# Posts by jean

Total # Posts: 501

**Chemistry**

An unknown element Q has two known isotopes: 60Q and 63Q. If the average atomic mass is 62.0 amu, what are the relative percentages of the isotopes?

**statistics**

Car seat belts are tested for strength, and it is found the results are normally distributed with a mean of 2400 lb and a standard deviation of 400 lb. Using the 68-95-99.7 rule, find the percentage of scores between 1600 lb and 3200 lb.

**physics**

the rate at which radiant energy from the sun reaches the earth's upper atmosphere is about 1.50kW/m2. the distance from the earth to the sun is 1.50*10^11m, and the radius of the sun is 6.96 * 10^8m. if the sun radiates as an ideal black body (e=1), what is the ...

**Math**

In a survey of students about favorite sports the results include 23 who like tennis 24 like football 7 like tennis and football 20 like football and baseball 5 like all three sports 9 like no sports. How many students like only tennis and football? How many like only tennis ...

**chemistry**

Consider the equilibrium reaction CO(g)+H2O(g)⇋CO2(g)+H2(g) Determine how each change in the left-hand column will stress the system and in which direction the equilibrium reaction will shift in response.

**math**

39

**physics**

How much effort force would be needed to roll a barrel with a resistance force of 100N up an inclined plane with a height of 2m and an inclined plane of 8m?

**Statistics**

what is the standard deviation for 57,61,57,57,58,57,61

**precalc**

Find the standard form equation for each ellipse described. 1) Major vertices at (0, 3) and (0, -3), minor vertices at (2, 0) and (-2, 0) 2) Major vertices at (7, 0) and (-7, 0), foci at (5, 0) and (-5, 0) 3) Minor vertices at (-2, -3) and (-2, -11), foci at (1, -7) and (-5, -7)

**statistics**

16/2704 =1/169 or 0.0059 144/2704 = 9/169 or 0.0533

**Intro to Ecology**

Global estimates of denitrification in terrestrial ecosystems vary widely but are of the order 200*102 g/yr, and more than half of that total occurs in wetland ecosystems. If restoration results in an increase in wetland area by approximately 25%, it would be expected that ...

**math**

7x-3y+4z=18 13x+6y+8z=30 11x-9y-12z=16 Find x,y,z please show the solution pleaseee

**chemistry**

4.3 cm would be 1.69 in

**statistics**

A multiple-choice quiz has 15 questions, each with 4 possible answers of which only 1 is the correct answer. What is the probability that a student gets 7 to 11 correct answer?

**Solid Mensuration**

A triangle has a base of 16 inches and an altitude of 8 inches. Find the dimensions of the largest rectangle that can be inscribed in the triangle if the base of the rectangle coincides with the base of the triangle.

**Calculus**

Thank You!!

**Calculus**

The balloon leaves the ground 80 ft. from an observer and rises vertically upward at 5 ft/s. (a) How fast is the balloon receding from the observer after 12 seconds? (b) find the corresponding acceleration? How do I sketch it? and what equation should I use? Please show the ...

**Calculus**

A man 5.5 ft tall walks away from a lamp post 10 ft high at the rate of 8 ft/s. (a) How fast does his shadow lengthen? (b) How fast does the tip of the shadow move? Can you please tell me what method/s you used to come up with a solution? I wasn't sure about the sketch I ...

**Calculus**

why was it multiplied to 10?

**calculus**

find the equation of the curve for which y'''=24x-6 if the curve passes through (-1,8) and is tangent to the line y=4x at (1,4). help please thanks :-)

**calculus**

if the driver of a car wishes to increase his speed from 20 mph to 50 mph while traveling a distance of 528 ft., what constant acceleration should he maintain?

**calculus**

a particle starts from rest and moves along a straight line with an acceleration equal to 24-15√t where distance and time are measured in terms of feet and seconds respectively. with what acceleration will the particle return to the starting point? help please thank you :-)

**calculus**

it's 904 ft. thank you :-)

**calculus**

a stone dropped from a balloon which was rising at the rate of 15 ft./sec. reached the ground in 8 seconds. how high was the balloon when the stone was dropped?

**calculus**

If the driver of a car wishes to increase his speed from 20 mph to 50 mph while traveling a distance of 528 ft., what constant acceleration should he maintain?

**calculus**

a particle starts from rest and moves along a straight line with an acceleration equal to 24-15√t where distance and time are measured in terms of feet and seconds respectively. with what acceleration will the particle return to the starting point?

**calculus**

A stone dropped from a ballon which was rising at the rate of 15 ft./sec. reached the ground in 8 seconds. how high was the ballon when the stone was dropped? please help :-) thank you

**calculus**

Thank you. You’re so helpful.

