Tuesday

October 13, 2015
Total # Posts: 1,064

**CHEMistry**

A 2.50-g sample of powdered zinc is added to 100.0 mL of a 2.00-M aqueous solution of hydrobromic acid in a calorimeter. The total heat capacity of the calorimeter and solution is 448 J/K. The observed increase in temperature is 21.1 K at a constant pressure of one bar. Using ...
*March 27, 2013*

**physics**

exp(2piji/M)beta j
*March 20, 2013*

**physics**

Got this result for above question: exp(2ðji/M)âj However it is graded as wrong, can someone help?
*March 20, 2013*

**Quantum Physics**

Meant thanks Helpman!
*March 20, 2013*

**Quantum Physics**

Thanks Anonymous and Gyanno! Anyone got Problem 3, 4 or 5?
*March 20, 2013*

**Quantum Physics**

Thank you! Did somebody figure out one or all of the QTF6 questions?
*March 20, 2013*

**Quantum Physics**

What is w? You can use e, pi, and M in your response. Please do not subtitute 6 for M. Got this result for above question but it is graded wrong, can someone help? e^i*pi/3
*March 20, 2013*

**Quantum Physics**

In Problems 1 to 5 we will work through example of QFTM for M = 6. Problem 1: What is w? You can use e, pi, and M in your response. Please do not subtitute 6 for M. Specify the probability amplitudes. You should use w to denote ƒÖ, but please fully simplify your ...
*March 20, 2013*

**Quantum Physics**

What is w? You can use e, pi, and M in your response. Please do not subtitute 6 for M.
*March 20, 2013*

**Quantum Physics**

Anyone for b, c, d?
*March 18, 2013*

**Physics**

A skier of mass 66 kg skis straight down a 11° slope at constant velocity. Draw a free-body diagram of the skier with the various external forces acting on her. Include the force of air resistance, which is directed opposite the velocity. (Do this on paper. Your ...
*March 16, 2013*

**Math**

A trainer for a professional football team keeps track of the amount of water players consume throughout practice. The trainer observes that the amount of water consumed is a liner function of the temperature on a given day. The trainer finds that when it is 90 degrees, the ...
*March 13, 2013*

**math**

A textbook store sold a combined total of 315 physics and chemistry textbooks in a week. The number of physics textbooks sold was two times the number of chemistry textbooks sold. How many textbooks of each type were sold?
*March 7, 2013*

**math**

the problem is 0 < less then or equal to 2x-4<8 I got the answer which is 2< less then or equal to x <6 how do i write this on a graph
*March 7, 2013*

**algebra**

solve the compound inequality write the solution in interval notation 2u+4>-6 and 3u-6> -3 =
*March 7, 2013*

**DYNAMICS**

The 10-lb has an initial velocity of 10ft/s on the smooth plane. If a force F=(2.5t), where t is in seconds, acts on the block for 3s, determine the final velocity of the block and the distance the block travels during this time.
*March 5, 2013*

**DYNAMICS**

The 10-lb has an initial velocity of 10ft/s on the smooth plane. If a force F=(2.5t), where t is in seconds, acts on the block for 3s, determine the final velocity of the block and the distance the block travels during this time.
*March 5, 2013*

**Physics**

An 67.6 kg object moving to the right at 38.7 cm/s overtakes and collides elastically with a second 48.9 kg object moving in the same direction at 19.2 cm/s. Find the velocity of the second object after the collision. Answer in units of cm/s
*March 5, 2013*

**help(reading)**

when a teacher tells you whats your novel, what does he or she mean?
*March 4, 2013*

**social studies**

just numbe 12 actualy
*February 28, 2013*

**social studies**

1. Which of the following helped to increase the populations of northeastern cities? (1 point) more diversity successful cotton crops growth of factories and trade building of the Erie Canal 2. A boundary was set between Canada and the United States as a result of (1 point) ...
*February 28, 2013*

