx / x(1 - √x)^2

**Calculus**

thanks Steve! You're a lifesaver

**Calculus**

Calculate the following integral: ∫ sec^4 (3x)/ tan^3 (3x) dx For this one, can I bring up the tan to tan^-3?

**Algebra**

Algebra Question: A team wins 15 of their first 20 games. If they win only half the time from now on, how many games will they have to play in order to win 60% of their total games? I have it figured out manually, but cant get it in equation form.

**Calculus - Question**

If I go with my first assumption I get this: ∫ sec^4 (3x) tan^-3 (3x) = ∫ sec^3 (3x) tan^-4 (3x) sec(3x)tan(3x) dx = ∫ sec^3 (3x) (sec^-4 3x - 1)sec(3x)tan(3x) dx u = sec(3x) dx du = 3sec(3x)tan(3x) dx > 1/3du = 1/3 ∫ u^3 (u^-4 - 1) du = 1/3 ∫...

**Calculus - Question**

Or do I use the rule of ∫ sec^n x dx divided by the rule of ∫ tan^n x dx?

**Calculus - Question**

Am I allowed to do this? for the integral of ∫ sec^4 (3x)/ tan^3 (3x) dx I change it to ∫ sec^4 (3x) tan^-3 (3x) From here I use the rule for trigonometry functions.

**Linear Algebra**

Last number from the sample test! A plane P passes by the coordinates: A(1,0,-7); B(-2,-1,0); C(0,0,-3) Using the equation of the line D: x= 7+12t, y= -1-6t, z= 2-2t, Find the equation of a line that's entirely part of the plane P and that is perpendicular to the line D at...

**Linear Algebra 2**

This is another question I can't figure out. Given planes pie1 and pie2 defined as: pie1: 2x + 5y - 7x + 2 = 0 pie2: x + y - z + 3 = 0 (b) Give the equation of the line of intersection of these two planes. I only found the answer for (a) where they ask to find the angle ...

**Linear Algebra**

THanks again Mate! You've been a big help lately, I really appreciate it.

**Linear Algebra**

So I'm studying for my first exam and I'm stuck on this number. Given both lines: D1: (x,y,z) = (2,0,0) + k(0,3,0) D2: (x,y,z) = (2,0,2) + k(0,0,1) (a) Give the algebraic equation of the plane containing both lines. I know that I have to start off by finding the ...

**Linear Algebra**

THanks Mate!

**Linear Algebra**

2 people move in the same direction along a line of equation: (x + 3)/10 = (y + 10)/20 = (z - 10)/-20 Mobile M1 is at a point A(-3, -10, 10) and moves at a velocity of 6m/s towards point B(7, 10, -10) where Mobile 2 is found, walking in the same direction at a velocity of 3m/s...

**Calculus**

THanks Steve and Reiny!

**Calculus**

Hello, I just wanted to verify if my work was good. Calculate the following integral by parts: ∫ upper limit is 1/5 and lower limit is 1/10. of 10sin^-1 (5x)dx so first I named the variables: u = 10 sin^-1 (5x) du = 50 / sqr(1-25x^2) dv = dx v = x so we get: = 10 sin^-1...

**Definite integral by parts (correction)**

Hello, I just wanted to verify if my work was good. Calculate the following integral by parts: ∫ upper limit is 1/5 and lower limit is 1/10. of 10sin^-1 (5x)dx so first I named the variables: u = 10 sin^-1 (5x) du = 50 / sqr(1-25x^2) dv = dx v = x so we get: = 10 sin^-1...

**Math**

Knowing u = (4,0,-3), v = (x,3,2) and that the orthogonal projection of v on u is a vector of norm 6, determine x. Thank you

**Linear Algebra**

Ok this is the last one I promise! It's from a sample exam and I'm practicing for my finals :) Verify if the following 4 points are consecutive vertices of a parallelogram: A(1,-1,1); B(3,0,2);C(2,3,4);D(0,2,3) (b) Find an orthogonal vector to the plane containing the ...

**Linear Algebra 2 question**

sorry I wrote D, but there is no D, just AB and C

**Linear Algebra 2 question**

Hello, I have another question from my linear algebra class. I'm asked to find the area of a triangle using determinants, but they don't give me the vertices, only the sides. Where A,B,C and D are the vertices, u and v are 2 out of the 3 sides. Now they give me u=(-3,1...

**Linear Algebra**

Knowing u = (4,0,-3), v = (x,3,2) and that the orthogonal projection of v on u is a vector of norm 6, determine x. Thank you

**science**

1.How many meters away is a cliff if heard one half second after the original sound? Assume that sound travels at 343m/s on that day

**Physics - Electromagnetism 2**

Two coils, held in fixed positions, have a mutual inductance of 165 µH. What is the peak emf in one coil when the current in the other coil is I(t) = 16.0 sin(1.15 103t), where I is in amperes and t is in seconds? Just a few hints on how to start it off would be very ...

**Physics - Electromagnetism**

An inductor in the form of a solenoid contains 440 turns and is 15.8 cm in length. A uniform rate of decrease of current through the inductor of 0.421 A/s induces an emf of 175 µV. What is the radius of the solenoid?

**Physics 2**

thanks. It's all good, I understand your approach and I really appreciate it!

**Physics 2**

thank you very much drwls, this is a question from a sample exam, getting ready for my finals tomorrow!

**Physics 2**

the character that doesn't show up is the emf (E)

**Physics 2**

Show that during the charging of the capacitor in an RC circuit, the charge of the capacitor, as a function of time, is: q(t) = C(1 – e-t/RC)

**Physics - Electromagnetism**

A charge +q is at the origin. A charge –2q is at x = 2.00 m on the x axis. For what finite value(s) of x is (a) the electric field zero? (b) the electric potential zero?