# Posts by Jack

Total # Posts: 1,821

**Chemistry**

50 mL of Water Ti = 20C Tf = 45C d = 1.00 g/mL C = 4.184 J/g * C 50 mL * 1.00g/mL = 50 g Delta T = 45-20 = 25 C q = m * C * T = (50) (4.184) (25) = - 5230 J -5230/-82800 = 0.061 mol Molar mass of CaCl2 = 110.98 g/mol 0.061 mol * 110.98 g/mol = 6.77 g

**7th grade**

What is the rule for this function? Input 1, 2, 4, 5, 10, 12 output 3, 5, 9, 11, 21, 25

**Calculus**

A particle is moving along the curve y = 2 √{3 x + 7}. As the particle passes through the point (3, 8), its x-coordinate increases at a rate of 5 units per second. Find the rate of change of the distance from the particle to the origin at this instant.

**Calculus**

A particle is moving along the curve y = 2 √{3 x + 7}. As the particle passes through the point (3, 8), its x-coordinate increases at a rate of 5 units per second. Find the rate of change of the distance from the particle to the origin at this instant.

**science**

a microscope has two types of these

**science**

a microscope has two of these

**math**

how do you show that line 3x+y-2=0 is a tangent of the curve y=(4x-3)(x-2) and how to find the point of contact??

**stats**

yes.. good job

**mathmath**

A study conducted by the Metro Housing Agency in a midwestern city revealed the information below concerning the age distribution of renters in the city. (Round your answers to four decimal places.) Age Adult Population, % Group Who Are Renters, % 21-44 53 64 45-64 29 43 65 ...

**Algebra**

Determine the number of terms in the expression 14m - 16.

**5th grade English**

She will become a physicist one day. Have to identify the verb or verb phrase and then tell if it contains a linking verb or does not. will become=verb phrase contains linking verb

**calculus**

Find the 1st derivative of the function: y = 1/4 sin^2 (2x) So confused...

**Math**

what is the prime factorization of 72

**math**

A(-1,-2) B(7,2) show that the lenght AB may be written in the form p root5 wjere p is an integer to be found?? is then ans just 4root5?? if not hep please thenks

**Math**

make up a data set of at least 12 numbers that have the following landmarks. maximum 18 mode 7 range 13 median 12

**physics college**

Water flows (velocity initial=0) over a dam at the rate of 660 kg/s and falls vertically 81 m before striking the turbine blades. Calculate the rate at which mechanical energy is transfered to the turbine blades, assuming 55% efficiency.

**Physics**

Water flows (velocity initial=0) over a dam at the rate of 660 kg/s and falls vertically 81 m before striking the turbine blades. Calculate the rate at which mechanical energy is transfered to the turbine blades, assuming 55% efficiency.

**chemistry**

the molar mass of a newly synthesized jluorocarbon was measured in a gas microbalance, This device consists of a gkass bulb forming one end of a beam, the whole surrouned by a closed container. The beam is pivoted and the balance point is attained by raising the pressure of ...

**Science**

How are the structures in genetics related?

**Science**

How do you represent data in a graph?

**chemistry**

A sample of an ideal gas at 15.0 atm and 10.0 L is allowed to expand against a constant external pressure of 2.00 atm at a constant temperature. Calculate the work in units of kJ for the gas expansion. (Hint: Boyle's law applies) Please explain thoroughly! thank you!

**math**

How do i show work for this math question. A puppet requires 3/4 yard of material. How many puppets can be made from 9 yards of material?

**Chemistry**

H2O (l) requires the largest amount of energy to raise the temperature of 25.0g H2O of the substance from 15.0 *C to 37.0 *C. Calculate the energy. Hg (l) has the largest temperature change when 550 g of the substance absorbs 10.7kJ of energy. Calculate the temperature change...

**Chemistry**

A sample of an ideal gas at 15.0 atm and 10.0 L is allowed to expand against a constant external pressure of 2.00 atm at a constant temperature. Calculate the work in units of kJ for the gas expansion. (Hint: Boyle's law applies) Please explain thoroughly! thank you!

**physics**

A picture hangs on the wall suspended by two strings, with è = 61°. The tension in string 1 is 1.8 N. è is connected to string 1, and 32° is connected to string 2. (a) Is the tension in string 1 greater than, less than, or equal to the tension in string 2...

**physics**

please help! physics doesn't click with me. thank you for your help! A 23 kg suitcase is being pulled with a constant speed by a handle that is at an angle of 25° above the horizontal. If the normal force exerted on the suitcase is 155 N, what is the force F applied to...

**Chemistry**

For every liter of sea water that evaporates, 3.70g of magnesium hydroxide are produced. How many liters of sea water must evaporate to produce 5.00 moles of magnesium hydroxide? Please show and explain all steps! Thank you!

**math**

Marcus want to make a stone walkway in his garden.the rectangular walkway will be 3 feet wide and 18 feet long.Each 2-foot by 3-foot stone covers an area of 6 sq. feet.How many stones will he need? is it 9?

