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Posts by sarah

Total # Posts: 5,821

math
Simplify the expression 23w^3-5w^2x+8wx^2-8w^3-13wx^2+30w^2x Group like terms so: 23w^3-8w^3= 15w^3 -5w^2x+30w^2x= 25w^2x 8wx^2-13wx^2 = -5wx^2 The final answer I got is: 15w^3+25w^2x-5wx^25wx Is this right? I had to simplify the expression.

Chemistry
When 0.010 moles of Zn(s) reacts with 30.0 mL of 1.0 M HCl, the H2 gas produced is collected in a 1.0 L flask at a temperature of 270 K. What is the pressure (atm) of H2 gas collected? Zn(s) + 2HCl(aq) = ZnCl2(aq) + H2(g)

Chemistry
When 0.010 moles of Zn(s) reacts with 30.0 mL of 1.0 M HCl, the H2 gas produced is collected in a 1.0 L flask at a temperature of 270 K. What is the pressure (atm) of H2 gas collected? Zn(s) + 2HCl(aq) = ZnCl2(aq) + H2(g)

Physics
An object is given two initial velocities, one that has a magnitude of 60.0 ms-1 and points along a direction that is 35.0° north of east and the other has a magnitude of 55.0 ms-1 that points 15.0°, also north of east. Determine the resultant velocity of the object.

Physics
A plane travels 3 km due north, then 5 km due northeast. Represent these two displacements graphically and determine the resultant displacement by finding is magnitude and direction.

Chemistry
2AgNO3(aq) + K2CrO4(aq) ==> Ag2CrO4(s) + 2KNO3(aq) Ag2CrO4(s) ===> 2Ag^+ CrO4^^2- Ksp = [Ag^+]^2[CrO4^2-] Ksp = (2x)^2(0.1)

Chemistry
Calculate the mass of solid AgNo3 that can be added to 2.0 L of 0.10M K2CrO4 solution in order to just start precipitation?

calculus
find y' if x^2y^4+3y-4x^3=5cos x-1 (2x*y^4)+dy/dx 4y^3*x^2)+dy/dx3+12x^2=5-sin-0 dy/dx=-5sin (x -12 x^2)/(2x*4y^3)+(12y^2+x^2) this is using implicit differenation is this correct

calculus
find y' if x^2y^4+3y-4x^3=5 cos x-1 (2x-y^4)+(dy/dx4y^3*x^) +dy/dx+12x^2=5(-sin x-1) is this started correctly

Physics
sorry, I forgot to inlcude the mass and the angle given. The mass is 10 kg and the angle is 45 degrees

Physics
The box is being pulled by a roope across a level floor as shown in the diagram. The box is accelerating at 1 m/s2, the coefficient of kinetic friction is 0.5. what is th tension in the rope?

Physics
mg sin theta - F = ma (9.8 sin 30) - 2 / (9.8 cos 30) = 0.34

Physics
you are skiing down a slope angled at 30 degrees to the horizontal. Your acceleration is 2m/s^2. what is the coefficient of kinetic friction between you and the hill?

math
Oh okay. So since there is a adding or subtracting sign with brackets, all you do is collect like terms? Okay. So it is not distributive property

math
Simplify  (5x+3)+(8x+1)  (5x)+(8x)= 13x^2  (5x)+(1)=5x  (3)+(8x)=11x  (3)+(1)=4  =13x^2+5x+11x+4  =13x^2+16x+4  Is this right or wrong? Simplify (2t^2-3t)-(7t^2-5t)  = (2t^2)-(7t^2)=-5t  = (2t^2)-(-5t)= 7t  =(-3t)-(7t^2)=-...

math
(2t^2-3t)-(7t^2-5t) = (2t^2)-(7t^2)=-5t = (2t^2)-(-5t)= 7t =(-3t)-(7t^2)=-10t =(-3t)-(-5t)=2t =-5t+7t-10t+2t I am confused. Why are all my answers "t" and none of them are "t^2"?

math
Simplify (5x+3)+(8x+1) (5x)+(8x)= 13x^2 (5x)+(1)=5x (3)+(8x)=11x (3)+(1)=4 =13x^2+5x+11x+4 =13x^2+16x+4 Is this right or wrong?

Math
A toy store has found that 30% of its customers spend more than $40 each visit. What is the probability that the next two customers will each spend more than $40?

physics
& this one... 4. A person drops 740 g rock originally held 6.5 ft above the ground. What is its velocity the moment before it hits the gound. (Assume rock doesn't gain/lose energy)... (Hint: You will need to calculate the P.E of the rock before it's dropped!

physics
Last one! Thankyou for the help thus far... calculate the KE in kJ of 9.100 x 10^5 atoms of silver moving at 1800. km/hr. ... the atoms part is what I'm confused about.

physics
I'm not sure with this conversion... getting 9.843x10^4 ft/min to m/s ? How do I get to m/s using a specification conversion without using online conversions?

