Wednesday
January 18, 2017

# Posts by Jack

Total # Posts: 1,734

Chemistry
Considering only the molecular orbitals formed by combinations of the s atomic orbitals in the valence shell, how many molecular orbitals can be formed by 5000 sodium atoms?
June 15, 2016

Math trig
Hello guys. I am just wondering if tan^2 A (tan squared A) = sin^2 A /cos^2A And 2tan A = 2sin A / 2cos A This has been bothering me when I have to simplify trig. Thanks in advance.
June 1, 2016

Algebra 1
An airplane travels for seven hours with a 60 mph tailwind on the return trip against the same wind it took the plane nine hours find the speed of the plane with no wind.
May 30, 2016

Maths , logarithms
Thank you Reiny Your answer is very clear and shows what I did wrong. Keep up the good work.
May 29, 2016

Maths , logarithms
Sorry it wasn't clear the problem was this 2^(2x+1) -9*2^2x = -4
May 29, 2016

Maths , logarithms
Hi bob For the first log problem , it was in a test and my answer was wrong , could it be a marking error?
May 29, 2016

Maths
2^2x+1 - (9)2^x = -4 Can someone please solve for x ? My answer is x= 2 , is this correct?? Please show your steps
May 29, 2016

Maths , logarithms
Can someone solve for x please. I don't understand it. 2^x . 7^x = log 14 My answer : 14^x = log 14 = log14÷log 14 = x X=1 Is this right????
May 29, 2016

english
Which of the following correctly defines blank verse? A. poetry with no structure or rhyme B. a type of long poem often used for plays C. a type of rhymed poetry Shakespeare uses throughout his plays D. unrhymed verse written in iambic pentameter i think it's A
May 24, 2016

Math
154lb person burns 420 calories per hour riding an exercise bicycle at a rate of 15 mi/hr. Write a function rule to represent the total calories burned over time by that person. Explain how the information in the problem relates to the function.
May 20, 2016

Trigonometry
A hinged crane which measures 19m makes an angle of 50° with the ground. A malfunction causes the lock on the hinge to fail and the top part (of 14.6m) of the crane swings down. How far from the base of the crane does the top hot the ground.
May 19, 2016

math
Can you help me? For the problem .6 is 266 2/3% of what number? would I change 266 2/3% to a decimal and put it over 100?
May 14, 2016

11. A basket contains the following pieces of fruit: three apples to oranges two pairs two bananas and five peaches. Jack pics of fruit at random and does not replace it then, Bethany pics of fruit at random. what is the probability that Jack gets a peach and Bethany gets an ...
May 9, 2016

math
T =ƒ­aƒy+ beƒ{^- kt (Equation 2) where T is the temperature at time t, and a, b and k are constants with values a = 20 „aC, b = 80 „aC and k = 2.6 ¡Ñ 10ƒ{4 sƒ{1. Differentiate Equation 2 with respect to t and thus give values...
May 5, 2016

Math
A boy is trying to find the height of a tree. When he stands 95.5 metres away from the tree (the distance D in Figure 2) the angle shown as è in Figure 2 is 31.5°. The boy’s eyes are 1.15 m from the ground (h in Figure 2). What is the height of the tree? You ...
May 5, 2016

Calculus
Use the trapezoidal rule with n = 5 to approximate. Keep at least 2 decimal places accuracy. Integrate: (cos(x))/(x) from x=1 to 5
May 3, 2016

Math
A florist used 12 flowers to make a bouquet, including 4 daisies. What is the probability that a randomly selected flower will be a daisy?
May 1, 2016

Software Engineering
Consider the following program (written in pseudo-code) begin x:= 0; y:= 1; z:= 1; while y <= n do x:= x+1; z:= z+2; y:= y+z; od sqrt := x; end Prove the partial correctness of the program with respect to the following predicates: Pre: {n>=0} Post: {sqrt2 <= n and n &...
April 21, 2016

