Saturday

February 13, 2016
Total # Posts: 2,155

**Physics**

Two speakers, one directly behind the other, are each generating a 264-Hz sound wave. What is the smallest separation distance between the speakers that will produce destructive interference at a listener standing in front of them? Take the speed of sound to be 342 m/s.
*February 5, 2016*

**Chem**

A solution is prepared by adding 1.50 mol glucose to 3.50 mol water. What is the vapor pressure of the solution at 25 oC given that the vapor pressure of pure water is 23.8 torr?
*January 27, 2016*

**math**

20 kids Are in a group . 7 of them have pets. How do u figure what percent of the group has pets? I multiplied 7 X 20 and got 14 percent. Is that the right way to figure percent if u have a total and don't have to use 100 as the total?
*January 25, 2016*

**physics**

an object takes 0.35 seconds to hit the floor, what height did it fall from? is the way to calculate it h = gt^2 / 2 so would it be = h = .5 * 9.8 * 0.35^2
*January 25, 2016*

**Pre-Calculus**

The question is "Find parametric equations for the line with the given properties: Slope -2, passing through (-10, -20)." I don't even know where to begin, or what to do. Please help! This is an example problem, not the main homework problem, I just need to know ...
*January 25, 2016*

**English**

A A C 100%
*January 24, 2016*

**math**

A rectangular picture frame measures 46 cm by 35 cm. What is the perimeter or distance around the picture frame in meters? m
*January 20, 2016*

**Math**

How much 12% acid must be added to 3 gallons of pure water to get a mixture that is 7% acid.
*January 11, 2016*

**Number Systems of Mathematics**

Solve using elimination and express answer as ordered pair: 2x + 3y = 7 x + 5y = 7
*January 1, 2016*

**Physics**

Two resistors 3 Ω and 6 Ω are connected in parallel across a 6 V battery. What is the current flow through the 3 Ω resistor? 6 A 3 A 4 A 2 A
*December 21, 2015*

**Human Behavior**

Existential psychology has four basic themes. Define the themes. How are those themes different from humanistic theory themes of positive psychology and suffering of existentialism?
*December 20, 2015*

**math**

What doea,the c mean when the math problem is 8c = how many pints? I tried 1 2 4 and 16 but don't know what to look for.
*December 19, 2015*

**PHYSICS**

A golfer rides in a golf cart at an average speed of 3.93 m/s for 43.3 s. She then gets out of the cart and starts walking at an average speed of 1.13 m/s. For how long (in seconds) must she walk if her average speed for the entire trip, riding and walking, is 1.99 m/s?
*December 16, 2015*

**PHYSICS**

A box is sliding up an incline that makes an angle of 21.8° with respect to the horizontal. The coefficient of kinetic friction between the box and the surface of the incline is 0.170. The initial speed of the box at the bottom of the incline is 3.48 m/s. How far does the ...
*December 16, 2015*

**algebra**

thank you guys so so much! I was trying to use elimination for this and it wasn't working at all.
*December 16, 2015*

**algebra**

What is the solution of the system? y = -3x 3x + 2y =6 I don't get this, please help.
*December 16, 2015*

**Inequalities - Algebra**

Ms. Sue I have a question, is 123 a possible answer for the # of text messages you can give/recieve?
*December 15, 2015*

**Inequalities - Algebra**

Thank u Ms. Sue
*December 15, 2015*

**Inequalities - Algebra**

Your cellphone plan costs $42.76 per month plus $0.14 for each text message you send or recieve. You have at most $60 to spend on your phone bill. What is the maximum number of text messages you can send or recieve next month?
*December 15, 2015*

**math**

First, you need to find the least common multiple, which is 12. Then you need to count on 12 school days from September 5th. So say that the 5th is on a Monday, so the next day would be the 6th, then Tuesday would be the 7th, and so forth.So keep counting. So the next time she...
*December 15, 2015*

**Physics**

A 56.5kg, 2.4m uniform ladder leans against a frictionless wall. A 95.5kg person is standing up 0.8m from the bottom of the ladder. The ladder makes an angle of 57 degrees with the horizontal. The coefficient of static friction between th eladder and the ground is 0.15. What ...
*December 14, 2015*

