Friday

October 21, 2016
Total # Posts: 143

**Calculus**

If x=2cos (z) and y= sin (z), then d^2y/dx^2=? What I got -sin (z) / -8cos (z)*sin (z) simplifies to 1/8cos (z) I don't think I'm right...

*October 10, 2016*

**CHEMISTRY**

[Update] I think I know what I did wrong. Instead of: (Mass Sample of NaHCO3 / Molar Mass of NaHCO3) * 100 = some value, it should be (Mass Sample of NaHCO3 / Total mass sample of unknown mixture) * 100 = some value. So, (.5517g NaHCO3 / 1.020g of unknown mixture) * 100 = 54....

*October 1, 2016*

**CHEMISTRY**

I'm trying to figure out the percent composition of a mixture of an unknown (a combination of NaHCO3 and NaCl). Here's my data: Mass of 150mL of empty beaker: 80.937g Mass of 150mL beaker w/ unknown: 81.957g Mass of 150mL beaker w/ unknown after reaction: 89.126g Mass ...

*October 1, 2016*

**Physics**

A rocket is fired vertically with an acceleration of 16m/s^2. After time T, the rocket's engine runs out of fuel and it begins to fall freely. The maximum height of the rocket is 940m, what is the minimum value of T?

*September 30, 2016*

**Math**

oh my bad it supposed to be = instead of +

*September 18, 2016*

**Math**

Solve each equation. Write each equation in simplest form. 7x/8 +21 A 24*** B 18.375 C 1.857 D 19

*September 18, 2016*

**Math**

Suppose two cards are drawn from a well-shuffled deck of 52-cards. What is the probability that both cards are face cards? What formula would I use?

*September 18, 2016*

**Math**

Simplify 1/(1*2*3) + 1/(2*3*4) + 1/(3*4*5) + ... + 1/(n*(n+1)*(n+2))

*August 6, 2016*

**math**

thanks

*March 12, 2016*

**math**

what percent of 300 is 60

*March 12, 2016*

**maths**

1. What is the value of X in a triangle that has 110° and 30°: 70°, 80°, 90°? 2. A map scale is 1cm to 20km. What is the real distance between two places which are 0.5 apart on the map? 3. When a jeweller sold a ring for €150, he made a profit of 50%. ...

*February 2, 2016*

**maths**

1. If a map has a scale of 1cm to 30km, what distance would 1mm represent? 2. If it takes a spacecraft 3 days to travel 250,000 kilometres, what length of time will it take to travel one million kilometres? 3. A publican makes 75 cents on every bottle of beer she sells. How ...

*January 27, 2016*

**maths**

1. A music store pays €14 for a CD. At what price must the CD be sold so the shopkeeper can make a profit of 25%? 2. What is the smallest number which can be divided evenly by 500, 600, 1000? 3. A map scale is 1cm to 30km. What is the real distance between two towns which...

*January 26, 2016*

**math**

1. A distance of 1 kilometre is represented on a map by a line 5cm in length. The scale is 1cm to ? m. 2. Value Added Tax at a rate of 20% is added to the price of a washing machine which costs €250 before tax. What will be its price after VAT has been added? 3. How much ...

*January 21, 2016*

**maths**

QUESTIONS!! 1.How much would it cost to carpet a room 4m by 3m at €9 per square metre? 2. A television set can be purchased for € 299 cash or a deposit of €50 and 12 monthly payments of €25. How much do I save by paying cash? 3. How many thousands in a ...

*January 20, 2016*

**maths**

Need help! 1. If a bus is travelling at a speed of 60km/hour,how longlshould it take to travel 10km? 2. Write two whole numbers greater than -5 but less than 0. <------|-----|-----|-----|-----> -10 -5 0 5 *A number line to help you* 3. How much will the lorry driver pay ...

*January 11, 2016*

**maths**

Stuck on these questions! 1. Clare is 1.5 metres tall. She is 13cm taller than Michelle. How tall is Michelle? 2. My sister has €40 in her bank account but wrote a cheque for €50 to pay for a new dress. By how much is her account now overdrawn?

