Monday
September 15, 2014

Posts by COFFEE


Total # Posts: 127

Surface Area
[Given] Fiber Linear Density = 1 denier = 1 g/9000m Fiber Density = 1.14 g/cm^3 [Find..] Fiber surface area in cm^2/g Assume that the fiber strand is a uniform cylinder [Answer] Surface area = 3,150 cm^2/g ....... how do i get to the answer? my professor gives us these notes: ...
September 14, 2007

calculus - power series ASAP please :)
using power series, integrate & evaluate to 4 dec. places integral from 0 to 1: sin x^2 dx i'm REALLY stuck on this. and i need help asap.. what is the inverse of "sin x^2" so that i could have it in a fraction that will fit the power series equation? and that is...
July 31, 2007

calculus - interval of convergence
infinity of the summation n=0: ((n+2)/(10^n))*((x-5)^n) .. my work so far. i used the ratio test = lim (n-->infinity) | [((n+3)/(10^(n+1)))*((x-5)^(n+1))] / [((n+2)/(10^n))*((x-5)^n)] | .. now my question is: was it ok for me to add "+1" to "n+2" to ...
July 30, 2007

calculus - ratio test
infinity of the summation n=1: (e^n)/(n!) [using the ratio test] my work so far: = lim (n->infinity) | [(e^n+1)/((n+1)!)] / [(e^n)/(n!)] | = lim (n->infinity) | [(e^n+1)/((n+1)!)] * [(n!)/(e^n)] | = lim (n->infinity) | ((e^n)(e^1)(n!)) / ((n+1)(n!)(e^n)) | ..the e^n...
July 30, 2007

calculus - derivatives
can you please find the first 5 derivatives for: f(x) = (0.5e^x)-(0.5e^-x) f'(x) = ? f''(x) = ? f'''(x) = ? f''''(x) = ? f'''''(x) = ? thanks :) f(x) = (0.5e^x)-(0.5e^-x) f'(x) = 0.5 e^x + 0.5 e^-x f''(x...
July 30, 2007

calculus - interval of convergence
infinity of the summation n=0: ((n+2)/(10^n))*((x-5)^n) .. my work so far. i used the ratio test = lim (n-->infinity) | [((n+3)/(10^(n+1)))*((x-5)^(n+1))] / [((n+2)/(10^n))*((x-5)^n)] | .. now my question is: was it ok for me to add "+1" to "n+2" to ...
July 29, 2007

calculus - ratio test
Posted by COFFEE on Sunday, July 29, 2007 at 6:32pm. infinity of the summation n=1: (e^n)/(n!) [using the ratio test] my work so far: = lim (n->infinity) | [(e^n+1)/((n+1)!)] / [(e^n)/(n!)] | = lim (n->infinity) | [(e^n+1)/((n+1)!)] * [(n!)/(e^n)] | = lim (n->infinity...
July 29, 2007

Calculus - ratio test
infinity of the summation n=1: (e^n)/(n!) [using the ratio test] my work so far: = lim (n->infinity) | [(e^n+1)/((n+1)!)] / [(e^n)/(n!)] | = lim (n->infinity) | [(e^n+1)/((n+1)!)] * [(n!)/(e^n)] | = lim (n->infinity) | ((e^n)(e^1)(n!)) / ((n+1)(n!)(e^n)) | ..the e^n...
July 29, 2007

Calculus - Taylor #2
Find the Taylor series for f(x) centered at the given value of 'a'. (Assume that 'f' has a power series expansion. Do not show that Rn(x)-->0.) f(x) = x3, a = -1 and what i've done so far: f (x) = x^3 f ' (x) = 3x^2 f '' (x) = 6x^1 f '&#...
July 28, 2007

Calculus - Taylor
could you please help me with solving this problem? #1) Find the Taylor polynomial Tn(x) for the function 'f' at the number 'a'. f(x) = sqrt(3+x^2) ; a=1; n=2; my work so far: f (x) = sqrt(3+x^2) = (3+x^2)^(1/2) f ' (x) = (1/2)(3+x^2)^(-1/2) f '' (x...
July 28, 2007

Calculus - series
I'm getting this answer wrong, can someone please help show me what i'm missing?? thank you :) Infinity of the summation n=0: [(-1)^n pi^(2n)] / [6^(2n) (2n)!] this is my work: [(-1^0) pi^(2*0)] / [6^(2*0) (2*0)!] + [(-1^1) pi^(2*1)] / [6^(2*1) (2*1)!] + [(-1^2) pi^(2*...
July 28, 2007

