Tuesday

March 31, 2015

March 31, 2015

Total # Posts: 10,341

**Physics**

X = -69 km/h Y = 215 km/h Tan Ar = Y/X = 215/-69 = -3.11594 Ar = -72.21o = Reference angle. A = -72.21 + 180 = 107.8o V=Y/sinA = 215/sin107.8=225.8km/h[107.8]
*March 19, 2014*

**phsyics**

Coefficient of Linear Exp.=(3.6*10^-5)/3 = 1.2*10^-5/C. L = Lo + a*(T-To)Lo L = 17 + 1.2*10^-5*(5-100)17 = 17 - 0.0194 = 16.981 m.
*March 19, 2014*

**Dont I need more info for this Math problem??**

Since the compounding frequency was not given, you'll have to use simple interest. P = Po + Po*r*t P=2,000 + 2000*0.03*4=2000 + 240 = 2240. Always show the Eq before plugging-in the values.
*March 19, 2014*

**phsyics**

a. Circumference = pi*2r = 3.14*2r = 6.28r V = C/t = 2pi*r/t b. V = 6.28*100m/14s = 45 m/s.
*March 19, 2014*

**phsyics**

a. V = Vp+Vw = 60 + (-40) = 20 km/h. b. V = 60 + 40 = 100 km/h.
*March 19, 2014*

**physics**

Vb = (Dc/Dw)*Vc = (100/1000)*Vc = 3 m^3 0.1Vc = 3 Vc = 30 m^3. = Vol. of cylinder.
*March 19, 2014*

**Physical Science**

P = V*I = 110 * 15
*March 19, 2014*

**physics**

Vo = 6.93 m/s[45.6o] Xo = 6.93*cos45.6 = 4.85 m/s Yo = 6,93*sin45.6 = 4.95 m/s. h = (Y^2-Yo^2)/2g = (0-4.95^2)/-19.6 = 1.25 m.
*March 19, 2014*

**physic**

a. KE = 0.5m*V^2 = 0.5m*0 = 0 J. The velocity is zero at the max. ht. b. V^2 = Vo^2 + 2g*h V^2 = 41.8^2 - 19.6*(34.5-8.88) V^2 = 1245.09 V = 35.29 m/s.
*March 19, 2014*

**Physics**

V^2 = Vo^2 + 2g*h = 0 at peak. Vo^2 - 19.6*16.6 = 0 Vo^2 = 325.4 Vo = 18.04 m/s = Speed at which ball was kicked.
*March 18, 2014*

**PHysiscs**

Fn = m*g = (83.5+68+62+55) * 9.8
*March 18, 2014*

**Maths**

10km[0o].
*March 18, 2014*

**Physics**

Circumference = pi * 2r = 3.14 * 0.20 = 0.6283 m/rev. Va = 24m/s * 6.28rad/0.6283m = 240 rad/s = Angular velocity. V = 24m/s * 1rev/0.6283m * 60s/min = 2292 RPM.
*March 17, 2014*

**Physics**

Circumference = pi * 2r = 3.14 * 0.620 = 1.95 m/rev. 8.5*10^7m * 1rev/1.95m = 4.36*10^7 Revs = 43.6 Million Revs.
*March 17, 2014*

**Physics**

a. Y^2 = Yo^2 + 2g*h = 0 m/s @ max. ht. Yo^2 - 19.6*0.750 = 0 Yo^2 = 14.7 Yo = 3.83 m/s. = Initial ver. velocity. b. Y = Yo + g*Tr = 0 m/s @ max. ht. Y = 3.83 - 9.8Tr = 0 9.8Tr = 3.83 Tr = 0.3908 s. = Rise time. Dx=Xo * Tr = 5m/s * 0.3908s. = 1.95 m. From basket.
*March 17, 2014*

**Physics**

Range = Vo^2*sin(2A)/g = 78 m. 34^2*sin(2A)/9.8 = 78 Solve for A.
*March 17, 2014*

