Total # Posts: 1,157
Suppose that you measured the moment of inertia of the system as I = 5.05 kg-m2. Assume the diameter of the pulley around which you wrap the string is d = 2.5 cm. a) suppose the system is initially spinning at angular speed ωo = 2.05 rad/s. After you drop a cube of mass ...
November 30, 2010
i still did not understand. if u don't mind could you please explain it again and also the question asks for the intervals and the points. could you give the intervals and points for the the questions above in the questions .. Thanks a bunch :).
November 29, 2010
Find: (a) the interval(s) on which f is increasing, (b) the interval(s) on which f is decreasing, (c) the open interval(s) on which f is concave up, (d) the open interval(s) on which f is concave down, and (e) the X-coordinate(s) of any/all inflection point(s). f(x)= (x^4) - (...
November 29, 2010
A cone of radius r centimeters and height h centimeters is lowered point first in at a rate of 1 cm/s into a tall cylinder of radius R centimeters that is partially filled with water. How fast is the water level rising at instant the cone is completely submerged?
November 19, 2010
A mass sitting on a horizontal, frictionless surface is attached to one end of a spring; the other end is fixed to a wall. 1.0 J of work is required to compress the spring by 0.12 m. If the mass is released from rest with the spring compressed, it experiences a maximum ...
November 15, 2010
physics please help
The femur is a bone in the leg whose minimum cross-sectional area is about 3.60 10-4 m2. A compressional force in excess of 6.90 104 N will fracture this bone. (a) Find the maximum stress that this bone can withstand. (b) What is the strain that exists under a maximum-stress ...
November 14, 2010
physics please help me
A 5.00 kg ball (ball 1), moving to the right at a velocity of +4.00 m/s on a frictionless table, collides head-on with a stationary 7.60 kg ball (ball 2). Find the final velocities of the balls if the collision is as specified below. (a) elastic collision ball 1 = -.825 ball 2...
November 7, 2010
physics please help me
The pole vault landing pad at an Olympic competition contains what is essentially a bag of air that compresses from its "resting" height of 1.1 m down to 0.1 m as the vaulter is slowed to a stop. (a) What is the time interval during which a vaulter who has just ...
November 5, 2010
P(x)= -x^3+15x^2-48x+450, x>/3 is an approximation to the total profit (in thousands of dollars) from the sale of x hundred thousand tires. find the number of hundred thousands of tires that must be sold to maximize profit.
November 4, 2010
Math please help!
x=speed of boat in still water. assuming the problem implies 26 miles each way. to figure this out, I wrote this out in simple miles per hour terms. Example: (hours/mile)*miles + (hours/mile)*miles = hours so: (1/(x+5))*26+(1/(x-5))*26=10.6 x+5 represents the speed of the boat...
November 3, 2010
so im done with everything except fro this question : A(n) 2.3 kg object moving with a speed of 8.6 m/s collides with a(n) 4 kg object moving with a velocity of 8.8 m/s in a direction39.0135◦ from the initial direction of motion mof the 2.3 kg object.What is the speed of...
October 27, 2010
Determine the mass of zinc sulphide,ZnS which is produced when 6.2 g of zinc and 4.5 g of sulphur are reacted. This question is really confusing me, and I'm not sure where to start. I think I have to calculate the moles of each given reactant first in which case I have: ...
October 17, 2010
I'm not understanding. what do you mean figure the moles of H2O2 in 3.4 g of water? You get the same number of moles of water? I calculated: nH2O2 = 3.4g/34.02g/mol= 0.0999412 mol Water on the other hand has 18.02 mol sorry but I'm not understanding. I think for this ...
October 17, 2010
Suppose you put 50mL of water in the can instead of 100mL and heated it to 40 degrees instead of 20 degrees. In what ways, if any, would this afect the results of the experiment? What would happen if you used 200mL of water and heated it only 10 degrees? Can you think of any ...
October 6, 2010
A car starts from rest on a curve with a radius of 150 m and accelerates at 1.50 m/s^2. How many revolutions will the car have gone through when the magnitude of its total acceleration is 3.20 m/s^2 ?
October 4, 2010
How many liters of carbon dioxide at 20 oC and 750 torr are produced when one gallon of toluene is burned? Convert liters to milliliters and then to grams. can you convert mil to grams?
October 3, 2010
1 gallon toluene = about 3,785 mL density = about 0.867 g/mL mass toluene = 3785 mL x 0.867 g/mL = 3282 grams. C7H8 + 9O2 ==> 7CO2 + 4H2O moles toluene = grams/molar mass = 3282/92 = about 36 moles. From the equation above, 1 mole C7H8 will produce 7 moles CO2; therefore, ...
