Thursday

May 5, 2016
Total # Posts: 1,915

**physics**

What is the wavelength of a 4MHz transducer?
*February 5, 2014*

**physics**

Yes, all my questions are for ultrasound physics. I should've mentioned that, sorry. Thanks for the help
*February 5, 2014*

**physics**

If an ultrasound beam at the focal zone has a power of 0.050 watts and the area at this focal zone is 4cm^2, what is the intensity of the beam?
*February 5, 2014*

**Physics**

I know the formulas, just having problems with the right units. I got 1205 Hz for this one????
*February 5, 2014*

**Physics**

If the period of a transducer is 0.83msec, what is the HZ?
*February 5, 2014*

**physics**

so would it be 0.2 microseconds? I just want to make sure I am understanding it correctly, with the correct units, thanks
*February 5, 2014*

**physics**

If the frequency of a transducer is 5MHz, what is the period?
*February 5, 2014*

**Chemistry**

The FDA recommends that women who are pregnant avoid eating more than three 6.00-oz servings of bluefish per month because of the relatively high mercury levels in that type of fish. If bluefish contains 0.341 ppm of mercury (that is, 0.341 oz of mercury per 1×106 oz of ...
*February 1, 2014*

**Chemistry**

An office heater puts out 2070 Btus (British thermal units) of energy in the form of heat per hour. Given that 1 Btu = 1.055 kJ, how many megajoules of energy in the form of heat can be produced per year (365 days) by the heater (assume continuous operation)?
*February 1, 2014*

**physics**

the total electric field e consists of the vector sum of two parts. one part has a magnitude of e1 = 1284 n/c and points at an angle θ1 = 30° above the +x axis. the other part has a magnitude of e2 = 1833 n/c and points at an angle θ2 = 62° above the +x axis...
*January 31, 2014*

**Chemistry**

A particular MP3 encoder can convert 79.0 kilobytes (kb) of music per second from a typical music CD. How many minutes will it take to convert 13.3 megabytes (Mb) of music from a CD?
*January 29, 2014*

**Algebra**

ok thanks
*January 22, 2014*

**Algebra **

Jena wants to paint the walls in her square shaped bedroom. each wall has an area of 130 sq ft. if one quart of paint covers 150 sq ft, how many quarts of paint will she need to buy to paint all four walls? Would I leave it 4.6 or round up to five quarts?
*January 22, 2014*

**someones GOTTA help me with this science...!!!**

1. B 2. A 3. C 4. D 5. A I'm in Connexus as well, and I got a 100% with those answers:)
*January 20, 2014*

**physics**

How long will it take a sample of polonium-210 with a half-life of 140 days to decay to one-sixty-fourth of its original strength?
*January 15, 2014*

**Science**

I mean I would like to know how to work it out and not just get the answer but thanks for the help.
*January 14, 2014*

**Science**

What is the radius in nm of the electron orbit of a hydrogen atom for n=3? What is the radius in nm of the electron orbit of a hydrogen atom for n=4?
*January 14, 2014*

**math**

A florist had an equal number of red and yellow tulips. She sold 624 red tulips. Then she had 4 times as many yellow tulips as red tulips. How many tulips did she start with? You must use a bar model to solve this problem.
*January 12, 2014*

**science please check my answer**

How do I find the average acceleration of the ball?
*January 11, 2014*

**science please check my answer**

I got 57. 06 N, is that correct?
*January 11, 2014*

**science please check my answer**

A boy climbs to the roof of his house and drops a 0.40 kg rubber ball from the 7.5-meter peak of the house. How much energy was lost in the process? So I got 48 J is this correct? The bounce takes place over a 170 ms time interval. What is the impulse given to the ball during ...
*January 11, 2014*

**science**

A boy climbs to the roof of his house and drops a 0.40 kg rubber ball from the 7.5-meter peak of the house. How much energy was lost in the process? The bounce takes place over a 170 ms time interval. What is the impulse given to the ball during this time?
*January 10, 2014*