**PHYSICS**

See previous post: Mon,3-17-14,8:03 PM.
*March 17, 2014*

**Physics**

m*g = 20 N. m = 20/g = 20/9.8 = 2.041 kg A. Work = 0.5m*Vo^2 - 0.5m*V^2 = mg*h 1.02*Vo^2 - 1.02*25^2 = 20*14.8 1.02Vo^2 - 637.5 = 290 1.02Vo^2 = 290 + 637.5 = 927.5 Vo^2 = 909.31 Vo = 30.15 m/s. B. h = (V^2-Vo^2)/2g = (0-30.15^2)/-19.6 = 46.38 m.
*March 17, 2014*

**physics**

Ratio = (331+0.6T1)/(331+0.6T2) = (331+0)/(331+60) = 0.847
*March 17, 2014*

**math**

-16t^2 + 120t = 0 Use Quadratic Formula and get: Tr = 3.75 s. = Rise time or time to reach max ht. Tf = Tr = 3.75 s. = Fall time. T = Tr + Tf = 3.75 + 3.75 = 7.50 s. To strike gnd.
*March 17, 2014*

**physics**

1. 15 - 6 = 9 N. = Net force. 2. a = Fn/m = 9/3 = 3 m/s^2.
*March 16, 2014*

**physics**

F = m*a = 60 * 2.5 = 150 N. V = Vo + a*t = 0 + 2.5*4 = 10 m/s.
*March 14, 2014*

**physics**

a=(V^2-Vo)/2d = (0-20^2)/1000=-0.4 m/s^2 F = m*a = 10000 * -0.4 = -4,000 N.
*March 14, 2014*

**Physics**

V = Vo + a*t = 0 + 0.3*30 = 9 m/s. d = (V^2-Vo^2)/2a = (9^2-0)/0.6 = 135 m.
*March 14, 2014*

**math**

F(x) = 5x^2 + 8x + 5 = 0 Quadratic Formula: X = (-B +- sqrt(B^2-4AC))/2a X = (-8 +- sqrt(64-100))/10 = (-8 +- sqrt(36*(-1))/10 = (-8 +- 6i)/10 = -0.8 +- 0.6i = -0.8 + 0.6i, and -0.8 - 0.6i. So we have 2 imaginary solutions.
*March 14, 2014*

**math**

x^2 + 5x - 2 < 0 Solve and graph: x^2 + 5x - 2 = 0 Use Quadratic Formula an get: X = -5.37, and 0.372 Solution to inequality:-5.37 < X < 0.372
*March 14, 2014*

**physics**

m*g = 15.7 * 9.8 = 153.9 N. = Wt. of block. Fn = 153.9*cos12.1 = 150.4 N.
*March 14, 2014*

**Physics**

PEmax=mg*hmax = 28*9.8 * 159=43,630 J. = KEmax @ bottom of hill with no friction. KE = 14*31.3^2 = 13,716 J. Energy lost = 43,630 - 13,716=29,914 J.
*March 14, 2014*

**physics-impulse**

Impulse = 2*m*V*cos45
*March 14, 2014*

**Physics**

Energy = m*g*h.
*March 14, 2014*

**math**

0.002N = 76 N = 38,000
*March 14, 2014*

**math**

GP = 22/day*6days + 0.18*2766.50 =
*March 14, 2014*

**Physics**

m*g = 295 * 9.8 = 2891 N. = Wt. of box. = Fn = Normal force. Fs = u*Fn = 0.2 * 2891 = 578.2 N. = Force of static friction. Fe-Fs = m*a Fe - 578.2 = m*0 = 0 Fe = 578.2 N. = Force of engine. Energy=Work = Fe*d = 578.2 * 2.8=1619 J.
*March 14, 2014*

**Algebra**

1. 18 = 1*18 = 1*2*9 = 1*2*3*3. Factors: N = {1,2,3,9,18}. 3a. 5.25x => 252 4a. Inequality: 88 < (78+93+x)/3 < 90 264 < 171 + x < 270 93 < X < 99 The inequality says: (78+93+x)/3 is greater than 88 but less than 90.
*March 13, 2014*

