# Posts by michelle

Total # Posts: 1,975

Physics
A thundercloud has an electric charge of 43.2 C near the top of the cloud and -38.7 C near the bottom of the cloud. The magnitude of the electric force between these two charges is 3.95 x 106 N. What is the average separation between these charges? (kc = 8.99 ×109 N &#...

Math
If the product of four tenths and six tenths is subtracted from the sum of four tenths and six tenths, what is the difference?

math 121
jennifer is asked to complete 5 of the 7 essay questions on her literature exam how many choices does jennifer have?

Engineering Math
sorry didn't mean to lol but it is lol

physics
Suppose a 28.5 kg object is moving at 38.4 m/s along the x-axis just before it strikes a stationary 13.0 kg object. After the collision, the 28.5 kg object is moving with a velocity of 20.0 m/s at an angle of 5.79 degrees relative to the x-axis. What is the magnitude of the ...

Chemistry
What is the density, in grams per liter, of N subscript 2 gas at STP

General math
7t-6=104

mt450
need to focus on the main critical elements of simulation

mt450
Now that you have turned in your Simulation Final Project paper, the next step is to turn in your PowerPoint presentation of it. In the workplace, presentations like this play a key part in conveying marketing plans. Presentation requirements: • A minimum of 8 slides and ...

Algebra
Thanks. I figuired out the working, but not sure how to use the Let statement. Would it be correct to say Let A = original scholarship amount A = 1-1/3 -1/4-1/4 x72,000 A = 1/6 x 72 = 432,000

Algebra
Mary, Margaret, Ron and Nick are to share a sholarship. Ron receives 1/3 of the scholarship; Nick gets 1/4 of the scholarship; Mary receives the same as Nick, and Margaret receives \$72,000. Find each person's share in the scholarship as well as the original scholarship ...

literature
In "Life without Principle," Thoreau writes, "If my wants should be much increased, the labor required to supply them would become a drudgery." What does this statement mean?

Chemistry
If 355 g Al(NO3)3 reacts with an excess of K2CrO4, how many moles of KNO3 would be produced?

chemistry
3.50 mol Al(NO3)3 reacts with 5.00 mols K2CrO4, the total number of moles of Al2(CrO4)3 and KNO3 would be? Here is the equation if it's needed. 2 Al(NO3)3(aq) + 3 K2CrO4(aq) → Al2(CrO4)3(s) + 6 KNO3(aq)

Chemistry
How many atoms of O are in 4 moles of (NH4)3PO4 - 6H2O? The answer is 2.41x10^25 I have no clue how to arrive at this answer.

Mathematics of Retailing
An owner of a laundry shop received an invoice for purchasing 200 bottles of liquid detergent at RM15 each, and 300 bottles of fabric softener at RM8 each. The invoice dated on 6th August 2010. He was offered trade discount 10% and 8%, with cash discount 10/10, 5/20, n/30. The...

A particle rotates counterclockwise in a circle of radius 6.5 m with a constant angular speed of 7.4 rad/s. At t = 0, the particle has an x coordinate of 3.3 m and y > 0 . A) Determine the x coordinate of the particle at t = 0.716 s. Answer in units of m ( I know this ...

physics
A particle rotates counterclockwise in a circle of radius 6.5 m with a constant angular speed of 7.4 rad/s. At t = 0, the particle has an x coordinate of 3.3 m and y > 0 . A) Determine the x coordinate of the particle at t = 0.716 s. Answer in units of m ( I know this ...

thank you!!!!! i must have messed up on my calculations

The motion of a piston in an auto engine is simple harmonic. The piston travels back and forth over a distance of 23 cm, and the piston has a mass of 1.7 kg. 2515 rpm 23 cm max speed of the piston 30.28757 m/s What is the maximum force acting on the piston when the engine is ...

statistics
Scores from a statistics exam are reported as deviation scores. Which of the following deviation scores indicates a higher position in the class distribution?

physics
A 28.6-g bullet is fired from a rifle. It takes 2.36 × 10-3 s for the bullet to travel the length of the barrel, and it exits the barrel with a speed of 710 m/s. Assuming that the acceleration of the bullet is constant, find the average net force exerted on the bullet.

chemistry
just a guess but would all but C be stable?

