Tuesday

October 21, 2014

October 21, 2014

Total # Posts: 1,699

**Physics **

two objects move toward each other collide and separate. there was no net external force acting on the objects but some kinetic energy was lost. is momentum conserved ? what is the explanation ?
*August 16, 2013*

**math**

= 27600 X 100/115 = 24000
*August 16, 2013*

**Physics **

An object with mass 20 kg is moving horizontally. if the velocity of the object is doubled, does the momentum increased or decreased ? what is the explanation ?
*August 16, 2013*

**math**

4/57(x+8)=1/3
*August 16, 2013*

**Chemistry**

3.00 g of Zn is allow to react with 1.75 g CuSO4 . calculate how many grams of Zn will remain after the reaction is complete ?
*August 11, 2013*

**Chemistry**

suppose 8.00 g of CH is allowed to burn in the presence of 9.00 g of oxygen. how much (in gram) CH4 , O2 and H2O remain after the reaction is complete ?
*August 11, 2013*

**Chemistry**

0.300 moles of bromine gas (Br2) and 0.500 moles of chlorine gas (Cl2) react to for tribromochlorine (Br3Cl). how many moles of this product will form ?
*August 11, 2013*

**biology**

Why all enzyme work well in their own optimum temperature and optimum pH ? i need more explanation about why different enzyme have different optimum temperature and different optimum pH to react. i hope to get a long explanation for my essay that contain 5 marks.
*July 31, 2013*

**Harvard Justice**

According to the Professor Sandel, if judgments about the good are unavoidable in debates about justice and rights, is it possible to reason about the good (these judgments about the good)? a) If reasoning about the good means that you must have a single principle or rule or ...
*July 31, 2013*

**biology**

Do all enzymes function within the different temperature range, like they do with pH?
*July 29, 2013*

**physics**

as i have known that centripetal force is directly proportional to the angular speed square. so, what is the relationship between angular speed and centripetal force ? when centripetal force increase, does angular speed increase too? i need more explanation.
*July 29, 2013*

**math**

solve my system of equation with full steps 3x+4y=29 2x–5y=-19
*July 24, 2013*

**english**

use athlete in the sentence an ____ training requires long hours of exercises.
*July 23, 2013*

**physics**

what is the source of error occur in experiment Standing Waves (tuning fork)?
*July 16, 2013*

**Physics Experiment**

sorry, wrong typo... the answer is when the water level is lower, the air in the glass tube. the changing of the L is to match the natural frequency of the air column inside the glass tube with the tuning fork that vibrate at fixed frequency. when the matching is achieve, the ...
*July 11, 2013*

**physics**

what is the source of error occur in experiment Standing Waves (tuning fork)?
*July 11, 2013*

**Chemistry**

Henry's Law says: Pressure(gas)=(Henry's Law Constant)(Molarity of the gas)… we are looking for Molarity so we can rewrite the above equation as… Molarity of the gas=Pressure(gas)/(Henry's Law Constant) so… M=1.95 bar/29.4 barM-1 the bar units cancel...
*July 5, 2013*

**phy**

An engine absorbs 2000j of heat from a hot reservoir and expels 750j to a cold reservoir during each poerating cycle, (i)what is the efficiency of the engine (ii)How much work is done during the cycle? (iii)What is the power output of the engine if each cycle last for 0.5 ...
*July 4, 2013*

**phy**

(Q1)A gas occupies a certain volume at 27c.If it is heated at constant pressure, its volume is exactly doubled at a temperature of. (a)54c(b)219c(c)327c(d)600c (Q2)If the specific heat capacity of water initially is4.2000/kg/k and the difference in temperature of water between...
*July 3, 2013*

**phy**

(Q1)the temperature at which the tungsten filament of a 12v and 36w lamp operates is 1730c.If the temperature coefficient of resistance of tungsten is 0.006/k, find the resistance of the lamp at room temperature of 20c (a)10.00(b)0.45ohms(c)0.39ohms(d)4.00ohms (Q2)At what ...
*July 3, 2013*

**phy**

(Q1)A wire of cross- sectional area of 0.00006m2 and length 50cm stretches by 0.2mm under a load of 3000n.Calculate the Young's modulus for the wire (a)80000000000Nm-2(b)125000000000Nm-2(c)25000000000Nm-2(d)5000000000Nm-2 (Q2)a square plate of side 10cm is made of a metal ...
*July 3, 2013*

**phy**

(Q1)calculate the electric power which must be supplied to the filament of a light bulb operating at 3000k. the total surface area of the filament is 0.000008m2 and iits emissivity is 0.92.(a)20.3w (b)33.8w(c)46.4w(d)56.7w (Q2) calculate the change in internal energy of 2kg of...
*July 3, 2013*

