Friday

October 24, 2014

October 24, 2014

Total # Posts: 9,337

**Physics**

We need to know the length of the hill. Length = 100 m? A = 30o m = 75 kg h = 100*sin30 = 50 m. = Ht. of hill. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*50 = 980 V = 31.3 m/s At bottom of hill. V^2 = Vo^2 + 2a*d a=(V^2-Vo^2)/2d=(31.3^2-0)/200=4.9 m/s^2 V = Vo + a*t = 31.3 0 + 4.9*t = ...
*November 28, 2013*

**math**

CORRECTION: Cost = 2375*0.85*0.80*0.80 = $1292. Discount = 2375 - 1292 = $1083.
*November 27, 2013*

**math**

Discount = 2375*0.15*0.20*0.20 = $14.25
*November 27, 2013*

**Physics**

V1 = 6N[180o] X1 = -6N Y1 = 0 V2 = 4.5N[45o] X2 = 4.5*cos45 = 3.18 N. Y2 = 4.5*sin45 = 3.18 N. X = X1 + X2 = -6 + 3.18 = -2.82 N. Y = Y1 + Y2 = 0 + 3.18 = 3.18 N. tan Ar = Y/X = 3.18/-2.82 = -1.12766 Ar = -48.43o = Reference angle. A = -48.43 + 180 = 131.6o R=Y/sinA = 3.18/...
*November 26, 2013*

**Finance - Annuities**

P = Po*(1+r)^n P = $2250/mo. * 48mo. = $108,000 r = (3%/12)/100% = 0.0025 = Monthly % rate expressed as a decimal. n = 1comp./mo * 48mo = 48 Compounding periods. a. P = (Po-12000)*(1.0025)^48 = 108,000 (Po-12000)*1.12733 = 108000 Po-12000 = 95,801.75 Po = $107,801.75 = Initial...
*November 26, 2013*

**math**

A*(1-0.0653) = 1,225,000 A*0.9347 = 1225000 A = 1,310,580.94
*November 26, 2013*

**physics**

F1 = m*g = 1.6kg * 9.8N/kg = 15.68 N F2 = (0.05m/1m) * 400N = 20 N. F1-Fs = m*a 15.68-Fs = m*0 = 0 Fs = 15.68 = Force of static friction. Fs = u*F2 = 15.68 u*20 = 15.68 u = 0.784 = Coefficient of static friction.
*November 26, 2013*

**Physic: Projectile Motion**

Range = Vo^2*sin(2A)/g = 15 m. Vo^2*sin(40)/9.8 = 15 Vo^2*0.0656 = 15 Vo^2 = 228.7 Vo = 15.12 m/s.
*November 26, 2013*

**Math**

2. A cube has 6 edges. As = 6 * 3^2 = 6 * 9 = 54 Sq. In.
*November 25, 2013*

**finance**

1. P = (Po*r*t)/(1-(1+r)^-t) r = (9%/12)/100% = 0.0075 = Monthly % rate expressed as a decimal. t = 12mo/yr * 5yrs. = 60 Months. Plug th above values into the givenEq and get: P = $12,455.01 I = P-Po 2. Monthly = P/t 3. P = Po + Po*r*t Po = $10,000 r = 0.0075 t = 60 Months ...
*November 25, 2013*

**physics**

Fap-Fk = m*a 30-Fk = 2 * 10 = 20 Fk = 30-20 = 10 N. = Force of kinetic friction.
*November 25, 2013*

**geometry**

See Related Questions: Thu,5-25-11,11:28 AM.
*November 24, 2013*

**Science, Physics, math, calculus**

a. h = 0.5g*t^2 = 0.77 4.9t^2 = 0.77 t^2 = 0.1571 t = 0.396 s. = Fall time. Dx = Xo * t = 5.15 m. Xo * 0.396 = 5.15 Xo = 13 m/s = Break speed. b. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*0.77 = 15.09 V = 3.88 m/s
*November 24, 2013*

**Physics**

h = 0.5g*t^2 = 50 m. 4.9t^2 = 50 t^2 = 10.2 Tf = 3.19 s. = Fall time. d = V*Tf = 100m/s * 3.19s = 319 m.
*November 24, 2013*