**calculus**

Verify that the Intermediate Value theorem applies to the indicated interval and find the value of c guaranteed by the theorem. f(x) = x^2 - 6x + 8, [0,3], f(c) = 0 I have no idea how to use the theorem :(

**science**

What is the chemical name for Polyurethane and what does it look like at it's resting state?

**Avon k 8 Center**

If 50 is the first number, what is the second number?

**6th grade**

Next, Tom remembers that he heard a doctor talking about something that takes two weeks to heal. I have to identify what type of pronoun that (second one in sentence) is. Would it be a relative pronoun?

**Chemistry**

ammonia gas reacts with copper (ii) oxide at high temperatures to produce elemental nitrogen, copper metal, and water vapor. Assume that 36.2g ammonia reacts with 180.8 g copper ii oxide. (balanced equation: 2 NH4 (ammonium) (g) + 4 CuO (copper ii oxide) ==> N2 (nitrogen ...

**Chemistry**

Find the limiting reagent. 2 NH4 (g) + 4 CuO (s) ==> N2(g) + 4 Cu(s) + 4H2O (g) Please explain, thank you!

**Chemistry**

Find the limiting reagent. 2 NH4 (g) + 4 CuO (s) ==> N2(g) + 4 Cu(s) + 4H2O (g) Please explain, thank you!

**Chemistry**

61.0 mL of a 1.50 M solution is diluted to a volume of 258 mL. A 129-mL portion of that solution is diluted using 167 mL of water. What is the final concentration?

**calculus**

Fond the limit of lim x -> 3 [1/(x+4)] - (1/4) _________________ x

**Chemistry**

DDT, an insecticide harmful to fish, birds, and humans, is produced by the following reaction: 2 C 6 H 5 Cl (Chlorobenzene) + C 2 H O Cl 3(chloral) ==> C 14 H 9 Cl 5 (DDT) + H 2 O In a government lab, 1142 g of chlorobenzene is reacted with 485g of Chloral. A)What mass of ...

**physics**

A hot air balloon has just lifted off and is rising at the constant rate of 1.8 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 11.2 m/s. If the passenger is 2.5 m ...

**physics**

An astronaut on Neptune drops a rock straight downward from a height of 0.95 m. If the acceleration of gravity on Neptune is 11.2 m/s2, what is the speed of the rock just before it lands? (m/s)

**Math**

State the Domain and show work. y = x + 2 / x^2 - 4x - 12

**MATH**

26=6(5-6A)

**calculus**

Find all possible radii of circle centered at (3,6) so that the circle intersects only one axis

**calculus**

Solve: sec(x)^2= 3tanx +1 *** It is suppose to be the sqaure root of 3 but i could find the symbol so just wrote the 3 without it but it is suppose to be the square root of 3 times tanx + 1

**math**

256 + 1,273

**PRE CALCULUS**

the question is actually square root of ( x+5) = x please ANSWER

**PRE CALCULUS**

How many real solutions does the equation ãx+5=x have? Please explain your answer to the best of your abilities thanks :)

**Pre CALCULUS**

How many real solutions does the equation x+5=x have? Please explain your answer to the best of your abilities thanks :)

**Pre Calculus**

As x increases from p/4 to 3p/2, the value of sin(x) : A.increases throughout the interval B.decreases at first, then increases C.increases at first, then decreases D.decreases throughout the interval E.none of the above please explain why the answer is as it is, I don't ...

**Calculus**

Solve for x: lnx^3 - 2lnx = 1 Please try and show how you got the answer best as you can thank you :)

**Calculus**

Solve : sec^2(x)= ã3*tanx + 1 on [0,radian-180 degrees) - couldn't find the symbol for radian on computer please try and explain how you got your answer best as yu can thanks so much :)

**Calculus**

The normal body temperature in humans ranges from 97.6 degrees fahrenheit to 99.6 degrees fahrenheit. Concert this temperature range into degrees celcius

**Calculus**

The celcius scale is devised so that 0 degrees celcius is the freezing point of water ( at 1 atmosphere of pressure) and 100 degrees celcius is the boiling point of water ( at 1 atmosphere of pressure) . If you are more familiar with the Fahrenheit scale, then you know that ...

**Chemistry**

A single 4p orbital can hold how many electrons? i got 6 is that correct or no? Would conducting electricity be considered a physical or a chemical property of ZINC?

**rounding**

(a) 455 cal to joules thats 1 903.72 joules but i need to round it to 3 sig figs how do u do that?

**9th grade**

we know that sum means adding. So which one of your choices deals with adding?

**plz help me for math**

you always want to start by putting like terms together. So why don't you do that first and then its really easy from there all you have to do is follow the signs(- or +) and add or subtract

**chemistry**

Would Conducting electricity be considered a physical or chemical property of zinc i got physical but just want to make sure.

**Chem**

Would conducting electricity be considered a physical or chemical property of ZINC i got phyiscal but just want to make sure.

**chemistry**

A single 4p orbital can hold how many electrons? i got 6 is that correct or no?

**Pre Calculus**

Determine the coordinates of the point (xy) where the curves y=(12)x−5 and y=x2+2x−15 intersect in the third quadrant

**Pre Calculus**

The strength of a cable is proportional to the square of its diameter. If a 2-cm cable will support 800kg, how much will a 3-cm cable support?