**phy**

an ungraduated mercury thermometer attached to a millimeter scale reads 22.8mm in ice and 242mm in steam at standard pressure. What will the millimeter read when the temperature is 20
*July 2, 2013*

**Chemistry **

How do I calculate this? How many grams of CaCl2 is in 500 mL 0.1 M solution of CaCl2
*June 25, 2013*

**physics**

A 2.0-m-tall, 30-cm-diameter concrete column supports a 3.0×105kg load. By how much is the column compressed (in mm) ?
*June 22, 2013*

**Math**

7/3a + 2/5= ?
*June 9, 2013*

**business math**

paychecks each week will be as follows : $325 x 40 = $13,000 (gross earnings /week) $13,000 x 0.062 = $806 (total combined social security) $13,000 x 0.0145 = $188.50 (total medicare taxes) social security : 806 medicare: 188.50
*June 8, 2013*

**physics **

A box is placed 50 cm away from a double convex lens. The image is on the opposite side of the lens, is inverted and 50 cm away from the lens. find: a)the focal length of the lens. b)the height of the image. c) using the focal length that you found, how far from the lens would...
*May 30, 2013*

**MATH **

1- increase 1000 dollars by 10% then decrrese ur answer by 10% wat do u notice? 2- my parents increased my pocket money by 10% then 3 months later increased it by further. 10%'. My father said there was an increase of 21% , can u explain this?
*May 25, 2013*

**Algebra**

Thank you
*May 22, 2013*

**Algebra**

You are building a rectangular deck. The area of the deck should be 250 ft squared. You want the length of the deck to be 5 ft longer than twice its width. What should the dimensions of the deck be? My work: 250=2x(x+5) Is this correct so far?
*May 22, 2013*

**Frenchhhhhhhhhh**

Thanj u all
*May 22, 2013*

**Frenchhhhhhhhhh**

1- avez vous des eu 2- tu en as / des as? 3- elles des ont?
*May 22, 2013*

**Frenchhhhhhhhhh**

Replace the capitalized words with either, le,la,en,des..
*May 22, 2013*

**Frenchhhhhhhhhh**

Please help! I have to replace 1- avez-vous eu DES CADEAUX pour votre anniversaire? 2- tu as des COURS DE FRANÇAIS tous les jours? 3-elles ont beaucoup D'AMIS au collége??
*May 22, 2013*

**Algebra **

Use the zero product property to solve the equation: -3n(2n-5)=0
*May 21, 2013*

**AP English Lit**

Thank you so much! I appreciate it. :)Kate
*May 21, 2013*

**AP English Lit**

I think your right but I've no idea what else it could be. I don't know what to do. :( Kate
*May 21, 2013*

**AP English Lit**

Hi, I was wondering what kind of poem "Dream Variations" by Langston Hughes is? I've narrowed it down to blank verse or free verse but I'm not sure. Please help. Here is the poem: Dream Variations To fling my arms wide In some place of the sun, To whirl and ...
*May 21, 2013*

**AP English Lit**

Well, it's not a sonnet because it has 12 lines. So, I'm not sure but I think it's blank verse? Maybe. But, it might also be couplets. By the way, thanks for getting back to me. Kate
*May 20, 2013*

**AP English Lit**

Hi, I have a question that I'm stuck on. Do you know what kind of poem William Butler Yeats's poem "When You Are Old" is? That is, is it a sonnet or an epic or something else altogether? Please help! Here is the poem: <strong>When You Are Old</strong...
*May 20, 2013*

**TRIGONOMETRY**

Can someone please show me step by step solutions? I'd appreciate if you did so I know how you get the answer. Thank you so much! Solve each equation, giving a general formula for all of the solutions: a)2sin^2 x-5sinx-3=0 b)(cosx-(sqrt2/2))(secx-1)=0 Would the general ...
*May 18, 2013*

**TRIGONOMETRY**

Aah, okay! That's easy enough! That makes total sense. Thanks!
*May 18, 2013*

**TRIGONOMETRY**

Evaluate the expressions: a) arctan(-sqrt(3)) a) Arctan(-sqrt(3)) So, I know how to find the answers with a calculator, but how do I find it step by step?
*May 18, 2013*

**Physics**

2 factors that increase static friction? Could it be weight or the ground?
*May 18, 2013*

**TRIGONOMETRY**

Yeah, I figured it out once I posted it. Sorry for that! But thanks for responding anyways. I misread read the question. You've been a huge help actually explaining these answers. I'm feeling really good about my final! :)
*May 18, 2013*

**TRIGONOMETRY**

Use the dot product to determine which of the following vector pairs are orthogonal. a. v1 = (-5,5) and v2 = (1,1) b. v1 = (154,169.4) and v2 = (88,64)
*May 18, 2013*

**TRIGONOMETRY**

Can someone please give me a step by step answer on how to find the complex cube roots of 8(cos(4π/5)+isin(4π/5))? I need to know how to do this for my trig final next week.
*May 17, 2013*