**calculus**

a parachutist falling at the rate of 15 ft./sec. drops a stone. if he was 904 ft. above the ground when the stone was dropped, how long would it take the stone to reach the ground?

**calculus**

Thank you very, very much. I'm really grateful.

**calculus**

a = 1/(t√t)

**calculus**

a particle moves according to the law a=1/t √t. if s=8 when t=1. and s=16 when t=4. find v when t=9.

**SLCS**

Paul and Juston are carrying a sack or rice weighing 6.02x10^2 N on a pole between them. If the pole is 2.0 m long and the load is .50m away from Juston,what force should each boy exert to make it equilibrium. Neclect the weight of the pole.

**Nutrition**

:can be converted to vitamin D, the answer is a.

**Math**

Serena is an account executive. She receives a base pay of $18 an hour plus a 15% bonus for all the sales she generates. Last week she generated $1,200 worth of business. What is the minimum number of hours she could have worked to make $500?

**Pharmacy Tech**

ah ok so basically warnings- can cause these symtoms and adverse reactions- things that was observed during clinical trials? that would be the difference?

**Pharmacy Tech**

20.) To find out if a drug causes nausea, you would look in this section of the drug monograph. a) adverse reactions b) contraindications c) how supplied d) warnings I am leaning towards a but not sure..I could also think it could be d as well...am confused and i keep ...

**physics**

a gun converts 200J of stored energy into kinetic energy of the 0.02kg bullet. What is the speed of the bullet as it leaves the gun? If the gun is fired straight up, how high will the bullet go?

**Physics**

60mph converts into 26.82m/s, a= (0-26.82 m/s) -26.82 m/s but don't understand how to get answer in Newtons which are kg m/s^2

**math**

solve: 2x + 5 = 3x - 9

**Trig**

How do you derive this identity? Cos(t)=1-sin^2(t/2)

**Math**

{0,9700} and {6,109000} just like in a normal x-y equation, slope={109000-97000}/{6-0} =12000/6=2000 using {0,97000} ,which would be the y-intercept y=2000x+97000

**MicroEconomics**

3000

**Persuasive Essay**

Should violent video games be prohibited from sale?

**calculus**

Use iterated integral to find the area enclosed by r=2sin2(theta). How do i graph this?

**calculus**

Z=square root of(x^2+y^2) + xy Find the partial derivatives: x, xx, y, yy, xy. Thanks.

**math**

The domain and range of ln(4-x-y). Thanks.

**math**

Z=square root of (x^2+y^2) + xy Find the partial derivatives: x, xx, y, yy, xy. Thanks.

**math**

But why wouldnt the answer be just xe^y cos(xy)? if the partial derivative with respect to x is just ye^y cos(xy).

**math**

The partial derivative with respect to y for z=e^y sin(xy) is: zy= xe^y cos(xy) + e^y sin(xy) How do i get to this answer? Thanks.

**math**

Find the rectangle with the maximum area inside the ellipse x^2/16 + y^2/4=1. Thanks.

**physics**

If a 2kg car with a momentum of 12kg m/s collides with a stationary 4kg car, the total momentum after the collision will be?

**Statistics – Lab Week 2**

Thanks for the help...

**Statistics ¨C Lab Week 2**

The corelation coefficient is: r=0.9982 Step 1: Find X⋅Y, X^ 2 and Y ^2 as it was done in the table below. X Y X⋅Y X⋅X Y⋅Y 67.273 69.78 4694.30994 4525.656529 4869.2484 0.764 1.40 1.0696 0.583696 1.96 2.533 4.21 10.66393 6.416089 17.7241 63.000 61.00 ...

**Statistics – Lab Week 2**

11. Using the empirical rule, 68% of male heights should be between what two values? Either show work or explain how your answer was calculated.

**Algebra**

x(a+b+2) (x+3)(a+b)

**equations**

Exact result: 3N/16 = 24

**math**

True

**Algebra**

Solution for the variable b b=a

**Science**

Yes second answer is correct.

**physics**

The vertical acceleration of a projectile A)equals g pointing sometimes upwards and other times downwards. B)equals g pointing upwards C)is zero. D)equals g pointing downwards E)continuously increases. Thanks!

**Accounting 9**

41

**physics**

Thanks!

**physics**

A child, who is 45 m from the bank of a river is being carried downstream by the river's swift current of 1.0 m/s. As the child passes a lifeguard on the river's bank, the lifeguard starts swimming in a straight line until she reaches the child at a point downstream. ...

