Monday
April 21, 2014

Posts by Rachel


Total # Posts: 1,164

chemistry
a sample of sodium-24 with an activity of 12 mCi is used to study the rate of blood flow in the circulatory system. If sodium-24 has a half-life of 15 h, what is the activity of the sodium after 2.5 days. please show work.

chemistry
why is a factor used to determine the equivalent dose?

Wine Chemistry
Is citric acid stronger than tartaric acid?

chemistry
How much heat is necessary to raise the temperature of a 15.0g metal from 15 degrees celsius to 25.0 degrees celsius?

chemistry
A total of 506 J of heat are added to 50.0 g of water initially at 15.0 degrees Celsius. What is the final temperature of the water?

Math - LCD
idk

Math - LCD
rg.naja;ogbns

College Algebra
A jet flies from Atlanta to Dubuque a distance of 900 miles. After traveling the same amount of time on the return flight,the pilot mentioned they still had 150 miles to go. The airspeed of the plane was 300 miles per hour. How fast was the wind blowing?

Chemistry
What is the hybridization of phosphorous in a P4 molecule

Math
Alex scored 13 points in the basketball game. This was 1/5 of the total points the team scored. Write and solve an equation to determine the total points t the team score.

science
why does the change for the atomic radii of the elements in period 3 look similar to period 2?

Geometry
Find the coordinate of the midpoint of a segment with the endpoints at –9 and 6. A.1.5 B.–1.5 C.2 D.–3

Chemistry
After 1.78 years, 1.990 g of a radioisotope remains from a sample that had an original mass of 2.000 g. Calculate the half-life of the isotope.

Physics
I need major help with this please!!! On a safari, a team of naturalists sets out toward a research station located 6.9 km away in a direction 42° north of east. After traveling in a straight line for 2.1 km, they stop and discover that they have been traveling 22° nor...

Math
4l=9w is the other equation the dimensions should be l=2.7 w=1.2

chemistry
is resistant to corrosion physical or chemical

chemistry
joules needed to melt a 525 g ice cube at 0 degree C and to warm the liquid to 15 degrees C (two steps please show work)

Math
The management of a private investment club has a fund of $114,000 earmarked for investment in stocks. To arrive at an acceptable overall level of risk, the stocks that management is considering have been classified into three categories: high-risk, medium-risk, and low-risk. ...

Physics
A driver in a car traveling at a speed of 67 km/h sees a cat 104 m away on the road. How long will it take for the car to accelerate uniformly to a stop in exactly 102 m?

math
The Russian mathmatician Pafnuti L. Chebychev pved a remarkable theorem called Chebybchev's Inequality: In any data set, if p is the fraction of the data that lies within k standard deviations to either side of the mean, then p is greater than or equal to 1-1/k^2. a. Accor...

math
how do i solve system by elimination 6x-y=18 2x+y=2

chemistry
a fish tank holds 35 gallons of water. how many pounds of water are in the fish tank?

math
Explain how you would write the number that is 2 tens more than 53.

Science
Container A and B both container the same kind of liquid. Container A has a volume of 5 mL and Container B has a volume of 8 mL. Which container, if either has the highest density? Explain your Answer.

chemistry
Water is 11.2% by mass hydrogen. How many kilograms of water would contain 5.0g of hydrogen. (using conversion factors)

chemistry
I need answer using conversion factors

chemistry
water is 88.8% by mass oxygen. How many grams of water would contain 2.25kg of oxygen?

math
suppose a data set has n elements with n greater than or equal to 6. as you know, if n is even, then the median of the set does not have to be an element of the set. for what values of n does the first quartile not have to be an element of the set?

math
on a 50-point history test the median was 34 and Q1 was 28. one student got a perfect paper and qualified as an outlier under the 1.5 X IQR criterion. what is the largest value Q3 could be?

math
Members of the west high school band were hard at work practicing for the annual homecoming parade.First they tried marching in rows of 12 but andrew was left by himself to bring up the rear. Then the director told the band to members to march in columns of eight but andrew wa...

Math
If you are asked to compare two numbers, what two operations might you use? why?

physics
If a truck is moving at 20m/s forward with relative to the ground, and a ball is fired 20m/s backward from the truck, what would be the velocity of the ball with respect to the ground?

math
Round each number to the place value indicated by the digit in bold. a. 3587 the 5 b. 148,213 the 1, in 148 c. 23,785 the 3 d. 2,357 the 5

math
Xuan saved $5340 in 3 years. If he saved $95 per month in the first year and a fixed amount per month for the next 2 years, how much did he save per month during the last 2 years?

math
the radius of a spherical tank 0.7 meter. how many liters of water can the tank hold?

