Saturday

April 19, 2014

April 19, 2014

Total # Posts: 247

**Physics**

A rope is used to pull a 5.19 kg block at constant speed 3.38 m along a horizontal floor. The force on the block from the rope is 3.23 N and directed 20.0° above the horizontal. What are (a) the work done by the rope's force, (b) the increase in thermal energy of the b...

**Physics**

A 540 g block is released from rest at height h0 above a vertical spring with spring constant k = 320 N/m and negligible mass. The block sticks to the spring and momentarily stops after compressing the spring 19.8 cm. How much work is done (a) by the block on the spring and (b...

**Physics**

Okay. So I got 2356J is that right?

**Physics**

Damon, this is my last question for today for you. Thanks for all your help. A gas is at an initial pressure of 1.24104 Pa and occupies a volume of 0.28 m3. The (slow) addition of 23,570 cal of heat to the system causes it to expand in an isobaric manner to a volume of 0.47 m3...

**Physics**

An ideal monatomic gas goes from p1 = 180 atm and V1 = 45 m3 to p2 and V2 through an adiabatic process. If p2 = 60 atm, what is V2?

**Physics**

An ideal gas heat engine operates in a Carnot Cycle between temperatures of 266 and 115°C. It absorbs 4250 cal per cycle at 266°C. What is its efficiency as a percentage?

**Global Studies (check please)**

1) B 2) D 3) D

**Physics**

A heat engine absorbs 126 kcal of heat and exhausts 77 kcal of heat in each cycle. Calculate the efficiency (as a percentage)

**Physics**

5.4377 was my final answer and that was right.

**Physics**

I figured it out.

**Physics**

How much (in Celsius degrees) is the temperature of 1.3 kg of alcohol raised by adding 4.1 kcal of heat? The following piece of information may come in handy: specific heat of alcohol is 0.58 kcal/kgC.

**Physics**

An aluminum calorimetry cup [mc = 0.6 kg, cc = 0.22 kcal/(kgC)] is filled with water [mw = 2.4 kg, cw = 1 kcal/(kgC)]. It is at a temperature of 30C. A sample of an unknown substance with mass mm = 2.34 kg, originally at a temperature of 210C, is added. After a while, the temp...

**Physics**

A weight lifter manages to lift a 147 kg weight a distance of 1.1 m. Treat her as a thermodynamic system and find how much heat (in kcal) she must put out if her internal energy decreases by 3620 J during the lift.

**Physics**

Help?

**Physics**

A weight lifter manages to lift a 147 kg weight a distance of 1.1 m. Treat her as a thermodynamic system and find how much heat (in kcal) she must put out if her internal energy decreases by 3620 J during the lift. Not sure how to answer this.

**Physics**

I can figure it out. Thanks for your help

**Physics**

A gas cylinder of volume 26 liters contains an ideal gas at temperature 27 degrees C and pressure 1920 kPa. Some of the gas leaks until the pressure falls to 1500 kPa. How many moles of gas leaked, assuming that the temperature remains constant during this process?

**Physics**

A can of gasoline has a rectangular base with dimensions of 13.5 cm by 13 cm. If there are 3 liters of gasoline in the can, how much does the surface of the gasoline rise (in mm) in the can when the temperature is raised by 45C? The coefficient for volume expansion of gasoline...

**Physics**

I got .13172 m is that correct?

**Physics**

By what amount will a 178 m long concrete slab on the Mackinac Bridge contract when going from +39C to -35C? The linear expansion coefficient is 10^-5 per C.

**English !!!**

dont have choices its fill in the blank

**English !!!**

To find out which key will open a lock, you try several until one works. This kind of learning is called ________________________.

**Physics**

My only question is how to find the speed of the particles

**Physics**

Thank you so much! I got 22.61x10^-21 is that right?

**Physics**

1. A gold atom has a mass of 3.287 • 10-25 kg and is at rest. It emits an alpha particle that has a mass of 6.646 • 10-27 kg. In this process, the gold atom is transformed into an iridium isotope. The alpha particle has a speed of 3.40 • 106 m/s. A. What is the ...