**physics**

V = Vo + g*t = 0 + 9.8*3 = 29.4 m/s
*March 13, 2014*

**phys**

m*g = 12kg * 9.8N/kg = 117.6 N. = Wt. of the crate. Fs = u*mg = 0.4 * 117.6 = 47.04 N. = Force of static friction. F*cos(-30) - Fs = m*a 0.8669F - 47.04 = m*0 = 0 0.866F = 47.04 F = 54.32 N.
*March 12, 2014*

**Science... plz help~!**

F = m*a = 40 * 10 = 400 N.
*March 12, 2014*

**finance**

P = Po*r*t/(1-(1+r)^-t) Po = $13,000 = Loan amount. r = (6%/12)/100% = 0.005 = Monthly % rate expressed as a decimal. t = 12mo/yr * 10yrs = 120 Months. P = (13000*0.005*120)/(1-(1.005)^-120) = $17,319.20 = Amt. to be paid. Monthly Payment = P/t = 17319.20/120 = $144.33 Payment...
*March 12, 2014*

**Gr 11 - math linear systems**

(10-2)x - 2000 = $16,000 8x - 2000 = 16000 8x = 18000 X = 2,250 Tickets.
*March 11, 2014*

**math**

2. Shifted 5units down. 5. -7x^2 + 6x + 3 = 0 Use Quadratic formula and get 2 solutions : -0.354, and 1.211. 6. Y = 3x^2 + 18x + 27 = 0 x^2 * 6x + 9 = 0 (x+3)(x+3) = 0 x+3 = 0, x = -3. x+3 = 0, X = -3. 2 solutions : -3, and -3. 11. Use Quad. Formula and get 3.54 s. 12. V = Vo...
*March 11, 2014*

**physics**

V = Vo + g*t = 0 + 10*1=10 m/s. T = 1s. d = Vo*t + 0.5g*t^2 d = 10*1 + 5*1^2 = 15 m.
*March 11, 2014*

**physics**

My answer is B also.
*March 11, 2014*

**Physics**

P = 16/12 = 1.333 s.
*March 11, 2014*

**Physics**

d = V*t = 305 m. V*(1.85/2) = 305 V = 329.7 m/s.
*March 11, 2014*

**physics**

a = (V-Vo)/t = (-8-16)/0.04 = -600 m/s^2 F = m*a = 0.2 * (-600) = -120 N.
*March 11, 2014*

**physics**

Xo = 0.9 m/s? D = Xo*t = 0.9m/s * 0.4s = 0.36 m.
*March 11, 2014*

**physics**

B. 10 m/s, North.
*March 11, 2014*

**physics**

PEmax = mg*hmax = mg*4.07 J. Change = 0-mg*4.07 = -3900 mg = 958.2 N. = Wt. of the vaulter.
*March 11, 2014*

**math**

Fp = 1.5*sin18 = Parallel Force(Wt.) Fn=1.5*cos18 = Normal or perpendicular force(Wt.).
*March 11, 2014*

**physics**

Fh = 151 Hz Vr = 28.7 m/s Vs = 343 m/s Fr = ((Vs+Vr)/(Vs-Vh)) * Fh Fr = ((343+28.7)/(343-0)) * 151 Hz = (371.7/343) * 151 = 163.6 Hz = Freq. heard by the receiver(Passenger).
*March 11, 2014*

**Physics**

P = F*d/t = 0.5 * 2.1/1.1 = 0.955 J/s = 0.955 Watts.
*March 10, 2014*

**Physics!**

PE = F*h = mg*h = 1.2*9.8 * 4 = 47.04 J.
*March 10, 2014*

**Science**

LiOH + W = 231 grams 33.7 + W = 231 W = 197.3 Grams of water. Concentration = LiOH/(W+LiOH) = 33.7/231 = 0.146 = 14.6%
*March 10, 2014*

**physics**

F*d = 25 J. F * 0.13 = 25 F = 192.3 N. k = 192.3N/0.13m = 1479N/m
*March 10, 2014*

