Thursday

September 18, 2014

September 18, 2014

Total # Posts: 9,091

**physics**

Fap-Fk = m*a 350-Fk = 38*7.3 = 277.4 -Fk = 277.4-350 = -72.6 Fk = 72.6 N. = Force of kinetic friction.
*September 15, 2014*

**Phsics**

Incomplete.
*September 15, 2014*

**math**

V=6-60=-54 Mi/h = -54Mi/h * 1600m/Mi * 1h/3600s = -24 m/s = 24 m/s Due South.
*September 15, 2014*

**math**

h = 1.9 m. Dx = 30 m. h = 0.5g*t^2 = 1.9 m. 4.9t^2 = 1.9 t^2 = 0.388 Tf = 0.623 s. = Fall time. Dx = Xo * Tf = 30 Xo * 0.623 = 30 Xo = 48.2 m/s. = Initial speed.
*September 15, 2014*

**Physics**

F = m*a = 15 * 0.7 = 10.5 N. Work = F*d = 10.5 * 12 = 126 Joules.
*September 15, 2014*

**Physics**

V = Vo + a*t t = (V-Vo)/a = t = (5.37*10^5-2.24*10^5)/2.2*10^14 = 3.13*10^5/2.2*10^14 = 1.42*10^-9 s.
*September 15, 2014*

**physics**

Incomplete.
*September 15, 2014*

**physics**

Xo = 26.4 m/s. Dx = 18.4 m. Tf = Fall time. Dx = Xo*Tf = 26.4 * Tf = 18.4 m. Tf = 0.697 s. h = 0.5g*Tf^2 = 4.9*0.697^2 = 2.38 m.
*September 15, 2014*

**physics**

Vo = 36m/s[24o] Xo = 36*cos24 = 32.9 m/s. Yo = 36*sin24 = 14.64 m/s. h = (Y^2-Yo^2)/2g = (0-(14.64^2))/-19.6 = 10.94 m.
*September 15, 2014*

**physics**

Xo = 25 m/s. d = 50 m Tf = Fall time. d = Xo*Tf = 25 * Tf = 50 m Tf = 2 s. h = 0.5g*Tf^2 = 4.9*2^2 = 19.6 m.
*September 15, 2014*

**physics**

h = 0.5g*t^2 = 1.9 4.9t^2 = 1.9 t^2 = 0.388 Tf = 0.623 s. = Fall time. D = Xo*Tf = 4.9m/s * 0.623s = 3.05 m.
*September 15, 2014*

**physics**

F = 365N[228o]CCW+224N[334o]CCW+488N [102o]CCW. Fx=365*Cos228 + 224*Cos334 + 488*cos102 = -144.4 N. Fy=365*sin228 + 224*sin334 + 488*sin102 = 107.9 N. Tan Ar = Fy/Fx = 107.9/-144.4 = -0.74718 Ar = -36.8o = Reference angle. A = -36.8 + 180 = 143.2o CCW = 36.8o N. of W. F = Fx/...
*September 15, 2014*

**physics**

a. d = 110-Vo*t = 110 - 20*0.7 = 96 m. b. a = (V^2-Vo^2)/2d = (0-20^2)/192 = -2.08 m/s^2. c. V = Vo + a*t = 0 t = -Vo/a = -20/-2.08 = 9.60 s.
*September 15, 2014*

**Physics**

a. h = ho+(V^2-Vo^2)/2g=(0-(5^2))/-19.6 =2.78 m. No. b. V^2 = Vo^2 + 2g*h Vo^2 = V^2-2g*h = 0 + 19.6*3.95 Vo^2 = 77.42 Vo = 8.8 m/s. c. V^2 = Vo^2+2g*h = 5^2 + 19.6*3.95 = 102.42 V = 10.12 m/s. Change = 10.12-5 = 5.12 m/s.
*September 15, 2014*

**Math**

In how many arrangements of the letters BERKELEY are all three E's adjacent? I think its (5!)*(6) i'm looking for some clarification.
*September 14, 2014*