**Calculus-Applied Optimization Quiz Problem**

A rancher wants to fence in a rectangular area of 23000 square feet in a field and then divide the region in half with a fence down the middle parallel to one side. What is the smallest length of fencing that will be required to do this?

**Physics**

A 67.0 kg astronaut on the planet Zircon (mass = 1.15 x 1023 kg and radius = 2.00 x 106 m) tosses a 8.00 g frog astronaut (a frogonaut?) horizontally with a speed of 7.45 m/s. The 8.00 g frog falls through a vertical distance of 1.40 m and lands a horizontal distance of 8.05 m...

**physics**

An archer shoots a 54.6 g arrow horizontally at a target 14.0 m away. The arrow is 18.0 inches long. The 54.6 g arrow is aimed directly at the center of the target, but it hits 60.0 cm lower. What was the initial speed of the arrow? (Neglect air resistance.)

**Math**

1/8(2sin2x-sin4x)= cosxsin^3x prove

**Biochemistry**

Calculate the ATPs resulting from the total oxidation of the following compounds: a. Fructose-6-phosphate b. 3-Phosphoglycerate c. Succinyl-CoA d. Stearic acid How do I begin?

**Biochemistry**

Based on free energies of hydrolysisgiven below, for each of the followingreactions: i)Determine the overall ∆G of thereaction ii)State whether it is favorable...

**calculus**

The demand function for a certain make of replacement cartridges for a water purifier is given by the following equation where p is the unit price in dollars and x is the quantity demanded each week, measured in units of a thousand. p=-0.01x^2-0.3x+19 Determine the consumers&#...

**language arts**

The answer is B you can tell from the context clues since the sentence refers to a scientist that would be a guest speaker. From this you can deduce that this person is going to do a sort of lecture which usually involves speech and writing. Reasons why other answers are wrong...

**calculus**

The demand function for a certain make of replacement cartridges for a water purifier is given by the following equation where p is the unit price in dollars and x is the quantity demanded each week, measured in units of a thousand. -0.01x^2-0.3x+19 Determine the consumers'...

**Chemistry**

is Fe3O4 + 4H2 = 3Fe + 4H2O spontaneous at 298 K? Delta H system= 149.8 kj/mol Delta S system= 610.0 kj/mol

**science**

How to do homework on soil erosion and soil conservation ?

**Math trigonometry**

Prove sinA/1+cosA =tan1/2A

**Math**

Find in terms of trigonometric function of x Tan(90° + x)

**Health**

The ________the concentration of HIV in semen or genital fluids, the more likely it is that HIV will be transmitted to a sex partner?

**Integration**

∫ sin2xcos3x dx using factor formula

**Trigonometry**

Prove 1-cosx+sinx / 1+cosx+sinx =tan x/2

**Physics**

Im looking for the same thing

**physical science help please!**

If a sample emits 1000 counts per second when the detector is 1 meter from the sample, how many counts per second would be observed when the detector is 2 meters from the sample?

**Chemisty **

how many mole of calcium sulfate are in a 100mL of .86M solution?

**english**

What is the verb (linking or action) in "Long ago, farmers milked cows by hand"

**4th grade math**

ugh, thank you so much! I was not thinking hard enough.

**4th grade math**

Can't divide by 8 either, so I am stuck. This problem was on my actual homework today.

**4th grade math**

I am a 2 digit number. You can divide me by every single digit except for 5 and 7. Add my digits together and the sum is 9. What number am I?

**Spanish Check**

Vamos a... Form sentences using the following information. Use ir a + infinitive in each sentence to express what the subject is going to do. Follow the model closely. 1.Leonardo / trabajar / las tres de la tarde -Leonardo está estudia las tres de la tarde 2. Marí...

**MATH, Calc**

P=0.3e^0.08t find the rate of growth.

**physics**

IP A jogger runs with a speed of 3.10{\rm m/s} in a direction 25.0{^\circ} above the x axis. Find the x and y components of the jogger's velocity.

**math**

I'm doing a unit on volume and surface area. So there's a diagram that shows a fish tank after a container of water is poured into the tank. How many containers of water are needed to fill the tank? What is the formula to finding this?

**Eng.**

Given that she previously belonged to high society and that later she had to move to a trailer park, she did not like to mix with the rif-raff in the park. What part of speech is GIVEN in this sentence.