*January 7, 2016*

**maths**

I am preparing myself for the Entrance Exams so I need help. 1. The middle number of 5 odd numbers is 297. What is the last number? 297 -->-----|-----|-----|-----|-----|-----<-- * Number line* 2. If there is a 10% service change in a restaurant, what is the service ...

*January 6, 2016*

**math**

There is a jar of jelly beans, Dad was hungry so he ate half. Brother wanted some too, so he ate a third, Mom saw brother eating some and ate a fourth. Mom gave 6 to Sister and gave 3 to Grandma. How many Jelly beans were in the jar originally? Justify your answer.

*December 14, 2015*

**maths: Lowest common multiple**

Hot dogs are sold in packages of 12 while hot dog buns are sold in packages of 8. Help me! Don't know what to do! (a) How many packs of each should you buy to have the same number of hot dogs and hot dog buns? (b) How many hot dogs in buns would you have?

*December 3, 2015*

**Mathematics**

Express the following limit as a definite integral. Show all the steps in your work. Lim as n approaches infinity of (3/n * (n)sigma(I=1) * (1+(3i/n))/(9+(1+(3i/n)^2)). I am utterly lost!

*November 27, 2015*

**Chemistry**

When CH3OH at its normal boiling point, does its entropy increase or decrease? Explain. - My opinion The entropy decreases because there is less order due to the less randomness of gas particles favoured when such an element is boiled not at normal boiling point?

*November 27, 2015*

**maths**

Stuck on these questions! Help! 1. A ball costing €50 was increased in price by 1%. What was the new price? 2. The perimeter of a swimming pool is 70 metres. If the width is 10 metres, what is the length of the pool? 3. A DVD player can be bought for €250 cash or for...

*November 26, 2015*

**maths**

1. A ball costing €50 was increased in price by 1%. What was the new price? 2. The perimeter of a swimming pool is 70 metres. If the width is 10 metres, what is the length of the pool? 3. A DVD player can be bought for €250 cash or for a down payment of €40 and ...

*November 26, 2015*

**maths**

Help me on these questions! 1. The teacher's bill for €15 worth of copies and 8 English workbooks was €35. What did each workbook cost? 2. Patrick spent 30% of his money on a football and 60% of it on football boots. If Patrick had €3 left, how much money ...

*November 25, 2015*

**maths**

My questions is: 25% of a class don't play basketball. 27 children do. How many are in the class?

*November 24, 2015*

**maths**

My 1st question is: What is the cost of 1.2kg of putty at €3 a kg? And last question is: A salesman bought a car for €5,000 but later had to sell it for €4,750. How much was his loss?

*November 19, 2015*

**maths**

My question is: A cheeseburger costs twice as much as a can of coke. If a cheeseburger and a can of coke cost €2.10, how much is the cheeseburger.

*November 18, 2015*

**maths**

Please help me on these questions. 1. Tom swapped 2/5 og his marbles gor 9 of Martha's. How many has Tom now? I got 15. I'm not sure if it's right. 2. A second-hand book shopmade a profit of €8 bh selling 10 books at €1.90 each. What price 2 was paid for ...

*November 16, 2015*

**maths**

Help me and show rough work please . First question:A cup holds 150 millilitres. How many cups of tea can be poured from a full teapot which holds 1.5 litres? 2. Put in order of size, smallest first: 2.2, 2.22, 2.199 3. Mom bought two pillows and paid with a €20 ...

*November 11, 2015*

**maths**

Please help me on these problem solving sums. Also show the rough work and answer. First question: If 15% of the children walk to school, 7% cycle to school and 30% come by bus, what percentage come by car ? 2. How much for forty steel nails at €2.50 per 100 ? 3. What is ...