**PHYSICS**

CORRECTION: T = 1.15 Milliseconds.
*November 24, 2013*

**PHYSICS**

CORRECTION: d. Vr = I*R = (0.8*0.857)*7 = 4.8 Volts Vi=6-4.8=1.2 Volts across the inductor. V/e^(T/0.714) = 1.2 6/e^(1.40T) = 1.2 e^1.40T = 6/1.2 = 5 1.40T*Ln e = Ln 5 1.40T = 1.609 T = 1.15 s. 7 =
*November 24, 2013*

**PHYSICS**

a. T.C.=L/R=5.0/7=0.714 Milliseconds b. T/TC = 0.25mS/0.714mS = 0.350 Vi = V/e^(T/TC) = 6/e^0.350 = 4.23 Volts after 250 uS. I=Vr/R = (V-Vi)/R = (6-4.23)/7= 0.253A. c. I=Vr/R = (V-Vi)/R = (6-0)/7 = 0.857A d. Vr=I*R = (0.8*0.857)*7 = 4.80 Volts. Vi = 6-4.8 = 1.2 Volts. = ...
*November 24, 2013*

**Math**

Incomplete.
*November 24, 2013*

**physics**

Fr = 975N[0o] + 745N[60o] + 1175N[90o] X=975 + 745*cos60 + 1175*cos90=1347.5 N Y = 745*sin60 + 1175*sin90 = 1820.2 N. tan A = Y/X = 1820.2/1347.5 = 1.31079 A = 53.5o Fr = Y/sin A = 1820.2/sin53.5=2264.3 N. [53.5o].
*November 24, 2013*

**physics**

Ht. = 50 m.? a. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*50 = 980 V = 31.3 m/s. b. V = Vo + g*t = 31.3 m/s. 0 + 9.8t = 31.3 t = 3.19 s. c. m = 2.0Lb * 0.454kg/Lb = 0.908 kg. KE = m*V^2/2 = 0.908*31.3^2/2 = 444.8 J.
*November 24, 2013*

**physics**

Ws = m*g = 77.7kg * 9.8N/kg = 761.5 N = Wt. of skier. Fp = 761.5*sin35.7 = 444.3 N. = Force parallel to slope. Fn = 761.5*cos35.7 = 618.4 = Normal = Force perpendicular to slope. Fk = u*Fn = 0.08 * 618.4 = 49.47 N. = Force of kinetic friction. Fp-Fk = m*a a=(Fp-Fk)/m=(444.3-49...
*November 22, 2013*

**science**

KE = 0.5m*V^2 = 2.5*4^2 = 40 J.
*November 22, 2013*

**Please help!- Physics**

d = 483[180o ] + 347[106o] + 347[106o] d = 483[180 + 694[106o] X = 483*cos180 + 694*cos106 = -674.3 km Y = 483*sin180 + 694*sin106 = 667.1 km tan Ar = Y/X = 667.1/-674.3 = -0.98935 Ar = -44.69o = Reference angle. A = 180-44.69 = 135.3o d = X/cosA = -674.3/cos135.3 = 948.7 km [...
*November 22, 2013*

**Math**

Incomplete.
*November 21, 2013*

**physics**

3.2 cm from equilibrium position: KE + PE = mg*d 0 + PE = mg*d/2 Halfway to the equilibrium position: KE + PE = mg*d mg*d/2 + mg*d/2 = mg*d KE = mg*d/2 = 0.5m*V^2 0.5m*V^2 = mg*d/2 = 3.92*0.032/2 0.2*V^2 = 0.06272 V^2 = 0.3136 V = 0.56 m/s.
*November 21, 2013*

**Physics**

CORRECTION: V = 81.6km/h[74.93o] D = 245 km[74.93o]
*November 20, 2013*

**Physics**

V = 100km/h[90o] + 30km/h[315o] X = 100*cos90 + 30*cos315 = 21.21 km/h Y = 100*sin90 + 30*sin315 = 78.79 km/h tan A = Y/X = 78.79/21.21 = 3.71461 A = 74.93o V=Y/sinA = 78.79/sin74.93=81.6 km/h [78.79] D=V*t = 81.6[78.79] * 3 = 245 km[78.8o]
*November 20, 2013*

