Monday

January 16, 2017
Total # Posts: 13,037

**Physics**

2. M*g = 1200*9.8 = 11,760 N. = Wt. of car. = Normal force(Fn). Fp = Mg*sin 0 = 0. Fk = uk*Fn = 0.1323*11,760 = 1556 N. Fp-Fk = M*a. 0-1556 = 1200a, a = -1.30 m/s^2. V^2 = Vo^2 + 2a*d. 0 = (20.1)^2 - 19.6d, d = ?.

*November 2, 2016*

**Physics**

Divide by Mg: 0.407-0.914u = a/g = 3.1/-9.81, 0.407-.914u = -0.316, uk = 0.791.

*November 2, 2016*

**Physics**

1. Fp = Mg*sin24 = 0.407Mg. Fn = Mg*Cos24 = 0.914Mg. Fk = u*0.914Mg. Fp-Fk = M*a. 0.407Mg-u*0.914Mg = M*a.

*November 2, 2016*

**physics**

V1 = Speed of 1st bus. V2 = 2V1 = Speed of 2nd bus. d1 + d2 = 240. V1*t + 2V1*t = 240, 3V1*t = 240, 3V1*1 = 240, V1 = 80 km/h. V2 = 2V1 = 2*80 = 160 km/h.

*November 2, 2016*

**physics**

1rev/12h * 1h/3600s. = 2.315*10^-5 rev/s.

*November 2, 2016*

**physics**

See previous post: Sat, 10-29-16, 2:04 PM.

*November 1, 2016*

**physics**

1rev/12h * 1h/3600s. = 0.00002315 = 2.315*10^-5 rev/s.

*November 1, 2016*

**physics**

See previous post: Sat, 10-29-16, 9:35 AM.

*November 1, 2016*

**Math**

Flavored.

*November 1, 2016*

**math**

Width = W meters. Length = 2W meters. W * 2W = 480 m^2. 2W^2 - 480 = 0, W^2 - 240 = W = 15.5 Meters. 2W = 2 * 15.5 = 31 Meters.

*November 1, 2016*

**Maths**

a. m = *y2-y1)/(x2-x1) = (6-5)/(-4-1) = -1/5. Use same procedure for part b, and c.

*November 1, 2016*

**Maths**

Consider the 4 points A(1,5), B(-4,6), C(0,0), D(-12,12). Find the gradients of the lines: (a) AB; (b) CD; (c) BD.

*November 1, 2016*

**Maths please help**

See previous post: Tue, 11-1-16, 11:33 AM.

*November 1, 2016*

**science**

d = r*t. 5+2 = 3*t, t = 2.33 s. r = d/t = 7m/2.33s. = 3 m/s. Disp. = 5-2 = 3 m. V = D/t = 3m/2.33s. = 1.29 m/s.

*November 1, 2016*

**maths**

(iii). x-1 = 3(-4-x). x-1 = -12-3x, X = -11/4. y-3 = 3(-1-y). y-3 = -3-3y, Y = 0.

*November 1, 2016*

**maths**

(1,3), (x,y), (-4,-1). (i). -4-x = 2(x-1). -4-x = 2x-2, X = -2/3. -1-y = 2(y-3). -1-y = 2y-6, Y = 5/3. (ii). x-1 = -4-x. X = -3/2. y-3 = -1-y. Y = 1.

*November 1, 2016*

**Physical**

Depth = Dwo/Dwa * h = (800/1000) * 0.5 = 0.40 m.

*November 1, 2016*

**Physics**

V = Vo + a*t. 0 = 32 - 1*t, t = 32 s.

*November 1, 2016*

**pre algebra 8th**

See previous post.

*October 31, 2016*

**pre algebra**

1. Your inequality is correct. 3200 + 0.02d >= 4000. 0.02d >= 4000-3200, 0.02d >= 800, d >= $40,000. 2. Correct.

*October 31, 2016*

**URGENT ANY PhYSIcs teacher help thouroighly pls**

M*g = 750 * 9.8 = 7350 N. = Wt. of car = Normal force(Fn). Fp = 7350*sin 0o = 0 = Force parallel to the plane. Fk = u*Fn = 0.5 * 7350 = 3675 N. = Force of kinetic friction. Fp-Fk = M*a. 0-3675 = 750a, a = -4.9 m/s^2. Or u = a/g. 0.5 = a/-9.8, a = -4.9 m/s^2.