Math
i'm a bit stuck with this.. 145/18 = x + x^2 what does x equal to? multiply each term by 18, then re-arrange to get 18x^2 + 18x - 145 = 0 This quadratic does not factor, so use the quadratic formula to get your two answers.
July 27, 2007

Math/Physics
Please check my work below and comment. A tank initially contains 80 gallons of fresh water. A 10% acid solution flows into the tank at the rate of 3 gallons per minute. The well-stirred mixture flows out of the tank at the rate of 3 gallons per minute. Find the amount of acid...
July 13, 2007

Math/Physics
I am given a damping constant of 20 dyne*sec/meter...do I need to convert this if the rest of my givens are, for mass = 2kg, k (spring constant) = 82 N/m. I am trying to find the equation of motion of a spring but cannot solve it until I know how to convert/if I need to ...
July 13, 2007

Math/Calculus
Please check my work and correct any errors/point out any errors. Thanks. Solve the initial-value problem using the method of undetermined coefficients. y''-4y=e^xcos(x), y(0)=1, y'(0)=2 r^2-4=0, r1=2, r2=-2 yc(x)=c1*e^2x+c2*e^-2x yp(x)=e^x[Acos(x)+Bsin(x)] y'p...
July 12, 2007

Math/Calculus
A series circuit contains a resistor with R = 24 ohms, an inductor with L = 2 H, a capacitor with C = 0.005 F, and a generator producing a voltage of E(t) = 12 sin(10t). The initial charge is Q = 0.001 C and the initial current is 0. (a) Find the charge at time t. 2Q"+24Q...
July 12, 2007

Math/Calculus
Solve the initial-value problem. Am I using the wrong value for beta here, 2sqrt(2) or am I making a mistake somewhere else? Thanks. y''+4y'+6y=0, y(0)=2, y'(0)=4 r^2+4r+6=0, r=(-4 +/- sqrt(16-4(1)(6))/2 r=-2 +/- sqrt(2)*i , alpha = -2, beta = 2(sqrt(2)) y=e^-...
July 12, 2007

Math/Calculus
Please take a look at my work below and provide a good critique: Solve the differential equation using the method of undetermined coefficients or variation of parameters. y'' - 3y' + 2y = sin(x) yc(x)= c1*e^2x+c2*e^x y"-3y'+2y=sin(x) r^2-3r+2=0 (r-1)(r-2)=...
July 11, 2007

Math/Calculus
A spring with a 4 kg mass has natural length 1 m and is maintained stretched to a length of 1.3 m by a force of 24.3 N. If the spring is compressed to a length of 0.8 m and then released with zero velocity, find the position of the mass at any time t. Here is my work so far: ...
July 11, 2007

Math
A series circuit contains a resistor with R = 24 , an inductor with L = 2 H, a capacitor with C = 0.005 F, and a generator producing a voltage of E(t) = 12 sin(10t). The initial charge is Q = 0.001 C and the initial current is 0. Find the charge at time t...
July 10, 2007

Calculus
Please look at my work below: Solve the initial-value problem. y'' + 4y' + 6y = 0 , y(0) = 2 , y'(0) = 4 r^2+4r+6=0, r=(16 +/- Sqrt(4^2-4(1)(6)))/2(1) r=(16 +/- Sqrt(-8)) r=8 +/- Sqrt(2)*i, alpha=8, Beta=Sqrt(2) y(0)=2, e^(8*0)*(c1*cos(0)+c2*sin(0))=c2=2 y'...
July 10, 2007

Calculus - Second Order Differential Equations
Solve the initial-value problem. y'' - 2y' + y = 0 , y(2) = 0 , y'(2) = 1 r^2-2r+1=0, r1=r2=1 y(x)=c1*e^x+c2*x*e^x y(2)=c1*e^2+c2*2*e^2=0 c1=-(2*c2*exp(2))/exp(2) c1=-2*c2 y'(x)=-2*c2*e^x+c2*e^x*(x-1) y'(2)=-2*c2*e^2+c2*e^2*(2-1)=1 c2(-2e^2+e^2)=1 c2=1...
July 10, 2007