**Math**

Parallel lines have equal slopes.
*November 20, 2013*

**Math**

Parallel lines have equal slopes.
*November 20, 2013*

**Math**

Parallel lines have equal slopes.
*November 20, 2013*

**Math**

2x - 3 = 4y Eq1: 2x - 4y = 3 m1 = -A/B = -2/-4 = 1/2 m2 = -(2/1) = -2 Y = mx + b Eq2: Y =-2x - 5/4.
*November 20, 2013*

**Math**

See previous post: Wed,11-20-13,6:18PM.
*November 20, 2013*

**Math**

Eq1: x + 2y = 10. m1 = -A/B = -1/2 The slope of the 2nd line = the negative reciprocal of m1: m2 = -(-2/1) = 2. Y = mx + b Eq2: Y = 2x - 10 or 2x - y = 10
*November 20, 2013*

**physics**

Energy = 120 * 5 *6h /1000=3.6 KWh Used Cost = 3.6kwh * 0.090/kwh = 0.324 or 32.4 Cents.
*November 20, 2013*

**Physics**

L = h/sin A = 2/sin 30 = 4 m. = Length of incline. KE = mg*h-Fk*L 0.5m*V^2 = mg*h-Fk*l 0.2*4.50^2 = 3.92*2 - Fk*4 4.05 = 7.84 - 4Fk 4Fk = 7.84-4.05 = 3.79 Fk = 0.948 N. = Force of kinetic friction.
*November 19, 2013*

**physics**

Fn = m * a =47 * 4.50
*November 19, 2013*

**Physics**

Yes. For a given initial velocity, the larger the angle the greater the vertical component of initial velocity. The increase in vertical velocity causes an increase in the max. ht.
*November 19, 2013*

**Physics - projectile**

V = Vo = 50 m/s.
*November 19, 2013*

**Physics**

b. h = Vo*t + 0.5g*t^2 = 3.05 8t + 4.9t^2 - 3.05 = 0 Use Quadratic Formula and get: t = 0.319 s. c. V^2 = Vo^2 + 2g*h V^2 = 8^2 + 19.6*3.05 = 123.78 V = 11.13 m/s.
*November 19, 2013*

**MATH**

A. Y = ho - 8X ho = The initial ht. B. When he got on the elevator, it was at the initial height(ho) and decreased at a rate of 8 feet per second for 12 seconds. C. Y = ho _ 8x = 240 Ft. ho - 8*12 = 240 ho = 240 + 96 = 336 Ft. above gnd. D. Y = 336 - 8x = 0 336 - 8x = 0 8x = ...
*November 19, 2013*

**math**

N = 0.57 * 11
*November 19, 2013*

**Physics**

d = 0.5g*t^2 = 75 4.9t^2 = 75 t^2 = 15.31 Tf = 3.912 s. = Fall time. d = V*Tf = 7-4 = 3 m. V * 3.912 = 3 V = 0.769 m/s.
*November 19, 2013*

**math**

Did your book give the total # of Robinsons? Something is missing.
*November 18, 2013*

**physical science**

P = F * d/t = 96 * 2.8/4.6 = 58.43 J/s = 58.43 Watts.
*November 18, 2013*

**college algebra**

4^(x-3) = 3^(2x) (x-3)*Log4 = 2x*Log 3 Divide both sides by Log 4: x-3 = 2x * 0.79248 = 1.5850x x - 1.5850x = 3 -0.5850x = 3 X = -5.1282
*November 18, 2013*

**science**

Magnitude = 210 N. Direction = 30o South of West = 210o CCW.
*November 18, 2013*

**science**

Magnitude = 200 N. Direction = 60o North of East = 60o CCW.
*November 18, 2013*

**science**

Magnitude = 125 N. Direction = North(Positive Y-axis).
*November 18, 2013*

**math**

Sally has X postcards. Marta has X postcards. X = 4(X-18) Solve for X.
*November 18, 2013*