**Physics**

b. The truck.
*March 10, 2014*

**Alegbra**

4a^2 + 9b^5 + 2a^2 + 6b^5=6a^2 + 15b^5 = 3(2a^2+5b^5).
*March 10, 2014*

**Alegbra**

(4.3*10^-8)(1.5*10^9)=6.45*10^1=6.45*10
*March 10, 2014*

**science**

1. True 2. 100kg-m/s. 5. Momentum = 52kg * 10m/s. = 520 kg-m/s 61kg * 8m/s = 488 kg-m/s
*March 10, 2014*

**physics**

What are the given angles?
*March 10, 2014*

**physics**

m = 85 kg? V = 450 L. V = 450L * 1000cm^3/L = 450,000cm^3 D = 85,000g/450,000cm^3 = 0.189 g/cm^3. Mass = 300cm^3 * 0.189g/cm^3 = 56.67 g = 0.0567 kg.
*March 10, 2014*

**integrated science**

m*g = 0.15 * 9.8 = 1.47 N. = Force of gravity. Fr = -1.47i + 50N[45o] = -1.47i + 50*cos45 + (50*sin45)i = -1.47i + 35.36 + 35.36i=35.36 + 33.89i = 49N[43.8o].
*March 9, 2014*

**physics**

a. Zero.
*March 9, 2014*

**science**

L = V/Fs = 600*10^-9 m. 300*10^6/Fs = 600*10^-9 Fs = 300*10^6/600*10^-9 = 5.*10^14 Hz = Freq. emitted by spaceship. a. L = 300*10^6/Fr = 200*10^-9 Fr = 300*10^6/200*10^-9 = 1.5*10^15 Hz. = Freq. observed by the receivers. Fr = ((Vl+Vr)/(Vl-Vs))*Fs = 1.5*10^15 ((3*10^8+0)/(3*10...
*March 9, 2014*

**physical science**

Fn = 10-3 = 7 N. = Net force.
*March 9, 2014*

**Math 12**

P = Po(1+r)^n Po = 0.85 * 275,000 = $233,750 r = (2.9%/2)/100% = 0.0145 = Semi-APR expressed as a decimal. n = 2comp/yr * 25yr = 50 Compounding periods. a. P = 233,750(1.0145)^50 = 480,124.85. 480,124.50/50 = $9,602.50 Semi-annually. 0r 480,124.85/300mo = $1600.42 Monthly. b. ...
*March 9, 2014*

**math**

0.002N = 76
*March 9, 2014*

**math**

GP = 22*6 + 0.18*2,766.50
*March 8, 2014*

**math**

C = 0.026*60000 + 0.034*(89,400-60,000) = $2559.60
*March 8, 2014*

**math**

P = 40h*8.25/h + 12h*1.5*8.25/h + 6h*2*8.25/h = $577.50
*March 8, 2014*

**Engineering science**

h = 0.5g*t^2 = 4.9*4.5^2 = 99.23 m. PE = mg*h = 6*9.8 * 99.23 = 5834 J.
*March 8, 2014*

**Physics**

m*g = 5.36k * 9.8N/kg = 52.53 N. = Wt. of object. a. KE = 0 J. = Initial KE V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*1 = 19.6 V = 4.43 m/s. KE = 0.5m*V^2 = 2.68*4.43^2 = 52.59 J. b. V^2 = Vo^2 + 2g*h V^2 = 4.43^2 + 19.6*1 = 39.22 V = 6.26 m/s. KEo = 2.68*4.43^2 = 52.59 J. KE = 2.68*6....
*March 8, 2014*

**physics**

Tr = To + (-Vo)/g = 4 + (-112.8)/-9.8 = 15.51 s. = Rise time. hmax = ho + (V^2-Vo^2)/2g hmax = 225.6 + (0-(112.8)^2)/-19.6 = 1506 m. Above gnd. hmax = 0.5g*t^2 = 1506 m. 4.9t^2 = 1506 t^2 = 307.3 Tf = 17.53 s. = Fall time. T = Tr + Tf = 15.51 + 17.53 = 33.0 s. = Time in air.
*March 8, 2014*