Calculus - Second Order Differential Equations
Posted by COFFEE on Monday, July 9, 2007 at 9:10pm. download mp3 free instrumental remix Solve the initial-value problem. y'' + 4y' + 6y = 0 , y(0) = 2 , y'(0) = 4 r^2+4r+6=0, r=(16 +/- Sqrt(4^2-4(1)(6)))/2(1) r=(16 +/- Sqrt(-8)) r=8 +/- Sqrt(2)*i, alpha=8, ...
July 10, 2007

Calculus - Second Order Differential Equations
Solve the initial-value problem. y'' + 4y' + 6y = 0 , y(0) = 2 , y'(0) = 4 r^2+4r+6=0, r=(16 +/- Sqrt(4^2-4(1)(6)))/2(1) r=(16 +/- Sqrt(-8)) r=8 +/- Sqrt(2)*i, alpha=8, Beta=Sqrt(2) y(0)=2, e^(8*0)*(c1*cos(0)+c2*sin(0))=c2=2 y'(0)=4, c2=4 y(x)=e^(8x)*(2*cos...
July 9, 2007

Calculus - Second Order Differential Equations
Solve the boundary-value problem. y''+5y'-6y=0, y(0)=0, y(2)=1 r^2+5r-6=0, r1=1, r2=-6 y=c1*e^x + c2*e^-6x y(x)=c1*e^x+c2*e^-6x y'(x)=c1*e^x-6*c2*e^-6x y(0)=c1+c2=0, c1=-c2 y(2)=c1*e^2+c2*e^(-12)=1 -c2*e^2-6c2*e^(-12)=1 -c2(e^2-6*e^-12)=1 c2=-1/(e^2-6e^-12) c1=...
July 9, 2007

calc check please?
Given the differential equation: dy/dx = y(1+x), y(0)=1, Use Euler's method with step size .1 to approximate y(.3). ... please check this for me! no one has responded to this question yet.. thanks. y' = y(1+x), y'(0) = 1(1+0)=1 ->the solution has slope 1 at the ...
July 2, 2007

calc: avg value
Find the average value of the function "f(x) = x^2 sqrt(1+x^3)" on the interval [0,2]. and this is what i did.. please check for mistakes. thanks :D f(x) = x^2 sqrt(1+x^3), [0,2] f ave = (1/(b-a))*inegral of a to b for: f(x) dx f ave = (1/(2-0))*integral of 0 to 2 ...
July 2, 2007

calc check: curve length
Find the length of the curve y=(1/(x^2)) from ( 1, 1 ) to ( 2, 1/4 ) [set up the problem only, don't integrate/evaluate] this is what i did.. let me know asap if i did it right.. y = (1/(x^2)) dy/dx = (-2/(x^3)) L = integral from a to b for: sqrt(1+(dy/dx)^2)dx L = ...
July 2, 2007

calc check: euler's method
Given the differential equation: dy/dx = y(1+x), y(0)=1, Use Euler's method with step size .1 to approximate y(.3). y' = y(1+x), y'(0) = 1(1+0)=1 ->the solution has slope 1 at the point (0,1); x0=0, y0=1, h=0.1, F(x,y)=y(1+x) y1=y0+h*F(x0,y0) y1=1 + 0.1(1(1+0)) ...
July 1, 2007

calc check: average value
Find the average value of the function "f(x) = x^2 sqrt(1+x^3)" on the interval [0,2]. and this is what i did.. please check for mistakes. thanks :D f(x) = x^2 sqrt(1+x^3), [0,2] f ave = (1/(b-a))*inegral of a to b for: f(x) dx f ave = (1/(2-0))*integral of 0 to 2 ...
June 30, 2007

calc check: hooke's law
A force of 27N is required to maintain a spring stretched from its natural length of 12cm to a length of 15cm. How much work is done in stretching the spring from 15 to 25cm? and this is what i did.. please check to see if i did it correctly.. thanks :) f=27N 12cm to 15cm f(x...
June 29, 2007

calculus
Given the differential equation: dy/dx = y(1+x), y(0)=1, Use Euler's method with step size .1 to approximate y(.3). y' = y(1+x), y'(0) = 1(1+0)=1 ->the solution has slope 1 at the point (0,1); x0=0, y0=1, h=0.1, F(x,y)=y(1+x) y1=y0+h*F(x0,y0) y1=1 + 0.1(1(1+0)) ...
June 29, 2007