**Math**

Y = 5 For all values of X. (0,5),(5,5),(2,5),(-3,5).
*November 18, 2013*

**science**

500+(65-47)sk/wk*105days*1wk/7days=770 Skunks.
*November 18, 2013*

**Phyics**

d1 = 0.5a*t^2 = 15 m. 0.5*t^2 = 15 t^2 = 30 T1 = 5.477 s. V = a*t = 1m/s^2 * 5.477s = 5.477 m/s. d2 = V * t = 5.477m/s * 15s = 82.2 m. D = d1 + d2 = 15 + 82.2 = 97.2 m. = Distance at which he was caught. T = T1 + T2 = 5.477 + 15 = 20.48 s To catch up.
*November 18, 2013*

**math**

(25%/15%/10% = (1-0.25)(1-0.15)(1-0.10)= 0.75 * 0.85 * 0.90 = 0.57375
*November 18, 2013*

**math**

a. X + 27.80*20 = 914 X = $358. b. C = 358 + 27.80x X = The number of years since 1981. c. 2000-1981 = 19 years. C = 358 + 17.80*19 = $528.20
*November 18, 2013*

**Check my answers please- Physics**

1. A force that makes the net force on an object 0. 2. It is equal in magnitude and opposite in direction. 3. An object in equilibrium must not be in motion. 7. 90 N.
*November 18, 2013*

**algebra2**

See previous post: Mon,11-18-13,11:59 AM.
*November 18, 2013*

**algebra2**

CD: $X Savings: $4X Mutual: $(15,000-5X) 0.02X + 0.01*4X + 0.1(15000-5x) = 210 0.06X + 1500 - 0.5X = 210 -0.44X = 210-1500 = -1290 X = 2931.82 4X = 4*2931.82 = $11,727.27 = Savings.
*November 18, 2013*

**math**

Bal. = 423.78 + 123.42 - 100 = 447.20 Int. = 447.20 *(0.15/12) * 1 = $5.59
*November 18, 2013*

**Physics**

Incomplete.
*November 18, 2013*

**Business math**

P = Po*(1+r)^n r = (0.75%/365)/100% = 2.055*10^-5 = Daily % rate expressed as a decimal. n = 1comp./day * 21days = 21 compounding periods. Plug the above values into the given Eq and get: $9,0003.88
*November 17, 2013*

**physic**

Vo=36mi/h * 1600m/mi * 1h/3600s=16 m/s. V = Vo + a*t = 0 16 + a*2.4 = 0 2.4a = -16 a = -6.67 m/s^2. F = m*a = 58 * (-6.67) = -386.7 N. The negative sign means that the force was in the opposite direction of the motion.
*November 17, 2013*

**Math**

P = 350hp * 746W/hp = 261,100 Watts.
*November 17, 2013*

**physics**

Wb = m*g = 7.6kg * 9.8N/kg = 74.48 N. = Wt. of block. Fs = 8 N ? Fs = us*Fv = 8 N. us*74.48 = 6 us = 0.081
*November 17, 2013*

**geometry**

See previous post: Sat, 11-16-13, 7:13 PM.
*November 17, 2013*

**GEOMETRY**

1. Triangle #1 a = 8 b = 15 c = 18 Triangle #2: d = 10 e = ? f = ?. a/d = b/e = c/f = 8/10 15/e = 8/10 e = 18.75 18/f = 8/10 f = 22.5 2. Scale Factor=5/4 = 15/12=25/20 = 1.25 3. x/r = y/p = z/n.
*November 16, 2013*

**physics**

Fn = m*a m = Fn/a = 50/25 = 2 kg
*November 16, 2013*

**Trig**

V1 + V2 = 1200[70o] + 900[205o] X = 1200*cos70 + 900*cos205 = -405.3 Y = 1200*sin70 + 900*sin205 = 747.3 tanAr = Y/X = 747,3/-405.3 = -1.84376 Ar = -61.53o = Reference angle. A = -61.53 + 180 = 118.5o Vr = Y/sinA = 747.3/sin118.5 = 850.3[118.5o] = Resultant vector.
*November 15, 2013*

