Wednesday

July 23, 2014

July 23, 2014

Total # Posts: 186

**Chemistry**

Calculate Kc. CH_4(g) + H_2O(g) <-> CO(g) + 3H_2(g) Kp= 7.7 x 10^24 at 298K. Should I use the formula Kp= Kc(RT)^Deltang If so I have no idea where to start.

**Chemistry**

The reaction has an equilibrium constant of Kp=2.26x10^4 at 298 K. CO(g) + 2H_2(g) <-> CH_3OH(g) Calculate Kp for the reactions and predict whether reactants or products will be favored at equilibrium. A. CH_3OH(g) <-> CO(g) + 2H_2(g) B. 1/2CO(g) + H_2(g) <->...

**biology**

Which photosystem-1 or 2-most likely evolved first?

**biology**

Which photosystem-1 or 2-most likely evolved first?

**6th grade science**

How do the differences in teh way land and water absorb and release energy cause local winds?

**Chemistry**

What mass of Carbon dioxide is produced from the complete combustion of 4.60x10^-3g of methane?

**math**

I mean B

**math**

Answer is A???

**math**

But A is (+)X(+)=sometimes +/- B is (-)X(-)=always negative C is (+)X(-)=always positive D is (+)X(-)=always negative So A,B & C are not true, only I can find the answer is D. No??

**math**

Which statement is true? A.The sum of two positive integers is sometimes positive, sometimes negative. B.The sum of two negative integers is always negative. C.The sum of a positive integer and a negative integer is always positive. D.The sum of a positive integer and a negati...

**Math**

Find the difference: 3-(-9) A. -12 B. -6 C. 6 D. 12 I got the answer on (D)12 but I am not 100% sure becuase they ask the difference, not the sum.

**Physics**

Please help me learn how to do this problem, step by step please. Engineers are developing new types of guns that might someday be used to launch satellites as if they were bullets. One such gun can give a small object a velocity of 4.1 km/s while moving it through a distance ...

**geometry**

If RS=ST=19, s<r and t=7, find s and r.

**Physics :) **

An object has a moment of Inertia of 300 kgm^2. A torque of 94 Nm is applied to the object. What is the angular acceleration of the object? Can someone please explain this to me and help me find the correct answer?! Thank you! :)

**math**

mikas piggy bank cotains 12 pennies6nickels4 dimes and 8 quarters.which best represents the fraction of mikas coins that are pennies1

**math 5**

During an art context at your school, you and a classmate each won blue ribbons for 1/3 of the pieces you entered in the contest. You won 2 blue ribbons and your classmate won 3 blue ribbons. Explain how this could be

**chemistry**

How many orbitals are contained in the n=2 level? Give the l and ml values of each of them.

**chemistry**

Calculate the energy of a photon of electromagnetic radiation at each of the following wavelengths.503 nm(wavelength of maximum solar radiation) i need help please!

**spanish**

¿Cómo se llama tu maestra favorita y Qué clase enseña?

**chemistry**

and what is the formula to convert to nm?

**chemistry**

so would i set it up (3.00 x 10^8)/(4.74 x 10^-7) ?

**chemistry**

calculate the wavelength (in nm) of the red light emitted by a neon sign with a frequency of 4.74 x 10^14 Hz. i have no idea how to even set this up. please someone help.

**Basic Physics**

What is the force of gravity between two spheres that have a mass of 8 kg and are separated by 27 m?

**chemistry**

The mass of a sample of boron atoms is 5.60 g. How many boron atoms are in this sample? Show your work here.

**chemistry**

deltaE=q+w q=570J w=-PdeltaV 1 atm = 1.01235 x 10^5 Pa 1,000 L = 1 m^3 .76L*1.01235*10^5Pa=76938.6 that is the answer i got but it said it was wrong and idk why

**chemistry**

The air within a piston equipped with a cylinder absorbs 570J of heat and expands from an initial volume of 0.12L to a final volume of 0.88L against an external pressure of 1.0 atm. What is the change in internal energy of the air within the piston?

**chemistry**

18.02g*4.18J/g*C*-3.9=-293.76204 -293.76204/1.25=-235.009632 -235.009632*80.6=-18941.77634J/mol -18941.77634J/mol=-18.94177634kJ/mol

**chemistry**

i tried using that formula and keep getting it wrong but i dont know why.

