Friday

August 28, 2015
Total # Posts: 10,919

**physics**

m*g = 7 * 9.8 = 68.6 N. = Wt. of book. Fp = 68.6*sin A = Force parallel to the plank. Fn = 68.6*Cos A = Force perpendicular to the plank. Fs = u*Fn = 0.4*68.6*Cos A Fp-Fs = m*a 68.6*sin A - 0.4*68.6*Cos A = m*0 = 0 68.6*Sin A = 0.4*68.6*Cos A Sin A = 0.4*Cos A Divide both ...
*September 24, 2014*

**Physics**

Q1. a = g = -9.8 m/s^2 = 9.8 m/s^2 Downward. Q2. h = 0.5g*t^2 = 4.9*3^2 = 44.1 m.
*September 23, 2014*

**algebra**

Multiply Eq1 by 1.25 and Eq2 by 0.25 and subtract: 0.3125x + 0.1875y = 3.125 0.3125x - 0.3125y = 1.875 Diff. : 0.5Y = 1.25 Y = 2.5 In Eq1, replace y with 2.5: 0.25x + 0.15*2.5 = 2.5 0.25x = 2.5 - 0.375 = 2.125 X = 8.5
*September 23, 2014*

**Mathematics and investment**

1. P = Po(1+r)^n P = $300,000 Po = Initial investment. r = (8%/4)/100% = 0.02 = Quarterly % rate expressed as a decimal. n = 4Comp/yr. * 3yrs. = 12 Compounding periods. P = Po*(1.02)^12 = 300,000 Po = 300,000/1.02^12 = $236,547.95 2. Same procedure as #1. 3. Po = 125,000 - ...
*September 23, 2014*

**math**

3(x+2)
*September 22, 2014*

**physics**

h1 = V*t + 0.5g*t^2 = 30 m. V*1 + 4.9*1^2 = 30 V = 30 - 4.9 = 25.1 m/s h = (V^2-Vo^2)/2g + h1 h = (25.1^2-0)/19.6 + 30 = 62.14 m. = Ht. of the peak.
*September 22, 2014*

**Math**

1/2 = 3/6 1/3 = 2/6 1 = 6/6 6/6 - 3/6 - 2/6 = 1/6 = Green 1/6 * M = 7 = Green M = 42 Marbles.
*September 22, 2014*

**Trigonometry (Math)**

Tan63.33 = Y1/X = 5/X X*Tan63.33 = 5 X = 5/Tan63.33 = 2.51 m = Distance from the point of observation. Tan40.17 = Y2/X = Y2/2.51 Y2 = 2.51*Tan40.17 = 2.12 m. h = Y1+Y2 = 5 + 2.12 = 7.12 m.
*September 22, 2014*

**physics**

Xo = 17 m/s. Yo = 15 m/s. a. Tr = -Yo/g = -15/-9.8 = 1.53 s. = Rise Time. b. h = 0.5g*Tr^2 = 4.9*1.53*2 = 11.47 m. c. T = Tr+Tf = 1.53 + 1.53 = 3.06 s. d. Dx = Xo*T = 17m/s. * 3.06 = 52.02 m.
*September 22, 2014*

**physics**

a. h = 0.5g*t^2 = 310 m. 4.9t^2 = 310 t^2 = 63.27 Tf = 7.95 s. = Fall time. b. c. X = Xo = 75 m/s. Remains constant. d. Y=Yo + g*Tf = 0 + 9.8*7.95=77.95 m/s e. Dx = Xo*Tf = 75m/s * 7.95s. = 596 m. Fom drop-off point.
*September 22, 2014*

**college physics**

A. h = 0.5g*t^2 = 0.90 m. 4.9t^2 = 0.90 t^2 = 0.184 t = 0.429 s. = Fall time. B. Dx = Xo*t = 1.6 m. Xo * 0.429 = 1.6 Xo = 3.73 m/s. = Hor. component. C. Y = Yo+g*t = 0 + 9.8*0.429 = 4.20 m/s = Ver. component. V^2 = Xo^2 + Y^2 = 3.73^2 + 4.2^2=31.55 V = 5.62 m/s. D. tan A = Y/...
*September 22, 2014*

