Friday

August 28, 2015
Total # Posts: 331

**math grade 12**

A sheet of plastic stops 25% of the light and lets through the residual 75%. What percentage of the light is let through by two sheets of the plastic ?
*August 17, 2015*

**math grade 12**

Sara got 85% and 89% on her first two Maths tests. What must she get on her third test to have at least a 90% test average. Assume three tests, represent the problem with an inequality and then solve it.
*August 17, 2015*

**Phenoix**

teresa buys 100 shares of XYZ sock on margin at $20 per share. If the margin requirement is 45 percent, the interest rate is 10 percent, and she holds the security for 1 year, how much interest must she pay?
*June 14, 2015*

**calculus**

find the exact arc length of the curve: y=0.5(e^x + e^-x) for 0 is less than or equal to x and x is less than or equals to ln2.
*May 6, 2015*

**calculus (please help)**

find the volume of the solid whose bounded by the circle x^2+y^2=4 and whose cross sections perpendicular to the y-axis are isosceles right triangles with one leg in the base. Please give explanation and steps
*April 22, 2015*

**math**

Find the volume of the solid formed by revolving the region bounded by f(x)= 2-x^2 and g(x)=1 about the line y=1.
*April 22, 2015*

**math**

A study of two types of weed killers was done on two identical weed plots. One weed killer killed 15% more weeds than the other. This difference was significant at the 0.05 level. What does this mean? A. The improvement was due to the fact that there were more weeds in one ...
*April 16, 2015*

**calc(very urgent)**

Imagine a flat-bottomed cylinderal container with a circular cross section of radius 4 in. a marble with radius 0<r<4 inches is placed in the bottom of the can. what is the radius of the bottom that requires the most water to cover it. (include first or second derivative...
*April 16, 2015*

**please help! someone plz**

Imagine a flat-bottomed cylinderal container with a circular cross section of radius 4 in. a marble with radius 0<r<4 inches is placed in the bottom of the can. what is the radius of the bottom that requires the most water to cover it. (include first or second derivative...
*April 16, 2015*

**math**

Imagine a flat-bottomed cylinderal container with a circular cross section of radius 4 in. a marble with radius 0<r<4 inches is placed in the bottom of the can. what is the radius of the bottom that requires the most water to cover it.
*April 16, 2015*

**MATH**

I'm sure what if this is the right answer that the question is looking for. since my eng. not that good i have hard time understanding. Please help me. Question: write a situation that can be modeled by the following linear system. Explain what each variable means, then ...
*March 31, 2015*

**Social Studies**

It's the Romans and Greeks since the Romans adopted the Greek pantheon of Gods and Goddess. That's why Greek and Roman mythology involve many of the same Gods and Goddesses.
*March 20, 2015*

**math**

A diamond is purchased for $3500. Its value increases 4% each year. Find the value of the diamond at the end of the sixth year of ownership.
*March 19, 2015*

**MATH**

Thank You
*March 18, 2015*

**MATH**

So the total of 4 equation have the same slope but different b values?
*March 18, 2015*

**MATH**

How do I write one equations in slope-intercept form, and three other lines in slope-intercept form that are perpendicular to the first line ?? for ex. If I pick the equation y=2/3x+4 for the first equation. and for the second line , the slope -2/3x +4 , how about the 3rd and ...
*March 18, 2015*

**math - slope-intercept**

How do I write one equations in slope-intercept form, and three other lines in slope-intercept form that are perpendicular to the first line ?? for ex. If I pick the equation y=2/3x+4 for the first equation. and for the second line , the slope -2/3x +4 , how about the 3rd and ...
*March 17, 2015*

**math**

How do I write one equations in slope-intercept form, and three other lines in slope-intercept form that are perpendicular to the first line ?? -- one line: y=mx+b second line perpendicular y= -x/m + c of course, you have to know m, b, c. ----- for the second line ...
*March 16, 2015*

**math**

for the second line perpendicular, example if it -2/3 slope. it will be use for the 3rd and 4th line perpendicular right ? and pick any value of for y-intercept for the 3rd and 4th ?
*March 15, 2015*

**math**

How do I write one equations in slope-intercept form, and three other lines in slope-intercept form that are perpendicular to the first line ?? Please Help, Thank you =)
*March 15, 2015*