chemistry
A magic number is the name given to certain numbers of protons or neutrons that have a high correlation to stability in nuclei. Magic # of protons: 2,8,20,28,50,82 Magic # of neutrons: 2,8,20,38,50,82,126, 184 Using general trends, predict the stability of the following nuclei...

calculus
1. (30 points) Consider a manufacturer whose total cost of producing x items is given by c(x)=10000+5x+1/9x^2. a. What is the average cost function A(x)= c(x)/x? b. How many items should the manufacturer produce in order to minimize average cost? c. What is the smallest ...

physics
An object is projected upward from the surface of the earth with an initial speed of 2 km/s. The acceleration of gravity is 9.81 m/s^2. Find the maximum height it reaches. Answer in units of km.

Math
A rectangle area spans . The length must be 20ft more than the width. What are the dimensions?

physics
Wow thank you so much! This problem has been bothering me for a week now

physics
A hydraulic brake system is shown. The area of the piston in the master cylinder is 6.32 cm^2, and the area of the piston in the brake cylinder is 1.83 cm^2. The coeﬃcient of kinetic friction between the brake shoe and the wheel drum is 0.443. How large is the ...

Math
When rolling two dice, what is the probability that the sum is 7 given that one die is a 5?

college physics
A hydraulic brake system is shown. The area of the piston in the master cylinder is 6.32 cm^2, and the area of the piston in the brake cylinder is 1.83 cm^2. The coeﬃcient of kinetic friction between the brake shoe and the wheel drum is 0.443. How large is the ...

chem
pH= -log [H+] pH < 7 is acidic and pH > 7 is basic. for example pH= - log [1.0e-11M] pH= 11 therefore basic solution.

physics
this is a huge help! thanks again!

physics
Wow thank you. I was really lost.

math
you deposit \$2200 in an account that pays 3% interest, after 15 years you withdraw, what is the balance if the interest is compounded continuously

physics
A liquid of density 1354 kg/m^3 ﬂows with speed 2.45 m/s into a pipe of diameter 0.29 m. The diameter of the pipe decreases to 0.05 m at its exit end. The exit end of the pipe is 7.82 m lower than the entrance of the pipe, and the pressure at the exit of the pipe is 1.4...

Chemistry
how do I convert moles of Cr2O3 to moles of H2CrO4? I don't understand what this means

Chemistry
3C3H8 + 20H2CrO4-> 9CO2 + 10Cr2O3 + 32H2O Suppose you want to make 1.50 g of chromium (III) oxide, how many ml of 6.25M chromic acid will you need to use if the percent yield of the reaction is 68.6%?

Phoenix
Why do you think Windows is so prevalent? What do the other systems have to offer that Windows does not? Who uses the other systems?

Financial management
what is the principle investment ? you have \$1728.34 compounded daily at 3.4% and its invested for 9 years

math
for the equations y=5x+50 and y=6x+25, for how many hats will the cost be the same and what is that cost?

Chemistry
Sodium vapor lamps, use for public lighting, emits 489 nm yellow light. What energy is emitted by: a) an excited sodium atom when it generates a photon? b) 1 mole of excited sodium atoms at this wavelength?

Chemistry
This helped me with the amount in grams of Cr2O3, but what do I do with the 2nd part, the 35.0 ml of 6.26M chromic acid?

Chemistry
3C3H8 + 20H2CrO4-->9CO2 + 10 Cr2O3 + 32H2O What mass of chromium (III) oxide will be formed by complete reaction of 1.50g of propane with 35.0ml of 6.26M chromic acid?

Chemistry
a stock solution of perchloric acid is 75.5% perchloric acid and has a density of 1.67g/ml. What is the molarity of the solution?

math
How high is a wall that casts a 15ft shadow at the same time that a 4ft flag pole casts a 4ft shadow?

college english
what is a good attention getter sentence on carpal tunnel syndrome?

statistics
The reaction time of subjects to a certain psychological experiment is considered to be normally distributed with a mean of 20 seconds and a standard deviation of 4 seconds. What is the reaction time such that only 10% of subjects are faster?

statistics
The reaction time of subjects to a certain psychological experiment is considered to be normally distributed with a mean of 20 seconds and a standard deviation of 4 seconds. What is the reaction time such that only 10% of subjects are faster?

statistics
Entry to a certain University is determined by a national test. The scores on this test are normally distributed with a mean of 500 and a standard deviation of 100. Tom wants to be admitted to this university and he knows that he must score better than 70% of the students who ...