**Math**

a. Tr = -Vo/g = -87/-32 = 2.72 s. = Rise time. h=-16*2.72^2 + 87*2.72 + 550=668.3 Ft. Above gnd. b. h = 0.5g*t^2 = 668.3 Ft. 16*t^2 = 668.3 t^2 = 41.77 Tf = 6.46 s. = Fall time. Tr + Tf = 2.72 + 6.46 = 9.18 s. To reach gnd.
*September 22, 2014*

**Math**

Y = x^2 + 8x - 11 h = Xv = -B/2A = -8/2 = -4. k = Yv = (-4)^2 + 8*(-4) - 11 = -27 V(h, k) = (-4,-27) Use the following points for graphing: (x, y). (-10,9) (-7,-18) (-6,-23) (-5,-26) V(-4,-27) (-3,-26) (-2,-23) (-1,-18) (2,9). X-intercepts: X1 will be negative. X2 will be ...
*September 22, 2014*

**Physics**

(245+r)/2 = 230 km/h 245 + r = 460 r = 460-245 = 215 km/h.
*September 22, 2014*

**physics**

Dx = Vo^2*sin(2A)/g = 33^2*sin33.6/9.8 = 65.13 m. 65.13m/2.74 = 23.8 or 23 Busses.
*September 21, 2014*

**science**

Correction: Tr = -Vo/g = -100/-10 = 10 s.=Rise time. h1 = Vo*Tr + 0.5g*Tr^2 h1 = 100*10 - 5*10^2=500 m. Above tower. Tf = 25 - 10 = 15 s. = Fall time. h1+h2 = 0.5g*Tf^2 = 5*15^2 = 1125 m. h1+h2 = 1125 500 + h2 = 1125 h2 = 1125-500 = 625 m.=Ht. of the tower.
*September 21, 2014*

**science**

Tr=-Vo/g = -100/-9.8=10.20 s.=Rise time. d = Vo*Tr + 0.5g*Tr^2 d = 100*10.20 - 4.9*10.20^2 = 510 m Above tower. Tf = 25 - 10.20 = 14.8 s. = Fall time. h+d = 0.5g*Tf^2 = 4.9*14.8^2 = 1073 m. h + d = 1073 h + 510 = 1073 h = 1073-510 = 563 m. = Ht. of the tower
*September 21, 2014*

**Maths**

Your problem will be easier to understand if you used punctuations and capital letters at the beginning of each sentence.
*September 21, 2014*

**physics**

Fx = 18-0.53N/m * 14m = 10.58 N. a = F/m = 10.58/6 = 1.76 m/s^2. V^2 = Vo^2 + 2a*d = 0 + 2*1.76*14 = 49.4 V = 7.03 m/s.
*September 20, 2014*

**physics**

See previous post: Sat, 9-20-14, 2:48 AM
*September 20, 2014*

**nova**

7a. V^2 = Vo^2 + 2g*h Vo^2 = V^2 - 2g*h = 25^2 + 19.6*15 = 919 Vo = 30.32 m/s. 7b. h = -(Vo^2)/2g = -(30.32^2)/-19.6 = 46.9 m. 8. a = F/m = 12/6 = 2 m/s^2 V^2 = Vo^2 + 2a*d Vo = 0, a = 2 m/s^2 d = 3 m. Solve for V.
*September 20, 2014*

**physics**

h = 78 * 6 = 468 m.
*September 20, 2014*

**physics- HELP**

See previous post: Fri, 9-19-14, 3:00 AM
*September 19, 2014*

**Math**

1.---3^1 = 3 cm. 2.---3^2 = 9 cm. 3.---3^3 = 27 cm. Y = 3^x. x = The # of hours. Y = The length. Y = 3^3 = 27 cm.
*September 19, 2014*