**math**

what is mental math?
*February 21, 2013*

**DYNAMICS**

A car has an initial speed of 25m/s and a constant deceleration of 3m/s^2. Determine thewvelocity of the car when t=4s. What is the displacement of the car during the 4-s time interval? How much time is needed to stop the car? How do i get the displacement?
*February 17, 2013*

**DYNAMICS**

A particle travels along a straight line with a velocity v=(12-3t^2) m/s, when t is in seconds. When t=1s, the particle is located 10m to the left of the origin. Determine the accelaration when t=4s, the displacement from t=0 to t=10s, and the distance the particle travels ...
*February 17, 2013*

**DYNAMICS**

A car has an initial speed of 25m/s and a constant deceleration of 3m/s^2. Determine thewvelocity of the car when t=4s. What is the displacement of the car during the 4-s time interval? How much time is needed to stop the car?
*February 17, 2013*

**math**

Franco went to sticker station. He bought 2 strips of 10 and 6 singles of frog stickers. He also bought 5 strips of 10 and 2 singles of butterfly stickers. How many stickers did Franco buy?
*February 6, 2013*

**math**

Franco went to sticker station. He bought 2 strips of 10 and 6 singles of frog stickers. He also bought 5 strips of 10 and 2 singles of butterfly stickers. How many stickers did Franco buy?
*February 5, 2013*

**math**

Franco went to sticker station. He bought 2 strips of 10 and 6 singles of frog stickers. He also bought 5 strips of 10 and 2 singles of butterfly stickers. How many stickers did Franco buy?
*February 5, 2013*

**Physics**

A projectile (mass = 0.17 kg) is fired at and embeds itself in a target (mass = 2.84 kg). The target (with the projectile in it) flies off after being struck. What percentage of the projectile's incident kinetic energy does the target (with the projectile in it) carry off ...
*January 22, 2013*

**physics**

A movig particle encounters an external electric field that decreases its kinetic energy from 9670 eV to 7540 eV as the particle moves from position A to position B. The electric potential at A is -66.0 V, and that at B is +16.0 V. Determine the charge of the particle. Include...
*January 18, 2013*

**physics**

The membrane that surrounds a certain type of living cell has a surface area of 4.4 x 10-9 m2 and a thickness of 1.6 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 4.1. (a) The potential on the outer surface of the ...
*January 18, 2013*

**physics (electric field)**

The drawing shows the potential at five points on a set of axes. Each of the four outer points is 6.2 x 10-4 m from the point at the origin. From the data shown, find the magnitude of the electric field in the vicinity of the origin.
*January 18, 2013*

**physics capacitor**

What voltage is required to store 8.0 x 10-5 C of charge on the plates of a 6.1-μF capacitor?
*January 18, 2013*

**Math**

64y^3y^4/5
*January 13, 2013*

**math**

Thank you guys!
*January 10, 2013*

**math**

A drivers distance varies directly as the amount of time traveled. After six hours, a driver had traveled 390 miles. How far had the driver traveled after 4 hours?
*January 10, 2013*

**FUNCTIONS 11**

Write an equation for nth term in the sequence: -2, 5, -10, 17, -26
*January 8, 2013*

**Math**

PLEASE HELP I DON'T KNOW WHAT TO DO D': I don't understand what to do or how to even start.... In the town of Niceville, a local lottery is held once a year for the residents. Lottery tickets cost 50 cents apiece. Each lottery ticket contains four numbers, from 1 ...
*December 30, 2012*

**in chem**

can u please tell me the number of molar mass i was using...
*December 24, 2012*

**in chem**

calculate the mass of this sample: 1.05 * 10 to the power of 26 atoms of neon, Ne(g) I know that I have to first divide by the avagadros constant, then once get the moles I need to multiply by the molar mass of neon to get the grams, I did that sevral times but I keep on ...
*December 24, 2012*

