Thursday

April 24, 2014

April 24, 2014

Total # Posts: 233

**Science URGENT help please**

Piano movers hoist a 200 kg piano 10 m high in 30 s using a rope and simple pulley. What is their power output? (Points : 1) 70 W 700 W 7,000 W 6 × 10^5 W

**physics **

The top floor of a building is 40m m above the basement. Calculate how much greater the water pressure is in the basement than on the top floor. Express your answer to two significant figures and include the appropriate units.

**pyhsics**

The top floor of a building is 40m m above the basement. Calculate how much greater the water pressure is in the basement than on the top floor. Express your answer to two significant figures and include the appropriate units.

**physics**

Calculate the average force per nail when Sarah (following figure), who weighs 130 pounds, lies on a bed of nails and is supported by 600 nails. (Figure 1) Express your answer using two significant figures.

**physics **

A dike in Holland springs a leak through a hole of area 0.60cm 2 cm^2 at a depth of 1.4m m below the water surface. How much force must a boy apply to the hole with his thumb to stop the leak? Express your answer to two significant figures and include the appropriate units.

**physics**

Find its density. Express your answer to two significant figures and include the appropriate units How does this compare with the density of water? Express your answer using two significant figures.

**physics **

In the sketch, the small hydraulic piston has a diameter of 2.5cm cm . The large piston has a diameter of 6.4cm cm . For each newton of force applied to the small piston, how many newtons of force are exerted by the large piston? Express your answer using two significant figur...

**Statistics**

Compare the standard deviation for the heights of males and the standard deviation for the heights of females in the class.

**accounting**

Heww Inc., issued a $50,000, 10 year bond with a stated interest rate of 6%. Assume interest payments are made semi-annually. What is the selling price of the bond if the market rate of interest is 5%? (Round to the nearest dollar.)

**Math easy please help**

I just need help with rounding for making sure I round my answer correctly. Can you round this 1.299678785 to the nearest hundredth Thanks :)

**Physics 112**

Moving a charge from point A, where the potential is 370V , to point B, where the potential is 190V , takes 4.1×10−4J of work. Part A What is the value of the charge?

**algebra**

using formula d(h)=8e^-0.4h to determine the milligrams d of a certain drug in bloodstream h hours after given.how many milligrams will be present after 6 hours?

**ALGEBRA**

7300 @ 7% COMPOUNDED SEMIANNUALLY FOR 3 YRS

**physics**

solid sphere of uniform density starts from rest and rolls without slipping down an inclined plane with angle è = 30o. The sphere has mass M = 8 kg and radius R = 0.19 m . The coefficient of static friction between the sphere and the plane is ì = 0.64. What is th...

**Algebra **

A rectangle is 5 times longer then it is wide. If perimeter of the rectangle is 222m. What are its dimensions

**math **

Phil invested $150 at an annual rate of 4% compounded continuously, what amout to the nearest cent will be in his account after 2 years? Graph the amount in his account over the first 8 years.

**math **

A cable company charges $40 plus $12 for each cable jack. If x is the number of jacks installed, the linear equation is C=12x+40. graph the total

**US HISTORY**

It was a stock market crash

**Physics**

A small object of mass 2.60 g and charge -17 µC "floats" in a uniform electric field. What is the magnitude and direction of the electric field?

**Physics**

Calculate the net charge on a substance consisting of a combination of 7.5 multiplied by 1013 protons and 3.5 multiplied by 1013 electrons. Answer in units of C

**Math**

I need help solving this equation using the Factoring Completely method. X⁴-x³

**Physics**

A guitar string is 90cm long and has a mass of 3.8g . The distance from the bridge to the support post is L=62cm , and the string is under a tension of 540N . What are the frequencies of the fundamental and first two overtones?

**Physics**

Two spheres of charge q1 and q2 that are equal in magnitude (i.e. |q1| = |q2|) are attached by a spring with a constant k = 1440kg/s2 and a rest length of x0 = 83.0cm. We take negative values of Äx for compression and positive Äx values for expansion. Knowing that q1...

**Geometry**

find the area of a triangle whose base(b) is 8 inches and whose height (h) is 12 inches

**Geometry**

If the length(L) of a rectangle is 15 inches and the Width(W) is =2 in. Then what is the area?

**Geometry**

If the base(b) of a triangle is 9 inches and the height(h)is =12 in. Then what is the area?

**Algebra**

Which is the correct answer to the following: Simplfy: 2 + 3 . 10 Devided by 5 . 3 - 9 A)"5 B) 21 C)"60 D) 11

**American Government**

True or False: The U.S. "Superior" Court is the Nation's most powerful court? (is Superior and Supreme one in the same?)