**Algebra 1**

I actually think it's c.
*December 14, 2015*

**math**

To find the area of a parallelogram you use the equation a=bh. You already know that the height is 4.5cm, which plugged in to the equation makes the equation a=b*4.5. The base is twice the height, and knowing that the height is 4.5cm, you just multiply that by two in order to ...
*December 14, 2015*

**science**

Tow masses are moving down a slope. One mass is traveling twice as fast as the other mass. How does the kinetic energy of one mass compare to the other?
*December 13, 2015*

**Mathematics**

Solve for X: (x-6)log4=(3x)log2
*December 13, 2015*

**Mathematics**

Solve: 4^(x-6)=2^(3x) show all workings.
*December 13, 2015*

**Mathematics**

Solve: 3^(2x+1)=12 Show your workings:
*December 13, 2015*

**Advanced algebra**

Find the 7th term of geometric progression if the second term is 75, the 5th term,3/5.
*December 13, 2015*

**Mathematics**

Solve: 3^x=7 3^2x+1=12 4^x-6=2^3x
*December 11, 2015*

**math**

How to figure out 22×11 in expanded algorithm
*December 10, 2015*

**Physics**

A projectile is fired from a height of h meters at a speed of 55m/s and at an angle of 10 degrees above the horizontal. The projectile hits a target at a horizontal distance of 80m from where it was fired and at a vertical height of 1.2m. Find the time for which the projectile...
*December 10, 2015*

**Comptuer Scinec **

Need help with my final project. Create and test a java program that will simulate customers waiting in line in a bank teller
*December 9, 2015*

**Math**

for 1 which is right?
*December 9, 2015*

**Math**

Leonard ran 4 miles more than Sheldon ran. The sum of their distances is 26 miles. How far did Sheldon run? The domain a. Define your variable. b. Write algebraic expressions for the distances each person ran. c. Write an equation that can help you solve the problem. d. Solve ...
*December 8, 2015*

**math**

what point of f(x)= e^(1-x^2) is concave down? I think it is -3/2
*December 6, 2015*

**Mathematics**

Can you get an extremely high gradient of a straight line for instance: m = 14375 I used the formula (y2-y1)/(x2-x1) or have I miscalculated?
*December 5, 2015*

**science**

I have researched for an hr. Can someone help me find what energy transformation takes place when a firecraxker explodes? The choices given to me are : a. Gravitational potential to mechanical and electromagnetic. B:NUCLEAR to kinetic and,chemical. C: mechanical to ...
*December 5, 2015*

**math**

Solve the following system by matrix reduction. Write your answer using parameter(s) if necessary. If there is no solution, state "no solution". x-2y-3z=-2 4x-3y+3z=-8
*November 30, 2015*

**math**

Solve the following system by matrix reduction. Write your answer using parameter(s) if necessary. If there is no solution, state "no solution". x-2y-3z=-2 4x-3y+3z=-8
*November 30, 2015*

**Math**

If log 3=a, log 5=b and log 7=c, express log_{15} 7 in terms of a,b and c.
*November 30, 2015*

**Physics**

The circular blade on a radial arm saw is turning at 293 rad/s at the instant the motor is turned off. In 17.9 s, the speed of the blade is reduced to 60 rad/s. Assume the blade to be a uniform solid disk of radius 0.17 m and mass 0.400 kg. Find the magnitude of the net torque...
*November 28, 2015*

**college algebra**

In a certain gear, a bicycle tire with a diameter of 27 inches makes 3 complete revolution of the pedal.If a cyclist is pedaling at a rate of 100 revolutions per minute, find the speed of the bicycle in miles per hour?
*November 24, 2015*

**Physics [Help, need answer in 10 min]**

During a solar eclipse, the moon (of mass 7.36 × 1022 kg), Earth (of mass 5.98 × 1024 kg), and Sun (of mass 1.99 × 1030 kg) lie on the same line, with the moon between Earth and the Sun. What gravitational force is exerted on the moon by the Sun? The ...
*November 19, 2015*