**physics**

a. Tan A = 48/77 = 0.62338 A = 31.94o Tan31.94 = Vc/1.2 Vc = 1.2*Tan31.94 = 0.748 m/s = Speed of the current. b. Vs = 1.2/Cos31.94 = 1.414 m/s = Speed of swimmer. c. The current shifted the swimmer 31.94o E. of the desired point. To offset the affect of the current, the ...
*September 10, 2014*

**physics**

Vp + Vw = 314i Vp + 71 = 314i Vp = -71 + 314i Tan Ar = 314/-71 = -4.42254 Ar = -77.26o = Reference angle. A = -77.26 + 180 = 102.74o CCW = 12.74o W. of N.
*September 10, 2014*

**Physics**

(Vs-Vc)t1 = 208 km. (Vs+Vc)t2 = 208 km. Vs*t1-Vc*t1 = 208 Vs*t2+Vc*t2 = 208 Eq1: 21.7Vs - 21.7Vc = 208 Eq2: 20.3Vs + 20.3Vc = 208 Multiply Eq1 by 20.3 and Eq2 by 21.7 and add the Eqs: 440.51Vs - 440.51Vc = 4222.4 440.51Vs + 440.51Vc = 4513.6 Sum: 881.02Vs = 8736 Vs = 9.92 km/h...
*September 10, 2014*

**physics**

Vp + Vw = -226 m/s. Vp + 32i = -226 Vp = -226 - 32i Tan Ar = -32/-226 = 0.14159 Ar = 8.06o = Reference angle. A = 8.06 + 180 = 188.06o,Q3. = 8.06o S. of W. = Direction.
*September 10, 2014*

**math**

Incomplete.
*September 10, 2014*

**Physics**

Dx = Xo*T = 10.18 * 3.30 = 33.6 m. h = (Y^2-Yo^2)/2g h = (-15.13)^2-(17.21^2)/-19.6 = ( 228.92-296.18)/-19.6 = 3.43 m. = Y.
*September 10, 2014*

**Physics**

Vo = 20m/s[59.4o] Xo = 20*cos59.4 = 10.18 m/s. Yo = 20*sin59.4 = 17.21 m/s. X = Xo = 10.18 m/s. Does not change. Y = Yo+g*t = 17.21 - 9.8*3.30=-15.13 m/s Downward.
*September 10, 2014*

**science**

Volume.
*September 10, 2014*

**algebra**

13h/0.5mi. = 26 h/mi. with new machine. d1 = 2h * 1mi/26h = 2/26= 1/13 Mi. by new machine. d2 = 13/26 - 2/26 = 11/26 mi. remaining. 15h/0.5mi. = 30 h/mi. with old machine. T = (11/26)mi * 30h/mi = 12.69 h.
*September 10, 2014*

**algebra**

X oz. @ $3.50/oz. (30-X) oz. @ $7.00/oz. 3.50x + 7.00(30-x) = 6.30*30 3.5x + 210 - 7x = 189 -3.5x = 189 - 210 = -21 X = 6 oz. @ 3.50/oz. 30-X = 30-6 = 24 oz. @ $7.00/oz.
*September 10, 2014*

**algebra**

Invested $X @ 4%. Invested $(14,000-X) @ 2.5%. 0.04X + 0.025(14000-X) = $458. Solve for X.
*September 10, 2014*

**physics**

h = 0.5g*t^2 = 1.19 m. 4.9t^2 = 1.19 t^2 = 0.243 Tf = 0.493 s. = Fall time. Tr = Tf = 0.493 s. = Rise time. Tr+Tf = 0.493 + 0.493 = 0.986 s. = Time in air.
*September 10, 2014*

**Trig**

We draw 2 rt. triangles with a common ver. side: 1. Draw a hor. line with points A, B, C. AB = 25Ft, BC = X Ft. 2. Draw ver. line CD and label it h. 3. Draw AD which makes a 44o angle with AC. Draw BD which forms a 65o angle with BC. Tan65 = h/X h = X*Tan65 = 2.14X Tan44 = h/(...
*September 10, 2014*

**Math Problem (please help)**

a. d = (120N/265N) * 0.15m b. (F/265) * 0.15 = 0.30 0.15F = 79.5 F = 530 N.
*September 10, 2014*