**TRIGONOMETRY**

I'm sorry, I mean could you convert w= 1+sqrt3i to polar coordinates. I already did the other. My bad.
*May 17, 2013*

**TRIGONOMETRY**

I don't understand how to convert -3-4i to polar coordinates. I need to know how so I am ready for my trig final next year. Can someone please show me step by step how to solve this? Thanks
*May 17, 2013*

**english**

Yeah, I'm sorry, I don't understand what you're "asking", Anonymous.
*May 17, 2013*

**english**

Are you asking if the sentence has correct grammar? If so, no revision is required.
*May 17, 2013*

**TRIGONOMETRY**

Can someone please show me step by step how to calculate the modulus and the argument for these complex numbers? I have a trig final next week and I am trying to finish this study guide so I am prepared. Thank you so much! If you can, please show my how you get the answer so I...
*May 17, 2013*

**TRIGONOMETRY**

y/r!! That makes much more sense! Someone else had told me y/x, so that's why it didn't work. Thanks!
*May 16, 2013*

**TRIGONOMETRY**

3. The rectangular coordinates of a point are given. Find the polar coordinates of each point. b. (0,3) I figured out a, but I canNOT figure out b. Can someone please explain? :)I need to know how to do this for my final next week.
*May 16, 2013*

**Math **

1- 75 is what percent of 500? 2- 30% of 30 is wat #? 3- 90% of wat num is 207?
*May 16, 2013*

**TRIGONOMETRY**

Can you please help me with this question on my study guide for my trig final? Thanks! I'd also appreciate if you can check out my other postings and check my work for some other study guide questions. I want to make sure I'm ready for my final. :) 4. Transform each ...
*May 16, 2013*

**TRIGONOMETRY**

Thanks, Steve! :)I appreciate your help!
*May 16, 2013*

**TRIGONOMETRY**

Can you check my work, please? This is for a trig study guide for my final next week. I'd like to know if I'm doing this right. :) 2. The polar coordinates of a point are given. Find the rectangular coordinates of each point. a. (5,(π / 4)) b. (-2,(π / 6)) ...
*May 16, 2013*

**TRIGONOMETRY**

I tried converting (0,3) myself, but I can't seem to get your answer. What am I doing wrong? b. (R, theta) R = sqrt(x^2 + y^2) R = sqrt(0^2 + 3^2) R = 3 theta = arctan y/x theta = arctan 3/0 theta = 1.249 = (3, 1.249)
*May 16, 2013*

**TRIGONOMETRY**

Aaah, so those are the formulas! I'll remember those. That helps so much! You're awesome! Thank you for not just giving me the answers. The point of a study guide is to study and know how to get to an answer. Usually people just give the answer without showing the ...
*May 16, 2013*

**TRIGONOMETRY**

Can you please help me with this question on my study guide for my trig final? Thanks! I'd also appreciate if you can check out my other postings and check my work for some other study guide questions. I want to make sure I'm ready for my final. :) 3. The rectangular ...
*May 16, 2013*

**Math**

A mixture of petrol and oil for a two stroke lawn mower contains 85% petrol, how much oil is required for 18 litres of the fuel mixture?
*May 16, 2013*

**Physics helpp**

Newtons 2nd law The force of earths gravity is about 10 N downward. Whats the acceleration of a 15kg backpack if lifted with a 15N force??
*May 14, 2013*

**Physics**

And how do i find the mass if its missing? Formula?
*May 14, 2013*

**Physics**

Newtons second law What net force acting on a 14kg wagon produces an acceleration of 1.5 m/s^2?
*May 14, 2013*

**history**

Sorry it was a typo, but thank you.
*May 13, 2013*

**history **

What does this quote mean? "It is honorable to be raised to a throne than to be born to one. Fortune bestows (gives) the one, merit obtains to other." -Francesco Petrarch
*May 13, 2013*

**English**

Does this sentence have correct parallelism? Using steam power helped people spin cotton and grind flour.
*May 10, 2013*

**Social**

Thanks alot
*May 9, 2013*

**Social **

What are the goal and practices of mormons?
*May 9, 2013*

**Physics**

1- you push a coin across a tabble, the coin stops. How does this motion relate to balanced and unbalanced forces?
*May 7, 2013*

**Physics**

Which causes an object in motion to stay in motion? A) friction b) gravity C) inertia D) velocity Its not friction..
*May 7, 2013*

**science**

what happens to the G-force as the speed of the centrifuge increases?
*May 5, 2013*

**Chemistry**

why is it important to know accurately the mass of water used in a calorimeter?
*May 5, 2013*

**Statistics**

The Education Testing Service conducted a study to investigate differences between the scores of males and females on the SAT. The study identified a random sample of 562 females and 852 males that had achieved the same high score on the math portion of the test. That is, both...
*May 3, 2013*