**algebra**

what is the inner diameter of a washer whose outside is l inch and thickness is 3/16 inche

**Math**

If a hallway is 90 feet long & 7 feet wide and it takes 1/2 ounce of cleaning solution to clean 1 square foot, how much cleaning solution is needed to clean the hallway?

**physics**

croquet ball must have a set mass of 0.50 kg. a red ball moving at 10.0 m/s, strikes an at-rest green ball head on. The red ball continues moving at 1.5 m/s after it hits the green ball. What is the final speed of the green ball?

**Milford DE**

#6 Plot Story map for the other wife

**Pre Algebra**

cone

**Visual Basic**

Write a statement that assigns the length of an array named strAddressBook to a variable named intAddressCount.

**Computers**

Write a statement that assigns the length of an array named strAddressBook to a variable named intAddressCount.

**chemistry**

very hot sinc will react with steam to form zinc oxide and hydrogen. If 5.4 liters of hydrogen was used to use up 20 g of zinc completely. What is the percent yield of this process

**20th century Europe**

The European dominance was replaced by what is also known as the globalization?

**20th century Europe**

to describe the international events and the economic, intellectual and cultural developments in the twentiet-first century

**20th century Europe**

The 20th century European dominance was replaced by what?

**american government**

the professional qualification model in the selection of judges holds that

**Science >.<**

if a wave is traveling at 60cm/second and has a wavelength of 15cm,what is the frequency

**Business math**

Using the price per dinner that you determined in the previous question, calculate the following. If Epicure offers a $1-off coupon in a newspaper advertisement, what markdown percent does the coupon represent? (Round percent to the nearest tenth.)

**Physics**

A rock is ejected vertically upward at 40 m/s. At what time is the rock moving at 20 m/s upward.

**math**

70-40=30 30/250=x/1000 30000/250=120 A) 120

**algebra**

Question Four x - 7y = 15 -3x + 21y = - 45

**economics**

Bob and his dad visited the hardware store on Saturday. They observed the following transactions: Mr. Harris bought 4 for 0.50, Mrs. Clarke bought 21 for $1.00, Mr. Montaro bought 1,134 for $2.00 and Ms. Park bought 450 for $1.50 What were they buying?

**American National government**

According to the trustee model of representation, members of Congress must do what

**math**

find the value of x in the equation 6x +4(70-x)=300

**Intro to Logic**

10. A strongly supported claim in science should be regarded as

**math**

simplifying expressions

**macro-economics**

1.In an attempt to curb the problem of unemployment and win the forthcoming elections the government of the republic of zambia has decided to hire unemployed workers who had previously been receiving unemployment benefits as government employees and will now pay them to do ...

**political science**

Critically evaluate plato's justification of rule by philosopher kings. Please help its needed the soonest

**science**

What is science

**chemistry**

balance net Ionic solution AgNo3 + NaOH

**political science**

is politics an art or a science? give proper reasons for chosen side.(its an essay)

**political science**

what are the argument for and against politics being a science

**political science**

Is politics a science or not? Give a reasons for answer

**economics**

John has a job that requires him to travel 3 of every 4 weeks. He has an annual budget and can travel either by train or by plaine. The airline on which he typically flies has a frequent traveler programme that reduces the cost of his tickets according to the number of milels ...

**economics**

John has a job that requires him to travel 3 of every 4 weeks. He has an annual budget and can travel either by train or by plaine. The airline on which he typically flies has a frequent traveler programme that reduces the cost of his tickets according to the number of milels ...

**Business Math**

Being inventory of 12 sets of paints at a cost of $1.50 each. During the year the store purchased 4 sets at $1.60, 6 sets at $2.20, 6 sets at $2.50, and 10 sets at $3.00. By the end of the year, 25 sets were sold. Caculate the number of paint sets in stock and the cost of ...

**Business Math**

Lee Corp. purchased 10 key chains on January 1, 2010 for $9.00 each and 5 key chains were purchased on December 1, 2010 for $10.00. Seven were sold. What would be the inventory amount for LIFO, what would be the inventory amount for FIFO

**Business Math**

Assume you lease a $45,000 BMW. Using a straight- line method with a 3- year ueful life and is a $16, 675 residual value, what is the book value of the BMW after the first year?

**Business Math**

Jim Clinnin purchased a used RV with 19,000 miles for $46,000. Originally the RV sold for $70,000 with a residual value of $20,000. After subtracting the residual value, depreciation allowance per mile was $.86. How much was Jim's purchase price over or below the book value?

**Business Math**

Jim Company bought a machine for $36,000with an estimated lofe of 5 years. The residual value of the machine is $6,000 Calculate (a) the annual depreciation and (b) the book value at the end of year 3. Assume straight-line depreciation