**Chemistry**

You found an unknown metal sample shaped as a cube with each side measuring 2.00 cm. The cube's mass is 48.0 . Your colleague examined the mystery cube with X-ray diffraction and told you that it contains just one element arranged in a body-centered-cubic -lattice, and tha...

**Chemistry**

there's a part c that I didn't know how to do either... c) Calculate the actual percent yield of Fe2O3(s)

**Chemistry**

A 500g iron (Fe) rod was left in air for a long period of time, and got covered with rust (Fe2O3) as a result of reaction with atmospheric oxygen. The mass of the rusty rod was determined as 560g. a) calculate the theoretical yield of Fe2O3(s), that is the mass of Fe2O3(s) tha...

**Chemistry**

For the following reaction, the equilibrium constant KC = 97.0 at 900 K. If the initial concentrations of NH3 and H2S are both 0.20 M, what is the equilibrium concentration of H2S? H2S (g) + NH3 (g) ---> NH4HS (s)

**Chemistry**

Thanks! I understand! You are the best :D

**Chemistry**

Okay so why is there a 1 here: Kc = 97.0 = 1/[(0.2-x)(0.2-x)] where did you get the 1 from? Also in this equation: H2S (g) + NH3 (g) ---> NH4HS (s) What if there was a 2 in front of the NH4HS(s)...would that make it a 2 in place of the one? So for example: Kc = 97.0 = 2/[(0...

**Chemistry**

initial....0.2......0.2.........0 change.....-x........-x..........x equil....0.2-x...0.2-x............ equil....0.2-x...0.2-x............ <----what goes here Did you forget to put an x?????

**Chemistry**

Ummmmm I'm waiting to confirm this with DrBob222...Thanks anyways ;D

**Chemistry**

Now what do I do next once I have the ice table?

**Chemistry**

Wait is this right? I: (0.2) (0.2) (0) C: (-x) (-x) (x) E: (0.2-x) (0.2-x) (x)

**Chemistry**

Wait is this right? I: 0.2 0.2 0 C: -x -x x E: 0.2-x 0.2-x x

**Chemistry**

Could you help me on the ice table..........I could only get the I part :( I: 0.2 0.2 0

**Chemistry **

For the following reaction, the equilibrium constant KC = 97.0 at 900 K. If the initial concentrations of NH3 and H2S are both 0.20 M, what is the equilibrium concentration of H2S? H2S (g) + NH3 (g) ---> NH4HS (s)

**chemistry**

Yes that is what I thought! Thank you! :)

**chemistry **

A saturated solution is prepared by dissolving 3.2 g of a salt in 9.10 g of water to yield a saturated solution. What is the solubility of the salt (in g salt/100g of H2O)?

**Chemistry**

Ohhh yeahh haha thanks DrBob222! I really appreciate it! :D

**Chemistry**

I got an answer of 8.02...is this right? :)

**Chemistry **

1.00 g of sodium is added to a large excess of water under conditions of constant pressure (1.00 atm) and constant temperature (25 °C ). The following reaction occurs: 2Na (s) +2H2O (l)------> 2NaOH (aq) +H2(g) Delta H°rxn =-369 kJ/mol Calculate the heat released af...

**physics**

70mtr

**English**

"shame is five-fingered.” IS THE METAPHOR..

**English**

Read the following passage by Picoult and identify the metaphor. Quote the metaphor in your response and explain what makes it fit the definition of metaphor. “My mother moves so fast I do not even see it coming. But she slaps my face hard enough to make my head snap back...

**physics**

When jumping straight down, you can be seriously injured if you land stiff-legged. One way to avoid injury is to bend your knees upon landing to reduce the force of the impact. A 79.1 kg man just before contact with the ground has a speed of 6.27 m/s. In a stiff-legged landing...

**physics please help**

A 690 kg elevator starts from rest. It moves upward for 2.56 s with constant acceleration until it reaches its cruising speed, 1.84 m/s. What is the average power of the elevator motor during this period? What is the power of the elevator motor during an upward cruise with con...