**physics**

1. Vo = a*t = 2.59 * 19 = 49.21 m/s. d1 = 0.5a*t^2 = 0.5*2.59*19^2 = 467.5 m. 2. d2 = Vo*t = 49.21 * (2.15*60)=6348 m. 3. V = a*t = -9.08 * 5.42 = -49.21 m/s. V-Vo = 49.21-49.21 = 0 = Final velocity. d3 = (Vf^2-Vo^2)/2g. Vf = 0 d3 = -(Vo^2)/2g = -(49.21^2)/-19.6 = 124 m. a. D...
*September 10, 2014*

**physics**

Vo = a*t = 28 * 9.5 = 266 m/s. ho = 0.5a*t^2 = 14*9.5^2 = 1264 m. h = ho + (V^2-Vo^2)/2g h = 1264 + (0-(266^2)/-19.6 = 4874 m. = 4.874 km.
*September 10, 2014*

**physics**

Tr = 3.70s/2 = 3.85 s. = Rise time. Tr = -Vo/g = 3.85 s. -Vo/-9.8 = 3.85 -Vo = -37.73 Vo = 37.73 m/s.
*September 10, 2014*

**physics**

1st Stone: 4.9t^2 = 49 t^2 = 10 Tf = 3.16 s. = Fall time. 2nd stone: h = Vo*t + 0.5g*t^2 = 49 t = 3.16-1 = 2.16 s. = Fall time. Vo*2.16 + 4.9*2.16^2 = 49 2.16Vo + 22.86 = 49 2.16Vo = 49-22.86 = 26.14 Vo = 12.1 m/s. = Initial velocity.
*September 10, 2014*

**Physics**

Fp = mg*sin30 = Force parallel to the incline. a = Fp/m = mg*sin30/m = g*sin30 = 9.8*0.5 = 4.9 m/s^2.
*September 10, 2014*

**Physics**

a. Vo = 12m/s[8o] Xo = 12*cos8 = 11.88 m/s. Yo = 12*sin8 = 1.67 m/s. Tr = -Yo/g = -1.67/-9.8 = 0.170 s. = Rise time. h = ho + (Y^2-Yo^2)/2g h = 1.67 + (0-(1.67^2))/-19.6 = 1.74 m. Above gnd. d = 0.5g*t^2 = 1.74-1.0 4.9*t^2 = 0.74 t^2 = 0.151 Tf = 0.389 s. = Fall time. Dx = Xo...
*September 10, 2014*

**physics**

m*g = 120kg * 9.8N/kg = 1176 N. = Wt. of the bed. Fp = 1176*sin37 = 707.73 N. = Force parallel to the incline. Fn = 1176*cos37 = 939.20 N. = Normal = Force perpendicular to the incline. Fap-Fp = m*a Fap-707.73 = m*0 = 0 Fap = 707.73 N. = Force applied parallel to the incline. ...
*September 10, 2014*

**engineering science**

m*g = 60 N. = Wt. of object. Fp = 60*sin17.5 = 18.04 N. = Force parallel to the incline. Fn = 60*cos17.5 = 57.22 N. = Normal = force perpendicular to the incline. Fap-Fp-Fs = m*a 44-18.04-Fs = m*0 = 0 Fs = 44-18.04 = 26 N. = Force of static friction.
*September 10, 2014*

**physics**

h = 4000*sin3 Dx = 3000 + 4000*cos3
*September 9, 2014*

**physics**

Va*t + Vb*t = Da + Db. 8.4t + 7.1t = 5.3 + 4.5 15.5t = 9.8 t = 0.63226 h = Time at which their paths cross. d = 4.5 - 7.1*0.63226 = 4.5 - 4.489 = 0.01097 km = 11 m. East of flagpole.
*September 9, 2014*

**Physics**

V = Vo + a*t = 16 m/s. 0 + 2.8*t = 16 t1 = 5.71 s. to reach 16 m/s. d1 = 0.5a*t^2 = 0.5*2.8*5.71^2 = 45.65 m d2 = V*t2 = 16 * 16 = 256 m. t1+t2+t3 = 5.71 + 16 + 3.6 = 25.31 s in motion. V = Vo + a*t = 0 16 + a*3.6 = 0 3.6a = -16 a = -4.44 m/s^2. d3 = (V^2-V0^2)/2a = (0-(16^2...
*September 9, 2014*