Calculus - Hydrostatic Pressure
Please check my work: Find the hydrostatic pressure on one end of a water trough full of water, the end of which is a trapezoid with given dimensions: top of trapezoid = 20 feet, sides of trapezoid both = 8 feet, bottom of trapezoid = 12 feet. Depth of water = 8 feet Density ...
June 26, 2007

Calculus - Seperable Equations
Solve the separable differential equation (dy/dx)=y(1+x) for y and find the exact value for y(.3). dy/dx = y(1+x) dy/y = (1+x)dx Integral (dy/y) = Integral (1+x)dx ln (y) = x + (1/2)x^2 + C y = e^(x + (1/2)x^2 + C) y(0.3) = e^(0.345 + C) I am stuck here. How do I solve for C ...
June 26, 2007

Calculus
Given the differential equation: dy/dx = y(1+x), y(0)=1, Use Euler's method with step size .1 to approximate y(.3). y' = y(1+x), y'(0) = 1(1+0)=1 ->the solution has slope 1 at the point (0,1); x0=0, y0=1, h=0.1, F(x,y)=y(1+x) y1=y0+h*F(x0,y0) y1=1 + 0.1(1(1+0)) ...
June 26, 2007

Calculus - Orthogonal Trajectories
Find the orthogonal trajectories of the family of curves: y = k*(e^-x) --------------- so k = y/(e^-x) differentiating we get: 1 = -k(e^-x)*(dx/dy) 1/(dx/dy) = -k(e^-x) dy/dx = -k(e^-x)...substituting for k: dy/dx = -(y/(e^-x))*(e^-x) dy/dx = -y Integral(1/=y)dy = Integral dx...
June 26, 2007

Calculus - Center of Mass
Find the exact coordinates of the centroid given the curves: y = 1/x, y = 0, x = 1, x = 2. X = 1/Area*Integral from a to b: x*f(x)dx Y = 1/Area*Integral from a to b: [(1/2)*(f(x))^2]dx How do I find the area for this? Once I know that, is this the correct set up? X = 1/Area*...
June 26, 2007

Calculus
Solve the differential equation. Let C represent an arbitrary constant. (Note: In this case, your answer willto have a negative sign in front of the arbitrary C.) (dz)/(dt) + e^(t+z) = 0 --------------- (dz/dt) + (e^t)(e^z) = 0 (dz/dt) = -(e^t)(e^z) dz = -(e^t)(e^z)dt (dz/e^z...
June 24, 2007

Calculus
The tank shown is full of water. Given that water weighs 62.5 lb/ft3, find the work required to pump the water out of the tank. The tank shown is a hemisphere with r = 5 ft. The water is to be pumped out at the top. First I solved for ri, ri / (5 - xi) = 5 / 5 ri = 5 - xi Vi...
June 23, 2007

Calculus
The tank shown is full of water. Given that water weighs 62.5 lb/ft3, find the work required to pump the water out of the tank. The tank shown is a hemisphere with r = 5 ft. The water is to be pumped out at the top. First I solved for ri, ri / (5 - xi) = 5 / 5 ri = 5 - xi Vi...
June 22, 2007

Calculus
Use Euler's method with step size 0.2 to estimate y(1.4), where y(x) is the solution of the initial-value problem below. Give your answer correct to 4 decimal places. y' = x - xy y(1) = 0 h = 0.2 Since I am at y(1) = 0 and not y(0) = 0 would I just do this twice? As in...
June 22, 2007

Calculus
Find the exact coordinates of the centroid. y = sqrt[x], y = 0, x = 9. -------------- Is this basically 1/4 of an oval/ellipse? If so then the area would be: pi*9*3, correct? So the X coordinate would equal: 1/Area * Integral from 0 to 9 of (x*f(x))*dx Which equals: (4/(27*pi...
June 22, 2007

Calc: euler's method
Use Euler's method with step size 0.2 to estimate y(1), where y(x) is the solution of the initial-value problem below. Give your answer correct to 4 decimal places. y' = 1 - xy y(0) = 0 y(1) = ____ ? ... help, this is what i've done but got the wrong answer.. h = 0...
June 20, 2007

Calculus
Find the exact coordinates of the centroid. y = sqrt[x], y = 0, x = 9. -------------- Is this basically 1/4 of an oval/ellipse? If so then the area would be: pi*9*3, correct? So the X coordinate would equal: 1/Area * Integral from 0 to 9 of (x*f(x))*dx Which equals: (4/(27*pi...
June 18, 2007

