# Posts by help

Total # Posts: 1,574

Chem Help!
Describe how you would prepare t-butyl-n-butyl ether. assume you are working on a 1 M scale. what reagents would you use? What solvent? what reaction conditions?

Physics help
an isolated container holding 5 kg of sulfuric acid is at 60 C. if 2.49x10^5 Joules of energy were transferred out of the acid, what would be the new temp. of the acid? show steps please!

Calculus-Newton Method Approximation
1/ 3(x^3) + 1/2(x^2) + 1 = 0, x1 = −3 newtons way to the 4th decimal

Fixed Answer Us= 1/2kx^2 =1/2(5286.0)(.40)^2=422.88 J

an athlete stretches a spring an extra 40.0 cm. how much energy has he transferred to the spring, if the spring constant is 5286.0 N/m? Us= 1/2kx^2 =1/2(5286.0)(.40)=1057.2 J Thanks!

physics
Rocket-powered sleds are been used to test the responses of humans to acceleration. Start- ing from rest, one sled can reach a speed of 510 m/s in 2.37 s and can be brought to a stop again in 3.15 s. Find the acceleration of the sled while ac- celerating. Answer in units of m/...

physics
The average car today has a mass of 1100 kg, and when accelerating from rest, covers 0.25 miles in 15 seconds. Each rim and tire together has a diameter of 46 cm and a mass of 9.1kg. If we agree the rim and tire have the shape of a solid disk that rotates through its geometric...

history

history
5. What was the eventual outcome of De Soto's expedition A. It encourage Spain to compete with France for land in the north america*** B. He founded a new colony in the name of the king C. He found great wealth and returned to Spain a hero D. He was captured and enslaved ...

History
i know 16 is A and is 14 B or A

History
is 16. C

History
Is 17. D

History
so 14-17 is wrong ?? and if so can you help me because i did read my book i mean read i couldn't find it and i am a A an B Enroll student so can you please help I need help.

History
14. D 15. B 16. D 17. A 18. A 19. C 20. D

History
14. Which statement best describes Georgia as a royal colony? (1 point) A. Georgia was ruled directly by the king through one of his royal governors. B. Georgia was ruled directly by the king through a council of elected officials. C. Georgia was ruled by an elected ...

MATHS
A boy spent 1/4 of his money on sweets and 3/8 on bus fares. What fraction of his money is left?

MATHS
how many twenties must be added to 3 tens to equal £2.10

science
Jay is right

Chemistry
This is still not correct. I do not know what I am doing wrong

Chemistry
Suppose that 0.250mol of methane, CH4(g), is reacted with 0.400mol of fluorine, F2(g), forming CF4(g) and HF(g) as sole products. Assuming that the reaction occurs at constant pressure, how much heat is released? Substance ΔH∘f (kJ/mol) C(g) 718.4 CF4(g) −679....

Chemistry
I ended up with the wrong answer can I ask what I did wrong? So I got the dHrxn which I found to be -1,679.54 I then determined the limited reagent was indeed F2 and that it produced .1 mol of CF4 I then divided -1,679.54 by .1 to get -16,795.4 and converted it to kilojoules ...

Chemistry
Please help Suppose that 0.250mol of methane, CH4(g), is reacted with 0.400mol of fluorine, F2(g), forming CF4(g) and HF(g) as sole products. Assuming that the reaction occurs at constant pressure, how much heat is released? Substance ΔH∘f (kJ/mol) C(g) 718.4 CF4(g...

Chemistry
Thank you I ended up solving it right after I posted this. I wasn't factoring in the mas of the rod.

Chemistry
A volume of 100.mL of H2O is initially at room temperature (22.00 ∘C). A chilled steel rod at 2.00 ∘C is placed in the water. If the final temperature of the system is 21.50 ∘C , what is the mass of the steel bar? Use the following values: specific heat of ...

math
Find 1 terminating decimal and 1 repeating decimal between 1/2 and 2/3.

Math HELP!!!!!
give 2 examples of mixed numbers that when multiplied by 3/4 give a product between 3/4 and 1 PLEASE HELP ME AND QUICK I HAVE A LOT DUE TOMORROW!!!!!