chemistry
A stock solution containing Mn2+ ions was prepared by dissolving 1.168 g pure manganese metal in nitric acid and diluting to a final volume of 1.000 L. Calculate the concentration of the stock solution.

health
c is right

Chem
?

statistics
Given that x is a normally distributed random variable with a mean of 60 and a standard deviation of 10, find the P(56 < x <74). Please show all your work and write your answer in a complete sentence. Using the information from question 1, what percentage of the populati...

business
I understand , thank you

business
Based on my knowledge it would be Foreign intermediary...but i want to double check

business
a wholesaler or agent who markets products for companies wanting to do business abroad is called a a. licensing agent b. marketing agent c. foreign intermediary d. wholesaling agent

chemistry
Calculate the change in pH when 4.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq). Delta pH=? Calculate the change in pH when 4.00 mL of 0.100 M NaOH(aq) is added to the original buffer solution. Delta pH=?

physics
Locate the position of a spaceship on the Earth-Moon center line such that, at that point, the tug of each celestial body exerted on it would cancel and the craft would literally be weightless. What is the distance (in m from the moon)

science
Three very small spheres of mass 3.00 kg, 5.00 kg, and 3.00 kg are located on a straight line in space away from everything else. The first one is at a point between the other two, 13.0 cm to the right of the second and 24.0 cm to the left of the third. Compute the net gravita...

help please :)
its not b either

math
find the area between the curve y= 1 divided by (1=3x)^2

calculus
the area under the curve y= square root of 9-x^2 with coordinates x=-3 and 3 , find the volume rotated aroudn the x-axis

Physics
A 25 N book sits on a table. What is the magnitude of the normal force the table exerts on the book?

chemistry
If you use 1 gram of salacylic acid and 3ml of acetic anhydride & 3 drops of phosphoric acid and 1 ml of water after boiling = 0.55 g of aspirin. What is the % yield?

Geometry
The equation (x + 6)^2 + (y + 4)^2 = 36 models the position and range of the source of a radio signal. Describe the position of the source and the range of the signals.

physics ...plzzzz help...
ya i m sorry ...i wrote the wrong expression by mistake

physics ...plzzzz help...
thank you ...so much..

physics ...plzzzz help...
1 ) If the mass of the Moon is 7.4 x 1022 kg and its radius is 1.74 x 106 m, compute the speed with which an object would have to be fired in order to sail away from it, completely overcoming the Moon’s  gravity  pull. 2 ) Show that if a satellite orbits very ne...

Math
write the equation of the circle in standard form. find the center, radius, intercepts, and graph the circle. x^2+y^2-6x-8y+25=36

Physics
A particle travels counterclockwise around the origin at constant speed in a circular path that has a diameter of 2.50 m, going around twice per second. Point Q is on the path halfway between points P and R, which lie on the x axis and the y axis, respectively. State the follo...

Physics
A particle travels counterclockwise around the origin at constant speed in a circular path that has a diameter of 2.50 m, going around twice per second. Point Q is on the path halfway between points P and R, which lie on the x axis and the y axis, respectively. State the follo...

Geometry
Find the distance between the given points. (2, 7, −10) and (11, 4, 0)

Geometry
A gardener wants the three rosebushes in her garden to be watered by a rotating water sprinkler. The gardener draws a diagram of the garden using a grid in which each unit represents 1 ft. The rosebushes are at (1, 3), (5, 11), and (11, 4). She wants to position the sprinkler ...

Geometry
fallen*

Geometry
A dead tree was struck by lightning, causing it to fall over at a point 10 ft up from the base of the tree. If the fall treetop forms a 40 angle with the ground, about how tall was the tree originally?

Algebra 2
5+(-5/2)+(5/4) Sn=189 Find n for the given sum if the geometric series

Algebra 2
Write the series with summation notation 3+9+19+33+51+73 I'm not sure what the equation would be. Would this situation have two equations and if so how would that look like in summation notation

beginning spanish
yes or yo se historia

math
Solve the system by graphing. Where necessary, indicate when the system has no solution or infinitely many solutions. y = –2x – 4 –2y = 4x + 8

Geometry
A special lottery is to be held to select the student who will live in the only deluxe room in a dormitory. There are 100 seniors, 150 juniors, and 200 sophomores who applied. Each senior's name is placed in the lottery 3 times; each junior's name, 2 times; and each so...

SOCIAL STUDIES URGENT
1. reeds 2. eastern rain forest 3. suspension bridges

SOCIAL STUDIES PLZZ HELP
1. Brasilia 2. the indigenous way of life. 3. Salvador Just got 100% :)

Physics
please i need help with this question. Initailly at rest, a car (mass=1300kg) accelerates north from a set of traffic lights at a constant rate for 10s. 11s after starting to accelerate it crosses an intersection and is hit by a second car (mass=1224kg) heading west at 65k/h. ...