Calculus
The hemispherical tank shown is full of water. Given that water weighs 62.5 lb/ft3, find the work required to pump the water out of the tank. ---------- What is shown is just the tank (a hemisphere) with a radius of 5 ft. ---------- First I calculated the Volume of the ...
June 18, 2007

Calculus
Find the exact coordinates of the centroid. y = sqrt[x], y = 0, x = 9. -------------- Is this basically 1/4 of an oval/ellipse? If so then the area would be: pi*9*3, correct? So the X coordinate would equal: 1/Area * Integral from 0 to 9 of (x*f(x))*dx Which equals: (4/(27*pi...
June 17, 2007

Calculus
The hemispherical tank shown is full of water. Given that water weighs 62.5 lb/ft3, find the work required to pump the water out of the tank. ---------- What is shown is just the tank (a hemisphere) with a radius of 5 ft. ---------- First I calculated the Volume of the ...
June 17, 2007

Calculus
A steady wind blows a kite due west. The kite's height above ground from horizontal position x = 0 to x = 80 ft is given by the following. y = 150 - (1/40)(x-50)^2 Find the distance traveled by the kite. y = 150 - (1/40)(x-50)^2 y = 150 - (1/40)(x-50)(x-50) y = 150 - (1/...
June 15, 2007

Calculus
A steady wind blows a kite due west. The kite's height above ground from horizontal position x = 0 to x = 80 ft is given by the following. y = 150 - (1/40)(x-50)^2 Find the distance traveled by the kite. y = 150 - (1/40)(x-50)^2 y = 150 - (1/40)(x-50)(x-50) y = 150 - (1/40...
June 13, 2007

Calculus
A steady wind blows a kite due west. The kite's height above ground from horizontal position x = 0 to x = 80 ft is given by the following. y = 150 - (1/40)(x-50)^2 Find the distance traveled by the kite. y = 150 - (1/40)(x-50)^2 y = 150 - (1/40)(x-50)(x-50) y = 150 - (1/40...
June 13, 2007

Calculus
Graph the curve and find its exact length. x = e^t + e^-t, y = 5 - 2t, from 0 to 3 Length = Integral from 0 to 3 of: Sqrt[(dx/dt)^2 + (dy/dt)^2] dx/dt = e^t - e^-t, correct? dy/dt = -t^2 - 5t, correct? So: Integral from 0 to 3 of Sqrt[(e^t - e^-t)^2 + (-t^2 - 5t)^2] Then what ...
June 13, 2007

calc: simpson's rule & arc length
i'm still getting this question wrong. please check for my errors: Use Simpson's Rule with n = 10 to estimate the arc length of the curve. y = tan x, 0 <or= x <or= pi/4 .. this is what i did: y' = sec(x)^2 (y')^2 = [sec(x)^2]^2 [f'(x)]^2 = sec(x)^4 ...
June 13, 2007

calc: arc length
Posted by COFFEE on Monday, June 11, 2007 at 11:48pm. find the exact length of this curve: y = ( x^3/6 ) + ( 1/2x ) 1/2 <or= x <or= 1 im looking over my notes, but i'm getting stuck. here's my work so far: A ( 1 , 2/3 ) B ( 1/2 , 49/48 ) y' = [1/6 (3x^2)] + [...
June 12, 2007

calc: arc length
find the exact length of this curve: y = ( x^3/6 ) + ( 1/2x ) 1/2 <or= x <or= 1 im looking over my notes, but i'm getting stuck. here's my work so far: A ( 1 , 2/3 ) B ( 1/2 , 49/48 ) y' = [1/6 (3x^2)] + [1/2 (-1x^-2)] y' = ( x^2 / 2 ) - ( x^-2 / 2 ) (y&#...
June 11, 2007

Math/Euler's Method
Consider a cooling cup of coffee whose initial temperature is 205°. The room temperature is held at 70°. Suppose k = 1/16. Let y be the temperature, and y' its time derivative. ----------------------------------- I have the differential equation: y' = (-1/16)(y...
June 7, 2007

Math/Calculus
How would I integrate the following: (2x^2 + 5)/((x^2+1)(x^2+4))dx I think I would start with making it a sum of two partial fractions.
May 29, 2007

Math/Calculus
How would I integrate the following by parts: Integral of: (x^2)(sin (ax))dx, where a is any constant. Just like you did x^2 exp(x) below. Also partial integration is not the easiest way to do this integral. You can also use this method. Evaluate first: integral of sin(ax)dx...
May 28, 2007