**Physics**

A 2.5 kg block of ice at a temperature of 0C and an initial speed of 5.7 m/s slides across a level floor. If 3.3*10^5 J are required to melt 1.0 kg of ice, how much ice melts, assuming that the initial kinetic energy of the ice block id entirely converted to the ice's inte...

**language arts**

Where is the comma needed in the sentence? After traveling to Bryce Canyon, Utah, Karen drove to Canyonlands National Park, Utah, where she took pictures of the sandstone formation. I put in the commas already, I just want to know if this is correct because I'm not sure.

**Physics**

An airline pilot pulls her 12.0 kg rollaboard suitcase along the ground with a force of 25.0 N for 10.0 meters. The handle she pulls on makes an angle of 42.5 degrees with the horizontal. How much work does she do over the ten-meter distance? Tried doing: (Cos(42.5) * 25N) * 1...

**Physics**

A hockey stick applies a constant force over a distance of 0.127 m to an initially stationary puck, of mass 152 g. The puck moves with a speed of 51.0 m/s. With what force did the hockey stick strike the puck?

**Math**

We already asked if there was a driver or anyone else. He said no. He wasn't trying to trick us or anything.

**Math**

I thought so, but he said it was close but not exact.

**Math**

Math. The girls are on the bus!! And the cats are inside their backpacks. I don't know, it's confusing though. Thanks for trying though!

**Math**

I did too? I don't think that it is supposed to be a trick question like that though!

**Math**

How did you get that answer?

**Math**

It's talking about the girls and cats legs? ^^

**Math**

There are 7 girls on a bus. Each girl is carrying 7 backpacks. In each backpack, there are 7 big cats. For each big cat, there is 7 little cats. How many legs are there? My answer was 10,990 legs. My teacher said it wasn't right, although it was very close. I don't see...

**pre Alg**

3(g-3)=6

**Physics**

If a velocity that is 1 cm long represents a velocity of 12 km/h, what velocity does a vector 3 cm long drawn to the same scale represent? km/h

**calculus**

Water is leaking out of an inverted conical tank at a rate of 1100 cubic centimeters per min at the same time that water is being pumped into the tank at a constant rate. The tank has height 15 meters and the diameter at the top is 4.5 meters. If the water level is rising at a...

**Calculus**

Water is leaking out of an inverted conical tank at a rate of cubic centimeters per min at the same time that water is being pumped into the tank at a constant rate. The tank has height meters and the diameter at the top is meters. If the water level is rising at a rate of cen...

**physics**

A 4.63-g bullet is moving horizontally with a velocity of +349 m/s, where the sign + indicates that it is moving to the right (see part a of the drawing). The bullet is approaching two blocks resting on a horizontal frictionless surface. Air resistance is negligible. The bulle...

**physics**

The drawing shows a human figure approximately in a sitting position. For the purposes of this problem, there are three parts to the figure, and the center of mass of each one is shown in the drawing. These parts are: (1) the torso, neck, and head (total mass = 40.5 kg) with a...

**physics**

The drawing shows a human figure approximately in a sitting position. For the purposes of this problem, there are three parts to the figure, and the center of mass of each one is shown in the drawing. These parts are: (1) the torso, neck, and head (total mass = 40.5 kg) with a...

**physics**

A 4.63-g bullet is moving horizontally with a velocity of +349 m/s, where the sign + indicates that it is moving to the right (see part a of the drawing). The bullet is approaching two blocks resting on a horizontal frictionless surface. Air resistance is negligible. The bulle...

**physics**

Two ice skaters have masses m1 and m2 and are initially stationary. Their skates are identical. They push against one another, as in Figure 7.10, and move in opposite directions with different speeds. While they are pushing against each other, any kinetic frictional forces act...

**physics**

A water slide is constructed so that swimmers, starting from rest at the top of the slide, leave the end of the slide traveling horizontally. As the drawing shows, one person hits the water 5.00 m from the end of the slide in a time of 0.386 s after leaving the slide. Ignore f...

**Science: Chemistry - Enthalpy**

162000 kJ

**math**

i have a three in the ones place,a 5 in the hundreths place.what are three numbers i can get

**exam study math guide CRUICAL**

The average of Anne's, Sara's, and Julie's test score is 72. Julie scored 100 and Anne scored 10 points higher than Sara.what were annes and saras scores?