World History
Who was firends with Joseph Stalin?
April 13, 2016

World History
what was Joseph Stalin favorite music, and movies?
April 13, 2016

Geometry
2513.27 cm^2
April 13, 2016

Geometry
John bought a conical hat on a recent trip to central Vietnam. The basic frame of the hat is 16 hoops of bamboo that gradually diminish in size. The hat is covered in palm leaves. If the hat has a diameter of 50 centimeters and a slant height of 32 centimeters, what is the ...
April 13, 2016

math
the first, second, and third terms in the geometric progression are k,k-6, 2k-28 respectively. given that all terms of the geometric progression are positive, calculate the value of constant k.
April 13, 2016

algerbra
a rectangle with width 2x+5 inches has an area of 2x^4+11x^3-5x^2-98x-120 square inches. Write a polynomial that represents its lenght
April 11, 2016

Math
For this problem (2)^0 (-2)^0 would I add the exponents? I f so what do I do with 2 and -2?
April 9, 2016

Calculus
Function is y=x2 . Take three points, x=2, x=3, x=4. Approximate this function at these three points for a deviation Δx =0.1. Which of the three points does the approximation works best? Which point does it works worst?
April 6, 2016

English
March 31, 2016

Math
It is 393
March 29, 2016

College Physics
A student of mass M = 82 kg takes a ride in a frictionless loop-the-loop at an amusement park. The radius of the loop-the-loop is R = 15 m. The force due to the seat on the student at the top of the loop-the-loop is FN = 696 N and is vertically down. What is the apparent ...
March 17, 2016

Physics
A jet plane is flying at a constant altitude. At time t1=0 it has components of velocity Vx=90m/s, Vy=110m/s.At time t2=30.0s the components are Vx=-170m/s, Vy=40m/s.a).Sketch velocity vectors at t1 and t2.How do these two vectors differ?. For this time interval calculate b). ...
March 6, 2016

Math
March 5, 2016

calculus
just wanted solutions and maybe working out as my previous year exams papers don't come with solutions. So I cant compare to see if I got it correct or not.
March 5, 2016

calculus
a) Let f(z) = z^2 and γ(t) = 1 + it^3, t ∈ [0,1]. i) Write out the contour integral ∫γ f(z)dz as an integral with respect to t. You do not need to evaluate this integral. ii) Evaluate the integral ∫0,1+i z^2dz iii) What is the relationship between ...
March 5, 2016

calculus
Thank you. Just wondering why 3T can be 3 pi, 5 pi, pi. Also just need c and d.
March 3, 2016

calculus
a) Obtain all solutions of the equation z^3 +1 = 0 b) Let z = x + iy. Obtain the real and imaginary parts of the function f(z) = 1/1+z c) Let f(x + iy) = x^2 - y^2 + iv( x,y). Determine a function v such that f is differentiable in the whole complex plane. Express f as a ...
March 3, 2016

Physics
A string under a tension of 43.0 N is used to whirl a rock in a horizontal circle of radius 2.25 m at a speed of 20.0 m/s on a frictionless surface as shown in the figure below. As the string is pulled in, the speed of the rock increases. When the string on the table is 1.00 m...
March 2, 2016

Quick Citation Question
I am citing books in MLA format and I am wondering about the publisher. If the publisher is: Smith and John Publication, Inc. Do I include the "inc." part with the period?
February 26, 2016

Algebra
A balloon is secured to rope that is staked to the ground. A breeze blows the balloon so that the rope is taut while the balloon is directly above a flag pole that is 30 feet from where the rope is staked down. Find the altitude of the balloon if the rope is 100 feet long. ...
February 21, 2016

geography,life science, business and maths lit
Can i study sport science or land survey with this subjects?
February 19, 2016

Math
8*6=48\3=16
February 15, 2016

Physics
You are in the supermarket, pushing a cart with a force of 92 Newtons in the horizontal direction. There is a constant force of kinetic friction operating on the cart of 16.8 Newtons. Calculate the net work done on the cart, if the cart is displaced 5.6 metres in a straight line.
February 11, 2016

Science
You drop a ball, mass 117.1 grams from a height of 68.9 cm. It bounces back to a height of 48.1 from the floor. What is the change in gravitational potential energy from the moment it is dropped, to the moment it reaches the maximum height from the bounce?
February 11, 2016

Science
1.A 2.B 3.C 4.A You will get 100%
February 11, 2016

Science
February 11, 2016

math
Yasmin lives 400m from Anton.Kevin lives 0.45km from Anton.Jared lives 40 000mm from Anton.who lives closest to Anton?how do you know?make sure to show your work?
February 8, 2016