**statistics**

A firm having 4000 employees took a random sample of 25 in order to estimate their average annual state tax payment with 99% confidence. If the results were X = $640 and s = $20, what is the best interval estimation?
*May 3, 2013*

**chemistry**

Methane gas is burned releasing Carbon Dioxide into the atmosphere. How much CO2 (g) is released if 78.5 Liters of Methane is burned? CH4 + O2 --> CO2 + H2O
*May 1, 2013*

**Calculus**

A particle moves along the curve y = sqr(1+x^3). As it reaches the point (2,3), the y-coordinate is increasing at a rate of 4cm/s. How fast is the x-coordinate of the point changing at that instant?
*May 1, 2013*

**art history**

What is the Etruscan influence on Roman, Byzantine and Romanesque visual culture?
*April 30, 2013*

**English**

1. If you are filled with anticipation about an event, you are (1 point) ***looking forward to it. planning to avoid it. hoping to delay it. 2. Read the following excerpt from Sky: We finally reached Enkhuizen, an ancient harbor town, where the brisk wind from the sea was ...
*April 28, 2013*

**Science question**

It is right microwave. Only certain types of microwaves use batteries. All phones, radios, and definately flashlights use batteries.
*April 23, 2013*

**math**

the product of 2 consecutive integers is 156. find the integers. I found them mentally 12 and 13 but, how do I find them while solving?
*April 18, 2013*

**math**

thanks
*April 11, 2013*

**math**

If the first of 1000 consecutive whole numbers is odd, their sum must be a) even b) odd c)prime d) negative Help?
*April 11, 2013*

**Math**

Two investments are made totaling $4800. In the first year they yield a total of $412 in simple interest. Part of the money is invested at 8% and the rest at 9%. Find the amount invested at each interest rate.
*April 11, 2013*

**Chemistry**

If you wanted to prepare 50.0 mL of hydrogen, collected over water at 25 C on a day when the barometric pressure was 730 torr, what mass of aluminum would you react with a hydrochloric acid? (Balance the equation first.) ___Al(s)+___HCl(aq)=___AlCl3(aq)+___H2(g)
*April 8, 2013*

**Chemistry**

A sample of iron reacted with hydrochloric acid. The liberated hydrogen occupied 40.1 mL when collected over water at 27 C at a barometric pressure of 750 torr. What is the mass of the sample of iron? (Because of the collection of gas over water, the vapor pressure of the ...
*April 8, 2013*

**Chemistry**

What volume of hydrogen, measured at 25 C and 1.00 atm can be produced by dissolving 5.0 g of magnesium in hydrochloric acid? (Write and balance the equation for the reaction first.)
*April 8, 2013*

**Chemistry**

Instead of a strip of pure Mg ribbon, you are accidentally given a strip of an aluminum-magnesium alloy. You calculate the mass of the strip as above. Would the mass of the strip be higher or lower than expected? Write the appropriate chemical equations (one equation for the ...
*April 8, 2013*

**Chemistry**

If the strips of MG ribbon are coated with white MgO, would this cause the mass of Mg that you calculate to be too high or too low? Why?
*April 8, 2013*

**Chemistry**

If your partner did not take into account the vapor pressure of water when calculating the moles of hydrogen produced, would the mass of Mg that was calculated at the end of the experiment be too high or too low? Why?
*April 8, 2013*

**la**

shoud students who fail their classes be retained and have to repeat the grade ?
*April 2, 2013*

**la**

shoud students who fail their classes be retained and have to repeat the grade ?
*April 2, 2013*

**chemistry**

Use the molar volume to find the volume, in liters, of 6.40g of O2 at STP.
*April 1, 2013*

**Pre-Algebra**

How many different ways can you choose 3 frozen yogurt toppings from 20? 6,840 1,140 60* 2,260 I think it is 60 because 3*20 however not positive.
*April 1, 2013*

**Finance **

They will need 200,000 in 18 years and they can expect a rate of return of 6 %. How much will they need to invest annually. I would have set it up and gotten $70068.76 but then do you divide by 18?
*March 28, 2013*

**science**

During condensation, what must be changed, temperature or heat energy?
*March 25, 2013*

**chemistry**

N2(g)+H2(g)-NH3(g) Calculate the volume of ammonia gas produced when20cm3 of nitrogen gas was reacted with an excess of hydrogen gas
*March 25, 2013*

**physics**

A bird wants to rech its nest that is located 53 meters (35 degrees south of west) from where it is perched. If the maximum speed that the bird can fly with respect to the air is 12m/s and there is a wind blowing from a direction of east 35 degrees south at a speed of 8.1 ...
*March 24, 2013*

Pages: <<Prev | 1 | **2** | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>