**physics**

82.069N Just input that as your right answer ;)
*November 18, 2015*

**physics**

A 5.9 kg bucket of water is raised from a well by a rope. The acceleration of gravity is 9.81 m/s/s If the upward acceleration of the bucket is 4.1 m/s/s, find the force exerted by the rope on the bucket of water. Answer in N
*November 18, 2015*

**Math**

Thanks for the help I really appreciate it.
*November 8, 2015*

**Math **

This is the second part of a two part question for an online class. It gave me the degree and the zeros and I had to give the factored form. I got that part right, but I need to know how to get the expanded form from the factored form. I have several more questions like this ...
*November 8, 2015*

**Physics**

An athlete swings a 3.06 kg ball horizontally on the end of a rope. The ball moves in a circle of radius 0.82 m at an angular speed of 0.25 rev/s. What is the tangential speed of the ball? Answer in units of m/s.
*November 3, 2015*

**trig**

Find the magnitude and direction angle of the vector v. v = 4(cos 125°i + sin 125°j) ||v|| = θ =
*November 2, 2015*

**math**

write an equation that I can use to find the distance I can drive on any number of gallons of gas
*October 29, 2015*

**chemistry**

Calculate the mass of oxalic acid needed to prepare 150 ml of 0.442 M C2H2O4
*October 27, 2015*

**Chemistry**

Solved it. 1:200 is 0.005 g, therefore you multiply it by 1000 mg/g to get mg. You then multiply it by 10 ml to get you the total amount of miligrams, which equals 50 mg.
*October 23, 2015*

**Chemistry**

How many grams of drug X are in 10 mL of a 1:200 solution of X?
*October 23, 2015*

**physics**

Some nucleus of 74X189 (atomic mass = 188.96191 u) undergoes - decay to become 75X189 (atomic mass = 188.95922 u). What is the energy (in MeV) released in this process?
*October 22, 2015*

**physics**

The number of radioactive nuclei present at the start of an experiment is 3.27 x 1015. The number present twenty days later is 7.66 x 1014. What is the half-life (in days) of the nuclei?
*October 22, 2015*

**physics is this correct**

What is the radius of a real or imaginary nucleus of 46X100 do I use the formula R = R_o * A^(1/3) and therefore (1.3*10^-15)* 100^(1/3) =6.0340655e-15?
*October 22, 2015*

**physics**

thankyou could you help me with what formula you used plz
*October 22, 2015*

**physics**

The refractive indices of materials A and B have a ratio of nA/nB = 1.68. The speed of light in material A is 1.26 x 108 m/s. What is the speed of light in material B
*October 22, 2015*

**physics**

An object is located 27.6 cm to the left of a converging lens whose focal length is 46.5 cm. (a) Determine the image distance and (b) the magnification.
*October 22, 2015*

**physics formula check please**

A mirror produces an image that is located 28.0 cm behind the mirror, when the object is located 9.90 cm in front of the mirror. (a) What is the focal length of the mirror? (b) Is the mirror 1 - concave or 2 - convex? (Give the number of the correct answer.) The refractive ...
*October 21, 2015*

**Physics please help**

An object that is 31 cm in front of a convex mirror has an image located 16 cm behind the mirror. How far behind the mirror is the image located when the object is 24 cm in front of the mirror? do I use the formula 1/f = 1/di + 1/do?? please help
*October 21, 2015*

**Math**

16-4c=20
*October 18, 2015*

**Physics**

A model airplane has a mass of 0.95 kg and moves at a constant speed on a circle that is parallel to the ground. Assume that there is no upward lift on the plane generated by its wings. Without such lift, the guideline slopes downward due to the weight of the plane. Find the ...
*October 16, 2015*

**English**

Identify the correct sentence. A. A giant spider with long legs are crawling on the wall in the living room. B. A giant spider with long legs is crawling on the wall in the living room. C. Neither the roach nor the spider are still alive. D. Neither the spider nor the roaches ...
*October 15, 2015*