Math/Calculus
How would I evaluate the following integral by using integration by parts? Integral of: (t^3)(e^x)? You mean (x^3)(e^x)? x^3 exp(x) dx = x^3 d[exp(x)] = d[x^3 exp(x)] - exp(x) d[x^3] = d[x^3 exp(x)] - 3 x^2 exp(x) dx So, if you integrate this you get x^3 exp(x) - 3 Integral of...
May 28, 2007

Math/Calculus
How would I solve the following integral with the substitution rule? Integral of: [(x^3)*(1-x^4)^5]dx Put 1-x^4 = y Then -4x^3 dx = dy Integral is then becomes: Integral of -1/4 y^5 dy ok, thanks a lot! I got it now.
May 28, 2007

Math/Calculus #2
Integrate: 1/(x-sqrt(x+2) dx I came up with: (2/3)(2*ln((sqrt(x+2))-2)+ln((sqrt(x+2))-1)) but it keeps coming back the wrong answer even though I integrated correctly. Is there a way to simplify this answer, and if so, how? I found: Ln[x-sqrt(x+2)] + 1/3Ln[(sqrt(x+2)-2)/(sqrt(...
May 27, 2007

Math/Calculus
Integrate: (2x^2+5)/((x^2+1)(x^2+4)) I came up with: (tan^-1)(x)-(1/2)((tan^-1)(2/x)) but it keeps coming back the wrong answer even though I integrated correctly. Is there a way to simplify this answer, and if so, how? Your answer is correct, but I think you are supposed to ...
May 27, 2007

physics - doppler effect
Two identical tuning forks can oscillate at 329.6 Hz. A person is located somewhere on the line between them. The speed of sound in the air is 343 m/s. Calculate the beat frequency as measured by this individual under the following conditions. (a) the listener is standing ...
April 21, 2007

physics - sound level
For two sounds whose sound levels differ by 69 dB, find the ratios (greater value / smaller value) of the following values. (a) the intensities Intensity Final/Intensity Initial = log^-1 (69 / 10) = 7.9x10^6 (b) the pressure amplitudes (c) the particle displacement amplitudes ...
April 21, 2007

physics - sound level
The source of a sound wave has a power of 2.50 µW. Assume it is a point source. (a) What is the intensity 6.70 m away? I used I = Power / 4*pi*r^2 and found I to be 4.43x10^-9 W/m^2 (b) What is the sound level at that distance? Sound level = 10 dB*log [(Intensity)/(...
April 21, 2007

physics - waves
Two sinusoidal waves, identical except for phase, travel in the same direction along a string producing a net wave y'(x, t) = (1.5 mm) sin(29x - 4.0t + 0.960 rad), with x in meters and t in seconds. (a) What is the wavelength of the two waves? I found the wavelength to be ...
April 15, 2007

physics - SHM
Calculate the speed of the pulse from the following: y(x,t) = 2/((x - 3t)^2 + 1) Well the speed of the pulse is given by: y(x,t) = f (x - vt) for a pulse traveling to the right and y(x,t) = f (x + vt) for a pulse traveling to the left but in this case the function is (x - 3t)^...
April 14, 2007

physics - SHM
Two sinusoidal waves with identical wavelengths and amplitudes travel in opposite directions along a string with a speed of 11 cm/s. If the time interval between instants when the string is flat is 0.33 s, what is the wavelength of the waves? wavelength = (wave speed) / (...
April 14, 2007

physics
The angle of the pendulum is given by θ = θmcos(ωt + φ), where ω = 3.24 rad/s. If at t = 0, θ = 1 rad and dθ/dt = -0.9 rad/s, what are φ and θm? So if I substitute in omega and t=0 I have θ = θmcos(φ). How do I solve ...
April 12, 2007

Physics check
A performer, seated on a trapeze, is swinging back and forth with a period of 9.55 s. If she stands up, thus raising the center of mass of the trapeze + performer system by 20.0 cm, what will be the new period of the system? Treat trapeze + performer as a simple pendulum. (a) ...
April 12, 2007

Physics - Pendulums
A uniform circular disk whose radius R is 32.0 cm is suspended as a physical pendulum from a point on its rim. (a) What is its period of oscillation? __ s (b) At what radial distance r < R is there a point of suspension that gives the same period? __ cm in the book.. it ...
April 12, 2007