October 3, 2010
f = ma μk * f(normal) = m*a μk *m*g = m*a μk *g =a so a = μk*g this is defined to be a negative acceleration since the friction force works in the opposite direction to the movement of the puck vFinal = v0 + at so t = (vF-v0)/a d = t*(vF+v0)/2 so d = (vF+v0...
September 29, 2010
If you have an insulated glass of water at 25 oC containing 10 fluid oz at 25 oC, how much ice would you have to add to end up with a final temperature of 0 oC and no ice left?
September 6, 2010
.In the early 1900s, two associates of New Zealander Ernest Rutherford bombarded thin sheets of gold with positively charged subatomic particles. They found that most of the particles passed right through the sheets but some bounced back as if they had hit something solid. ...
September 3, 2010
You are offered two different sales jobs. The first company offers a straight commission of 4% of the sales. The second company offers a salary of $ 500 per week plus 2% of the sales. How much would you have to sell in a week in order for the straight commission to be equal to...
August 30, 2010
HOW DO I find the net icome for this company with this information? Beginning of the year: ASSETS WERE $810,000 lIABILTES WERE:$324,000 eND OF YEAR: aSSETS WERE: $1,296,000 AND lIABILTES WERE:$540,000. cAPITAL STOCK OF $162,000 WAS ISSUSED dIVIDENDS OF $72,OOO WERE PAID
August 29, 2010
How do I find the net income for this company ,with this information? Beginning of year Total Assets were:$810,000 Total liabilites were:$324,000 End of year Total Assets were:$1,296,000 Total liabiltes were:$540,00 Capital stock of $162,000 was issued dividends of $72,000were...
August 27, 2010
I'm stuck on this one: factoring polynomials from algebraic expressions (and it says you can use the substitution method): 3m^2(2p^2+3)over (x^2+y)(2x-y^2) minus 6m(2p^2+3)over (y^2-x)(2x-y^2)= Do I find the GCF? I get 3m(m-2) over (x^2+y)(2x-y)(y^2-x) ????
August 15, 2010
I'm stuck on this one problem. The directions say: Solve the following leaving the sq. rt. in it's simplest form: sq.rt of 33+ sq.rt of 96 - sq.rt of 3 = I think it can't be simplifed---am I correct? (the directions did say that some of the problems can't be ...
August 14, 2010
It took a stopping train 41/4min to travel between two stations 11.2km apart.The train accelerated uniformly during the first 11/4min of the journey,and decelerated uniformly to rest during the last 3/2min of the journey.The train had moved with uniform speed during the ...
July 11, 2010
A flywheel rotating at 5.3 revolutions per second has an angular retardation of 4/5 radian per second per minute.calculate:(i)its angular velocity after 45 seconds(ii),the number of revolutions it makes in 1 minute, and in coming to rest.
July 10, 2010
You're thinking of investing in a automation project to reduce cost of production. -Investment in Fixed Assets: $900,000 at t=0; salvage value of $300,000 at t=6; straight line deprectiation over 6 years (assume book value is 0 at t=6) -Investement in NWC: $250,000 at t=0...
June 19, 2010
algebra-is this right
A basketball player has a vertical leap of about 36 in. If the equation d=48t^2 describes his hang time t as a function of his vertical leap d. what is his hang time? Show your work. 36=48t^2 t^2=3/4 t=(1/2)sqrt(3)seconds
April 25, 2010
When Professor Sum was asked by Mr. Little how many students were in his classes, he answered, All of them study either languages, physics, or not at all. One-half of them study languages only, one-fourth of them study French, one-seventh of them study physics only, and ...
April 15, 2010
Question from the Classroom: 10 A student claims that the equation Ö(-x) = 3 has no solution, since the square root of a negative number does not exist. Why is this argument wrong?
April 13, 2010
math 213 #18
A student claims that every prime greater than 3 is a term in the arithmetic sequence whose nth term is 6n + 1 or in the arithmetic sequence whose nth term is 6n 1. Is this true? If so why?
April 13, 2010
Suppose you have a friend named Ed. He and his four friends are having ice cream. There are only three flavors available at the ice cream store they are visiting: chocolate, vanilla, and strawberry. One of Eds friends, Stacey, eats chocolate exclusively. How many ...
March 30, 2010
According to Sal's map he is is 6 units away from the grocery. The grocery store is 5 units away from the coffee shop. The coffee shop is 1 unit away from Sal's house. How is this possible?
March 16, 2010
Midsummer Night's Dream: The fourth act opens with Bottom at center stage. What is your opinion of Bottom's character? How might he be the antithesis, or opposite of Theseus's character?
February 15, 2010
An element has bcc packing with a body-centered cubic unit cell. Its density is 19300 kg/m3 and the unit cell volume is 3.17 x 10-26 L. Calculate the molar mass (g/mol) of the element to three significant figures. The element rubidium has bcc packing with a body-centered cubic...
February 8, 2010