**Physics**

cart A with mass: 512g (0.512kg) is on a horizontal table. the cart is connected to cart b with mass: 51.0g (0.051kg) through a string that is crossing a pulley. cart A is released from rest at 60 cm(0.60m), it passes a photogate with a velocity of 0.90m/s. What is the work ...
*December 20, 2012*

**Chemistry**

an explanation please? i need a formula!
*December 14, 2012*

**Chemistry**

can someone give me a formula?
*December 14, 2012*

**calculus**

find the function that is finally graphed after the following transformations are applied to the graph of y=square root x in the order listed. a. reflected about the y-axis b. shift down 3 units c. shifht left 9 units please show work
*December 13, 2012*

**calculus**

write the function whose graph is the function of y=(x+5)^2 but is reflected about the x-axis. y=
*December 13, 2012*

**Algebra**

Mr. Scrooge bought 4 packages of ground beef. The second package weighed three times as much as the first, and the third package weighed half as much as the second. The fourth package weighed fifteen ounces, which was three ounces more than the third package. How many ounces ...
*December 12, 2012*

**chemistry**

* A 50 gram sample of an unknown metal warms from 18 to 58 after absorbing 800 joules of energy. what is the specific heat of the metal? *copper has a specific heat of 0.387 j/g degree celsius. what is the mass of a piece of copper that undergoes a 21.0 C temperature change ...
*December 11, 2012*

**Math**

2) which set of measure could be the side lengths of a right triangle? A. 0.9 cm, 1.2 cm, 1.5 cm B. 4 in, 4 in, 4 in C. 7 m, 8m, 9m****** D. 2ft, 3ft, 4ft
*December 6, 2012*

**Math**

Sorry meant rational number?
*December 6, 2012*

**Math**

Which of these is an irrational number? A.. Sq root of 14 B. -sq root of 9 C. -sq root of 34 D. Sq root of 72
*December 6, 2012*

**Math**

1) 3r + 5 _____. + 2 = 12-2r 2 Find value of r
*December 6, 2012*

**Chemistry**

The fictitious compound, arrhenium fluoride ( ), reacts with itself to form a dimer with the formula Ah2F2 . The reaction is second order in AhF. The value of the rate constant is 8.591x10-3 M-1s-1. What is the initial rate of reaction in a reactor filled with AhF to a ...
*December 4, 2012*

**PHYSICS**

After 6.00 kg of water at 80.4 oC is mixed in a perfect thermos with 3.00 kg of ice at 0.0 oC, the mixture is allowed to reach equilibrium. When heat is added to or removed from a solid or liquid of mass m and specific heat capacity c, the change in entropy can be shown to be...
*December 1, 2012*

**PHYSICS**

The wattage of a commercial ice maker is 226 W and is the rate at which it does work. The ice maker operates just like a refrigerator and has a coefficient of performance of 3.90. The water going into the unit has a temperature of 15.0°C, and the ice maker produces ice ...
*December 1, 2012*

**CHEMISTRY**

The standard electrode potential for the reduction of Eu3+(aq) to Eu2+(aq) is −0.43 V. determine which of the following is capable of reducing Eu3+(aq) to Eu2+(aq) under standard-state conditions? (a) Sn2+(aq) (b) ln(s) (c) HCN(aq) (d) La(s)
*November 30, 2012*

**statistics**

Working on "Inferences from Dependent Samples" trying to find the standard deviation of the difference data. Differences: 24, 53, 100, 40, -10,71,77,70, 39, 50 n=10 d=51.4 sd=??? (Answer suppose to be 30.8336 but not coming close to this number at all)
*November 30, 2012*

**CHEMISTRY**

Co(s) will oxidize Fe(s) while leaving Cu(s) unreacted, please write a balanced equation for the reagent involved?
*November 30, 2012*

**chem **

A 0.01020 mg sample of an unknown compound was found to contain 0.0084 mg of C, and 0.0018 mg of H. It was also determined that the unknown compound had a molecular weight of 58.12 g/mol. What is the molecular formula for this compound?
*November 29, 2012*