**college algebra**

The procedure is the same except the inequality sign is reversed when multiplying or dividing by a negative number.
*September 9, 2014*

**math help**

(y^3)^-2(y^2)^0/y^-3 = y^-6*y^0/y^-3 = y^-6/y^-3 = y^-3 = 1/y^3
*September 9, 2014*

**physics**

See previous post: Tue, 9-9-14, 9:45 AM.
*September 9, 2014*

**physics**

V = 86km/h = 86000m/3600s = 23.89 m/s. a=(V-Vo)/t = (23.89-0)/5.2 = 4.59 m/s^2
*September 9, 2014*

**Algebra**

E/A = 0.75 Replace E with A-D: (A-D)/A = 0.75 Multiply both sides by A: A-D = 0.75A A - 0.75A = D 0.25A = D D/A = 0.25
*September 9, 2014*

**Algebra**

N/S = 12 S = N/12 S/A = 8.50 Replace S with N/12: (N/12)/A = 8.50 N/12A = 8.50 Multiply both sides by 12: N/A = 102
*September 9, 2014*

**Finance**

Net Profit = $58,247-0.26*58,247-36014- 18361-2198-7821-3228 = $-24,519.22
*September 9, 2014*

**Algebra**

a. 8 Weights. b. 1, 3, 5, 7, 9, 11, 13, 15 oz. c. Same as b.
*September 9, 2014*

**physics**

Vavg = (X2-X1)/(t2-t1) Vavg = (-4.3-8.0)/(-6.9-3.5) =
*September 9, 2014*

**math**

X = -B/2A = -150/-0.0006 = 25,000 Units.
*September 9, 2014*

**physics**

2. Continued. When the 2nd stone catchup, they will be the same distance above gnd.: h1 = h2 30 + 15t - 4.9*t^2 = 40*t - 4.9t^2 The 4.9t^2 terms cancel: 30 + 15t - 40t = 0 -25t = -30 t = 1.2 s. To catchup. h = 40*1.2 - 4.9*1.2^2 = 48 - 7.06 = 40.9 m. Above gnd. = Height at ...
*September 9, 2014*

**physics**

1a. d1 = d2 V*t = 0.5a*t^2 15*t = 1*t^2 Divide by t: t = 15 s. 1b. r = a*t = 2 * 15 = 30 m/s. = Speed of officer. 1c. D = 15*t = 15 * 15 = 225 m. 2. 1st Stone: Tr = -Vo/g = -15/-9.8 = 1.53 s. = Rise time. h = ho + (Vo*t - 0.5g*t^2) h = 30 + (15*1.53 - 4.9*1.53^2) = 30 + 22.96...
*September 9, 2014*

**math**

-3(u-2v-4) = -3u+6v+12.
*September 9, 2014*

**math**

(16/10)m^2 = 1.6 m^2.
*September 8, 2014*

**physics**

Vo = 100m/s[50o] Xo = 100*cos50 Yo = 100*sin50
*September 8, 2014*

**Math**

Use the Quadratic Formula and get: X = 0.926, and -0.364.
*September 8, 2014*

**Physicsl Science**

V = a*t
*September 8, 2014*

**Physics**

h = 4.9t^2 - 5.66t = 106 h = 4.9t^2 -5.66t - 106 = 0 Use Quadratic Formula. t = 5.264 s.
*September 8, 2014*

**physics**

Incomplete.
*September 8, 2014*

**Physics**

a. X = A = -13 Units. Y = B = ? Z= A+B = 16.8 Units = Resultant. X^2 + Y^2 = Z^2 (-13)^2 + Y^2 = 16.8^2 Y^2 = 16.8^2 - (-13)^2 = 282.24 - 169 = 113.24 Y = 10.64 Units = B. b. Tan Cr = Y/X = 10.64/-13 = -0.81846 Cr = -39.3o = Reference angle. C = -39.3 + 180 = 140.7o CCW = 39....
*September 8, 2014*