Precalc
Taxes on a house assessed at \$64,000 are \$1500 a year. If the assessment is raised to 85,000 and the tax rate did not change, how much would the taxes be( round to two decimal places)
February 7, 2016

Maths
A glass is designed in the shape of a cylinder. it has a radius 5cm, and holds 1 litreof liquid, what's the height of the glass
February 4, 2016

Calculus(PLZ HELP)
That website isn't helpful since the problem is a box cross sectional problem. But thank you for trying to help
February 2, 2016

Calculus(PLZ HELP)
A serving bowl has an inside diameter of 12 inches and a depth of 4 inches. The bowl is fashioned from part of a sphere. Find the capacity (volume) of the bowl.
February 2, 2016

Sidney flew in an airplane five times during her vacation.The flights averaged 2 hours 8 minutes long.The lengths of her first four flights were 2 hours 10 minutes,3 hours 20 mins,1 hours 15 minutesand 2hours 40 minutes.What was the length of her last flight
February 1, 2016

Science
What is the centripetal acceleration a satellite is orbiting the Earth at an altitude of 300.22 km?
February 1, 2016

Physics
dont be a dick bob
January 31, 2016

History
d for dick
January 31, 2016

physics
Imagine a parallel universe in which the electric force has the same properties as in our universe but there is no gravity. In this parallel universe, the sun carries charge Q, the earth carries charge −Q, and the electric attraction between them keeps the earth in orbit...
January 31, 2016

physics
An electron is projected with an initial speed of (1.90x10^6 m/s) into the uniform field between two parallel plates. Assume that the field between the plates is uniform and directed vertically downward, and that the field outside the plates is zero. The electron enters the ...
January 31, 2016

Math
Actually, rounding to the nearest whole number is incorrect. For example, 24 4/7 rounds up to 25, not the best number to divide by 4 to get your estimate. What you need to do is to find the nearest number (up or down) that is compatible with 4. So in this case, 24 4/7 would ...
January 23, 2016

Maths
The scale of a map is 1:500. Find the length of a road in real life if it is 6cm long on the map
January 23, 2016

Language arts
based on the text preview as well as research about the background of the novel and the author's life a reader can predict that the novel will most likely be about Deez nuts HA GOT EM
January 20, 2016

Social studies
Hey ms. sue . I went to the link that you put in here but I didn't see what I was looking for? could you pls help me>
January 18, 2016

Math
I need help please. Assume that one dollor is equal to 1.14 euros. If 500 g of an item is selling for 25 euros, what is its price in dollars per kg?
January 14, 2016

Algebra
write equation of given translation of y=|x| 1 unit down 5 units right 10 units left 4 units up 6 units left
January 4, 2016

Math -Algebra
write equation of given translation of y=|x| 1 unit down 5 units 10 units left 4 units up 6 units left
January 4, 2016

MATHS HELP URGENT(TIME AND WORK)
A can do a piece of work in 12 days whereas B can destroy the work in 3 days. A does the work for 10 days and then B destroys the work up to 2 days. In how many days will the work be finished?
January 1, 2016

math
You need 4 more ounces
December 30, 2015

Algebra 2 (Math)
Divide 3x^3 + 3x^2 + 2x – 2 by x + 3 using long division. Check my answer please. 3x^2 – 6x + 20 3x^2 + 12x – 16 3x^2 + 12x – 16, R 58 3x^2 – 6x + 20, R -62 (I think that it's this one)
December 22, 2015

science
D. Firecrackers are converted to thermal energy when they burn.
December 5, 2015

Physics
You jump from a height of 1.0m from the surface of the Earth. The Earth will actually move a bit as you land. a.) Explain Why b.) Estimate the distance the Earth moves, listing any assumptions you make
December 2, 2015

social studies
K thank you
November 30, 2015

social studies
How did Muslim Turks influence turkey's development?
November 30, 2015

Social Studies Check My Work
People can do what they want... who cares if its a quiz in CCA? Btws 3,4,7 are all wrong and if you submit her answers you get a 70% (I learned that by experience xD)
November 25, 2015

Social Studies Check My Work
People can do what they want... who cares if its a quiz in CCA?
November 25, 2015