**Pre-Calc**

F(x) = x^2 - 8x + 15 15 = (-1)*(-15 = (-3)*(-5). Choose the pair of factors whose sum = B = -8. (X-3)(X-5) = 0 x-3 = 0 X = 3. x-5 = 0 X = 5.
*September 19, 2014*

**math**

Factors of 27y^3z = 1,3,5,9,27,y,y^2. Factors of 45x^2y = 1,3.5,9,15,45,x,y. CF = 1,3,5,9,y. GCF = 9.
*September 19, 2014*

**physics**

Dx = Vo^2*sin(2A)/g = 7.04 m Vo^2*sin(37.4)/9.8 = 7.04 Solve for Vo.
*September 19, 2014*

**physics**

a. Vo = 85.3m/s[45o] Xo = 85.3*Cos45 = 60.32 m/s. Yo = 85.3*sin45 = 60.32 m/s. h = 0.5g*t^2 = 587 m. 4.9t^2 = 587 t^2 = 119.8 Tf = 10.95 s. = Fall time. Dx = Xo * Tf = 60.32m/s * 10.95s=660 m. b. Y = Yo + g*Tf = 0 + 9.8*10.95 = 107.3 m/s. Tan A = Y/Xo = 107.3/60.32 = 1.77822 A...
*September 19, 2014*

**physics**

m*g = 16.3*9.8 = 159.74 N. Fp = 159.74*sin28 = 75 N. Fn = 159.74*cos28 = 141 N. Fp-Fk = m*a 75-Fk = m*0 = 0 Fk = 75 N. KE = 0.5m*V^2 = 0.5*16.3*1.8^2=26.41 J. Fp*d = KE-Fk*d 75 * d = 26.41-75*d 75d + 75d = 26.41 150d = 26.41 d = 0.176 m.
*September 19, 2014*

**Physics**

Vo = 38km/h = 38000m/3600s = 10.56 m/s. a = (V^2-Vo^2)/2d = (0-10.56^2)/0.018m = 6195 m/s^2. F = m*a = 850 * 6195 = 5,265,920 N. Maybe we shouldn't stop it on a dime!
*September 19, 2014*

**Physics**

Dx = Vo^2*sin(2A)/g = 4.50 m. Vo^2*sin(80)/9.8 = 4.50 0.1Vo^2 = 4.50 Vo^2 = 45 Vo = 6.70 m/s[40o]. = Initial velocity.
*September 18, 2014*

**physic**

V = Vo * a*t = 29 - 2*4 = 21 m/s. d = (V^2-Vo^2)/2a = (21^2-29^2)/-4 = 100 m.
*September 18, 2014*

**Physics**

Dx = Vo^2*sin(2A)/g Dx = 23^2*sin80/9.8 =
*September 18, 2014*

**PHYYYYYSICS 9**

See previous post.
*September 18, 2014*

**PHYYYYYSICS 8**

h = 0.5g*t^2 = 40 m. 4.9t^2 = 40 t^2 = 8.16 t = 2.86 s.
*September 18, 2014*

**PHYYYYYSICS 5**

V = 56Mph[75o] - (- 40Mph[210o]) = Vb = 56[75o] + 40[210] X = 56*Cos75 + 40*Cos210 = -20.15 Mph Y = 56*sin75 + 40*sin210 = 34.1 Mph Vb^2 = (-20.15)^2 + (34.1)^2 = 1568.83 Vb = 39.6 Mph = Brian's speed.
*September 18, 2014*

**PHYYYYYSICS 4**

Vp = Vo + Vw = 71i - 23 = -23 + 71i. Tan Ar = 71/-23 = -3.08696 Ar = -72.0o S. of E. A = -72.0 + 180 = 108o CCW.
*September 18, 2014*

**PHYYYYYSICS 3**

Vo = 31.7m/s[55o] Xo = 31.7*cos55 = 18.18 m/s. Yo = 31.7*sin55 = 25.97 m/x. Dx = Vo^2*sin(2A)/g=31.7^2*sin(110)/9.8 = 96.4 m.
*September 18, 2014*