**Physics**

a = g = 9.8 m/s^2.
*September 8, 2014*

**Geometry**

TS = RS + TR
*September 8, 2014*

**physics**

a = 24/5.8 = 4.14 m/s^2.
*September 8, 2014*

**math 3**

An integer IS a whole number.
*September 8, 2014*

**physics**

d = V*t = 12km/h * 1h
*September 8, 2014*

**Physics**

Speed = d/t = 3.6km/(40/60)h
*September 8, 2014*

**Physics**

Vo = 19.2m/s[5.3o] Xo = 19.2*cos5.3 = 19.11 m/s. Yo = 19.2*sin5.3 = 1.77 m/s. Tr=-Yo/g = -1.77/-9.8 = 0.181 s. = Rise time. h=ho + -Yo^2/2g = 2.1 + -(1.77^2/-19.6 = 2.1 + 0.160 m. = 2.26 m. = Max. ht. above gnd. d = 0.5g*t^2 = 2.26 - 1.07 = 1.19 m. 4.9t^2 = 1.19 t^2 = 0.243 Tf...
*September 8, 2014*

**Physics**

V = Vo + g*t = 0 + 17*2 = 34 m/s.
*September 8, 2014*

**math**

Slope = 6. The pair of points whose slope is 6 are on the line. (0.-1), (5,29). m = (29-(-1)/(5-0) = 30/5 = 6.
*September 8, 2014*

**Physics**

Vw = 50*sin40 = 32.14 mph. Vn = 50*cos40 = 38.30 mph.
*September 8, 2014*

**physic**

a. d = 89 + 141km[64o[]CCW. d = 89 + 141*Cos64 + i141*sin64 d = 89 + 61.8 + 126.7i = 150.8 + 126.7i = 196.9km[40o] Speed = d/t = 196.9km/2h = 98.4km/h. b. V = 196.9km[40o]/2h = 98.4km/h[40o]. = 98.4km/h[50o] E of N.
*September 8, 2014*

**Physics**

d1 = 0.5g*t^2 = 4.9*0.62^2 = 3.04 m = 1/2 the distance. d = 0.5g*t^2 = 2*3.04 = 6.08 m. 4.9*t^2 = 6.08 t^2 = 1.24 t = 1.114 s. passed during entire trip.
*September 8, 2014*

**business math**

I = Po*r*t I = 8000*(0.11/365)*89 = $214.58
*September 7, 2014*

**Physics**

t = (V-Vo)/a = (3.4-23)/-2.1 = 9.33 s.
*September 7, 2014*

**physics**

a. V = 93.3km/h = 93,300m/3600s = 25.92 m/s a=(V-Vo)/t = (25.92-0)/4.1 = 6.32 m/s^2. m = F/a = 5000/6.32 = 791.1 kg. b. m*g = 791.1kg * 9.8N/kg = 7753 N. = Wt. of car.
*September 7, 2014*

**physics**

F=MA----(1) where F=force=5000N M=mass of car A=acceleration 1st)calculate acceleration. A=speed/time-------(2) (dont forget to convert speed into m/s) 2nd) replace A in (1), and solve for M :)
*September 7, 2014*

**Physical Science**

You must know the density of the substance. Assume 2g/cm^3 V = 90g/Density = 90/2 = 45 cm^3.
*September 7, 2014*

**science**

Where is the following?
*September 7, 2014*

**Chemistry (concentrations)**

Could you explain me, how u reached to that answer?
*September 7, 2014*

**Chemistry (concentrations)**

A liquid mixture has 12.6 parts per thousand of MgCl2 dissolved. Calculate the [Cl-] in ppt? Im stuck plz help!
*September 7, 2014*

**pre cal**

V(t) = Po - Po*r*t V(t) = 25,000 - 25000*0.05*t V(t) = 25000(1-0.05t)
*September 7, 2014*

**physics**

a = F/m = 390N[90o]/220 = 1.77m/s^2[90o] =1.77m/s^2, North.
*September 7, 2014*

**Math**

Change = -17 - (-10) = -17 + 10 = -7o C.
*September 6, 2014*

**Math**

Change = -17-(-10) = -17 + 10 = -7o C.
*September 6, 2014*

**physics**

a. V = a*t = 1.4 * 14 = 19.6 m/s. d = 0.5a*t^2 + V*t2 + (Vf-V)/2a b. d = 0.5*1.4*14^2 + 19.6*23 + (0-(19.6^2)/-2.6 = 137.2 + 450.8 + 147.8 = 736 m.
*September 6, 2014*