**Algebra **

Explain why n*0=0
*January 9, 2014*

**Math**

Write the equation of the line in standard form: (-3, 6); m = 1/2 (1, 0) & (-5, 3) Write the equation of the line perpendicular to 4x – 5y = -10 through the point(2, 3). Write the equation in slope intercept form.
*January 8, 2014*

**Math**

Write the equation of the line in slope intercept form: (4, 7); m = -3/8
*January 8, 2014*

**Math**

They all equal 3/4 cool thanks
*January 8, 2014*

**Math**

For the data in the table, does y vary directly with x? If it does, write an equation for the direct variation. X 52 = 32 = 20 = 8 Y 39 = 24 = 15 = 6
*January 8, 2014*

**Math**

Part 1: When writing linear equations, how do you determine which form of a line to use? Part 2: Choose 1 set of points from the choices below. Then, solve the problem and post your solution, showing your steps. Write an equation in point-slope form for the line that passes ...
*January 8, 2014*

**Math**

Find the range of each function for the given domain. 1. f(x) = -2x + 1; {-6, -2, 0} 2. f(x) = x3 + 1; {-2, -1, 3}
*January 7, 2014*

**Algebra**

Help Please Write a function rule that represents each sentence. 1. 11 less than the product of a number y and -2 is z. 2. 5 less than the quotient of a number n and 4 is m.
*January 7, 2014*

**chemistry**

1- A compound is 87.5% nitrogen and 12.5% hydrogen. The molecular weight of the compound is 32 g/mol. Describe the molecule referencing shape, and inter-molecular forces. 2- Gaseous butadiene, C4H6 , reacts with hydrogen gas in the presence of a platinum catalyst to form ...
*January 6, 2014*

**chemistry**

Consider the following reaction: CH3X + Y CH3Y + X At 25oC, the following two experiments were run, yielding the following data: Experiment 1 : [Y]0 = 3.0 M [CH3X] Time(hr) 7.08 x 10-3M 1.0 4.52 x 10-3M 1.5 2.23 x 10-3M 2.3 4.76 x 10-4M 4.0 8.44 x 10-5M 5.7 2.75 x 10-...
*January 6, 2014*

**Physics**

Mutiple choice: A car travelling at 10 m/s accelerates at 3 m/s^2. Its new velocity is A.) 12 m/s B.) 22m/s C.) 17 m/s D.) Can not be determined. Which of the following is not acceleration? A.) rate of change of speed in a particular direction B.) rate of change of motion in a...
*December 17, 2013*

**Physics**

The innerspring mattress on your grand- mother’s bed is held up by 23 vertical springs, each having a spring constant of 6000 N/m. A 43 kg person jumps from a 1.93 m platform onto the innersprings. The acceleration of gravity is 9.8 m/s2 . Assume: The springs were ...
*December 16, 2013*

**physics**

A child and sled with a combined mass of 47.4 kg slide down a frictionless hill that is 8.61 m high. If the sled starts from rest, what is its speed at the bottom of the hill?
*December 5, 2013*

**math**

Angela scored in the 90th percentile of her class math test. If 27 students scored the same as or lower than she did, how many students are in the class?
*December 5, 2013*

**math**

In a game played with 50 letter tiles, 21 of the tiles are vowels. If a tile is drawn at random, what is the probability that it is a consonant.
*December 5, 2013*

**math**

A recipe for a fruit shake calls for 5 parts milk, 3 parts banana puree, and 2 parts strawberry juice. Find the quantity of each ingredient necessary to make an 8 ounce shake.
*December 5, 2013*

**math**

A laptop that originally cost $1,200 is on sale for $950. Find the discount rate.
*December 5, 2013*

**Algebra 1 **

Name the property that is demonstrated by the example. 1. (2x)^3=2^3*x^3=8x^3 I am not sure what to put
*December 2, 2013*