**geometry**

What is the area of a triangle if the base is 12 inches and the height is 18 inches?

**Algebra**

Simplify: 2 + 3 . 10 Devided by 5 . 3 - 9 (Thanks and Happy New Year!)

**Algebra**

What is the evaluation of: a - 13 when a = 33. Thanks & Happy New Year :)

**Algebra**

What is the value of 3a when a = `4. (Thank you in advance & Happy New Year!)

**Algebra**

What is the value of 20x when x = 10. (Thank you in advance and Happy New Year! :)

**Algebra**

True or False: If an agebraic expression calls for Y=8, that means that you will use the number 8 to replace the letter Y in order to solve the expression?

**English**

Mr. Smith, my Spanish teacher, is going on vacation. is this correct PUNCTUATION AND GRAMMER

**Physics**

Force equals mass times acceleration...the mass of your vehicle is the same, always. The acceleration is also to be considered the same for both problems. So if both equations, (one for collision with wall, and one for other car) have the same numbers, then the forces are equa...

**Physics**

hah I love how everyone in physics with Kaminsky is looking here

**Algebra**

What is the inverse of y = (3/7)x + 9 I know you have to switch x and y so I get to x-9=(3/7)y from there I don't know what to do.

**Physics- PLEASE HELP**

Two boxes of fruit on a frictionless horizontal surface are connected by a light string as in the figures below, where m1 = 15 kg and m2 = 17 kg. A force of 58 N is applied to the 17 kg box. Repeat the problem for the case where the coefficient of kinetic friction between each...

**Physics- PLEASE HELP**

Two boxes of fruit on a frictionless horizontal surface are connected by a light string as in the figures below, where m1 = 15 kg and m2 = 17 kg. A force of 58 N is applied to the 17 kg box. Repeat the problem for the case where the coefficient of kinetic friction between each...

**physics**

A bicycle wheel of radius 0.4 m is spinning at a rate of 40 revolutions per minute. What is the centripetal acceleration of a point on the edge of the wheel? What is the period of the wheel's motion?

**Math**

The way this is written you need to A:conduct three trials using three different coins (1 for each trial). For each trial flip the coin three times & record the results (heads even & tails odd). Each flip represents one of the three misses for that route. B: Actually do the ex...

**statistics**

thanks!

**statistics**

So if a scale has 30 items in it, and if an individual gets a score of 20 what does this mean? The only way to answer this is to look at the standardization sample, find out what the mean score in the sample was, let's say 15, and standard deviation in the population was f...

**statistics**

So if a depression scale has 30 items in it, and if an individual gets a score of 20 what does this mean? The only way to answer this is to look at the standardization sample, find out what the mean score in the sample was, let's say 15, and standard deviation in the popul...

**Physics**

HELP WITH c.!!! A electric bill showed 1200 kilowatt hours (kWh) purchased at a cost of $150.00. a. What does PECO charge per kWh? $0.125 b. An electric dryer is rated at 5400 W. It takes 40 minutes to dry a normal load. What is the cost per load? $0.45 c. Two 100 watt securit...

**physics**

Microwaves are electromagnetic waves transmitted at a normal frequency of 2.45 GHz. Find the wavelength of the microwaves.

**SCIENCE**

WHAT IS THE FUNCTION OF GUARD CELLS?

**PHYSICS**

A BODY CHANGES IT'S VELOCITY FROM 20M/S UNTIL IT COMES TO REST IN 10 SECONDS.WHAT IS IT'S ACCELERATION

**PHYSICS**

A LORRY INCREASES VELOCITY FROM 6m/s TO 10m/s IN 25 SECOND.FIND THE ACCELERATION.

**Physics 121**

Two block are connected by a rope that runs over a pulley. The block on the tables has mass 4kg, the hanging block has mass 2kg, and the pulley has mass 0.5kg and radius 0.25m. Assume that the table is friction-less. If the block are released from the rest, determine their spe...

**Math**

1. P = positive results / total attempts. In this case, 11/50 = .22 = 22% 2. Increase the sample size. The more data he accrues, the closer the experimental probability will be to the theoretical probability.

**Chemistry**

1. You are correct. The strength of a weak acid is proportional to its dissociation constant, which is directly proportional to the concentration of ions and inversely proportional to the concentration of the undissociated acid molecules. 2. Yes, this is correct. The pH decrea...

**physics help please**

My answers would be a, b, and d, where b and d are the same force. This assumes you are traveling very fast.

