Friday

July 1, 2016
Total # Posts: 1,463

**physics**

An elevator (cabin mass 540 kg) is designed for a maximum load of 3500 kg, and to reach a velocity of 4 m/s in 3 s. For this scenario, what is the tension the elevator rope has to withstand?
*January 28, 2012*

**physics**

A 3.24 kg block located on a horizontal frictionless floor is pulled by a cord that exerts a force F=11.8N at an angle theta=23.0degrees above the horizontal, as shown. What is the magnitude of the acceleration of the block when the force is applied? b.) What is the horizontal...
*January 28, 2012*

**physics**

A 3.24 kg block located on a horizontal frictionless floor is pulled by a cord that exerts a force F=11.8N at an angle theta=23.0degrees above the horizontal, as shown. What is the magnitude of the acceleration of the block when the force is applied?
*January 28, 2012*

**physics**

A professor drives off with his car (mass 840 kg), but forgot to take his coffee mug (mass 0.37 kg) off the roof. The coefficient of static friction between the mug and the roof is 0.7, and the coefficient of kinetic friction is 0.4. What is the maximum acceleration of the car...
*January 28, 2012*

**physics**

A professor drives off with his car (mass 840 kg), but forgot to take his coffee mug (mass 0.37 kg) off the roof. The coefficient of static friction between the mug and the roof is 0.7, and the coefficient of kinetic friction is 0.4. What is the maximum acceleration of the car...
*January 28, 2012*

**physics**

An object glides on a horizontal tabletop with a coefficient of kinetic friction of 0.65. If it comes to rest after 0.9 seconds, what was its initial velocity?
*January 28, 2012*

**physics**

An object glides on a horizontal tabletop with a coefficient of kinetic friction of 0.55. If its initial velocity is 4.1 m/s, how long does it take for the object to come to rest?
*January 28, 2012*

**math**

Factor the given expression. a) 6y^2 − 53y − 9 b) Set the expression equal to zero and solve for y. y= (smaller value) y= (larger value)
*January 27, 2012*

**math**

27,907,200
*January 27, 2012*

**Honors Algebra 3-4**

can the cubed root of 15x^2, over 3 be simplified any more. (original problem: cubed root of 5/3x) the directions were to rationalize the denominator of each expression. Thankss!!!!!
*January 24, 2012*

**Algebra 1**

Find the greatest common factor of 12x^2+18x-36
*January 17, 2012*

**physics**

At 1:00 p.m. a car, traveling at a constant velocity of 98 km/h toward the west, is 19 km to the west of our school. How far from the school will it be at 3:30
*January 15, 2012*

**Chemistry**

Determine the volumes of 1 M acetic acid and 1 M NaOH required to make a 200mL 0.1 M buffer with a pH of 5.5. (Assume the pKa of acetic acid is 4.76).
*January 15, 2012*

**algebra**

Including a 9% sales tax, an inn charges $127.53 per night. Find the inns nightly cost before tax is added
*January 14, 2012*

**algebra**

Club A offers a starter fee for $17 plus a monthly fee of $11. Club B offers a starter fee of $23 and a monthly fee of $14. How many months untill the prices will be the same?
*January 14, 2012*

**math**

f:(x)= x^2+5 find f(0)
*January 12, 2012*

**trig**

evaluate sin (11pi/6) to the nearest thousandth.
*January 11, 2012*

**math**

a+4(6a+2b^2)+(a^2-6b^2)
*January 5, 2012*

**algebra 1**

Maria sells paintings in an art gallery. She ears $375 each week plus a commission equal to 2.5% of her sales. This week her goal is to earn at least $500. What is the minimum amount of sales she must have this week to achieve her goal?
*January 5, 2012*

**Physics**

is it possible to solve without the initial temperature of the copper?
*January 5, 2012*

**Physics**

A 500 g glass beaker is in thermal equilibrium with 100 ml of 20 Degrees celsius water in it. If a 5 g sample of copper is placed into the water and the system is allowed to come into thermal equilibrium, what will the final temperature of the system be? (assuming no heat loss...
*January 5, 2012*

**Chemistry**

5 - got it
*January 4, 2012*

**Chemistry**

How would you make an irreversible isothermal expansion/compression cycle of a gas closer to a reversible one? 1. Increase the temperature 2. Decrease the number of steps during expansion and compression 3. Increase the difference between internal and external pressures 4. ...
*January 4, 2012*

**algebra 1**

Which expression is the greatest common factor of (125t^3 m^5+60t^4 m^4+85t^5 m^2)
*January 4, 2012*