**business math**

8.25(40+18+12) = 70 * 8.25 = $577.50
*March 8, 2014*

**physics**

F1 = (x,y) = (3.85N,-2.85N) F2 = (x,y) = (2.95N,-3.65N). a. Fr=X+Yi=(3.85+2.95) + (-2.85i-3.65i)= 6.8 - 6.5i = 9.41N[316.3o] = Resultant force. 2.10kg particle Location: (x,y) = (-2.30m,-3.60m) a(x) = Fx/mass = 6.8/2.1 = 3.24 m/s^2 Vx=Vox + a*t = 0 + 3.24*11.8= 38.21 m/s. a(y...
*March 7, 2014*

**physical science**

d = 200mi/h[120o] * 1.5h = 300mi[120o] X = 300*cos120 = -150 mi = 150 mi West. Y = 300*sin120 = 260 mi North.
*March 7, 2014*

**physics**

P=F*V = mg*V = 106*9.8 * 34.5=35,839 J/s =35,839 Watts.
*March 7, 2014*

**math**

11. Y = (1/2)x^2 + 2x - 3 Use Quadratic Formula and get: X = 1.16228, and -5.16228. 27. 3x^2-5x = -3x^2+6 3x^2+3x^2-5x = 6 6x^2 - 5x - 6 = 0 Use the AC method of factoring: A.C = 6*(-6) = -36 = 3*(-12)=4*(-9). Choose the pair of factors whose sum = B or -5: We choose 4, and -9...
*March 7, 2014*

**Math Geometry**

1 1/4 in. = 5/4 in. Width = W in. Length = 5/4 * W = 5W/4 in. Area = Length * Width = 5W/4 * W = 180 1n^2. 5W^2/4 = 180 Multiply both sides by 4: 5W^2 = 720 W^2 = 144 W = 12 in. = Width 5/4 * 12 = 15 in. = Length.
*March 7, 2014*

**Science**

V^2 = Vo^2 + 2g*h = 0 + 19.6*3 = 58.8 V = 7.67 m/s. V^2 = Vo^2 + 2g*h = 0 @ max ht. Vo^2 - 19.6*2.2 = 0 Vo^2 = 43.12 Vo = 6.57 m/s. a = (-6.57-7.67)/0.002s = -7120 m/s^2. F = m*a = 0.20 * (-7120) = -1424 N.
*March 7, 2014*

**physical**

Xo = 250 km/h A = 30o Vo = Xo/cosA = 250/cos30 = 288.7 km/h. Yo = Vo*sin30 = 288.7*sin30 = 144.3 km/h
*March 7, 2014*

**Physics**

See previous post: Wed,3-5-14.9:29 PM.
*March 7, 2014*

**Science**

My answer is "a" also.
*March 6, 2014*

**physic**

A+B = 7[45] + 10[45] = 17[45o]. Since the angles are equal, we add the vectors directly.
*March 6, 2014*

**physics**

I = V/R = 1.5/3 = 0.5A. The voltage across each resistor is 1.5 volts.
*March 6, 2014*

**physics**

R = V/I = 2/3.2*10^-3
*March 6, 2014*

**geometry**

X = 4 r = 7 = hyp. cos A = X/r = 4/7 = 0.57143 A = 55.15o
*March 6, 2014*

**math**

Value = 50,000 + 0.03*3*50,000=$54,500
*March 6, 2014*

**physics**

Vs = 3m/s[135o] + 2m/s[270o] X = 3*cos135 = -2.12 m/s. Y = 3*sin135 + 2*sin270o = 0.1213 m/s. Tan Ar = Y/X = 0.1213/-2.12 = -0.05723 Ar = -3.275o = Reference angle. A = -3.275 + 180 = 176.7o Vs = X/cosA = -2.12/cos176.7=2.123 m/s. [176.7o]
*March 5, 2014*