Physics
A roller coaster is initially at a height of 40 m above the ground and has an initial velocity of 15 m/s. Using conservation of energy, find the velocity of the roller coaster at a height of 5 m above the ground.

Chemistry
What mass of Uranium (in mg) is contained in 1ml of 4.55M (UO2)3(PO4)3 solution? How do I solve this? *all numbers are subscripts

physics what am i doing wrong?
I figured it out......i don't understand why no one has helped me yet in the past week

physics what am i doing wrong?
Three masses are arranged in the (x, y) plane. 3kg (0,0) 7kg (10,0) 6kg (0,3) What is the magnitude of the resulting force on the 3 kg mass at the origin? The value of the universal gravitational constant is 6.6726 × 10^−11 N · m^2/kg^2. Answer in units of N...

An object of mass 154 kg moves in a smooth straight tunnel of length 2990 km dug through a chord of a planet of mass 3.19 × 10^24 kg and radius 1 × 10^7 m Find the eﬀective force constant of the harmonic motion. The value of the universal gravitational ...

english
Ms. Sue can you please check for #1 The Gerund Phrase is water skiing , sailing, and swimming Direct Object ?

PHYSICS!
An object of mass 154 kg moves in a smooth straight tunnel of length 2990 km dug through a chord of a planet of mass 3.19 × 10^24 kg and radius 1 × 10^7 m Find the eﬀective force constant of the harmonic motion. The value of the universal gravitational ...

chemistry
. What is the mass concentration (titer) is a solution of sulfuric acid with the molar concentration equivalent 0.5 mol/dm3?

chemistry
Potassium nitrate weighing 15 g was dissolved in water volume of 200 cm3. Calculate the mass fraction of KNO3 in solution.

chemistry
What is the mass of dry NaCl sample should be taken for 100 cm3 of 0.5 mol/dm3 aqueous solution?

chemistry
Determine the molality 0.8 mol/dm3 solution of Fe2 (SO) 4. Density equal to 1 g/cm3.

chemstry
What mass of sucrose must be taken for solution weight of 200 g, which is equal to molality 0.05 mol / kg?

chemistry
What mass of sucrose must be taken for solution weight of 200 g, which is equal to molality 0.05 mol / kg?

social studies

physics
A 11.1-kg block rests on a horizontal table and is attached to one end of a massless, horizontal spring. By pulling horizontally on the other end of the spring, someone causes the block to accelerate uniformly and reach a speed of 3.12 m/s in 1.17 s. In the process, the spring...

physics
When an object of mass m1 is hung on a vertical spring and set into vertical simple harmonic motion, it oscillates at a frequency of 14.2 Hz. When another object of mass m2 is hung on the spring along with the first object, the frequency of the motion is 3.40 Hz. Find the ...

physics
A block rests on a frictionless horizontal surface and is attached to a spring. When set into simple harmonic motion, the block oscillates back and forth with an angular frequency of 9.0 rad/s. The drawing shows the position of the block when the spring is unstrained. This ...

physics
A 82.5-kg climber is scaling the vertical wall of a mountain. His safety rope is made of a material that, when stretched, behaves like a spring with a spring constant of 1.82 x 103 N/m. He accidentally slips and falls freely for 0.739 m before the rope runs out of slack. How ...

Physics
In New Hampshire the average horizontal component of Earth's magnetic field in 1912 was 16 uT, and the average inclination or "dip" was 73 degrees. What was the corresponding mag-nitude of Earth's magnetic field?

X=D(p)=400-p

X=D(p)=400-p

Math
Draw two scalene triangles that are not congruent, but have exactly five sets of parts (sides and angles) that are congruent. Make a drawing that is to scale. Label yourmeasurements.

Chemistry
what mass of nitrogen dioxide (8NO2) will form by reaction of 3.50 mole of perchloric acid (13HClO4) with excess methylamine (8CH3NH2)? Answer is 99.1 g. How do you work this?

Chemistry

Chemistry
what mass of water will be formed by reaction of 3.50g of methylamine (8CH3NH2) with 15.0g of perchloric acid (13HClO4)? Answer is 99.1. How do you work this?