**Science**

pressure=100N/20M/S
*December 19, 2011*

**algebra 1**

16
*December 15, 2011*

**algebra 1**

Evaluate: 2m^2-(n-p) when m=3, n=-2, p=-4
*December 15, 2011*

**chemistry**

Okay this makes sense thank you!
*December 12, 2011*

**chemistry**

What mass of barium sulphate can be produced when 100.0 mL of a 0.100 M solution of barium chloride is mixed with 100.0 mL of a 0.100 M solution of iron (III) sulphate? Please explain!
*December 12, 2011*

**present annuity**

What is the present value of an annuity that consists of 28 monthly payments of $260 at an interest rate of 8% per year, compounded monthly? (Round your answer to the nearest cent).
*December 11, 2011*

**algebra 1**

There are 16 coins in a piggy bank. The coins are all nickels and dimes. All together the total amount of money in the bank is $1.05. How many of each coin are there?
*December 7, 2011*

**Geometry**

Line AB (0,0) is perpendicular to line BN (3,4) in the diagram at the right. Angle B is a 90 degree angle. What are the coordinates of point N?
*December 7, 2011*

**3rd grade math**

No the answer is 36. Try plugging it into the problem. 36 divided by 2 is 18, which is 6 times 3. Then if you add (the opposite of subtracting) 3 groups of 3 (nine) from 3 multiplied by nine (27) you get 36
*December 6, 2011*

**3rd grade math**

Well first 3 x 6= 18 so multiplied by two to get your answer 18x2=36 to check use the second part of the problem: 3x9=27 36-27=9 subtract three groups of three (9) 9-9=0 so we have the correct answer
*December 6, 2011*

**chemistry**

Sorry, but how did you find the total volume of the solution?
*December 6, 2011*

**chemistry**

Thank you so much, I really appreciate your help!
*December 6, 2011*

**chemistry**

Aqueous silver nitrate reacts with aqeous potassium iodide in a double-replacement reaction to produce a precipitate of silver iodide. If 34.6 ml of 0.563 M silver nitrate are used with 148.4 ml of potassium iodide: a) What molarity of potassium iodide will be needed to ...
*December 6, 2011*

**algebra 1**

Is it right?
*December 6, 2011*

**algebra 1**

i actually wrote the second part wrong. Its supposed to be y=.8x+7.2 not 72. and when i solved it i got 10.4 for y and my x is 4.
*December 6, 2011*

**algebra 1**

Solve by substitution. y=.8x+72 20x+32y=48 How do you get y? i got the x part but i can't seem to get the y part.
*December 6, 2011*

**Astronomy-HELP PLEASE!!!!!**

Some quasars (quasi-stellar radio source) have the largest red shifts ever observed. If this phenomenon is due to cosmic expansion, what can you say about their distance? What can you say about the age of the quasar at the time the light we now see left the quasar compared to ...
*December 5, 2011*

**ASTRONOMY-HELP PLEASE!!!!!**

if count ibis is correct the answer would be 15400 accroding to another person you would get 15, 022.9 which is correct?
*December 5, 2011*

**Chemistry**

C2H6 --> 2CH3 at a temperature where the half-life is 21 minutes. If the initial concentration is 8.0 mM, what would the concentration be after 46.0 minutes? How long would it take to convert 95% of C2H6 at this temperature?
*December 2, 2011*

**calculus**

Maximimum profit: you operate a tour service that offers the following rates: (1) $200 per person if 50 people (the minimum number to book the tour) go on the tour. (2) for each additional person, up to the maximum of 80 people total, everyones charge is reduced by $2. it ...
*November 27, 2011*

**algebra 1**

solve by substitution. 0.5x+0.25y=36 y+18=16x
*November 21, 2011*

**Chemistry**

how many moles of lead (II) sulfate will be produced when 500 grams of magnesium sulfate is allowedto react with lead (II) nitrate?
*November 20, 2011*

**government**

why was amendment 17 significant and how were the state governments represented before this amendment?
*November 20, 2011*

**speech**

This might be a hard question to answer but I need an example for my speech for speech class. My speech is a persuasive on why you should foster an animal. I am talking about the benfits and how learning responsibility is a benefit. I know there are organizations out there ...
*November 20, 2011*

**Another Question **

the friday after thanksgiving so this year its the 25th
*November 19, 2011*

**Another Question **

are you talking about 8th grade in school? No school just gives out awards. You can sometimes get awards if you participate in sports such as track, softball, etc.
*November 19, 2011*

**Another Question **

Each grade gets tougher as you go allow. For me 8th grade was not that bad. The grades that you get in 8th grade do not go towards your high school gpa unless you are taking a high school credit course. But, even so, you still want to try your best! If you are in 8th grade or...
*November 19, 2011*

**Question **

I website I like is student questions . com
*November 19, 2011*

**Chemistry**

In an organic chemistry lab, why is the organic layer usually the upper layer in the separatory funnel while the aqueous layer is usually the bottom layer?
*November 16, 2011*

**Chem**

So, for the rate of formation of C, would it be 2.5E-5 x (5/4)?
*November 14, 2011*