**math**

write a four equations in slope-intercept form of four different lines that are parallel and graph the line ?? HELP pleaseee!! thank you
*March 13, 2015*

**math**

Each homeroom of a middle school receives 1/12 of a 5/6 acre of land. How many homerooms receive a plot of land?
*February 27, 2015*

**Chemistry**

Thank you so much :)
*February 13, 2015*

**Chemistry**

Methanol ---> Normal BP: 64.6°C --> dHvap: 35.3kJ/mol iso-Propanol ---> Normal BP: 82.3°C --> dHvap: 45.4kJ/mol Cyclohexane ---> Normal BP: 80.7°C --> dHvap: 33.1kJ/mol Question: Ethanol has a normal BP of 78.3°C. Why is the normal BP higher ...
*February 13, 2015*

**Chemistry**

Okay thank you, since they did not give me the data plots, I'm guessing I should sketch the graph on my own.
*February 13, 2015*

**Chemistry**

The equation for the best fit line was y = -4058.7x + 16.10. Using the equation of the best fit line, calculate the heat of vaporization (delta H) and the NORMAL BOILING POINT (in Celsius) of this volatile liquid. Calculated: dHvap = 33.7kJ/mol ----> I'm really confused...
*February 13, 2015*

**physicsss**

An oxygen molecule consists of two oxygen atoms whose total mass is 5.3 x 10^-26 kg and whose moment of inertia about an axis perpendicular to the line joining the two atoms, midway between them, is 1.9 x 10^-46 kg*m^2. Estimate, from these data, the effective distance between...
*February 3, 2015*

**chemistry**

how many moles are present in 2.45 x 10²³ molecules CH₄?
*February 1, 2015*

**Math**

Thank you sooooo much for helping me
*January 18, 2015*

**Math**

Wouldn't it be 12.5
*January 18, 2015*

**Math**

Ms. Sue how much of the pizza is left? How Do I find that out
*January 18, 2015*

**Math**

12.5
*January 18, 2015*

**Math**

50.27 divided by 1/4
*January 18, 2015*

**Math**

Then what do I do
*January 18, 2015*

**Math**

Or is it just 4
*January 18, 2015*

**Math**

Is it 50.27
*January 18, 2015*

**Math**

A=πr2
*January 18, 2015*

**Math**

I got 12.56 as my area
*January 18, 2015*

**Math**

Oh okay and I don't get number five
*January 18, 2015*

**Math**

I mean I get about five cookies
*January 18, 2015*

**Math**

If I divide them then I can't about five cookies
*January 18, 2015*

**Math**

Yes ma'am I got 28.26 it was an accident and do I divide both of them
*January 18, 2015*

**Math**

My mistake- 6 inch cookie have an area of 28.27 and then 12 inch cookie has an area of 113.1 do I subtract both of them
*January 18, 2015*

**Math**

On #4 both of them have an area of 113.1
*January 18, 2015*

**Math**

Could you please help me with #4 and 5
*January 18, 2015*

**Math**

So 16 is the correct answer
*January 18, 2015*

**Math**

So would it be about 16 rolls of ribbon or 15
*January 18, 2015*

**Math**

On number two I got 15.7
*January 18, 2015*

**Math**

On #1 I got 131.88 And on #2 I got 25,120
*January 18, 2015*

**Math**

Well I just needed help solve each of these problems that's all
*January 18, 2015*

**Math**

Q#1-josh just put new tires on his car. if the wheels have a diameter of 14 inches, determine how far will the wheels travel in 3 revolution, to the nearest hundredth? Q#2-Melanie wants to put ribbon around the circumference of a circular section of the park. Ribbon comes in ...
*January 18, 2015*

**Biology**

Thank you very much!
*January 1, 2015*

**Biology**

A cell is lacking in its supply of amino acids. Which of the following will occur? A- mRNA will not be formed because enzymes may not be present. B- The ribosomes will not work properly because there will be no proteins. C- tRNA may not be able to fulfill its job. D- all of ...
*January 1, 2015*

**Biology**

Okay! Thank you so much for explaining and helping me with this! I really appreciate it! :)
*December 31, 2014*

**Biology**

Which of the following . is true about the DNA molecule during transcription? A- It opens up all of the way, one gene at a time. B- It unwinds from both ends. C- It makes a copy of itself. D- Only a small area is opened. My choice is C.
*December 31, 2014*