**MATH :)**

For each of the following measurements state the number of significant digits: A length of 2.3 meters A volume of 0.65 liters A time of 0.0004 secs A population of 65,000,000 A distance of 1.30 x 104 I got: 1. 2 2. 2 3. 1 4. 2 5. 2 Just need someone to check my answers please ...
*November 30, 2013*

**Algebra 1**

oh thanks
*November 25, 2013*

**Algebra 1**

Sorry problem on left answer on right
*November 25, 2013*

**Algebra 1**

The problem is on the right and the answer is on the left
*November 25, 2013*

**Algebra 1**

square root to nearset integer 125 11 200 14 -47 -6
*November 25, 2013*

**Statistics**

Many dairy cows now receive injections of BST, a hormone intended to spur greater milk production. A group of 53 Jersey cows increased average milk production from 43 to 52 pounds per day, with a standard deviation of 4.8 lbs. Is this evidence that the hormone maybe effective ...
*November 24, 2013*

**painting**

how can you paint
*November 22, 2013*

**Decision Sciences**

Use graphical sensitivity analysis to determine the range of demand probabilities for which each of the decision alternatives has the largest expected value. I have two possible decisions, each with a favorable and unfavorable outcome. How do I do this?
*November 18, 2013*

**Statistics**

A survey was conducted to determine if there is a difference in gasoline mileage for two types of trucks, truck A and truck B. A random sample was taken for each model of truck, and the mean gasoline mileage, in miles per gallon, was calculated. Identify the appropriate ...
*November 15, 2013*

**Statistics**

To do inferential procedures comparing two proportions, we need another variance formula (our ruler). This formula is based on what principle? A) The variance of the difference of two statistics is the difference of the variances of each statistic. B) The variance of the ...
*November 15, 2013*

**math**

Do I use the Foil method to find the product of (9-3i)(9+4i)?
*November 15, 2013*

**Statistics**

You are given the following information obtained from a random sample of 6 observations. Assume the population has a normal distribution. 13 14 17 14 17 15 a. What is the point estimate of µ? b. Construct an 80% confidence interval for µ. c. Construct a 98% ...
*November 12, 2013*

**Statistics**

The monthly incomes from a random sample of workers in a factory are shown below. Monthly Income (In $1,000) 4.0 5.0 7.0 4.0 6.0 6.0 7.0 9.0 a. Compute the standard error of the mean (in dollars). b. Compute the margin of error (in dollars) at 95% confidence. c. Compute a 95% ...
*November 12, 2013*

**Math**

jim claims that the ratio of males to females in his class of 26 students is 3:2. Could jim be correct?
*November 11, 2013*

**Math**

Thank you so much Ms. Sue! You have been so much help :)
*November 11, 2013*

**Statistics**

The U.S. Department of Labor and Statistics released the current unemployment rate of 5.3% for the month in the U.S. and claims the unemployment has not changed in the last two months. However, the states statistics reveal that there is a decrease in the U.S. unemployment rate...
*November 11, 2013*

**Statistics**

To plan the budget for next year a college needs to estimate what impact current economic downturn might have on student requests for financial aid. Historically, this college has provided aid to 35% of its students. Officials look at a random sample of this year’s ...
*November 11, 2013*

**Chemistry **

A sample of unknown metal has a mass of 36.7 g. This metal was placed in boiling water at 96.0oC until the metal had reached the temperature of the water. The metal was then placed in a foam cup with 50.0 g of water in it at 20.0oC. The cup absorbs 42.0 J/oC, and the ...
*November 10, 2013*

**Statistics**

Hoping to lure more shoppers downtown, a city builds a new parking garage in the central business district. The city hopes that the parking revenues will pay for the garage. During a recent two month period (44 days), the city statistician calculated the 95% confidence ...
*November 10, 2013*

**Statistics**

Hoping to lure more shoppers downtown, a city builds a new parking garage in the central business district. The city hopes that the parking revenues will pay for the garage. During a recent two month period (44 days), the city statistician calculated the 95% confidence ...
*November 10, 2013*