**College chemistry**

This is an example of a combustion reaction involving a hydrocarbon (in this case propane) reacting with oxygen. The products of such reactions are almost always water and carbon dioxide. C3H8(g) + O2(g) → H2O + CO2 First balance the number of Carbons on both sides. Ther...

**chemistry**

You are actually really close. First remember that ΔG = Greactants - Gproducts. In this case the equation is: Ba2+ + NO3- -> Ba(NO3)2 But that equation isn't balanced! For this to work you have to balance the equation first like so: Ba2+ + _2_NO3- -> Ba(NO3)2 Th...

**physics**

A +50 micro coulomb and 30 micro coulomb charge are placed 50cm apart. a)what is the direction and magnitude of thee electric field at a point P, in between them, that is 10cm from the 30 micro coulomb charge? b)if an electron is placed at rest P, what will its acceleration be...

**physics**

A +50 micro coulomb and 30 micro coulomb charge are placed 50cm apart. a)what is the direction and magnitude of thee electric field at a point P, in between them, that is 10cm from the 30 micro coulomb charge? b)if an electron is placed at rest P, what will its acceleration be...

**MATH**

if I scored 72 out of a 100, what do i need to score to bring up may average to 80%

**Physics**

HELP! A tennis ball is attached to a .8m long string whirled around in a circle with a constant frequency of 1.2 Hz. What is the linear(tangential) velocity of the tennis ball?

**physics**

A wooden box weighing 271 N is pushed across the floor by a workman who exerts a horizontal force of 144 N. If the force of friction between the box and the floor is 28 N, what is the acceleration (in meters/second^2) of the box?

**Probability**

how many can 5 people be arranged in a row if the father is on the far right?

**Physics**

A vibration platform oscillates up and down with an amplitude of 10.2 cm at a controlled variable frequency. Suppose a small rock of unknown mass is placed on the platform. At what frequency will the rock just begin to leave the surface so that it starts to clatter?

**Physics**

Two electrons are fixed 2.99 cm apart. Another electron is shot from infinity and stops midway between the two. What is its initial speed?

**Physics**

This question contains a graph: h t t p : / / i . i m g u r . c o m / Q z l x d . p n g

**Chemistry**

Calculate the heat released from 61.5 g of steam at 111 degrees C is converted to water at 39 degrees C. Assume the specific heat of water is 4.184 J/g*C, the specific heat of steam is 1.99 J/g*C and the enthalpy.H.vap= 40.79 KJ/mol of water

**Chemistry**

What is the Heat Change in kilojoules when 61.5 g of steam is cooled from 111 degrees C to 100 degrees C?

**Physics**

Figure (a) shows charged particles 1 and 2 that are fixed in place on an x axis. Particle 1 has a charge with a magnitude of |q1| = 12.0e. Particle 3 of charge q3 = +13.0e is initially on the x axis near particle 2. Then particle 3 is gradually moved in the positive direction ...

**Physics**

Figure (a) shows charged particles 1 and 2 that are fixed in place on an x axis. Particle 1 has a charge with a magnitude of |q1| = 12.0e. Particle 3 of charge q3 = +13.0e is initially on the x axis near particle 2. Then particle 3 is gradually moved in the positive direction ...

**Math**

What's the least common multiple of 2 and 2.5?

**Physics**

This problem contains a graph: h t t p : / / i . i m g u r . c o m / p s z e p . p n g

**Physics**

Here is the problem in image form: h t t p : / / i . i m g u r . c o m / g n 1 j R . p n g

**Physics**

Sphere W (with an initial charge of zero) is touched to sphere A and then they are separated. Next, sphere W is touched to sphere B (with an initial charge of -26e) and then they are separated. Finally, sphere W is touched to sphere C (with an initial charge of 46e), and then ...

**Physics**

They're all the same size.

**Physics**

Sphere W (with an initial charge of zero) is touched to sphere A and then they are separated. Next, sphere W is touched to sphere B (with an initial charge of -26e) and then they are separated. Finally, sphere W is touched to sphere C (with an initial charge of 46e), and then ...

**homework**

every yellow marble is expensive.one -half the orange marbles are expensive.one -half of all expensive marbles are yellow. there are 40 yellow marbles and 25 expensive marbles that are niether yellow nor orange. how many orange marbles are there?

**Statistics**

Suppose you know ó and you want an 85 percent confidence level. What value would you use to multiply the standard error of the mean by?

**Electric Fields**

In a particular region of Earth's atmosphere, the electric field above Earth's surface has been measured to be 151 N/C downward at an altitude of 280 m and 167 N/C downward at an altitude of 430 m. Calculate the volume charge density of the atmosphere, assuming it to b...