**English**

Thanks
*October 15, 2015*

**English**

Identify the incorrect sentence. A. There is a good variety of mugs in the cabinet. B. There are a good variety of mugs in the cabinet. C. A number of glasses have been broken. D. The number of broken glasses has increased.
*October 15, 2015*

**maths**

6.79
*October 15, 2015*

**Algebra**

-4(a+3)-a
*October 14, 2015*

**Math 208 (Linear)**

a person purchased a $142,819 home 10 years ago by paying 15% down and signing a 30-year mortgage at 10.5% compounded monthly. Interest rates have dropped and the owner wants to refinance the upaid balance by signing a new 15-year mortgage at 6.3% compounded monthly. How much ...
*October 12, 2015*

**physics**

A container holds 1.9 mol of gas. The total average kinetic energy of the gas molecules in the container is equal to the kinetic energy of a 8.0x10-3 kg bullet with a speed of 960 m/s. What is the Kelvin temperature of the gas? do I use the formula? T= (mv^2)/u No 3k
*October 12, 2015*

**Physics**

Identical +2.83 μC charges are fixed to adjacent corners of a square. What charge (magnitude and algebraic sign) should be fixed to one of the empty corners, so that the total potential at the remaining empty corner is 0 V? φ =k•q/r φ1+ φ2 + φ3 =0...
*October 12, 2015*

**Math**

(X+4)^2=3 X^2+8x+16-3=0 X^2+8x+13=0 Use quadratic formula X=(-8±sqrt(64-4*13))/(2) =-(8±sqrt(12))/2 =-4±sqrt (3)
*October 11, 2015*

**Chemistry**

Calculate Delta H for the reaction CH4(g)+NH3(g)-->HCN(g)+3H2(g) given, N2(g)+3H2(g)->2NH3(g) DeltaH=-91.8kj C(s)+2H2(g)->CH3(g) DeltaH=-74.9kj h2(g)+2C(s)+N2(g)->2HCN(g) DeltaH=270.3kj
*October 11, 2015*

**maths**

if it takes 8 men 3 hours to clean a house, how many men would it take to get job done in 2.5 hours
*October 11, 2015*

**Physics **

A container holds 1.9 mol of gas. The total average kinetic energy of the gas molecules in the container is equal to the kinetic energy of a 8.0x10-3 kg bullet with a speed of 960 m/s. What is the Kelvin temperature of the gas? do I use the formula? T= (mv^2)/u No 3k
*October 10, 2015*

**math**

When the movie is half over, popcorn sells for half price. Full price popcorn is $3.50, and drinks are $1.35. Determine the cost for purchasing 3 orders of popcorn and 3 drinks when the movie is half over. $
*October 3, 2015*

**chemistry equilibrium **

phsophorous trichloride and phosphorous pentachloride equilibrate in the presence of molecular chlorine according to PCl3 (g) +Cl2 (g)->PCl5 (g) Kc = 2.01 at 500k If a 1.000L reaction vessel is charged with .300 mol of PCl5(g) and allowed to equilibrate at this temperature...
*October 1, 2015*

**chemistry**

phsophorous trichloride and phosphorous pentachloride equilibrate in the presence of molecular chlorine according to PCl3 (g) +Cl2 (g)->PCl5 (g) Kc = 2.01 at 500k If a 1.000L reaction vessel is charged with .300 mol of PCl5(g) and allowed to equilibrate at this temperature...
*October 1, 2015*

**calc 2**

A loaf of bread is removed from an oven at 350 degrees F and cooled in a room whose temperature is 70 degrees F. If the bread cools to 210 degrees F in 20 minutes, how much longer will it take the bread to cool to 155 degrees F. Round to the nearest minute.
*September 29, 2015*

**maths**

I need explanation to this question.solve 48 base12 multiply by 15 base12.i can solve it by first converting to base ten and back to base 12,but i need to be able to solve directly in base12.Thanks
*September 29, 2015*

**Biology**

You find 3 trees where each tree gives a different coloured fruit: red, pink or orange. You perform crosses between all three trees and get the following results: P: red x pink ---F1: ½ red: ½ pink P: red x orange --- F1: ½ red: ½ orange P: pink x ...
*September 27, 2015*