**chemistry**

A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the ...

**chemistry**

Which of the following properties is a chemical property of phosphorus? Answer a) it burns in air b) it is a white waxy solid c) it melts to form a viscous liquid at 44.1 oC d) Both a and c are both examples of chemical properties. e) a, b, and c are examples of chemical ...

**chemistry**

Convert a density of 2.74 x 103 g/L into a density with dimensions of kg/mL. please show how would this conversion be done.??

**physics**

A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the ...

**Mayans and aztecs**

how did the aztecs acquire most new pieces of land

**Chemistry**

Are significant figures relevant in temperature? ex: (-459 *F - 32 *F)(5 *C/ 9 *F) = -272.78 *C So would I leave my answer as -272.78 *C? or -273 *C because of significant figures?

**Chemistry**

Are significant figures relevant in temperature? ex: (-459 *F - 32 *F)(5 *C/ 9 *F) = -272.78 *C So would I leave my answer as -272.78 *C? or -273 *C because of significant figures?

**math**

find the range of the function. g(x) = 5 + (square root of) (4 - x) please show all steps.

**Math**

Solve the following equation. 4.7 = 1.13x^2 Do i square root the 1.13x^2 first? or divide both sides by 1.13?

**5th grade math**

what is 2 to the first and second power? component problem

**math**

It took a faster runner 10 sec. longer to run a distance of 1500 m than it took a slower runner to run a distance of 1000 m.If the rate of the faster runner was 5 m/sec more than the rate of the slower runner,what was rate of each?

**math**

which has greater volume? a) 1.0 kg of feathers or 1.0 kg of lead b) 100 g of gold or 100 g of water c) 1.0 L of copper or 1.0 L or mercury

**math**

write 480 in a) 1 significant figure b) 2 significant figures c) 3 significant figures d) 4 significant figures

**math**

what is the role of derrivatives in the subjects other than mathematics.

**5th grade English**

However, misfortune and trouble did not stop Ray Charles. Subject=misfortune, trouble Verb= did stop

**Math**

A pair of fair dice is rolled. Let E denote the event that the number landing uppermost on the first die is a 3, and let F denote the event that the sum of the numbers landing uppermost is 6. Determine whether E and F are independent events

**math**

corp provides issuance of 200,000 shares of common stock. 40,000 shares were originally issued and 500 were reacquired. What is the number of shares outstanding?

**math**

corp provides issuance of 200,000 shares of common stock. 40,000 shares were originally issued and 500 were reacquired. What is the number of shares outstanding?

**physics**

"A one meter board with uniform density, hangs in static equilibrium from a rope with tension T. A weight hangs from the left end of the board 0.2m away in distance. What is the mass of the board"

**MATH**

1/2, 3/4, 3/8

**MATH**

FIND THE L.C.D. OF EACH AND EXPRESS THE FRACTIONS OF EACH IN TERMS OF THE L.C.D.

**Chemistry**

107.8?????

**algebra**

solve by multiplication -7/8x = -9/10

**math**

the equation is actually 2t^3-4t^2+3

**math**

Consider the function defined below. y = 2t3 - 4t2 + 3 (a) Calculate the second derivative. y '' = (b) Calculate the third derivative. y ''' =

**math**

which one is part a and part b.

**Statistics**

Total plasma volume is important in determining the required plasma component in blood replacement theory for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that sample of 61 male firefighters are ...

**Statistics**

Assuming that the heights of college women are normally distributed with mean 62 inches and standard deviation 3.5 inches, what percentage of women are between 58.5 inches and 72.5 inches? 34.1% 84.0% 15.7% my answer was 13.6 13.6% is this correct 97.6%

**Statistics**

x=3-0 . What percentage of the area under the normal curve lies to the left of ( 16.0% 15.80% 2.50% 0.50% having trouble with this my answer was 15.00% 0.15%

**physics**

A ball is launched from ground level at 31.8 m/s at an angle of 35° above the horizontal. How far does it go before it is at ground level again? A) 14 m B) 21 m C) 43 m D) 86 m E) 97 m

**physics**

A ball is rolled horizontally off a table with an initial speed of 4.0 m/s. A stopwatch measures the ball's trajectory time from table to the floor to be 0.34 s. What is the height of the table? (g = 9.8 m/s2 and air resistance is negligible)

**algebra**

okay I understand thanks!

**algebra**

Ms. Sue how did you get -8? is this the common number?

**algebra**

first you would need to find the value of x I divided -720 by 9 and got -80 however this is not correct so I tried -90 and it proved to be true. So x = -90 I also would like to know what a simpler way of solving this problem would be?

**Algebra**

What similarities and differences are there between functions and linear equations?

**Math**

1. You would need to multiply the total check by 15%. 2. Assuming your commission rate is that of the clients payment... you would do the same as the first question... multiply.

**math**

32 times

**chemistry**

What is the standard heat of reaction (Delta H^0) for the decomposition of hydrogen peroxide? 2H2O2 (l) ==> 2H2O (l) + O2(g)