Physics - SHM
An oscillating block-spring system has a mechanical energy of 1.00 J, an amplitude of 11.2 cm, and a maximum speed of 1.08 m/s. (a) Find the spring constant. ___ N/m (b) Find the mass of the block. ___ kg (c) Find the frequency of oscillation. ___ Hz .. im having difficulty ...
April 12, 2007

Physics - angular acceleration
An object rotates about a fixed axis, and th angular position of a reference line on the object is given by THETA(t)=0.4e^2t, where THETA is in radians, and t is in seconds. [a.] what is the object's angular acceleration at t = 2 s? ..this is my work so far THETA(t) = 0.4e...
April 8, 2007

Physics - Conservation of Angular Momentum
a man is standing on the center of a platform that is rotating without friction. his arms are outstretched holding a brick in each hand. the rotational inertia of the system consists of the man, bricks, and platform about the central vertical axis of the platform. by moving ...
April 8, 2007

Physics - Angular Momentum
When the angular momentum changes, the 'change' in the angular momentum vector (ie. dL) is ____. [a.] perpendicular to the torque vector. [b.] parallel to the angular momentum vector. [c.] parallel to the torque vector. .. im confused on this one.. i think it's [A...
April 8, 2007

Physics Phase Constant
Figure A [[which i tried to recreate below]] is a partial graph of the position function x(t) for a simple harmonic oscillator with an angular frequency of 1.1 rad/s. [a] ............x(cm).............. .................5...
April 4, 2007

Physics Phase Constant
..im really stuck on this. can someone please explain? ------- Figure A [[which i tried to recreate below]] is a partial graph of the position function x(t) for a simple harmonic oscillator with an angular frequency of 1.1 rad/s. [a].....x(cm)....... ........5...
April 4, 2007

Physics SHM
An automobile can be considered to be mounted on four identical springs as far as vertical oscillations are concerned. The springs of a certain car are adjusted so that the oscillations have a frequency of 4 Hz. (a) What is the spring constant of each spring if the mass of the...
April 4, 2007

Physics - Torque
A particle is acted on by two torques about the origin: T1 has a magnitude of 4.3 N*m and is directed in the positive direction of the x axis, and T2 has a magnitude of 3.2 N*m and is directed in the negative direction of the y axis. What are the magnitude [in N*m] and ...
March 31, 2007

Physics - Torque
A particle is acted on by two torques about the origin: T1 has a magnitude of 4.3 N*m and is directed in the positive direction of the x axis, and T2 has a magnitude of 3.2 N*m and is directed in the negative direction of the y axis. What are the magnitude [in N*m] and ...
March 31, 2007

Re: Physics
Posted by COFFEE on Friday, March 30, 2007 at 4:25am. A 1.1 kg particle-like object moves in a plane with velocity components Vx = 30 m/s and Vy = 90 m/s as it passes through the point with (x, y) coordinates of (3.0, -4.0) m. (a) What is its angular momentum relative to the ...
March 31, 2007

Re: Physics (check)
Posted by COFFEE on Friday, March 30, 2007 at 4:16am. A sanding disk with rotational inertia 1.1 x 10^-3 kg*m^2 is attached to an electric drill whose motor delivers a torque of 6 Nm about the central axis of the disk. What are the following values about the central axis at ...
March 31, 2007

Physics
A 1.1 kg particle-like object moves in a plane with velocity components Vx = 30 m/s and Vy = 90 m/s as it passes through the point with (x, y) coordinates of (3.0, -4.0) m. (a) What is its angular momentum relative to the origin at this moment? _____ kg*m^2/s k (b) What is its...
March 30, 2007

Physics
A sanding disk with rotational inertia 1.1 x 10^-3 kg*m^2 is attached to an electric drill whose motor delivers a torque of 6 Nm about the central axis of the disk. What are the following values about the central axis at the instant the torque has been applied for 185 ...
March 30, 2007

Physics - KE
In Figure 11-32 (which shows a ball at the top of an incline, at the bottom of the incline a loop begins with radius R and Q a point on the loop lined up with the center of the loop), a solid brass ball of mass m and radius r will roll without slipping along the loop-the-loop...
March 27, 2007

Physics - KE
In Figure 11-32 (which shows a ball at the top of an incline, at the bottom of the incline a loop begins with radius R and Q a point on the loop lined up with the center of the loop), a solid brass ball of mass m and radius r will roll without slipping along the loop-the-loop...
March 27, 2007