**Chem**

Consider the following reaction: 6A + 2B 5C + 4D Determine the following rates at a time when the rate of consumption of B is 2.5E-05 M/s. a) rate of consumption of A M/s b) rate of formation of C M/s c) rate of formation of D M/s d) rate of reaction M/s
*November 14, 2011*

**algebra 1**

write an equation for the line that is perpendicular to the given line and that passes through the given point. (6,4);y=3x-2
*November 14, 2011*

**algebra**

Suppose that Jane borrows 7800 dollars from a bank on April 24 at an annual rate of 7 percent simple interest. How much does she owe on August 14 of the same year?
*November 14, 2011*

**reading**

whay would a leaf be a good rug for a lady bug
*November 10, 2011*

**Chemistry**

In the experiment shown below, you add some salt to water. A = All of the solid dissolves (no solid at the bottom). B = You add more water and the solid stays dissolved. Select all of the following that are true about solutions A and B. The same number of ions are dissolved in...
*November 10, 2011*

**Trig**

Im having serious issues with verifying Trig. identities. Please help! Here is an example: (tanX-secX)^2= 1-sinX/1+sinX
*November 7, 2011*

**calculus**

water in a paper conical filter drips into a cup. let x denote the height of the water in the cup. if 10 in^3 of water are poured into the filter, find the relationship between dy/dt and dx/dt so the paper filter is 4 inches tall whith a radius of 2 inches. x is the height of ...
*November 6, 2011*

**calculus**

a billboard 20ft tall is located on top of a building with its lower edge 60 ft above the level of a viewers eye. how far from a point directly below the sign should a viewer stand to maximize the angle (theta) between the lines of sight of the top and bottom of the billboard...
*November 6, 2011*

**Chem**

The coordination compound has five stereoisomers (geometric plus optical isomers). Select all that apply... A:NH4[Pt(NH3)Cl3] B: tris(ethylenediamine)cobalt(III) sulfate C: tetraaquadichloronickel(IV) chloride D: [Co(NH3)2(en)Cl2]Cl E: [Co(en)2Cl2]Br F: sodium hexacyanoferrate...
*November 4, 2011*

**physics**

a laser beam with wavelength 632.8nm is incident normal to the plane of a diffraction grating with a slit separation d=2000nm. if the diffraction pattern is viewed on a screen 1m from the grating, find the distance separating the first, second, adn third maxima in the pattern.
*October 30, 2011*

**speech**

I am doing a speech on how to decorate a cupcake. But.. i do not know how to start it. I need an attention grabber any ideas?
*October 29, 2011*

**physics**

When the Sun is directly overhead, a hawk dives toward the ground at a speed of 3.07 m/s. If the direction of his motion is at an angle of 57.2 ◦ below the horizontal, calculate the speed of his shadow along the ground. Answer in units of m/s
*October 27, 2011*

**calculus**

im having so much trouble figuring out how to get these answers. i already know the answers i just need to figure out how to get them... directions: find the points of inflection and discuss the concavity of the graph of the function... 1. f(x)=(1/2)x^4+2x^3 2. f(x)=x^3-6x^2+...
*October 23, 2011*

**Chemistry**

Sorry, I need to clarify. My question is why does a precipitate begin to form even though the solution is still basic (before enough HCl is added to make it acidic). Enough HCl is added to make the solution acidic, then it is submerged in an ice bath where the precipitate ...
*October 23, 2011*

**Chemistry**

You isolate an acidic compound in an experiment by first separating it from the organic layer. Then you have a solution containing a salt of an acid. You acidify it using concentrated HCl. A precipitation begins to form while the solution is still basic.. why? You continue the...
*October 23, 2011*

**Biology**

35.49
*October 20, 2011*

**Chemistry**

Would this be the quickest/most efficient method: Take a small test tube, add roughly 1mL of water. Add a single drop of one of the unknown solutions. If the drop is miscible with water then it is from the aqueous phase; if it sinks to the bottom (or floats) it is the organic ...
*October 19, 2011*

**Chemistry**

During an experiment involving separation, you forget to label your beakers and you are unsure of which beaker contains the aqueous layer and which contains the organic layer. How could you quickly and efficiently determine which one is the aqueous layer?
*October 19, 2011*

**Korean**

I am Korean and your translation is right. However, your grammar should be changed into He is always unlucky in love :)
*October 19, 2011*

**Algebra 1**

oh wait never mind. I see my mistake now. Thanks for the help.
*October 18, 2011*

**Algebra 1**

5. And wouldn't it be -12n?
*October 18, 2011*

**Algebra 1**

3n+40=-6(-2n+1)+1
*October 18, 2011*

**Algebra 1**

Thank you so much.
*October 18, 2011*

**Fibonacci Numbers**

I need to find f24. I know F23=28657 and f25=75025. I have figured out that F24 is 46368 using F(n)=F(n-1)+F(n-2). My problme is asking me for two values of n for which Fn=n. I do not understand what it is asking.
*October 17, 2011*