**chemistry**

Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin plastic divider. When the divider is broken, the ammonium nitrate dissolves according to the following endothermic reaction: NH_4NO_3(s) rightarrow NH_4...

**chemistry**

what is Ccal?

**chemistry**

When 0.558g of biphenyl (C_12H_10) undergoes combustion in a bomb calorimeter, the temperature rises from 25.7^\circ C to 30.1^\circ C. Find DeltaE_rxn for the combustion of biphenyl in kJ/mol biphenyl. The heat capacity of the bomb calorimeter, determined in a separate experi...

**chemistry**

The air within a piston equipped with a cylinder absorbs 570J of heat and expands from an initial volume of 0.12L to a final volume of 0.88L against an external pressure of 1.0 atm. What is the change in internal energy of the air within the piston?

**chemistry**

How much heat is necessary to change a 52.0 g sample of water at 33 degrees celsius into steam at 110 degrees celsius?

**Chemistry**

The total mass that can be lifted by a balloon is given by the difference between the mass of air displaced by the balloon and the mass of the gas inside the balloon. Consider a hot air balloon that approximates a sphere 5.00 m in diameter and contains air heated to 65 C. The ...

**Chemistry**

The total mass that can be lifted by a balloon is given by the difference between the mass of air displaced by the balloon and the mass of the gas inside the balloon. Consider a hot air balloon that approximates a sphere 5.00 m in diameter and contains air heated to 65 C. The ...

**Physics**

You are in a boat that is traveling across a river from east to west at 4.0 m/s. the river runs north at 3.0 m/s. what is the resultant velocity of the boat?

**Physics**

A 0.05 kg paper drag racer is launched at a speed of 33 m/s. If the launcher is 4.8 kg, at what speed does the launcher move in the opposite direction?

**Physics**

What is the magnitude of the electric field 0.3 m from a 10-4 C point charge?

**7th grade math Ms. Sue please help I have no idea!**

actually i got #12 its 6/3 = 70/h 6 x h = 3 x 70 6h = 210 6 ÷ 6 = 210 ÷ 6 h = 35

**physics **

Two particles moving along parallel paths in the same direction pass the same point at the same time. Particle A has an initial velocity of 8.7 m/s and an acceleration of 1.2 m/s^2 Particle B has an initial velocity of 4.3 m/s and an acceleration of 7.7 m/s^2 At what time will...

**Physics **

9)A car, moving along a straight stretch of highway, begins to accelerate at 0.0153 m/s 2 . It takes the car 29.2 s to cover 1 km. How fast was the car going when it ﬁrst began to accelerate? Answer in units of m/s

**Physics **

A train is moving parallel and adjacent to a highway with a constant speed of 27 m/s. Initially a car is 41 m behind the train, traveling in the same direction as the train at 39 m/s and accelerating at 4 m/s 2 . What is the speed of the car just as it passes the train? Answer...

**7th grade science Ms. Sue please check**

4. only one-celled organisms. 5. Lysosomes; digestive chemicals the rest are right

**Problem solving:for 3rd grade**

Jimmy gave 10 cupcakes to his best friend Bob. Bob ate 3. How many did Jimmy have left? 10 - 3 = 7 So, Jimmy has 7 cupcakes left over.

**Physics**

Joyce and Efua are skating. Joyce pushes Efua, whose mass is 40 kg, with a force of 16 N. The force of friction between Efua's skates and the ice is 2 N. What is the magnitude of the net force exerted by Joyce on Efua?

**Physical science**

A hot iron ball is dropped into 200g of cooler water. The water temperature increases by 2.0 degrees C and the temperature of the ball decreases by18.6 degrees C. What is the mass of the iron ball?

**algebra**

the houston texans sell styrofoam fingers to make a profit. Profit made from styrofoam fingers sales is function of numbers sold. Which of the following is the independent quantity in this function?

**algebra**

Which linear equation represents the statement "the quotient of 17 and y is 9 less than four times x"?

**Physics**

The acceleration of gravity at the surface of a newly discovered planet is 5.2 m/s^2. An astronaut throws a rock straight up at 10.5 m/s on this planet. How high will it go? Please help!!!