**Biology**

Thank you! :)
*December 31, 2014*

**Biology**

Which of the following is one role of RNA polymerase during transcription? A- to break down an already existing protein B- to produce a start sequence C- to build a molecule of mRNA D- to switch uracil with thymine on the exposed gene My choice is C.
*December 31, 2014*

**Physics~ ONE MOREE**

Thanks soooo much, I always doubt myself when I get really simple looking problems so then I start to over think it too much. At least I now know I should stick with the answer I first get :)
*December 29, 2014*

**Physics~ ONE MOREE**

Which of the following must the investigator measure during an experiment? independent variable dependent variable <<<<< controlled variable
*December 29, 2014*

**So what about this one bob? Physics**

Yessssssssss :D
*December 29, 2014*

**So what about this one bob? Physics**

Which of the following is closer to a guess? hypothesis<<<<< law question theory
*December 29, 2014*

**Physics**

Which of the following statements is true? A hypothesis always leads to a theory which leads to a law. A hypothesis always leads to a law which leads to a theory. A hypothesis must lead to a theory only. A hypothesis can lead to either a theory or a law. <<<<<&...
*December 29, 2014*

**math**

not to be personal or anything ms sue why do u help on jiskha were u a professor at one point do u know the other professors
*December 11, 2014*

**math**

noel started going to yoga class on november 3, and went every third day after that. Lana also started classes on november 3, and went every fourth day after that. In how many days will they be in class together again?
*December 11, 2014*

**math**

the cost of a midnight madness movie ticket, is reduced by 2/5 of the original cost, to a cost of 3/5c. which expression is equivalent to the new cost? A)c-3/5c B)1-3/5c C)1-2/5c D)c-2/5c
*December 10, 2014*

**Derivative Test( as in the consept) **

Second derivative test to test the critical points
*December 9, 2014*

**Derivative Test**

Consider the function y = 3x5 – 25x3 + 60x + 1. Use the first or second derivative test to test the critical points. How many relative maxima did you find? I got 2 as the relative maxima, is this done correctly?
*December 9, 2014*

**physics**

An egg rolls off a kitchen counter and breaks as it hits the floor. The counter is 1.0 m high, the mass of the egg is about 50 g, and the time interval during the collision is about 0.010 s. How large is the impulse that the floor exerts on the egg? use equations of motion to ...
*December 7, 2014*

**physics**

An airplane traveling at v = 163 m/s emits a sound of frequency 1730 Hz. At what frequency does a stationary listener hear the sound as the plane approaches? Use 340 m/s for the speed of the sound and answer in Hz.
*December 1, 2014*

**physics**

Assume that there is no friction between m2 and the incline, that m2 = 2.4 kg, m1 = 1.2 kg, the radius of the pulley is 0.10 m, the moment of inertia of the pulley is 4.8 kg m2, and θ = 25.0°. a) Find the combined mechanical energy of both masses the instant the ...
*November 26, 2014*

**physics**

Two sounds have measured intensities of I1 = 102 W/m2 and I2 = 408.00 W/m2. By how many decibels is the level of sound 1 lower than that of sound 2? Answer in dB
*November 24, 2014*

**physics**

Elephants communicate via infrasound, at frequencies as low as 14 Hz that can travel up to 10 km. The intensity of these sounds can reach 103 dB, measured a distance of 5.0 m from the source. Determine the intensity level of the infrasound 10 km from the source, assuming the ...
*November 24, 2014*

**Algebra 2**

Step 1: 5x-6=0 +6 +6 Add the six to both sides Step 2: Then divide the five to both sides isolate the x 5x=6 /5 /5 Answer should be: x=6/5 Then do the same to the second one and you should get x=-25 if you did it right
*November 12, 2014*

**Science**

1. A balloonist drops an apple weighing 1.5 N over the side of the balloon's gondola. As it falls and increases speed, the drag force from the air upward on it increases. When the upward force is 0.7 N, what is the direction and magnitude of the net force on the apple? 9.8...
*November 7, 2014*

**Physics**

1.A plane traveling at 300.0 km/h attempts to land on a 500 m runway. The plane’s engines and brakes accelerate uniformly at –5.0 m/s2. Will the plane be able to land safely? Show all your work. Include any equations used, the given and unknown. Show all calculations...
*October 22, 2014*