**nature of science**

A. The speed and direction.
*November 15, 2013*

**Math**

V1 = 1.5 *1.5 * 0.25 = 0.5625 in^3. V2 = 3.25 * 3.50 * 0.25 = 2.844 in^3. V2/V1 = 2.844/0.5625 = 5.056 = 505.6%. % Increase = 505.6% - 100% = 405.6 %.
*November 15, 2013*

**physics**

h = 9.7*sin30 = 4.85 m. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*4.85 = 95.06 V = 9.75 m/s.
*November 14, 2013*

**Physics**

F1=m*g = 0.151[26.2o]*9.8=1.480N[26.2o] F2 = 0.215[281o]*9.8 = 2.107N[281o] F3[Ao] F = F1 + F2 + F3 F=1.480N[26.2o] + 2.107N[281] + F3[Ao] X = 1.480*cos26.2+2.107*cos281+F3*cosA=0 X = 1.328 + 0.4020 + F3*cosA = 0 F3*cosA = -1.73 cosA = -1.73/F3. Y = 1.480*sin26.2+2.107*sin281+...
*November 14, 2013*

**MATH**

P = Po + Po*r*t P = 15,000 + 15,000*0.045*(8/12) Solve for P.
*November 14, 2013*

**Math**

6w + 20 = 60 6w = 40 W = 6 4/6 or 7 Weeks.
*November 14, 2013*

**4th grade math**

1. a/7 = 20 Multiply both sides by 7: a = 7 * 20 = 140. Check: 140/7 = 20 2. Same procedure as #1. 3. Same procedure as #1.
*November 14, 2013*

**Physics**

a. F*cos20-Fk = m*a = m*0 = 0. F*cos20-u(Fn+F*sin20) = 0 300*cos20 - u(1000+300*sin20) = 0 281.9 - 1102.6u = 0 1102.6u = 281.9 u = 0.256 = Coefficient of kinetic friction. b. m*g = 1000N. m = 1000/g = 1000/9.8 = 102 kg. 300*cos20 - 0.256(1000-300*sin20)=m*a 281.9 - 229.7 = m*a...
*November 14, 2013*

**math**

Scott ate X Fries Mike ate (2x+1) Fries. Holly ate (x-5) Fries. Total fries ordered = Fries ate + 6: ORDER = X + (2x+1) + (x-5) + 6 = 4x + 2.
*November 14, 2013*

**physics**

Tr + Tf = 4.8s. = Rise time + Fall time = Time in air. Tr = Tf = 4.8/2 = 2.4 s. Dx = 60yds * 3Ft/yd * 1m/3.3Ft=54.55 m. Dx = Xo * (Tr+Tf) = 54.55 m. Xo * 4.8 = 54.55 Xo = 11.36 m/s. = Hor. component of initial velocity. Y = Yo + g*Tr = 0 @ max ht. Yo - 9.8*2.4 = 0 Yo = 23.52 m...
*November 14, 2013*

**physics**

See your 6:11 PM post.
*November 13, 2013*

**physics**

Work = F*d = 1 * 2000 = 2000 Joules. Calories = 2000J * 1cal/4.184J = 478
*November 13, 2013*

**Physics**

V = 90km/h = 90000m/3600s = 25 m/s. a = (V-Vo)/t = (25-0)/6 = 4.167 m/s^2 d = 0.5a*t^2 = 0.5*4.167*6^2 = 75 m. P = F*d/t = mg * d/t P = 13720 * 75/6 = 171,500 J/s.
*November 13, 2013*

**Math-Algebra**

1. F = m*a = 25 * 3 = 75 N.
*November 13, 2013*

**Fly Ball Lab - Projectile Motion Please HELP FAST!**

Dx = Xo * T = 48.9 m. Xo * 3.60 = 48.9 Xo = 13.58 m/s = Hor. component of initial velocity. Tr = Tf = T/2 = 3.60/2 = 1.80 s. = Rise and fall times. Y = Yo + g*Tr = 0 @ hmax. Yo - 9.8*1.8 = 0 Yo = 17.64 m/s = Ver. component of initial velocity. tan A = Yo/Xo = 17.64/13.58 = 1....
*November 12, 2013*