**Math**

Sorry I repeated these question to you because I forgot to add there are repeating numbers or ellipsis.
*November 29, 2012*

**Math .. Please help Reiny**

Reiny, do u think 1st question about blankets should b written differently? For e.g. If we say b= 5, then the first part of the equation will equal 175+ 5= 80. I'm thinking it should be written as this: 25 (7+b) = 300 175 + 25b = 300 25b = 125 Pls let me know what you ...
*November 29, 2012*

**CHEMISTRY HWK MAKES NO SENSE **

How many grams of C are required to make 464.99 grams of this compound? compound= C3H8
*November 29, 2012*

**Math**

Reiny ...Thank you so much for your helpfulness and kindness. Goodnight...
*November 29, 2012*

**Math**

Ok.. Can u check these for me too please? Rename each repeating decimal as a fraction in lowest terms. Using let statement, an equation, a proper solution (using properties of equality) 1) 0.87 (repeating nos are 87) So.. Let X = 0.87 100X = 87.87 - &...
*November 29, 2012*

**Math**

I know, but wanted to be sure about the let statement, equation parts they were asking for. Thanks.
*November 29, 2012*

**Math**

Tickets to King Middle School play cost $1 for King students and $3 for everyone else. Rose, a student at King Middle School, went to the play with friends from another school. the group paid a total of $13 for the tickets. How many friends went to see the play with Rose? ...
*November 29, 2012*

**Logic**

Help this too!
*November 4, 2012*

**math**

please help, I'm having a hard time set up the problem. Thank you Sally drove a distance of 520 mile. Had she averaged 15mph faster, the trip would of taken 2.4 hours less. find the average speed that she drove.
*October 29, 2012*

**algebra**

Sally drove a distance of 520 mile. Had she averaged 15mph faster, the trip would of taken 2.4 hours less. find the average speed that she drove.
*October 29, 2012*

**physics**

A light of ray is incident at an angle of 58degrees on the plane surface of a block of glass of refractive index 1.60. Some light is reflected on the other side of the normal att he same angle as the angle of incidence. Find: a.the angle between the light reflected from the ...
*October 24, 2012*

**Algebra**

Year, t Sales, S(t) 1 62 2 246 3 664 4 1579 5 3258 6 8430 7 14,532 (c) If S−1 exists, find S−1(3,258).
*October 24, 2012*

**physics**

State the surface powers required to produce the following lenses with +6.25D front curves. a. -0.50 DS b. +0.50 DS c. +1.75 DS Is a -6.75DS?....
*October 23, 2012*

**physics**

is a =-6.75DS?...
*October 23, 2012*

**physics**

state the surface powers required to produce the following lenses with +6.25D front curves. a. -0.50 DS 6. +0.50 DS c. +1.75 DS
*October 23, 2012*

**Discrete Mathematics**

okay ive got the answer as 2*389-3.5*222 but i done it with trial an error with random numbers, dont no the actual formula
*October 20, 2012*

**Discrete Mathematics**

ive got 389 = 1*222 +167 then 222= 1*167 +55 167= 3*55 +2 55= 27*2 +1 2= 2*1 and hence 1 = GCD of (389,222) but im not sure how you work out the a,b values??
*October 20, 2012*

**Physics**

help
*October 20, 2012*

**math **

why isnt anybody answering my questiions? do u have to have an account or something? if you do just tell me and ill get one!!!1 because everybody else has an answer! you should at least tell me that i need an account if i do!
*October 14, 2012*

**physics**

Snowballs are thrown with a speed of 12.5 m/s from a roof 7.8 m above the ground. Snowball A is thrown straight downward; snowball B is thrown in a direction 16° above the horizontal. (a) Is the landing speed of snowball A greater than, less than, or the same as the ...
*October 12, 2012*