**calculus**

water is poured into a conical paper cup so that the height increases at the constant rate of 1 inch per second. if the cup is 6 inches tall and its top has a radius of 2 inches, how fast is the volume of water in the cup increasing when the height is 3 inches?
*October 16, 2011*

**calculus**

the cross section of a 5-ft long trough is an isosceles trapezoid with a 2 foot lower base, a 3-foot upper base, and an altitude of 2 feet. water is running into the trough at a rate of 1 cubic foot per minute. how fast is the water level rising when the water is 1 foot deep?
*October 16, 2011*

**math**

A ladder is resting against a wall. the foot of the ladder is 8 feet from the wall, and the top of the ladder is 19 feet from the ground. FIND THE slope of the ladder
*October 16, 2011*

**Fibonacci Numbers**

I posted the question several days ago and Mathmate helped to guide me along. I am just unsure if I do not understand what he is saying or if I did complete the problem right. I would appreciate any input. 1.618034 - -.618034 = 2.236068/sqrt 5 = 1.00000 I understand how to use...
*October 15, 2011*

**calculus**

a large ferris wheel is 100 feet in diameter and rises 10 feet off the ground. each revolution of the wheel takes 30 seconds. A) express the vertical distance "H" of the seat off the ground as a function of time "t" if t=0 corresponds to a time when the ...
*October 13, 2011*

**Biology**

What is the first step in replication?
*October 12, 2011*

**Fibonacci Numbers: Understand one part not another**

I understand how to use a calculator to write the decimal point using the golden ratio which is 1.618034 and the conjugate is -.618034. I also know that the relationship between the decimal expansions is that everything to the right of the decimal is the same except one is neg...
*October 12, 2011*

**Check Fib. Number problem please**

For any prime number p except 2 and 5, either Fp-1 or fp+1 is divisible by p. If I showed that this is true for p=7, the answer should be F8---is this correct because f8 is 21. P=11 would be divisible by 55 which is F10.
*October 10, 2011*

**physics**

is the speed of the cannon ball relative to the car or the ground??
*October 10, 2011*

**Chemistry**

A .1360 g sample of a mixture of magnesium and calcium carbonates when treated with HCL evolves 32.25 cm cubed of carbon dioxed measured dry at STP. Calculate the percent of magnesium carbonate in the mixutre.
*October 4, 2011*

**chemistry**

What is the pH of a solution prpared by mixing 50.0 ml of .200 M HCLO4 with 10.0 ml of .100 M KOH
*October 4, 2011*

**Physics**

A rope attached to an engine pulls a 240 Newton crate up an 14.7 degree ramp at a constant speed. The coefficient of kinetic friction for the surfaces of the crate and ramp is .32. What is the magnitude of the force that the rope exerts on the crate parallel to the ramp? (...
*October 4, 2011*

**math**

problem> mystery numbers: Bob is thinking of 2 numbers their sum is 26. their product is 165. what numbers is bob thinking about?
*October 3, 2011*

**Geology**

What is the defining characteristic of the troposphere? (Straight forward answers please & thank you)
*October 2, 2011*

**Geology**

A thunderstorm tends to be more severe and have a longer duration if the axis of the storm is: tilted, perpendicular to the ground, or it makes no difference. (Straight forward answers, if possible use the answer choices provided please & thank you)
*October 2, 2011*

**Geology**

How is a mid-latitude cyclone formed: thunderstorms on the west side of an occluded front, frontal systems in association with the Jet Stream, a lot of hot air, or cyclonic circulation around a sub-tropical high? (Straight forward answers, if possible use the answer choices ...
*October 2, 2011*

**Geology**

which 2 would create a low pressure at the surface? warm temp., cold temp., air moving through a terrain constriction, or air moving out of a terrain constriction. What is the main reason hail is not associated with tropical thunderstorms: lack of sufficient moisture in the ...
*October 2, 2011*

**Geology**

How is a mid-latitude cyclone formed
*October 2, 2011*

**Geology**

When will a thunderstorm tend to be more severe and have a longer duration in reference to the axis of a storm.
*October 2, 2011*

**Geology**

Winds blow whenever there are: cold temperatures, pressure inequalities in the atmosphere, or the earth rotates on its axis
*October 2, 2011*

**Geology**

When a hurricane approches a costal area the damage from the storm surge is greater if it occurs: low tide, high tide, tide makes no difference? The dew point of a prcel of air refers to: its elevation above the surface, the temp. at which condesation will occur, the pressure ...
*October 2, 2011*

**Geology**

why do fall winds always warm as they descend the lee side of a mountain
*October 2, 2011*