Chemistry
you have 5% formic acid solution and a 5% acetic acid solution. You titrate 5mL each with .1868M NaOH. A. Which will need more NaOH to reach the end point? B. How much more?
November 24, 2015

math
What is the expected value of the cost of of claims on a males drivers policy? Note: number of drivers is 9634 number of claims is 977 and the average cost per claim is 6108 euro
November 23, 2015

Physics
A small rock with mass m moves at velocity v0 and hits a rod of mass M as shown. The rod is initially at rest. The collision is completely inelastic. a) What is the angular velocity of the rod after the collision? b) What is the maximum angle the rod makes with the vertical?
November 23, 2015

Algebra II
How can you completely factor the following polynomial: 6x^5-51x^3-27x
November 18, 2015

chem
Calculate the equilibrium concentration of NH3,Cu^2+,[ Cu(NH3)]^2+ ,[Cu(NH3)2]^2+,[Cu(NH3)3]^2+,and[Cu(NH3)4]^2+ in a solution made by mixing 500.0 ml of 3.00 M NH3 with 500.0 ml of 2.00*10^-3 M Cu(NO3)2. The sequential equilibria are Cu^2+ +NH3---->[Cu(NH3)]^2+ ka1=1.86x10...
November 17, 2015

chem
Thanks!
November 17, 2015

chem
the following experiment was performed in the laboratory : an excess of solid SrCrO4 is vigorously shaken in water until a saturated solution is obtained. The excess solid is filtrated from the solution and 25.00 ml of the solution is titrated with 0.0115 M fe(no3)2 solution. ...
November 17, 2015

Physics
A block is on the end of a massless cable that is tied to a frictionless wheel (uniform disk) as shown in the figure at right. The wheel has a radius of 0.4 m. The system is initially at rest. If the block moves downward, with a constant acceleration, a distance of 2 m in 3 s...
November 17, 2015

Chemistry
You have a 250ml solution of 0.13M calcium iodate. How many grams of potassium iodate need to be added to the solution to begin to precipitate calcium iodate? The solubility product constant for calcium iodate is6.47 *10^-6. B) you have a 250ml solution of 0.13 M calcium ...
November 14, 2015

physics
How did you get three? .-.
November 12, 2015

physics
Upwards
November 12, 2015

physics
A stone is thrown from a height of 1.8 with a velocity of 29.4. How long does it take to reach its greatest height? I'm sure it has something to do with the s=ut+1/2 at squared not sure though
November 12, 2015

Marie Ernestine
Math/Science A car starts from rest and moves at the speed of 30 kph after half an hour. What is the cars acceleration?
November 11, 2015

science help ASAP
The answer for the first one is correct and the answer for the second one is D.
November 10, 2015

physics
Any ideas? A bird flying at 3m/'s west is given an acceleration of 1ms after five seconds what I'd it's velocity and how far has it travelled from its starting point?
November 5, 2015

physics
Got the answer it's basically 5-2/2.1=1.43s
November 5, 2015

physics
Relating to the first question. How long did it take to do this?
November 5, 2015

physics
Thanks. I understand it now. But we have like set formulas in our tables for incidence like v=u+at etc. I have learnt the changing velocity over time but in a test situation would I have to use the formulas given or the method appove?
November 5, 2015

physics
So basically I got this question and it's baffling. Over a distance of 5m the speed of a bicycle increase's from 2ms to 5ms what I's the magnitude of acceleration?
November 5, 2015

Social Studies
Yeah what is the second answer
November 5, 2015

Math
A boat pilot wishes to go in a straight line across a river from the east dock to the west dock in a ferryboat that has a still water speed 8.0 knots. If the river has a Southward current of 2.5 knots, what compass heading should be maintaned while crossing the river? What is ...
November 3, 2015

kon
can someone edit my essay?
October 24, 2015

history
what event convinced south Carolina to spend representatives to the first continental congress ? A. passage of the currency act B. passage of the intolerable act C. passage of the navigation act D. passage of the stamp act is it D
October 20, 2015

calculus
find the first and second derivatives for 3x^4-4xy^2+7=2y
October 14, 2015

Algebra 1
A drama club wants to raise at least \$500 in ticket sales for its annual show. The members of the club sold 50 tickets at a special rate of \$5. The usual ticket price the day of the show is \$7.50. At least how many tickets do they need to sell the day of the show to meet the ...
October 11, 2015