**Physics**

A chair with a mass of 30.0kg is shot with a 10g bullet traveling at a speed of 250m/s. The bullet goes 6cm into the chair. The given kinetic friction for for this problem is .2. How far does the chair slide in cm?

**Physics**

The coefficient of kinetic friction for a 22 kg bobsled on a track is 0.15. What force is required to push it down a 6.0° incline and achieve a speed of 64 km/h at the end of 75 m?

**Physics**

A person throws a ball upward into the air with an initial velocity of 15.0 m/s. Calculate the following: a.) how high it goes. b.) how long the ball is in the air before it comes back to his hand. c.) at what time(s) will the ball pass a point 8.00 m. If you got multiples tim...

**Physics**

Units count. Show all steps, not just the numerical substitutions. Show the equations you used. No information is missing. A person throws a ball upward into the air with an initial velocity of 15.0 m/s. Calculate the following: a.) how high it goes. b.) how long the ball is ...

**Modern Physics**

(7) Show that if a particle moves at an angle θ with respect to the x-axis with speed u in frame S, then it moves at an angle θ′ with the x′-axis in frame S′ with tanθ′ = sinθ /( γ(cos θ − v/u)) Assume that S′ m...

**University Physics**

If vector B is added to vector C = 6.7 + 6.9, the result is a vector in the positive direction of the y axis, with a magnitude equal to that of vector C. What is the magnitude of vector B?

**University Physics**

If is added to = 6.7 + 6.9, the result is a vector in the positive direction of the y axis, with a magnitude equal to that of . What is the magnitude of ?

**physics**

Determine the stopping distances for a car with an initial speed of 93 km/h and human reaction time of 3.0 s for the following accelerations: -4.00 m/s^2 -8.00 m/s^2

**physics (non-calc)**

A particle of charge 2.5x10(^-6)C is moving at 1000 m/sec in a direction 30 degrees North of east. At the location of the particle the magnetic field has size 0.2 T. The particle is experiencing an instantaneous magnetic force (due to this sheild) of 1.71x10(^-4) newtons direc...

**game theory**

Two companies, A and B, produce widgets. Each can produce 0, 1, 2, 3, or 4 widgets (they canâ€™t produce fractions of widgets). Let X be the number of units produced by A, and Y be the number of units produced by B. Given X and Y, widgets will sell at a price e...

**economics**

Two companies, A and B, produce widgets. Each can produce 0, 1, 2, 3, or 4 widgets (they canâ€™tÂ produce fractions of widgets). Let X be the number of units produced by A, and Y be the number of units produced by B. Given X and Y, widgets will sell...

**Chemistry**

Trista is almost correct. However she failed to realize that the problem called for 100 mg which is equal to 0.1 grams. This means that (7.05x10^-3)g/L / 0.1g = 0.0705/1L (Where the L is in the denominator). So in order to finalize this problem all you have to do is take the i...

**Math**

How many ml are there in .032L ?

**Physics **

Can someone please help me? The brakes of a truck cause it to slow down by applying a retarding force of 2.60 103 N to the truck over a distance of 930 m. What is the magnitude of the work done by this force on the truck? Is the work positive or negative? Explain Why?

**Calculus**

Find the equation of the plane through (1,2,-2) that contains the line x = 2t, y = 3 - t, z = 1 +3t

**Calculus 3**

Show that if a, b, c are in V3, then (a x b) dot [(bxc)x(cxa]) = [a dot (b x c)]^2 I dont know what properties to use

**Vectors**

Show that if a, b, c are in V3, then (a x b) dot [(bxc)x(cxa]) = [a dot (b x c)]^2 I dont know what properties to use

**physics**

The answer is 200N in the sense that an increase in force will produce an increase in the acceleration.

**physics**

The answer is 200N in the sense that an increase in force will produce an increase in the acceleration.

**Physics**

Nevermind. The answer is 250 degrees Celsius. Duh!

**Physics**

(brass diameter)*(1+(brass coefficient)*(change in brass temperature)) = (iron diameter)*(1+(iron coefficient)*(change in iron temperature)) where: brass coefficient = 19*10^-6 K^-1 iron coefficient = 12*10^-6 K^-1

**Physics**

A brass plug is to be placed in a ring made of iron. At 20 degrees Celsius, the diameter of the plug is 8.737 cm and that of the inside of the ring is 8.723 cm. They must both be brought to what common temperature in order to fit? (ANSWER: -210 degrees Celsius) What if the plu...