Math
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math
if 1/2 times 3/4 is 3/8 why is it less than 3/4?

physics
a stone is dropped from the peak of a hill . IT covers the distance of 30m in last second of its motion. Find the height of the peak?

Help Ms.Sue
1/4 : 1/3 : 1 1/12 Can you simplify it with whole numbers?

math help
Is there a way to simplify it in numbers completely?

math help
(1+3 1/4) : (1 1/4 + 3 1/3) Simplify as a ratio?

ART! URGENT
What was the anwser for this assessment?

science
yes sorry i mean krebs cycle. i just can't figure it out and I've looked everywhere in my book

science
Krebs Circle produces A)NADH and Carbon Dioxide B)ADP and NADP C)Acytol CoA and sugars D)Water and Carbon Dioxide

Math
Kate is 5 years older than Lenny. Lenny is 2 years younger than Maria. Maria is twice as old as Norman. If Norman is 10 years old, how old is katie?

math
if 2 chickens can lay 8 eggs in 3 days, how many eggs can 5 chickens lay in 6 days?

Physics
Two telescopes A and B spot a star. Telescope A reports the position of the star to be in the East 60 degrees above the horizontal line joining A and B. Telescope B, which is 500 km West of telescope A spots the star at 30 degrees above the horizontal line joining A and B. ...

Language Arts
Which statement best expresses a central theme of the story teller? A. People with no children to care for are usually better at handling children. B. It is important to instruct children about right and wrong at all times. C. The best way for adults to deal with children is ...

Physics
The coefficient of rolling friction between the floor and the hardened steel balls of an anesthesia trolley (anesthesia machine with ventilator and monitor) is 0.0015. If a hospital crew needs 77 N to push the trolley at an angle of 30 degrees below the horizontal with ...

math
A merchant blends tea that sells for \$4.40 a pound with tea that sells for \$2.30 a pound to produce 120 lb of a mixture that sells for \$3.00 a pound. How many pounds of each type of tea does the merchant use in the blend?

math
A college student earned \$8900 during summer vacation working as a waiter in a popular restaurant. The student invested part of the money at 10% and the rest at 9%. If the student received a total of \$831 in interest at the end of the year, how much was invested at 10%?

Math
How do you expand and simplify (x-2)(x+2)?

microsoft powerpoint
1. c 2.b

physics
A sprinter has a mass of 82.0 kg. If the sprinter is running at a speed of 22.5 km/h, determine his kinetic energy. __________ × 103 J.

physics
A 130.0 g object is moved from a shelf 0.2 m high to one that is 5.0 m high. The change in potential energy for the object is __________ .

physics
A hockey player lifts a 600 g trophy up into the air a distance of 75.0 cm. The work done against gravity on the trophy is __________ J.

physics
When an object travelling at 12.7 m/s [E] speeds up to a velocity of 21.5 m/s [E] in 3.45 s, the magnitude of the acceleration is __________m/s2.

Life sciences
So no one can take it/Security. They're pretty rare. Is this supposed to be written in a paragraph though?

Math
Thanks alot.

Math
After Michael 110 baseball cards to Sally and 75 to Heidi, he still has 315 left. What percent of his cards did Michael give away? 110 + 75... and then??

Math
No. 500% is right. I tried it on my online homework. Thanks :)

Math
Umm, isn't it 5000? :)

Math
Thank you

Math
If the investment rises from \$1000 to \$5000, the percent is what from the original?

science
A mass m=5.2 kg is attached to the end of a spring with a spring constant of k=15.6 N/m. The mass moves through a viscous damping medium with a damping constant b=1.8 kg/s giving a velocity dependent damping force Fdamp= -bv. The motion occurs in zero gravity so set the force ...

statistics
M&M’s The candy company claims that 10% of the M&M’s it produces are green. Suppose the candies are packed at random into small bags containing about 25 M&M’s per bag. A class of elementary students learning about percentages opens several bags, counts the ...

USA Colonists History
thx, but what about the land?

USA Colonists History
i think that 1. They could trade the things they dig, find and then sell it. 2. They could make materials from the trees they find, etc., and sell them.

what were they?