**Math**

I mean .20 and .020
*October 2, 2014*

**Math**

so is it .02 and .002?
*October 2, 2014*

**Math**

Janice thinks that 20 hundredths is equivalent to 2 thousandths because 20 hundreds is equal to 2 thousands. Use words and a place value chart to correct Janice’s error.
*October 2, 2014*

**chemistry**

How much benzoic acid is still dissolved when 73.53 mL of saturated boiling water is cooled to 20oC. The solubility at 20oC is 0.029g/10mL.
*September 17, 2014*

**algebra**

Thank You
*September 11, 2014*

**algebra**

$4.99 for 48 fluid ounces
*September 11, 2014*

**algebra**

Find the price of any container of lemonade at a local grocery store. (You can also find prices in advertisements and on the Internet.) Make sure you write down the number of fluid ounces in the container. Determine the unit price and post the information.
*September 11, 2014*

**math**

If f(x)=x^2+2 then f(x+h)=???
*August 19, 2014*

**math**

If a ball is thrown directly upward with a velocity of 14 m/s, its height (in meters) after t seconds is given by y = 14t − 4.9t2. What is the maximum height attained by the ball? (Round to two decimal places.) ______ m After how many seconds is that height attained? (...
*August 14, 2014*

**Physics**

It says top of the ball, so you need to minus both of the heights by 8cm. h1 = 0.8 -0.08 = 0.72 It is given that kinetic energy before striking the surface is 0.75 J. So you just nid to use potential energy formula(mgh) to calculate the mass of the ball . h2 = 0.45 - 0.08 = 0....
*May 31, 2014*

**Math**

Oh I see what I did yes I got 256 thank you
*April 17, 2014*

**Math**

448*
*April 17, 2014*

**Math**

Thank you. but how did you get 256? I tried plugging it back into the original h(4)=-16t+128t but I got 446
*April 17, 2014*

**Math**

Two kids are building a rocket for science class. once the rocket is launched its height in feet, h(t) can be found using the function h(t)=-16t^2+128t where t represents time in seconds. They record the time from the moment the rocket launches until it falls to the ground. (...
*April 17, 2014*

**Chemistry**

1)(750psi)(625cm3)/293k=(v)(750psi)/193k
*April 16, 2014*

**Chemistry**

519 cm3 and 775 torr?
*April 16, 2014*

**Chemistry**

Help please? 1)A sample of propane gas occupies 625 cm3 at 20.0 °C and 750 torr. What is the final volume in cubic centimeters at -80.0 °C and 750 torr? 2)If oxygen gas is collected over water at 25 °C and 775 torr, what is the partial pressure of the O2? The vapor...
*April 16, 2014*

**chemistry**

How would I figure out the pressure?
*April 15, 2014*

**chemistry**

If 1.50mol of oxygen gas exerts a pressure of 1500mmHg at 20∘C, what is the volume in liters?
*April 15, 2014*

**physics**

An infinitely long thin metal strip of width w=12cm carries a current of I=10A that is uniformly distributed across its cross section. What is the magnetic field at point P a distance a=3cm above the center of the strip as shown? This one requires some integration! I suggest ...
*April 7, 2014*

**chemistry **

PLS HELP ME AND THANK YOU:) What is the molarity if 2.18 grams of CO(NO3)2.6H2O dissolved in 50.00ml of solution?
*April 6, 2014*

**Math**

A shirt is on sale for 40% off. The sale price is $12. What was the original price? What was the amount of the discount?
*April 1, 2014*

**Math (help)**

Nikki made 2 gallons of punch with fruit juice and ginger ale. The recipe requires 1 gallons of ginger ale. What percent of the total recipe is fruit juice? A- 50% B- 33 1/3% C- 25% D- 10% I got 50% because u need 1/2 more but the answer is 25 please explain
*March 22, 2014*

**physics **

The Achilles tendon is attached to the rear of the foot as shown in (Figure 1) . A person elevates himself just barely off the floor on the "ball of one foot." Assume the person has a mass of 80kg and D is twice as long as d.Find the tension FT in the Achilles tendon...
*February 17, 2014*

**math;)**

a kitchen is shaped like a rectangle with dimensions of 11 1/2 ft. by 9 1/2 ft. the floor of the room is made of square tiles with a side length of 1.2 ft. What is the number of tiles that will cover the kitchen floor?
*February 9, 2014*