Accounting
What types of cost information are reported to support managerial purposes and decisions? Describe 2 major categories of purposes that are supported by cost information. Describe how cost information supports both of these categories. What is a cost object and how is it used b...

Chemistry
What mass of sodium benzoate should you add to 150.00 ml of a 0.15M benzoic acid solution to obtain a buffer with a pH of 4.25?

physics
Sam, whose mass is 82 {\rm kg}, takes off across level snow on his jet-powered skis. The skis have a thrust of 240 {\rm N} and a coefficient of kinetic friction on snow of 0.11. Unfortunately, the skis run out of fuel after only 15 {\rm s}.

physics
1.3 m/s^2 upward

Statistics
What does mu represent for this problem?

Statistics
A coffee company wants to make sure that there coffee is being served at the right temperature. If it is too hot, the customers could burn themselves. If it is too cold, the customers will be unsatisfied. The company has determined that they want the average coffee temperature...

physics
Square Root

english 11
so are any of these right????

english 11
so are any of these right????

Chemistry
how do I balance the following skeleton redox equation for a reaction occurring in acidic solution. HNO2 + MnO4- yield to Mn2+ + NO3-

physics
John Johnson set a world record for the "100.0" m run with a time of 9.86 s. If, after crossing the finish line, John walked directly back to his starting point in 90.9 s, what is the magnitude of his average velocity for the 200.0m?

physics
John Johnson set a world record for the "100.0" m run with a time of 9.86 s. If, after crossing the finish line, John walked directly back to his starting point in 90.9 s, what is the magnitude of his average velocity for the 200.0m?

trigonometry
If a planet has a semimajor axis of 2 AU (astronomical units) a) what would the semimajor axis of a superior planet be if the angle of greatest elongation for the inferior planet is 20 degrees as viewed from the superior planet? b) assuming a day on the superior planet is 30 h...

Chemistry
A base has a Kb of 2.5 x 10–11. Which of the following statements is true? This is a concentrated base. This base ionizes slightly in aqueous solution. This is a strong base. An aqueous solution of this base would be acidic.

physics
A hot-air balloon is rising upward with a constant speed of 2.50 m/s. When the balloon is 3.00 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?

math
what is the prime factorization of 63?

Medical billing and coding
Thank you that helps a lot.

Medical billing and coding
compare and contrast contributory negligence with comparative negligence.

physics
thanks

physics
Assume that the Earth is spherical and recall that latitudes range from 0° at the Equator to 90° N at the North Pole. Consider Dubuque, Iowa (42.50° N latitude), and Guatemala City (14.62° N latitude). The two cities lie on approximately the same longitude. Do...

Math
Assume that the Earth is spherical and recall that latitudes range from 0° at the Equator to 90° N at the North Pole. Consider Dubuque, Iowa (42.50° N latitude), and Guatemala City (14.62° N latitude). The two cities lie on approximately the same longitude. Do ...

Finance
A firm has an opportunity to invest in a new device that will replace two of the firm’s older machines. The new device costs $570,000 and requires an additional outlay of $30,000 to cover installation and shipping. The new device will cause the firm to increase its net wo...

Physics
A 1 kh pendulum os pulled sideways so that it is raised a vertical distance of 2 m above it's resting point. Find the max. Speed the pendulum reaches after being vertical

Math
2x+y=12 3x-y=13 Please help me solve the system of equation and show your work.

Math
Jillian must average at least 90 on two quiz scores before she can move to the next skill level. Jillian got a 92 on her first quiz. What scores could Jillian get on her second quiz in order to move to the next skill level? Please help me and show your work thanks

physics
A uniform ladder 10.0 m long is leaning against a frictionless wall at an angle of 60.0° above the horizontal. The weight of the ladder is 21.8 lb. A 57.8-lb boy climbs 4.38 m up the ladder. What is the magnitude of the frictional force exerted on the ladder by the floor?

Math
a+s=1970 8a+5s=12220 Please help me solve the system of equation and show your work thanks

physics
At 1:00 p.m. a car, traveling at a constant velocity of 86 km/h toward the west, is 22 km to the west of our school. How far from the school will it be at 3:30 p.m.? Answer in units of k

chemistry
How much HCL would be needed to neutralize 250mL of 6 M NaOH (HCL = 1.5 M)?

physics
A water balloon was dropped from a high window and struck its target 3.9 seconds later. If the balloon left the person's hand at -8.4 m/sec, what was its velocity on impact?

Physics
King Kong carries Fay Wray up the 321 m tall Empire State Building. At the top of the skyscraper, Fay Wray’s shoe is knocked off with an initial upwards velocity of 5.1 and falls towards the ground. With what final velocity will the shoe be moving when it hits the ground?

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