*October 31, 2016*

**physics**

Incomplete.

*October 31, 2016*

**Physics**

Correction: 70-10 = 60 Addition seconds to stop.

*October 31, 2016*

**Physics**

Vo = 7.0rev/s. V = 60rev/10s = 6rev/s. V = Vo + a*t. 6 - 7 + a*10, a = -0.1 rev/s^2. V = Vo + a*t. 0 = 7 - 0.1*t, t = 70 s. = Stopping time. 70 - 6 = 64 additional seconds to stop.

*October 31, 2016*

**Math**

V = Vo + g*Tr. 0 = 64 - 32Tr, Tr = 2 s. = Rise time. h = -16Tr^2 + 64Tr + 192. h = -16*2^2 + 64*2 + 192 = 256 Ft. h = 0.5g*Tf^2. 256 = 16Tf^2, Tf = 4 s. = Fall time. Tr+Tf = 2 + 4 = 6 s. To hit gnd.

*October 30, 2016*

**math**

Cash: Cost = 0.80 * 20,000 = sh 16,000. Term: 12 * 2000 = sh 24,000. 24,000 - 16,000 = sh 8,000 more.

*October 30, 2016*

**Math Compound Interest**

d. P = Po*e^rt. P/Po = e^rt. r*t = 0.045/yr. * 11yrs. = 0.495, e^0.495 = P/Po, 1.6305 = P/500, P = $820.25.

*October 29, 2016*

**Math Compound Interest**

a. P = Po(1+r)^n. Po = $500. r = 0.045/yr. = Annual % rate. n = 1Comp/yr. * 11yrs. = 11Compounding periods. b. r = 0.045/yr. * 0.5yr. = 0.0225 = Semi-annual % rate. n = 2Comp./yr. * 11yrs. = 22 Compounding periods. c. r = 0.045/yr. * 0.25yr. = 0.01125 = Quarterly % rate. n = ...

*October 29, 2016*

**math**

250mi/h * 0.5h = 125 mile head start. 280T = 125 + 250T. 30T = 125, T = 4.17 Hours. = 4h and 10 Min. to catchup. 2:30 + 4:10 = 6:40 PM.

*October 29, 2016*

**physics**

Ham = 1000/9 = 111 Sandwiches. Bread = 1200/50 = 24 " """ 1. 24 Sandwiches. 2. 24*(9+50) = 1416 Grams. 3. Ham. 4. M =(111-24)sand. * 9g/sand. = 783 g.

*October 29, 2016*

**physics**

V = Vo + a*t. 1300 = 150 + a*1, a = 1150 rpm/s^2.

*October 29, 2016*

**math**

p = 100% - 2% = 98%.

*October 28, 2016*

**easy Math**

ho = 12 Ft.

*October 28, 2016*

**PHYSICS**

a. V^2 = Vo^2 + 2g*h. V^2 = 0 + 19.6*1 = 19.6, V = 4.43 m/s. b. V^2 = Vo^2 + 2g*h. 0 = Vo^2 -19.6*0.35, Vo = 2.62 m/s. c. M*V-M*Vo = 0.15*4.43 - 0.15*2.62 = 0.272Mass-m/s. d. V = Vo + a*t. -2.62 = 4.43 + a*0.06, a = -117.5 m/s^2. F = M*a = 0.15 * 117.5 = 17.6 N.

*October 28, 2016*

**Physics**

a. V = Vo + a*t. 9 = 30 + a*3, a = -10 m/s^2. F = M*a. The retarding force will be negative. b. V^2 = Vo^2 + 2a*d. 0 = 30^2 -20d, d = ?. c. Work = F*d in Joules.