Physics!
stuck on this one!

Physics
calculate K.E in Joules of a baseball w/ a mass of 237.2 cg moving at 85.00 mph

Physics
The dipole moment of a water molecule is 6.37E-30 Cm. What is the electric potential's magnitude 1.58 nm from a water molecule along the axis of the dipole?

Math
Can I please see your solution?Thanks!

science
What can people do to reduce global warming?

science
what causes clouds to form?

Chemistry
Which of the following statements cannot be assumed for the vapourization of a liquid? A)Enthalpy is positive B)Entropy is postive C)Temperature (in degrees Celcius) is positive D)They are all true

Chem
Yes

Chem
Specify the concentration of each ion in solution for the following: .10 M AlCl3 (aq) and .15 M (NH4)2SO4 (aq)

Chem
21.7 mL of 1.15 M KOH (aq) was required to titrate 25 mL of H2SO4 (aq) as follows: H2SO4 (aq) + 2KOH (aq) --arrow-- K2SO4 (aq) + 2H2) (l) What is the molarity of the H2SO4 (aq)?

Chem
Add them all together and then divide by the number of dimes. Put your answer in the ones place.

Physics
a periscope is an optical instrument made of two plane mirrors inclined at an angle 45 with respect to the axis of the tube. an observer places her eye at point O. draw the path of a ray light issued from A. determine the position and the nature of the image of A given by two ...

english 101
yes you are right bc they had drove is wrong bc drove isnot pp

english 101
no they had drove make sounds better since its a past perfect ??am I right??tnx

english 101
hi guys I need a help in my grammer class?? After throwing their sleeping bags into the backseat of their cars they-- ((had drove/drove/drivig/having driving))--more than 400 miles to reach their destination. I think driving is right.??

Spanish 202
I have some answers for my spanish class. I was hoping the grammar could be checked. Antes de estudiar esponal había dormido. Con $100000 compraría una mona. Mi passión ideal sería bombero. Comería muy mucha comida todo día. Si no ...

Chemistry
You start with 2.5L of a KNO3 stock solution and wish to prepare 10.0 L of 1.5 M KNO3. What percentage (m/v) would the potassium nitrate stock solution need to be if you were to use it all? (MW of KNO3: 101g/mole)

Chemistry
Consider a one step reaction. Which of the following does not describe the activation energy of the process? The minimum amount of energy needed for a reaction to occur The energy difference between the starting point and the transition state The energy required to distort or ...

Chemistry
Benzene (C6H6) has a normal freezing point of 5.50oC and a density of 0.88 g/mL. When 1.28 g of naphthalene (C10H8) is dissolved in 125 mL of benzene, the freezing point of the solution is 5.03oC. Determine the molal freezing point constant for this solvent.

Chemistry
Consider a one step reaction. Which of the following does not describe the activation energy of the process? The minimum amount of energy needed for a reaction to occur The energy difference between the starting point and the transition state The energy required to distort or ...

math
.20x+x=? what is ?

Physics
Which is the best example of Newton's Third Law of Motion? A hockey puck sliding on the ice will keep going until it is hit by another player or hits the wall. It takes more force to move a large tractor trailer than it does to move a small sports car. A swimmer who jumps ...

Biology
I forgot to mention that the volume of the amalyse stock is 50 ug/ml. and 2.5ml amylase stock and 2.5 ml buffer.......so i think I should take: 50ug/ml/5.0 ml = 10 The the dilution factor is 10x Is this correct do you think?

Biology
If I have 2.5 amylase stock solution, 2.5 PBS Buffer, and final amylase concentration of 25 [ug/ml] , how do you calculate the amylase dilution factor?

calculus
limx--->0 3sin 3x/4x would it be 9/4

calculus
limx-->3 sin 3x/4x

Physics
A baseball is thrown at 40 m/s. Jose Bautista hit it back in the opposite direction at a speed of 65 m/s. The ball is in contact for 1.2 ms. What distance does the ball travel while it is in contact with the bat?

Math
f(x+h)?f(x)=8hx^2+2hx+2h^2x?3h^2?4h^3. Find f?(x).