Chemistry for Eng.
delta H3: energy associated with the formation of water-ion interactions delta Hsoln: the enthalpy of solution

math
A section of the railway has a slope of about 0.73. In this section, a vertical change of 1 unit corresponds to a horizontal change of what length?

AP Physics C
An electron follows a helical path in a uniform mag-netic field of magnitude 0.300 T. The pitch of the path is 6.00 um, and the magnitude of the magnetic force on the elec-tron is 2.00x10^-15 N. What is the electron's speed?

Physics: Kinematics
A speed boat moving at 33.7 m/s approaches a no-wake buoy marker 93.3 m ahead. The pilot slows the boat with a constant deceleration of 2.9 m/s 2 by reducing the throttle. How long does it take the boat to reach the buoy? current work done: x = Vot + (1/2)at^2 93.3 = 0(t) + (1...

Art 101 college
Explain how Florence reflects the ideals of the dominant city-state and how some of the geographical, economical, social, and artistic forces shape this ideal. Use one example from Gardner’s Art through the Ages and one example from the Internet.

Algebra 2
(index of 3)square root of 3r-6(equals 3)

physics
As a result of friction, the angular speed of a wheel changes with time according to d(theta)/dt = w0 e^-(aplpha*t) where w0 and alpha are constants. The angular speed changes from an initial angular speed of 4.87 rad/s to 4.27 rad/s in 33.93s. A) Determine the magnitude of ...

science
A balloon with an initial volume of 2.8L at a temperature of 296K is warmed to 375K . What is its volume at the final temperature? (Assume constant pressure.)

Chemistry
148.6

Physics
A military helicopter on a training mission is flying horizontally at a speed of 60.0 m/s and accidentally drops a bomb (fortunately not armed) at an elevation of 350 m. You can ignore air resistance. Find the horizontal and vertical components of its velocity just before it ...

Physics
A pistol that fires a signal flare gives the flare an initial speed (muzzle speed) of 185 m/s. (a) If the flare is fired at an angle of 45° above the horizontal on the level salt flats of Utah, what is its horizontal range? You can ignore air resistance. (km) (b) If the ...

Physics
A ball is fired from the ground with an initial speed of 2.38 * 10^3 m/s (approximately seven times the speed of sound) at an initial angle of 56.0° to the horizontal. Neglect air resistance. (a) Find the ball's horizontal range.(m)

fin/370
a bond that has a 1000 par value (face value and a contract or coupon interest rate of 10.9%. the bond have a current market value of \$1,120 and will mature in 10 years. the firm's marginal tax rate is 34%. the cost of captial from this debit is

Chemistry
How many photons with a wavelength of 450 nm is required to have mass of 1.25 micrograms?

chemistry
A 230 g sample of a compound contains 136.6 g of carbon, 26.4 g of hydrogen, and 31.8 g of nitrogen. The rest is oxygen. What is the mass percent of oxygen in the compound?

chemistry
Consider the following overall reaction which is experimentally observed to be second order in AB and zero order in C: AB+C -> A+BC Determine whether the mechanism below is valid for this reaction AB+ AB -> AB(sub 2) + A slow AB(sub2) + C -> AB+BC fast

A.P. Environmental Sciences
.5 grams of pure copper sulfate powder and 2L of water were used to create a copper sulfate solution with a concentration .5ppm. How was this done?

chemistry
Consider the following overall reaction which is experimentally observed to be second order in AB and zero order in C: AB+C -> A+BC Determine whether the mechanism below is valid for this reaction AB+ AB -> AB(sub 2) + A slow AB(sub2) + C -> AB+BC fast

calculus
Find the derivative of the function 1)f(t)=tan(e^2t)+e^tan2t f'(t)= [im not quite sure with this. im assuming the implicit differentiation] 2) F(t)=e^(8tsin2t) [for this one i got 2e^(8t)(4sin(2t)+cos(2t)) but it is incorrect.

calculus
well i entered it in again and now it took that first answer. i think theres a glitch with the program but thank you for showing me how you got the answers. it helps so much!

calculus
I've tried entering in 36x+1 earlier and it told me it was incorrect. I thought I did it wrong. Thanks for getting back to me.

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