**PHYYYYYSICS 2**

Vo = 39.7m/s[55o] Yo = 39.7*sin55 = 32.52 m/s. = Vertical component. Y^2 = Yo^2 + 2g*h h = (Y^2-Yo^2)/2g = (0-(32.52^2)/-19.6 = 54 m.
*September 18, 2014*

**PHYYYYYSICS**

Vo = 28.6 m/s[20o] Xo = 28.6*Cos20 = 25.18 m/s. Yo = 28.6*sin20 = 9.78 m/s. Dx = Xo * t = 25.18m/s * 1.05s. = 26.4 m
*September 18, 2014*

**physics**

V^2 = Vo^2 + 2g*h = 0 + 40*10 = 400 V = 20 m/s. 0.5g*t^2 = 10 m. 10*t^2 = 10 t^2 = 1 t = 1 s. Or V = Vo + g*t = 20 V = 0 + 20t = 20 t = 1 s.
*September 18, 2014*

**physics**

Where are the tables?
*September 18, 2014*

**physical science**

r = 100m/10.79s. = 9.27 m/s.
*September 18, 2014*

**physical science**

Superfly: Mass = 1*10^-3 kg V = 840*10^6km/h = 840*10^9m/3600s. = 2.333*10^8 m/s. Momentum = M*V = 1*10^-3 * 2.33*10^8 = 2.33*10^5. Locomotive: Mass = 20,000kg V = 40km/h = 40,000m/3600s = 11.11 m/s. Momentum = M*V = 2.*10^4 * 11.11 = 2.22*10^5. Superfly has the greater ...
*September 18, 2014*

**physics**

(Vs-Vw)t1 = 750 m. (1.10-0.4)t = 750 0.7t1 = 750 t = 1071.4 s. = 17.9 min. = Time to swim upstream. (1.10+0.4)t2 = 750 m. 1.5t2 = 750 t2 = 500 s. = 8.33 min. = Time to swim downstream. t1+t2 = 17.9 + 8.33 = 26.2 min. = Time to swim upstream and back. t3 = d/V = (750+750)/1.1...
*September 16, 2014*

**science**

1a. F2*d2 = F1*d1 100*d2 = 300*0.5 = 150 d2 = 1.5 m. 1b. 150*d2 = 300*0.5 = 150 d2 = 1.0 m.
*September 16, 2014*

**Physics**

All angles are CCW. 459km/h[140o] + Vw = 498km/[156o] Vw = 498[156] - 459[140] X = 498*Cos156 - 459*Cos140 =-103.3 km/h Y = 498*sin156 - 459*sin140 = -92.48km/h Tan Ar = Y/X = -92.48/-103.3 = 0.89530 Ar = 41.84o = Reference angle. A = 41.84 + 180 = 221.84o CCW = 41.84o S. of W...
*September 16, 2014*

**physics**

Vo = 500m/s[30o] Xo = 500*cos30 = 433 m/s. Yo = 500*sin30 = 250 m/s. Tr = -Yo/g = -250/-9.8 = 25.5 s. = Rise time. Tf = Tr = 25.5 s. = Fall time. Tr+Tf = 25.5 + 25.5 = 51 s. = Time in air. Dx = Xo*(Tr+Tf) = 433*51 = 22,083 m. = Distance travelled by the shell. D = Dx + Dt = 22...
*September 16, 2014*

**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*

**geometry**

A.(x,y), (-9,-10), (-1,9). -9-x = 1/2(-1-x). -18-2x = -1-x. -x = 17. X = -17. -10-y = 1/2(9-y). -20-2y = 9-y. -y = 29. Y = -29. B. (x,y), (4,8), (9,-10). 4-x = 1/2(9-x). Multiply both sides by 2, and Solve for x. 8-y = 1/2(-10-y).
*September 11, 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*