*November 10, 2015*

**maths**

Eugene spent half his money in one shop and half of what was left in another shop. He then had€1.25. How much had he in the beginning. I am not sure if I got it right so O got €5.00\€6.25. So please do show your rough work and answer. Thank You! :D

*November 9, 2015*

**Organic Chemistry 2**

hi

*November 7, 2015*

**Math**

Hey guys I need some help with this question PLZ: A telecommunications company offers a rental deal which costs $30 per month plus 50c per call. a) Find the total cost (T1) for making x calls in a given month b)Find the total cost for making 52 calls in a given month ANOTHER ...

*November 4, 2015*

**grammar**

Please explain why the sentence, The flat creek bed was made of warm soft mud is neither a compound subject nor a compound predicate?

*September 20, 2015*

**Maths**

A rectangle has area 6 cm^2 and diagonal length 2 square root 5cm. What is its perimeter

*July 27, 2015*

**technology**

0.001

*April 29, 2015*

**Algebra Word Problem**

A large hotel finds that it can rent 95 rooms when it charge $100 per room. For each $1 increase in room cost it rents one room less. (Likewise, for each $1 decrease in room cost it rents one room more) What price should it charge in order to maximize the revenue?

*April 28, 2015*

**Math**

3 animals need to be chosen. There are 3 tigers, 6 bears, and 4 dogs. Find the probability that: a) 1 tiger, 1 bear, and 1 dog are chosen b) 3 bears are chosen c) no tigers are chosen by the way, we are learning combinations and permutations. Thank you for your help!!!

*March 30, 2015*

**Chemistry **

A solution is prepared by dissolving of pure HC2H3O2 and of NaC2H3O2 in of solution (the final volume). (a) What is the pH of the solution? (b) What would the pH of the solution be if of 0.250 M NaOH were added? (c) What would the pH be if of 0.40 M HCl were added to the ...

*February 22, 2015*

**Are there even any physics tutors here???**

I don't think it matters when the last question was answered I too noticed that there's a lot of physics questions that go unanswered I think samdata is just asking if there are more physics tutors

*February 2, 2015*

**eng**

would u be able to edit my story and help me come up with a title ? & then delete it !!

*October 27, 2014*

**eng**

i did ,but it's sorta confusing

*October 27, 2014*

**eng**

i can't think of any more ideas , can you please help?

*October 27, 2014*

**eng**

oh well how would you describe the feeling you get when you are scared

*October 27, 2014*

**eng**

describe your adrenaline when you are scared & terrified & don't know what to do!

*October 27, 2014*

**english**

how can i describe a plane crash using imagery in first person point of view ?

*October 26, 2014*

**Algebra**

Use the quadratic formula to solve the equation for x in terms of y and y in terms of x. (Enter your answers as a comma-separated list. If there is no solution, enter NO SOLUTION.) 2x^2 + 7xy + 1 − y^2 = 0 y in terms of x y =

*September 15, 2014*

**Math**

Use the quadratic formula to solve the equation for x in terms of y and y in terms of x. (Enter your answers as a comma-separated list. If there is no solution, enter NO SOLUTION.) 2x^2 + 7xy + 1 − y^2 = 0 (a) x in terms of y x = (b) y in terms of x y =

*September 14, 2014*

**Math**

Two forces of magnitude 15N and 4root2N are acting in the directions 3i-4j and i+j respectively, find the magnitude of the resultant of the two forces.

*May 8, 2014*

**Math**

Two towers P and Q are 600m apart with P being due east of Q. A church is on a bearing of 210 degrees from P and 125 degrees from Q. Find the distance of the church from P and Q.

*April 7, 2014*

**Science **

what mass of sulphuric acid must be added to a 750 ml to have a ph of 2.27

*March 11, 2014*

**Physics**

A hammer thrower accelerates the hammer (mass = 7.30 kg) from rest within four full turns (revolutions) and releases it at a speed of 21.0 m/s. Assuming a uniform rate of increase in angular velocity and a radius of 0.80 m, calculate the angle of this force with respect to the...