**Statistics**

According to a study by the Centers for Disease Control, the national mean hospital stay after childbirth is 2.1 days. Reviewing records at her own hospital, a hospital administrator calculates that the mean hospital stay for a random sample of 81 women after childbirth is 2.3...
*November 10, 2013*

**Statistics**

According to a study by the Centers for Disease Control, the national mean hospital stay after childbirth is 2.1 days. Reviewing records at her own hospital, a hospital administrator calculates that the mean hospital stay for a random sample of 81 women after childbirth is 2.3...
*November 10, 2013*

**Statistics**

According to a study by the Centers for Disease Control, the national mean hospital stay after childbirth is 2.1 days. Reviewing records at her own hospital, a hospital administrator calculates that the mean hospital stay for a random sample of 81 women after childbirth is 2.3...
*November 10, 2013*

**Algebra 1 HELP**

Thank You
*November 9, 2013*

**Algebra 1 HELP**

The number of gallons needed of paint needed to cover a wall varies directly with the area of the wall. The Robertsons find that they have used 1/2 gallon of pain to cover 540 square feet of wall. Which of the follow equations shows the number of gallons of paint they will ...
*November 9, 2013*

**Statistics**

30 randomly selected cans of Coke are measured for the amount of cola in ounces. The sample values have a mean of 12.18 ounces and a standard deviation of 0.118 ounces. The 99% confidence interval is ( ounces, ounces). Round each result to two decimal places.
*November 9, 2013*

**Statistics**

30 randomly selected cans of Coke are measured for the amount of cola in ounces. The sample values have a mean of 12.18 ounces and a standard deviation of 0.118 ounces. Test the claim that cans of coke have a mean amount of cola greater than 12 ounces. What is the p-value? A) ...
*November 9, 2013*

**Statistics**

A researcher performs a hypothesis test to test the claim that among girls aged 9-10, the mean score on a particular aptitude test differs from 72, which is the mean score for boys of the same age. Data were collected from a random sample of 43 girls aged 9-10 years and the 95...
*November 8, 2013*

**Statistics**

A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful if the average time spent on the deliveries does not exceed 30 minutes. The owner has randomly ...
*November 8, 2013*

**physics**

A 66.5 kg ice skater moving to the right with a velocity of 2.09 m/s throws a 0.14 kg snowball to the right with a velocity of 22.5 m/s relative to the ground. (a) What is the velocity of the ice skater after throwing the snowball? Disregard the friction between the skates and...
*November 3, 2013*

**Algebra 1**

Can someone help me I really don't get this one The table shows the number of trolley buses in operation in the United States during certain years. Describe the rates of change in the number of buses during the time period. (Table) Year 1980 1985 1990 1995 2000 Number 823 ...
*October 31, 2013*

**chemistry **

A microwave oven heats by radiating food with microwave radiation, which is absorbed by the food and converted to heat. Suppose an oven's radiation wavelength is 12.5 cm. A container with 200 mL of water was placed in the oven and heated. How many photons are required to ...
*October 23, 2013*

**Algebra 1**

y=x+1 Domain: -2,-1,0,1,2 what is the range? Is it -1,0,1,2,3
*October 23, 2013*

**chemistry**

if 5.2 grams of bismuth react under certain conditions with 10.0 g of oxygen what is the empirical formula of the bismuth formed
*October 22, 2013*

**Geography**

I have to write a three paragraph essay on the causes of terrorism. One paragraph for each cause. All I am helping is finding 3 good causes and a little information about how they cause terrorism.
*October 20, 2013*

**chemistry**

why is the copper/sulfur mass ratio different from the mole ratio?
*October 19, 2013*

**Physics**

How do you find total displacement to and from a place?
*October 17, 2013*

**Can someone check these answer for me?**

RJC I HATE YOU I GOT 0/5 0% NEXT TIME IF YOUR DUMB AND DONT KNOW THE ANSWERS STFU AND FAIL ON YOUR OWN
*October 17, 2013*