**math**

0.25 - (-1.5) = 0.25 + 1.5 = 1.75
*November 12, 2013*

**math**

1 1/2 - 2 = 3/2 - 4/2 = -1/2.
*November 12, 2013*

**Physics**

1. F = 250*2 + 25 = 525 N. Work = F*d = 525 * 2 = 1050 Joules. 2. P = F*d/t = 525 * 2/3 = 350 J/s. = 350 Watts.
*November 12, 2013*

**Physics**

Wt = m*g = 24kg * 10N/kg = 240 N.
*November 12, 2013*

**MATH**

A. P1 = Po*r*t/(1-(1+r)^-t) Po = $225,000 r = (5%/12)/100% = 0.004167 = Monthly % rate expressed as a decimal. t = 12mo/yr * 30yrs = 360 Months. Plug the above values in the given Eq and get: P1 = $434,810.88 I = P1-Po B. P2 = (Po*r*t)/(1-(1+r)^-t) Use same procedure as A.
*November 12, 2013*

**physics**

a=(V^2-Vo^2)/2d=(0-90^2)/1.2m=-6750m/s^2 F = m*a = 0.04 * -6750 = -270 N.
*November 12, 2013*

**math**

a = (V-Vo)/t = (0-35)/0.02 = -1750 m/s^2 F = m*a = 0.15 * -1750 = -262.5 N.
*November 11, 2013*

**Math**

611/14 = 43.64 Estimate = 600/15 = 40. 76 + 8 = 84 Estimate = 75 + 10 = 85 Estimates can be done without the calculator when the proper numbers are chosen.
*November 11, 2013*

**Math**

x = 3y - 6 = 0 3y - 6 = 0 3y = 6 Y = 2 = y-int.
*November 11, 2013*

**Math**

2/1 < 2x/5 < 3/1 Multiply the inequality by 5: 10 < 2x < 15 Divide by 2: 5 < X < 7 1/2 Solution: X = 6, and X = 7.
*November 11, 2013*

**Math**

2y = x - 8 Replace x with 0 and solve for y: 2y = 0 - 8 Y = -4 = y-int. Eq: Y = -2x - 4
*November 11, 2013*

**algebra**

5.7*10^4.
*November 11, 2013*

**algebra**

db=10*Log(2.42*10^5)=10*Log(242000) = 54
*November 11, 2013*

**physics**

Fr = 283N.[41o] + 283N.[0o] X = 283*cos41 + 283 = 496.6 N. Y = 283*sin41 = 185.7 N. Fr^2 = X^2 + Y^2 Fr^2 = 496.6^2+185.7^2 = 281,096.05 Fr = 530.2 N. Ff = u*mg = 0.283 * 264.6 = 74.9 N. a = (Fr-Ff)/m=(530.2-74.9)/27=16.9 m/s^2
*November 10, 2013*

**physics**

Wb = m*g = 29kg * 9.8N/kg = 284.2 N. = Wt. of the block. 1. Fp = 284.2*sin A = Force parallel to the incline. Fn = 284.2*cos A = Normal or Force perpendicular to the incline. Fs = us*Fn = 0.7*284.2*cos A=199*cos A Fp-Fs = m*a = m*0 = 0 284.2*sinA - 199*c0sA = 0 284.2sinA = ...
*November 10, 2013*

**Physics**

h = 0.5g*t^2 = 2.4 m. 4.9t^2 = 2.4 t^2 = 0.490 Tf = 0.7 s. Dx = Xo * Tf = 4.8m/s * 0.7s = 3.36 m from the table.
*November 10, 2013*

**Physics**

d = 0.5g*t^2 = 24.6 m. 0.5g*3.4^2 = 24.6 Solve for g.
*November 9, 2013*

**physics**

Dr = 12km[30o] + 8km[90o] + 4km[165o] X = 12*cos30+8*cos90+4*cos165 = 6.53 km Y = 12*sin30+8*sin90+4*sin165 = 15.0 km tan A = Y/X = 15/6.53 = 2.29709 A = 66.5o Dr = Y/sin A = 15.0/sin66.5 = 16.4 km[66.5o].
*November 9, 2013*

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