Math
James takes a ruler and measures the width of the piece of paper. He find that the actual width is 48.8 cm. Find the width of each strip.

math
A new cruise ship line has just launched 3 new ships: the Pacific, the Caribbean, and the Mediterranean. The Caribbean has 32 more rooms then the Pacific. The Mediterranean has 38 fewer rooms than FOUR times the number of rooms on the Pacific. Find the number of rooms for each...

English
> rain's <

math
thanks

math
the value is 56 my bad

math
The value of an uncirculated mint state-65 1950 jefferson nickle minted in denver is 4/3 the value a 1945 nickle minted in philadelphia is similar condition. together the total value of the two coins is \$21.00

calculus
Consider the motion of a particle of mass m falling vertically under the earth’s gravitational field, and suppose the downward motion is opposed by a frictional force p(v) dependent on the velocity v(t) of the particle. Then the velocity satisfies the equation mv0(t) = &#...

SCIENCE
c b a b

Math

networks
what method can be used to reduce packet jitter

networks
Sorry but what causes packet jitter

probability

alg.
Solve. (If there is no solution, enter NO SOLUTION.) y= x^2-x-4 y=x+4 (x, y) = ( , ) (smaller x-value) (x, y) = ( , ) (larger x-value) x^2 + y^2 =10 x+y=4 (x,y)= ( , ) smaller value (x,y)= ( , ) larger value

Accounting
Target Company issues bonds with a par value of \$900,000 on their stated issue date. The bonds mature in 10 years and pay 10% annual interest in semiannual payments. On the issue date, the annual market rate for the bonds is 12%. What is the selling price of the bond

4x+2=3x+9 Move 3x to the other side so it will become -3x ( 4x-3x) same with the constant number ( 9-2) . Just combine the constant and the number that has coefficient. Solution: 4x+2= 3x+9 4x-3x=9-2 X=7

Probability
Since we are trying to determine variance should it be assumed to be discrete measurement based on continuous observation?

Probability
Any clue how you got the term ti, I'm getting only ti^2

Probability
Any idea what the answer to last question is?

Probability
Any clue for the case p>= 1/3?

Probability

physics
Eva is in a closed, dark room. She uses her arm muscles to turn on a lamp. When she moves her hand closer to the lamp, the light heats her hand. The light bounces off the pages of a book and into her eyes. If this room is a closed system, what happens to the total amount of ...

Science**updated asnwers**
these are four the first 13 qeustions? i s he right?

Chemistry
Why don't you just answer the question and help not beat people down I needed help with this problem too but couldn't find it because of you DrBob222.

urgent (physics)
A 2 kg brick falls at 5.1 m/s from a height of 6 m above a spring that has a spring constant of 47 N/m. The brick strikes and compresses the spring until it stops moving. Ignore friction effects. How much is the spring compressed by the brick? Assume that there is no Eg after ...

ENG 122

science
Are the answers 1-A 2-C 3-A ???? Plz Help ASAP

Physics
A 2 kg block has an initial velocity of 16 m/s at the bottom of the ramp (see diagram below). The coefficient of kinetic friction between the block and the ramp is 0.1. The spring has length 3 m and has a spring constant of 100 N/m. What maximum compression will the spring ...

Algebra 1
Explain why any two regular n-sided polygons would be considered to be similar and how knowing this information could help in solving real-world problems.

Math
what is a measurement that is not equal to 8 cups?

Biology
Which of the following is correctly matched with its tissue system? cortex/dermal tissue system cuticle/vascular tissue system phloem/dermal tissue system stele/vascular tissue system>>>> my choosen answer

social studies
Can someone help me with 8 9 and 10

math
17.Given that 3•2 = 9, 2•6 = 64, 1•7 = 1 and 4•4 = 256. What is the value of 10•5? A)50 B)100 000 C)5000 D)5 plz explain how you get this answer i am studying the sample questions for the math olympics tommorow so i need to know what they will be like.

physics
A missile is launched at an angle of 25 degrees to the ground. It hits a target at 301.5 meters from the point of launch. find the initial velocity

Physics
A 14g bullet is traveling at 306m/s when it strikes a block of wood. If the block of wood exerts a force of 50,000 N opposing the motion of the bullet, how far will the bullet penetrate the block of wood?

Chemistry
Calculate the Ph and POH of an aqueous soltuion that is 0.500 M in HCl(aq) and 0.085 M in HBr (aq) at 25 degrees C.

science