*February 2, 2014*

**2nd grade math**

80m/11 lights = 7.2728 m between lights, 7.2728 * 4 for a distance of 4 lights in between the two is = 29.1 m

*February 2, 2014*

**Math**

A sample of 5 people is selected from 3 smokers and 12 non-smokers. In how many ways can the 5 people be selected?

*January 24, 2014*

**Mathis**

You have £100 you have to buy 100 animals. 1 chicken costs 50p,1pig costs £10,1 sheep costs £2?

*January 19, 2014*

**Chemistry**

What are the individual orders of the reactants involved in the oxidation of methylene blue by ascorbic acid? Rate of reaction= [MB+]^m * [H2A]^n * [HCl]^p What are m, n, and p?

*November 26, 2013*

**Telecommunications**

If a Signal with a power level of 40 mW is inserted onto a transmission line and the measured power some distance away is 10 mW, calculate the loss of signal strength is decibels.

*October 18, 2013*

**Telecommunications**

We send a frame of 256 bits. If the probability that a bit changes in transmission is 0.001 and each bit is independent. a. What is the probability that exactly 6 bits change? b. What is the probability that exactly 0 bits change ?

*October 18, 2013*

**Telecommunications**

1. System A consists of a single ring with 100 stations, one per repeater. System B consists of four 25 stations rings linked by a bridge. If the probability of a link failure is , a repeater failure is , and a bridge failure is , derive an expression for parts (a) to (d). a) ...

*October 18, 2013*

**Biology**

Enantiomers, like L-alanine and D-alanine, are so similar that ribosomes will incorporate either one into a protein during synthesis. True or False?

*September 21, 2013*

**math**

I am a decimal number and when you multiply me by the number that is 10 times greater than me you get the answer 291.6

*April 8, 2013*

**math**

two trees on a street have the heights of 3 meters and nine metres respectively. at a certain time of day the shorter tree casts a shadow length of five meters how far apart are the trees?

*March 13, 2013*

**math linear alegba**

Find the distance from the point (1, 1, 1) to the line given as the intersection of planes x+2y− 2z = 5 and 6x − 3y + 2z = 8.

*March 4, 2013*

**math**

Anna and Jamie were at track practive. The track is 2/5 kilometers around. Anna ran 1 lap in 2 minutes. How many minutes does it take Anna to run one kilometer?

*December 3, 2012*

**chem**

An erlenmeyer flask contains 56.7 g of KMnO4. How many grams of manganese is in the flask?

*November 29, 2012*

**physics**

a 65kg oak trunk is placed on a board, inclined at an angle of 30 with the horizontal. What is the weight? The Normal Force of the trunk? The Applied force down the ramp?

*November 18, 2012*

**Physics**

You need to move a 129-kg sofa to a different location in the room. It takes a force of 90 N to start it moving. What is the coefficient of static friction between the sofa and the carpet?

*November 17, 2012*

**physics**

A staging that weighs Wstaging supports a painter weighing 170 N. The reading on the left scale is 490 N and the reading on the right scale is 220 N. 490 N 220 N What is the weight of the staging? Answer in units of N

*November 13, 2012*

**Physics**

A circular loop with 30 turns and area of 0.25 m2 rotates at 100 rad/s. The axis of rotation of the loop is perpendicular to the direction of the magnetic field of 0.04 Tesla. What is the maximum emf induced in the loop? 15 V 30 V 45 V 60 V I got 15 V but that doesn't seem...

*October 23, 2012*

**Physics**

Which of the following is correct for a step-down transformer? Number of turns in the primary coil is less than the number of turns in the secondary coil. Step-down transformer increases the voltage from low value to high value. Number of turns in the primary coil is more than...