**Physics**

a. V^2 = Vo^2 + 2g*h = 0 @ max ht. Vo^2 - 19.6*1.45 = 0 Vo^2 = 19.6*1.45 = 28.42 Vo = 5.33 m/s = Initial velocity after striking the floor. Impulse = m*V = 0.20*5.33 = 1.067 kg-m/s b. V^2 = Vo^2 + 2g*h = 0 + 19.6*1.95 = 38.22 V = 6.18 m/s. = Velocity just before striking the ...
*March 5, 2014*

**Physics**

a. D = d1 + d2 + d3 = 70*(45/60) + 95*(10/60) + 55*(30/60) = 95.83 km. T = 45 + 10 + 30 + 20=105 min=1.75 h. Avg. Speed=D/T=95.83km/1.75h=54.8 km/h. NOTE: My procedure is the same as Bob's, but he forgot to include the 20 min for eating and buying gas. Your answer in Part...
*March 5, 2014*

**phy**

Vo = 2m/s[-45o] Xo=2*cos(-45)=1.414 m/s=Hor. component. Yo=2*sin(-45)=-1.414 m/s=Ver. component. Depth = Yo*t + 0.5g*t^2 = -1.414*1.3 + 4.9*1.3^2 = 6.44 m.
*March 5, 2014*

**physics**

P2/P1 = ((2V)^2/R)/(V^2/R)= (4V^2/R)*R/V^2=4V^2/V^2 = 4 Alternate Method: P1 = V1^2/R = 10^2/100 = 1. Watt. P2 = V2^2/R = 20^2/100 = 4 Watts. P2/P1 = 4W/1W = 4 So the power is increased by a factor of 4.
*March 5, 2014*

**Physics**

F = 10N[45o] + 8N[330o] -7.5N X = 10*cos45 + 8*cos330 - 7.5 = 6.50 N. Y = 10*sin45 + 8*sin330 = 3.07 N. Tan A = Y/X = 3.07/6.50 = 0.47247 A = 25.29o Fr = X/cosA = 6.50/cos25.29=7.19N[25.29] = Resultant force. a = Fr/m = 7.19[25.29o]/49=0.147[25.29]
*March 4, 2014*

**Physics**

L = V/F = 0.333 m. L = V/15000 = 0.333 V = 0.333 * 15,000 = 4995 m/s. 4995 - 343 = 4652 m/s faster.
*March 4, 2014*

**physics**

X = 130 km/h Y = 275 km/h V^2 = 130^2 + 275^2 = 92,525 V = 304.2 km/h.
*March 4, 2014*

**Physics**

F = 4.8 - 0.6 = 4.2 N.
*March 4, 2014*

**Math**

Y = 2x + 3 Eq1: -2x + y = 3 X = 1 - 2y Eq2: x + 2y = 1 Multiply Eq2 by 2 and add Eq1 and Eq2: -2x + y = 3 +2x + 4y = 2 sum: 5y = 5 Y = 1 In Eq2, replace Y with 1 and solve for x: x + 2*1 = 1 X = -1. Solution set: (x,y) = (-1,1). One common solution.
*March 4, 2014*

**Basic algebra**

Speed = r mi/h going to work. Speed = (r+10)m/h returning. d = r mi/h * 1 h = (r+10)mi/h * 0.5h r * 1 = (r+10) * 0.5 r = 0.5r + 5 0.5r = 5 r = 10 mi/h r+10 = 10+10 = 20 mi/h d = 10 * 1 = (10+10) * 0.5 = 10 mi.
*March 4, 2014*

**Physc**

Tr = 20/2 = 10 s. = Rise time. Range = Xo * T = 80 m. Xo * 20 = 80 Xo = 4 m/s = Hor. component of initial velocity. a = 0 = Hor. acceleration. a = g = 9.81 m/s^2. = Ver. acceleration.
*March 4, 2014*

**Physics**

Wt. of crate = m * g = 3.2kg * 9.8N/kg = 31.36 N. Fp = 31.36*sin35 = 17.99 N. = Force parallel to the incline. F = Fp*cos35 = 17.99*cos35 = 14.74 N.
*March 4, 2014*

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