**physiscs**

Correction: Mass = 150kg/6 = 25kg on the moon.
*September 6, 2014*

**physiscs**

g = 9.8 on earth = 9.8/6 on the moon. Mass = 150g/6 = 25 Grams.
*September 6, 2014*

**physical science**

F2*d2 = F1*d1 F2*0.2 = 60 * 1.2 0.2F2 = 72 F2 = 360 N.
*September 6, 2014*

**(Please Help!) Analytic Geometry**

See previous post: Thu, 9-4-14, 6:20 AM
*September 6, 2014*

**physics**

Do you mean 2 meters away? If so, Dx = Vo^2*sin(2A)/g = 2 m. 6.8^2*sin(2A)/9.8 = 2. 46.24*sin(2A) = 19.6 sin(2A) = 0.42388 2A = 25.1o A = 12.54o
*September 6, 2014*

**Physics**

D = 745.6[298o] + 178[204o] + 490[55o] X=745.6*cos298 + 178*cos204 + 490*cos55= 468.5 Paces. Y=745.6*sin298 + 178*sin204 + 490*sin55= -329.3 Paces. Tan A = Y/X = -329.3/468.5 = -70291 A = -35.1o = 324.9o CCW = Direction. Displacement=X/Cos A = 468.5/Cos 324.9 = 573 Paces.
*September 5, 2014*

**physics**

D = 5.54km[47.9o] - 1.29km[24.60] X = 5.54*cos47.9 - 1.29*cos24.6=2.54 km. Y = 5.54*sin47.9 - 1.29*sin24.6=3.57 km. Tan A = Y/X = 3.57/2.54 = 1.40691 A = 54.6o Displacement = Y/sin A = 3.57/sin54.6 = 4.38km[54.6o]. a. Magnitude = 4.38 km. b. Direction = 54.6o N of E.
*September 5, 2014*

**AP Physics**

Since both vehicles are travelling at the same speed, they will meet at the midpoint. d = V*t = 7km/2 = 3.5 km. t = d/V = 3.5/85 = 0.04117647 h = 2.47 min.
*September 5, 2014*

**Business Math**

Correction: Cost = 40 * 3.20 = $128 A = 128 + 0.8*128 = $230.40 = Amt. to be received. (40-8)dinners * $D/dinner = 230.40 32D = 230.40 D = $7.20/dinner. (7.20-1.00)/7.20 = 0.861 = 86.1% % Markdown = 100 - 86.1 = 13.9
*September 5, 2014*

**Business Math**

Cost = 40*3.20 + 0.2*40*3.26 = $153.60 P=153.6 + 0.8*153.6 = $276.48 = Selling price for 40 dinners. 276.48/40 = $6.91 Each. (6.91-1.00)/6.91 = 85.5% % Markdown = 100%-85.5% = 14.5%
*September 5, 2014*

**Business Math**

P = Po - 0.1Po = 259.92 0.9Po = 259.92 Po = 288.80 Before 10% markdown. P = Po + 0.3Po = 288.80 1.3Po = 288.80 Po = $222.15 = Cost to Dylan.
*September 5, 2014*

**Business Math**

Correction: Cost = 600Lbs * 5.59/Lb. = $3354. A = 3354 + 0.6*3354 = $5366.40 = Amt. to be received for 60% markup. A = (600-60)Lbs. * $D/Lb. = 5366.40 540D = 5366.40 D = $9.94/Lb. to allow for 10% spoilage.
*September 5, 2014*

**Business Math**

Cost=600Lbs * 5.59/Lb. + 60Lbs*5.59/Lb. = $3689.40 P = 3689.40 + 0.6*3689.40 = $5903.04 = Selling Price for 600 Lbs. $5903.04/600Lbs. = $9.84/Lb.
*September 5, 2014*

**Math**

P = 5.12 + 0.55*5.12 = $7.94 /yd^2
*September 5, 2014*

**Physics**

a. d^2=X^2 + Y^2=1030^2 + (1950-1480)^2 = 1,281,800 d = 1132 m. b. Tan A = Y/X = (1950-1480)/1030 = 0.45631 A = 24.5o S. of E.
*September 5, 2014*

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