**Physics**

Thank you so much!!!!
*September 27, 2015*

**Physics**

A fireman d = 33.0 m away from a burning building directs a stream of water from a ground-level fire hose at an angle of θi = 21.0° above the horizontal as shown in the figure. If the speed of the stream as it leaves the hose is vi = 40.0 m/s, at what height will the ...
*September 27, 2015*

**information technology**

write a pascal program which reads price of an item. the program should compute 25% discount on the original price, it should display the discounted amount and the discounted price of an item.
*September 16, 2015*

**Physics**

You toss a tennis ball straight upward. At the moment it leaves your hand it is at a height of 1.5 m above the ground, and it is moving at a speed of 7.8 m/s. (a) How much time does it take for the tennis ball to reach its maximum height? (b) What is the maximum height above ...
*September 16, 2015*

**physics**

A quarterback takes the ball from the line of scrimmage, runs backward for 18.0 yards, then runs sideways parallel to the line of scrimmage for 16.0 yards. At this point, he throws a 49.0-yard forward pass straight down the field. What is the magnitude of the football’s ...
*September 16, 2015*

**physics**

Vector B~ has x, y, and z components of 9.6, 6, and 8.5 units, respectively. Calculate the magnitude of B~ .
*September 16, 2015*

**physics**

A descent vehicle landing on the moon has a vertical velocity toward the surface of the moon of 34.1 m/s. At the same time, it has a horizontal velocity of 53.5 m/s. At what speed does the vehicle move along its descent path? Answer in units of m/s.
*September 16, 2015*

**physics**

Bob heads out into a lake at an angle of 27◦ with respect to the shore. If his boat is capable of a speed of 1.3 m/s, how far from land will he be in 2 min and 28 s ? Answer in units of m.
*September 16, 2015*

**CHEM**

The following data were collected for determining the concentration of suspended solids in a water sample. (D= 1.01 g/mL). Express all calculated data with the correct number of significant figures. Volume of sample (mL): Trial 1: 25.0 trial 2: 20.0 trial 3: 50.0 trial 4: 25.0...
*September 15, 2015*

**algebra**

sorry Isiah is C. 0.625
*September 15, 2015*

**algebra**

Are you serious sue i have been reading some of his math questions and all I see at the end is your dumb ass saying what chart, what graph, duh its 12 or obvious don't see a graph. and now your telling him how to make profiles wtf. get a life sue if your not going to help ...
*September 15, 2015*

**physics**

As soon as a traffic light turns green, a car speeds up from rest to 50.0 mi/h with constant acceleration 7.50 mi/h-s. In the adjoining bike lane, a cyclist speeds up from rest to 17.0 mi/h with constant acceleration 14.50 mi/h-s. Each vehicle maintains constant velocity after...
*September 15, 2015*

**chem**

oh, i am sorry. I meant "data"
*September 14, 2015*

**chem**

The following state were collected for determining the concentration of suspended solids in a water sample. (D= 1.01 g/mL). Express all calculated data with the correct number of significant figures. Volume of sample (mL): Trial 1: 25.0 trial 2: 20.0 trial 3: 50.0 trial 4: 25....
*September 14, 2015*

**Math 10**

What is the circumference of the largest circle you could cut from a 30 cm by 20 cm sheet of paper? What area of paper would you cut away. PLZ HELP GUYS TEST TOMMOROW OH MA GAWD!
*September 14, 2015*

**Chem**

A 25.0 mL aliquot of a well-shaken and filtered sample of river is pipetted into an evaporating dish. The sample was heated to dryness. Assume the density of the river water was 1.01g/mL. The following data were collected for Trial 1. Complete the data. Record values with the ...
*September 14, 2015*

**Chem**

The following state were collected for determining the concentration of suspended solids in a water sample. (D= 1.01 g/mL). Express all calculated data with the correct number of significant figures. Volume of sample (mL): Trial 1: 25.0 trial 2: 20.0 trial 3: 50.0 trial 4: 25....
*September 14, 2015*

**Math**

Oh an also how do I solve this. 9 x (7-16) + 9
*September 14, 2015*