**Physics**

If a ball has an initial downward speed of 24 m/s, how far does the ball drop during the 4 s to 5 s interval

**Physics**

A ball is dropped from rest off a 34 m building. How long does it take to hit the ground at the bottom of the building?

**Math**

Oh I typed it wrong!! Haha

**Math**

More specific @Miss.Sue?

**Math**

Unit rate Driving 180 miles for 18 people? I think its 60 ? Am I right?

**Math**

Unit rate 160 words typed in 4 minutes?

**math**

HELP?! Unit rate for 54 hotdogs for 18 people? Show work so I can understand thanks!

**Math**

1)The break-even point is the ticket price for which the event's income will equal expenses. Another way to think of the break even point is the ticket price when profit is $0. The equations given in an earlier problem were: P=((4000-25X)x)-7500 I=((4000-25x)x) S=4000-25x ...

**math**

7 & 11 are both prime numbers between 6 & 15. 7*11=77

**help please :)**

Disability Insurance. In 1954, Congress made full disability (the physical or mental inability to work) part of the Social Security Act. If a worker qualifies for social security and becomes totally disabled, he or she can receive the same benefits as a person retiring at 65. ...

**trig**

(-10√2, -10√2), find te magnitude and direction angle of the vector, measure the direction angle in [0, 360). Please help!

**Physics**

-34.3 J and 45.93m/s

**Algebra**

The area of a circle is given by the formula A+pier^2, where r is the radius. If increasing the radius of a circle by 1 inch gives the resulting circle an area of 100pie square inches, what is the radius of the original circle?

**Chemistry**

A solution of NaOH with pH 13.68 requires 35.00 mL of 0.128 M HClO_4_ to reach the equivalence point. How do you calculate [Na^+^] and [ClO_4_^-^] at the aquicalence point? (volumes are additive)

**Chemistry**

How do you get the pH 13.68 into OH^-^?

**chemistry**

How do I do convert the pH to the OH?

**chemistry**

A solution of NaOH with pH 13.68 requires 35.00 mL of 0.128 M HClO_4_ to reach the equivalence point. What is the volume of the NaOH solution?

**Math:Ratios**

This is 6th Grade math by the way.

**Math:Ratios**

The Ratios for students who have a computer to those who do not are 22;8 while the ratio for the ratio of students who have a cell phone to those who do not is 12;18. Which is greater?

**math**

At one tennis match, there were about 6000 people.about 40% more people attended the second match than the first match about how many people were at both games?

**math**

if two triangles are similar, what can you say about the ratios of the two side lengths within one triangle and the ratios of the corresponding side lengths in the other triangle? HELP ASAP!! THANK YOU TO WHOEVER HELPS!!

**Marketing**

Can you give me an example of a product and its marketing mix? By marketing mix, I am referring to the 4 P’s of Marketing- Price, Product, Place and Promotion For example like Yoplait, but I am not sure how the company uses the 4 P’s

**math**

At a given time, the height of an object is directly proportional to the length of the shadow that is cast on the ground. A person 6 feet tall casts a shadow 1 foot long at noon. a) What is the length of the shadow cast by a flagpole known to be 20 feet tall? b) A tree cast a ...

**3 grade english**

*The light from stars travels a long way.*

**Calculus AB**

Ugh the pi symbol didn't work. All of the ð should be pi. so it would be a(t) = picos(pit) and my answer should be sin(pit) + C

**Calculus AB**

A particle is moving along the x-axis so that at time t its acceleration is a(t)=ðcos(ðt) At time t=1/2, the velocity v of the particle is 1/2. Find the velocity of the particle at any time t. I think I got that right, as sinðt + C. Now it wants the minimum velocit...

**Trigonometry**

Oh that makes sense. That 2sin^2x + 13sinx - 7 can be factored. Thanks!

**Trigonometry**

2cos^2(x) = 13sinx - 5 How do i solve for x? I think i have to use the sin^2x + cos^2x = 1, but I'm not sure how to use that. I thought about maybe doing 2(1-sin^2x) = 13sinx - 5 but then i get stuck. Any suggestions?