**physics**

In a game of basketball, a forward makes a bounce pass to the center. The ball is thrown with an initial speed of 3.1 m/s at an angle of 15.0° below the horizontal. It is released 0.82 m above the floor. What horizontal distance does the ball cover before bouncing? Please ...
*October 12, 2012*

**Physics**

Vector Aarrowbold points in the negative y direction and has a magnitude of 8 units. Vector Barrowbold has the same the magnitude and points in the positive x direction. Find the direction and magnitude of the following vectors. a) Aarrowbold + Barrowbold magnitude direction &...
*October 12, 2012*

**Chemistry**

what are redox/non-redox not getting it? Can you break it down?
*October 12, 2012*

**Chemistry**

how do you balance equations to get the formula?
*October 11, 2012*

**Chemistry**

How many moles of H2 can be produced? (2.14 mol)
*October 11, 2012*

**statistics**

The heights of women aged 20 to 29 follow approximately the N (64, 4) distribution. Men the same age have heights distributed as N (69.8, 1.1). What percent of young women are taller than the mean height of young men?
*October 10, 2012*

**science**

kill science
*October 8, 2012*

**Chem**

Zinc, copper, lead, and mercury ions are toxic to Atlantic salmon at concentrations of 6.42 times 10 to the -2 mM, 7.16 times 10 to the -3 mM, 0.965 mM, and 5.00 times 10 to the -2 mM, respectively. What are the corresponding concentration is milligrams per liter? A. ...
*October 1, 2012*

**Math grade 7**

thx
*September 10, 2012*

**Math grade 7**

The number 7 is a factor of 1001. explain how you know 1001 is a multiple of 7? How does knowing that 7 is a factor of 1001 help you to get another factor of 1001?
*September 10, 2012*

**math**

1. Divide. Write your answer in simplest form. 2/3 / 1/4 2. Find the product. 1/2 x 3/7 3. Divide. Write the quotient in simplest form. 3/5 / 2/10 4. Divide. Write the quotient in simplest form. 3/4 / 4/5 plz help me
*August 31, 2012*

**lang arts**

on number two the sentence is the first one
*August 31, 2012*

**lang arts**

1. Which sentence describes setting? As much as it saddened her, the first thing Nan had to do was leave her beloved family home. Marcy wanted to go to the dance, but Rob’s treatment of her that day gave her second thoughts. Steve was fairly short, with glasses and dark ...
*August 31, 2012*

**chemistry **

molecules of two different compounds contain the same number of atoms of each element but have different arrangement of atoms. which term correctly describes these two substances? a) isomers b) isotopes c) polymers d) none of the above
*August 27, 2012*

**chemistry **

molecules of two different compounds contain the same number of atoms of each element but have different arrangement of atoms. which term correctly describes these two substances? a) isomers b) isotopes c) polymers d) none of the above
*August 27, 2012*

**chemistry **

the elements of group VII A form ions with a charge of: A) +1 b) -1 c) -2 d) +2 can u please explain too? thankyou
*August 27, 2012*

**physics**

what are convex lenses?
*August 25, 2012*

**writing**

Which of the following does not belong in a conclusion paragraph? A. An attention grabbing sentence. B. A restated thesis sentence. C. A conclusion sentence. D. A summary of supporting details
*August 24, 2012*

**stats**

What does a p value p>0.05 mean? does it mean significant or insignificant? also, what does significant and insignificant mean?
*August 21, 2012*

**Math 1**

In audition for school play, 70% passed the quality of the jurors for the first week. of those remaining, 20% were chosen. if only 7 were qualified, how many tried their luck?
*July 21, 2012*

**math**

Please note, this is one section of the problem. I didn't feel the need to post the entire question as I understand how to do it...minus this one part. (2 tan pi/3) apparently becomes 2 sqrt 3.....explain?
*July 15, 2012*

**Statistics**

A local fire station receives an average of 0.5 rescue calls per day. Find the probability that on a randomly selected day, the fire station will receive fewer than two calls.
*July 13, 2012*