MATH @Damon @ms. Sue
Belinda wants to invest $1000. The table below shows the value of her investment under two different options for three different years: Number of years 1 2 3 Option 1 (amount in dollars) 1100 1210 1331 Option 2 (amount in dollars) 1100 1200 1300 Part A: What type of function, ...

MATH @Damon @ms. Sue
Part A:Option 1 is linear because it increased arithmetically by $110.00 a year. Option 2 is exponetial because it is increased geometrically by $1.09 a year Part B: Option 1 100x+1000 5.5x^2+93.5+1001 Option 2 100(20)+1000 2000+1000=300 Part C: After 20 years she would get $...

MATH @Damon @ms. Sue
Can Someone check my Work Belinda wants to invest $1000. The table below shows the value of her investment under two different options for three different years: Number of years 1 2 3 Option 1 (amount in dollars) 1100 1210 1331 Option 2 (amount in dollars) 1100 1200 1300 Part ...

Physics
let me try this again area formula is 1/2 x b x h 1/2 x 2.705 x 6.22 m/s = 8.4125 m is this correct? so after 11.7 seconds the particle position will be 8.4125 m?

Physics
I just saw related questions so I figured it out. (28.7/53.56)(sin 106) = 0.515 sin-1 0.515= 31.00deg 31.00deg -19deg = 12.00 deg

Physics
Two geological field teams are working in a remote area. A global positioning system (GPS) tracker at their base camp shows the location of the first team as 38 km away, 19deg north of west, and the second team as 28.7 km away, 35deg east of north. When the first team uses its...

calculus
I have a definition lim theta approaching 0 sin theta/theta = 1 so show if the limit x approaching 0 sin2x/5=2/5

Physics
A boy kicks a rock off a cliff with a speed of 15.5m/s at an angle of 53.5° above the horizontal. The rock hits the ground 5.37s after it was kicked. How high is the cliff? I found the height of the cliff which is 7.45*10^1 m. What is the speed of the rock right before it ...

Chemistry
The density of water at 60 degrees C is 0.98338 g/mL. What is the mass of 37.48 mL of water in a graduated cylinder (not including the mass of the graduated cylinder)

Math
It takes 3 mins to fill a tub to the top and five minutes to drain the full tub.if the faucet and drain are both open how long will it take to fill the tub

MATH @Damon @ms. Sue
Thank you so much Steve :)

MATH @Damon @ms. Sue
Given the function f(x) = 2(3)^x, Section A is from x = 0 to x = 1 and Section B is from x = 2 to x = 3. Part A: Find the average rate of change of each section. Part B: How many times greater is the average rate of change of Section B than Section A? Explain why one rate of ...

Biology
Explain the meanings of Mendel’s principle of segregation and principle of independent assortment. Under what circumstances does the principle of independent assortment hold true? Give an example in which this law does not apply.

Pre calc
Evaluate the expression given that cosine a=4/5 with 0<a<pi/2 and sin b=-15/17 with 3pi/2< b<2pi

Calculus algebra review
((1/2+h) -(1/2)) / h found LCD of numerator ((2)-(2+h)/2(2+h))/h is it 1

Physics
ok i got it, thanks. 4.10*10^5

Physics
An auditorium measures 43.0m × 18.0m × 15.0m. The density of air is 1.20 kg/m3. What is the volume of the room in cubic feet? (Do not input units. Note that 1m = 3.28ft) My Answer 43x18x15 = 11,610 m^3 11,610m3 * 3.28ft m = 38,080.8 ft When I used this number I got...

math
6. You are given a sheet of cardboard that is 8.0 in. x 11.0 in. How many full circles with a diameter of 3.0 inches can you cut from the cardboard? What is the percentage of waste if the

social studies
Thank you!

social studies
In America, citizens with voting rights can A. Make the laws. B. Vote for or against any law. C. Propose new laws. D. Vote for or against the officials who make the laws. <<<<< somebody please help me

Stoichiometry
Determine the mass % (m/m) of a NaCl solution if 58.5 grams of NaCl was dissolved in 50 ml of water (assume the density of water to be 1.0 g/ml).

Mathematics
F(x, y) represents a velocity field of a fluid over a surface S defined by z = 6 ? 3x ? 2y. If the magnitude of the velocity in the direction of the unit normal vector, n?, on S is 3z??14, compute the flux of F(x, y) over the surface S in the first octant oriented upward, ...

Math
a photocopier increase the sides of a square in a ratio of 5:4. what percentage has the size increased?

English
Either individuals chose to face their conflict, and fight for it in a positive manner. Or they can run away from their problems, and deal with them in a negative manner. Its MORE important for individuals to face their conflicts and fight for them. The way they choose to ...