**Physics**

Lai threw a ball downwards with an initial velocity of 11.0 m/s. What is in meters the displacement of the ball during the 2.9 seconds after she threw it? (don't include units in the answer, use 10.0 m/s2 for g and use the upward direction as positive)

**Calculus AB**

Nevermind I think I figured it out. I can just leave k in there and solve for it later.

**Calculus AB**

The rate of growth dP/dt of a population of bacteria is proportional to the square root of t, where p is the population size and t is the time in days (0<equal t <equal 10). That is, dp/dt = ksqrt(t). The initial size of the population is 500. After 1 day the population ...

**Calculus AB**

Find a, b, c, and d such that the cubic function ax^3 + bx^2 + cx + d satisfies the given conditions Relative maximum: (2,4) Relative minimum: (4,2) Inflection point: (3,3) So this is what I have so far: f'(x) = 3a^2 + 2bx + c f''(x) = 6ax + 2b f(2) = a(8) + b(4) +...

**math**

This is going to involve trig functions. you have the angle, and if you draw a triangle and fill in the numbers, you'll see that the length of the slide is the hypoteneuse of this triangle. You are looking for the height of the triangle, which is the side opposite of the a...

**Happiness**

80%

**chemistry**

Please help me! i have no clue how to do this and its for my hw!

**chemistry**

well how do you work them out?

**chemistry**

are this 2 equations the same NIE? and if not how come? Write a net ionic equation for the reaction that occurs when aqueous solutions of ammonia and acetic acid are combined. Write a net ionic equation for the reaction that occurs when aqueous solutions of acetic acid and amm...

**chemistry**

well it said it was wrong the way it was done on the other one

**chemistry**

Write a net ionic equation for the reaction that occurs when aqueous solutions of sodium hydroxide and perchloric acid are combined.

**cheistry**

Write a net ionic equation for the overall reaction that occurs when aqueous solutions of hydrosulfuric acid and potassium hydroxide are combined. Assume excess base.

**Chem**

Does any solid PbCl2 form when 3.1 mg NaCl is dissolved in 0.228 L of 0.12 M Pb(NO3)2. Find the Qsp.

**College Chemisrty**

Molarity is moles/Liter. First you need to convert 140g to moles. After you do that, you divide your answer by .400L to get your molarity.

**Math**

0 = 5+2(3+4x) Subtract 5 from both sides -5 = 2(3+4x) Distribute the 2 -5 = 2(3) + 2(4x) Simplify -5 = 6 + 8x Subtract 6 from both sides -11 = 8x Divide both sides by 8. -11/8 = x y = 5-2(3+4x) 0 = 5-2(3+4x) -5 = -2(3+4x) -5 = -6 - 8x 1 = -8x -1/8 = x Now you try the last one

**physics**

Two objects with masses of 3.00 kg and 7.00 kg are connected by a light string that passes over a frictionless pulley (a) Determine the tension in the string. .N (b) Determine the magnitude of the acceleration of each mass. .m/s2 (c) Determine the distance each mass will move ...

**physics**

A woman at an airport is towing her 21.0 kg suitcase at constant speed by pulling on the strap at an angle of è above the horizontal (Fig. P4.40). She pulls on the strap with a 34.0 N force, and the friction force on the suitcase is 11.0 N. (a) What angle does the strap...

**physics**

A hockey puck is hit on a frozen lake and starts moving with a speed of 10.6 m/s. Five seconds later, its speed is 6.10 m/s. (a) What is its average acceleration? m/s2 (b) What is the average value of the coefficient of kinetic friction between puck and ice? (c) How far does t...

**Chemistry**

What is the element oxidized and the element reduced in the equation: HAsO2 + 2 Ag+ + 2 H2O 2 Ag + H3AsO4 + 2 H+

**Physics**

A boat moves through the water with two forces acting on it. One is a 1500 N forward push by the motor, and the other is an 1400 N resistive force due to the water. (a) What is the acceleration of the 1100 kg boat? m/s 2 (b) If it starts from rest, how far will it move in 7.0 ...

**science**

jason weighs 10kg. the force of gravity is 9.8 m/s2. what is the amount of force jason is applying to the ground when standing?

**science**

jason weighs 10kg. the force of gravity is 9.8 m/s2. what is the amount of force jason is applying to the ground when standing?