**Newtons Second Law Physics**

If a cart and a string are attached and there is a weight on the end of the string to pull the cart, and both the cart and the weight on the string were the same.. what would I expect acceleration to be using Newton's second law?
*October 16, 2013*

**Physics Newtons Law**

If a cart and a string are attached and there is a weight on the end of the string to pull the cart, and both the cart and the weight on the string were the same.. what would I expect acceleration to be using Newton's second law?
*October 15, 2013*

**MATH**

Which of the following is an irrational number? a. negative square root of 5 B. 1/8 c. 0.3858585... d. negative square root of 64
*October 15, 2013*

**Chemistry**

Assuming the gas is ideal, we use the formula ρ = P*MM / RT where ρ = density (g/L) P = pressure (atm) MM = molar mass (g/mol) R = gas constant = 0.0821 L-atm/mol-K T = temperature (K) Note that this formula is just derived from the ideal gas law (PV = nRT). Convert ...
*October 15, 2013*

**vocab**

I need help on rootwords im stuck on sepect meaning look I have to find 3 words with sepect in it then put the meaning
*October 14, 2013*

**chem**

The reaction is Br2 (g) <---> 2Br (g). It occurs at T = 1600 C. When 1.05 mol Br2 are placed in a 2 Liter flask, 2.50% of Br2 undergoes dissociation. Calculate the Kp for the reaction. Okay so i did the ICE table for this, Br2 (g) <---> 2Br (g) I : 1.05/2 ..... 0 C...
*October 14, 2013*

**Algebra 1**

A cyclist can travel 29.6 miles in 2 hours. At this rate, how far can the same cyclist travel in 45 minutes? A: 14.8 B: 22.2 C: 11.1 D: 16.2
*October 10, 2013*

**Algebra 1**

A cyclist can travel 29.6 miles in 2 hours. At this rate how many gallons will it need to travel 650 miles. A: 14.8 B: 22.2 C: 11.1 D: 16.2
*October 10, 2013*

**algebra 1**

4-10y=22-6x Solve the Equation for y
*October 7, 2013*

**Algebra 1**

An architectural firm makes a model of a science center they are building. The ratio of the model to the actual size is 1 in.:85 ft. Estimate the height of the building if the model is 1.5 inches tall.
*October 5, 2013*

** Algebra 1**

You are making up your own mix of concrete to patch a set of stairs. In order to have the proper mix, you need to mix 1 part of Portland cement with 2 parts of sand and 3 parts of gravel. A. How many total parts are in one batch of concrete? B. You make a mix with 4 parts of ...
*October 5, 2013*

**Algebra 1**

23=2x+(x+3)+x I know the answer is 5 but I don't know how to show the work.
*October 1, 2013*

**Algebra 1**

what is the value of x in the rectangle Perimeter=24 meters the side is (x+3) The bottom is 2x
*October 1, 2013*

**Math**

ben deposits $320 in an account that earns 3.5% simple interest per year. what is the balance in the account year?
*September 19, 2013*

**Math- Help Please**

Find a polynominal of degree 4 that has integer coefficients and zeros 4,-4,5 and 1/2.
*September 16, 2013*

**Math**

V(t)=175(1-(t/45))^2 Find the inverse V^-1=?
*September 12, 2013*

**language arts**

why is rikki tikki tavi not afraid to fight a cobra snake
*September 11, 2013*

**Chemistry**

325
*September 11, 2013*

**physics**

You are arguing over a cell phone while trailing an unmarked police car by 25.0 m; both your car and the police car are traveling at 120 km/h. Your argument diverts your attention from the police car for 2.0 s (long enough for you to look at the phone and yell,“I won'...
*September 5, 2013*

**physics**

if a ball is tossed from ground level upward at a speed of 44 m/s how long will it take to reach its maximum height
*September 4, 2013*

**Geography**

Thanks! Great job by the way :)
*September 2, 2013*