*October 22, 2012*

**science**

A point object is acted upon by forces of 4N, 5N and 6N is in equilibrium. IF=f the 6N force is removed, what is the resultant force on the object now? I really want to know how tow find relationship between 3 forces, and is there anything to do with cos rule??? HELPPPPP-.-

*October 11, 2012*

**science**

An aircraft travels through the air with a velocity of 200m/s due east. It is found to be travelling over the ground with a velocity of 220m/s in a direction of 20(degree) south of east.The difference between the two is due to thw wind velocity. What is the wind velocity?

*October 10, 2012*

**science**

what is the best way to study for my chemistry test tomorrow

*September 20, 2012*

**math**

how do i do the problem 3.14=7x=2y

*September 20, 2012*

**physics**

A train travels at 3m/s and parallel and very near to the train is a wall the has a slope of 12degrees, the window you see this wall through is .9m high, 2m across, and when you look out you first see the top edge at the lower left of the window, moving towards the top right ...

*August 29, 2012*

**math**

45+35=80

*April 26, 2012*

**ENGLISH--HELP**

they will get more education...duh

*April 12, 2012*

**ENGLISH--HELP**

Every sentence in the paragraph below violates some principle of good persuasive writing. Revise the paragraph, following the directions at the end of each sentence; use your imagination where necessary. Type the revised paragraph in the text box provided below. CAUTION: ...

*April 12, 2012*

**math**

if it takes 1/2 hour to clean 1/8 mile, how long will it take to clean 2.5 miles

*January 29, 2012*

**writing**

Do you have any tips for writing an opinion paper?

*December 1, 2011*

**lit**

is this right? punctuation wise. Franklin Roosevelt said that December 7, 1941, was "A date which will live in infamy."

*October 27, 2011*

**social studies**

How were different religious group (puritans, Quakers)impacted by by the French and Indian War?

*October 6, 2011*

**physical science**

thank you very much!

*April 26, 2011*

**physical science**

how much power is used when a weightlifter lifts a 1250-n barbell 2 meters in 3 seconds...

*April 26, 2011*

**physical science**

Trying to find the power to this ?. A weightlifter lifts a 1250-n barbell 2meters in 3seconds. How much power was used to lift the barbell? Do you have to find the work first??

*April 26, 2011*

**physical science**

whatis the answer to the question???

*April 26, 2011*

**physical science**

It is the the MA of a machine without friction. MA being the ratio of the output force to the input force.

*April 26, 2011*

**physical science**

A mover uses a ramp to push a stereo into the moving van. The ramp is 3 meters long and 1.5 meters high. What is the ima of this ramp?

*April 26, 2011*

**physical science**

ideal mechanical advantage. That is the answer that I got too. It seemed to easy?! Thank you!!

*April 26, 2011*

**physical science**

A screwdriver with a 1-cm shaft and a 4-cm handle is used to tighten a screw, what is the ima?

*April 26, 2011*

**physical science**

can you show me the formula that you used?

*April 26, 2011*

**physical science**

A painter uses a fixed pulley to raise a 1-k can of paint a distance of 10 m,what is the ima??

*April 26, 2011*

**Algebra 2**

i need help, step by step, in solving for fractional coefficients. can someone walk me through?

*April 25, 2011*

**stats**

A sample of 12 observations is selected from a normal population for which the population standard deviation is known to be 4. The sample mean is 19. (Round your answers to 3 decimal places.) (a) The standard error of the mean is The 90 percent confidence interval for the ...

*March 28, 2011*

**6th grade math**

Tonya's car averages 240 miles for each 10 gallons of gasoline. How many gallons of gasoline will the car need travel 216 miles?

*March 24, 2011*

**math**

I'm totally lost and I didn't want to continue posting under my name tootie. Thinking that I wouldn't get the help since I had too many posts

*February 20, 2011*

**math**

The National Association for Women in Science asked recent high school grads if they had taken certain science classes. Of those surveyed, 32 said they had taken physics, 51 said they had taken chemistry and 15 said they had taken both. Ten said they had taken neither. How ...

*February 20, 2011*

**math**

; 21 girls to 13 boys

*February 14, 2011*