Chemistry
Hi , I have this question and I do not know what steps to follow. Please help guide me. It will be really appreciated. Calculate the extent of oxidation in a stream where water it's in equilibrium with atmospheric oxygen and had a pH pic 6.5 (a(H3O+) =antilog (-6.5) ). The...

Math
Mr. Jones makes 3% commission on his sales of widgets. At a different company, Mr. Smith makes 5% commission selling the same widgets at the same price. Mr. Smith sold 500 fewer widgets than Mr. Jones, and they both earned the same commission. How many widgets ...

Math
If two pounds of meat will serve 5 people, how many pounds will be needed to serve 13 people?

Math
How do you find the constant rate of change?

Math
Under ideal? conditions, a population of rabbits has an exponential growth rate of 11.8?% per day. Consider an initial population of 300 rabbits. Find the exponential growth function.

Chemistry
Then if H+ equals antilog pH, M- would also be equal to H+ , so then what will I be solving for? Because H2M species is given Sorry if this is a stupid question, I really don't know Thanks you!!

Chemistry
Okay so my lecturer has this in our slides and there are no notes just a heading saying speaciation, I have tried google and everything I have read does not include pH in their question. Please help me Calculate the equilibrium concentrations of the different species in a 0....

math
Juan has three rain sticks measuring 8 inches, 6 inches, and 12 inches each. what is the least common multiple of 8, 6, and 12? A.12 B.24*** C.48 D.96 is it B?

Calc
If y=tanu, u=v-(1/v), and v=lnx. What is the value of dy/dx at x=e?

Calc
If x=t^3-t and y=?(3t+1), then dy/dx at t=1 is what?

Calc
If f(x)=6x^3-4x then d/dx(f(lnx)) would be what equation?

Calc
The tangent line to the graph of y=f(x) at both x=3 and x=4 is y=-x+5. Which of the following statements must be true? The function f(x) is the line y=-x+5 f(3)=f(4) f'(3)=f'(4) f(x) is not differentiable at x=3 and x=4 None of the above

Chemistry
What size volumetric flask do you need to dilute a 0.150M NaOH to 0.390M if you pipette 1500ml?

science
In The Darkest Part Of The Mansion, Where The Winds Are Set To High, A Man Fears His Presents, Where The Cotton Lies, Where Am I?

Chemistry
In Cl2 + 2KBr -> 2KCl and Br2 produce that brown yellow effect?

Physics
You are given five identical resistors each of resistance r. How can you arrange all these resistors (in series, in parallel, or both) in order to have an equivalent resistance of 7r/2, 7r/3 or 2r

Statistics
The heights of women in a certain population have a Normal distribution with mean 64 inches and standard deviation 3.5 inches. We select three women at random from this population. Assume that their heights are independent. Find the probability that the tallest of these three ...

Dr.Bob Chemistry
Is HOET associated with E1 or E2? I think it is E2.

Chemistry
Sample A: Solid appearance:crystals, solids, white Solid Conductivity:no Solubility: soluble Solution appearance:substance disappears slowly Solution Conductivity: yes Relative melting point:2nd Sample B: Solid appearance:brown, tiny solids, dirt appearance Solid Conductivity...

Chemistry
When you try to leave your room you learn that the only door out is locked. Assuming there is no air flow into the room (air tight with no ventilation system) how long can you survive in the room (5 meters long, 5 meters wide, 5 meters high) -Human tidal volume (volume of air ...

urgent math
That's what is difficult for me. I have trouble drawing the diagram. Otherwise I know how to solve these problems. I need help drawing diagrams of these word problems. Is there a way you can possibly teach me how to draw diagrams?

urgent math
Paul is standing on a 39 m high building. The angle of elevation to the top of a taller building is 47 degrees and the angle of depression to the bottom of the same building is 36 degrees. What is the height of the taller building to the nearest tenth. 

French
Can someone who is fluent in french look over this and make sure it makes sense? Ma maison de rêve est à Paris. Il a le sous-sol, le rez-de-chaussée, et le premier étage. Il a la cuisine, la salle à manger, la salle de séjour, trois la ...

English
Choose the meaning of the bolded vocabulary word in each passage in the next six questions. I can't bold them so the word will be in caps. Check my answers * = My answer 1. "Once, the listener fancied that he could DISTINGUISH the accent of town's people of his ...

Math
Consider sequence Uvn=2x^2. Find (?u)vn and write u as an accumalation sequence

Calc
How do I find the indefinite integral of: sec(y)(tan(y) - sec(y)) dy

Science
D, does anyone here go to NCCA?

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