Physics - KE/inertia
The rigid body shown in Figure 10-66 (it is a triangle with the upper mass = to M and the bottom two corners/masses equal to 2M. The bottom side length equals .70 cm with point P in the middle of the side and the other two sides equal .55 cm)consists of three particles ...
March 27, 2007

Physics - KE/Inertia
The rigid body shown in Figure 10-66 (it is a triangle with the upper mass = to M and the bottom two corners/masses equal to 2M. The bottom side length equals .70 cm with point P in the middle of the side and the other two sides equal .55 cm)consists of three particles ...
March 26, 2007

Physics - KE/rotation
In Figure 11-32 (which shows a ball at the top of an incline, at the bottom of the incline a loop begins with radius R and Q a point on the loop lined up with the center of the loop), a solid brass ball of mass m and radius r will roll without slipping along the loop-the-loop ...
March 25, 2007

Physics - KE/Inertia
The rigid body shown in Figure 10-66 (it is a triangle with the upper mass = to M and the bottom two corners/masses equal to 2M. The bottom side length equals .70 cm with point P in the middle of the side and the other two sides equal .55 cm) consists of three particles ...
March 25, 2007

Re: PHYSICS
"Relative" is an important word. Block L of mass mL = 1.90 kg and block R of mass mR = 0.500 kg are held in place with a compressed spring between them. When the blocks are released, the spring sends them sliding across a frictionless floor. (The spring has ...
February 27, 2007

PHYSICS, still cant get it
A man (weighing 915 N) stands on a long railroad flatcar (weighing 2805 N) as it rolls at 18.0 m/s in the positive direction of an x axis, with negligible friction. Then the man runs along the flatcar in the negative x direction at 40.00 m/s relative to the flatcar. What is ...
February 27, 2007

Re: PHYSICS
A stationary block explodes into two pieces L and R that slide across a frictionless floor and then into regions with friction, where they stop. Piece L, with a mass of 2.0 kg, encounters a coefficient of kinetic friction µL = 0.40 and slides to a stop in distance dL = ...
February 27, 2007

Re: PHYSICS
"Relative" is an important word. Block L of mass mL = 1.90 kg and block R of mass mR = 0.500 kg are held in place with a compressed spring between them. When the blocks are released, the spring sends them sliding across a frictionless floor. (The spring has ...
February 27, 2007

Re: PHYSICS
A man (weighing 915 N) stands on a long railroad flatcar (weighing 2805 N) as it rolls at 18.0 m/s in the positive direction of an x axis, with negligible friction. Then the man runs along the flatcar in the negative x direction at 40.00 m/s relative to the flatcar. What is ...
February 27, 2007

RE: PHYSICS
A man (weighing 915 N) stands on a long railroad flatcar (weighing 2805 N) as it rolls at 18.0 m/s in the positive direction of an x axis, with negligible friction. Then the man runs along the flatcar in the negative x direction at 40.00 m/s relative to the flatcar. What is ...
February 26, 2007

RE: PHYSICS
A stationary block explodes into two pieces L and R that slide across a frictionless floor and then into regions with friction, where they stop. Piece L, with a mass of 2.0 kg, encounters a coefficient of kinetic friction µL = 0.40 and slides to a stop in distance dL = ...
February 26, 2007

RE: PHYSICS
"Relative" is an important word. Block L of mass mL = 1.90 kg and block R of mass mR = 0.500 kg are held in place with a compressed spring between them. When the blocks are released, the spring sends them sliding across a frictionless floor. (The spring has ...
February 26, 2007

Physics
"Relative" is an important word. Block L of mass mL = 1.90 kg and block R of mass mR = 0.500 kg are held in place with a compressed spring between them. When the blocks are released, the spring sends them sliding across a frictionless floor. (The spring has ...
February 25, 2007

Physics
A stationary block explodes into two pieces L and R that slide across a frictionless floor and then into regions with friction, where they stop. Piece L, with a mass of 2.0 kg, encounters a coefficient of kinetic friction µL = 0.40 and slides to a stop in distance dL = 0...
February 25, 2007

Physics
A vessel at rest at the origin of an xy coordinate system explodes into three pieces. Just after the explosion, one piece, of mass m, moves with velocity (-30 m/s)i and a second piece, also of mass m, moves with velocity (-30 m/s)j. The third piece has mass 3m. (a) Just after ...
February 25, 2007

Pages: 1 | 2 | Next>>

Search
Members