*October 27, 2016*

**physics**

C = pi*2r = 3.14 * 4.4 = 13.8 m. = Circumference. Va = 3m/s * 1rev/13.8m * 6.28rad/rev = 1.37 rad/s. Momentum = M*Va = 46 * 1.37 = 1.87 kg.rad/s.

*October 27, 2016*

**physics**

Vo = 0.6m/s[20o]. Range = Vo^2*sin(2A)/g. Range = 0.6^2*sin(40)/9.8 =

*October 27, 2016*

**physics**

Vo = 1.5m/s[30o]. Xo = 1.5*Cos30 = 1.30 m/s. Yo = 1.5*sin30 = 0.75 m/s. Y = Yo + g*Tr. 0 = 0.75 - 9.8Tr, Tr = 0.077 s. = Rise time. h = ho + Yo*Tr + 0.5g*Tr^2. h = 0.75 + 0.75*0.077 - 4.9*0.077^2 = 0.779 m. Above the floor. h = 0.5g*Tf^2. 0.779 = 4.9Tf^2, Tf = ?. = Fall time. ...

*October 27, 2016*

**physics**

M1*V + M2*V = M1*V1 + M2*V2. 1380*4890 + 2970*4890 = 1380*5660 + 2970*V2. V2 = ?.

*October 27, 2016*

**physics**

b. KE1 = 0.5M*V1^2+0.5M*V2^2+0.5M*V3^2. KE1 = M(0.5V1^2+0.5V2^2+0.5V3^2). KE1 = 21,500(4.96 + 0.72 + 0.72) = 137,600 J. KE2 = 0.5M*V^2 = 32,250*1.8^2 = 105,300 J. KE!-KE2 = 137,600 - 105,300 = 32,300 J. lost.

*October 27, 2016*

**physics**

a. M1*V1 + M2*V2 + M3*V3=M1V+M2V+M3V 21500*3.15+21500*1.2+21500*1.2 = 64,500V. 116,100 = 64,500V, V = 1.6 m/s.

*October 27, 2016*

**math**

Granny is X yrs. old. Kiwi is (2x-13) yrs. old. x + (2x-13) = 77. 3x - 13 = 77, X = 30 yrs. old. 2x-13 = 2*30 - 13 = 47 yrs. old.

*October 27, 2016*

**Physics**

C. magnitude of a vector is greater than either of its components.

*October 27, 2016*

**Physics**

B. Velocity includes speed and direction(angle). The speedometer measures speed only.

*October 27, 2016*

**Physics**

Vo = 40m/s[30o]. Xo = 40*Cos30 = 34.64 m/s. Yo = 40*sin30 = 20 m/s. Y = Yo + g*Tr. 0 = 20 - 9.8Tr, Tr = 2.04 s. ha = Yo*Tr + 0.5g*Tr^2. ha = 20*2.04 - 4.9*2.04^2 = 20.4 m. = Ht. above tower. h = 20.4 + 60 = 80.4 m. Above gnd. 0.5g*Tf^2 = 80.4. 4.9Tf^2 = 80.4, Tf = 4.05 s. = ...

*October 27, 2016*

**Physics**

Tan A = (-18)/3 = -6, A = -80.5o = 80.5o S. of E.

*October 27, 2016*

**Physics**

Vo = 10m/s[20o] S. of E. Xo = 10*Cos20 = 9.4 m/s. h = 0.5g*Tf^2 = 8 m. 4.9Tf^2 = 8, Tf = 1.28 s. - Fall time. Dx = Xo*Tf = 9.4m/s * 1.28s = 12 m.

*October 27, 2016*

**Physics**

Vb = -7 + 5i = 8.6km/h[-35.5o] = 8.6km/h[35.5o] N. of W.

*October 27, 2016*

**Math GRE**

Avg. = (10+x)/2 = 12. 10 + x = 24, X = 14%.

*October 26, 2016*

**castor financial math**

Ar = Ab-I = 380 - 11.40 = $368.60 = Amt. received or proceeds.

*October 26, 2016*

**castor financial math**

I = Ab*r*t = 380*(0.18/360)*60 = $11.40

*October 26, 2016*

**physics**

Fn = M*g-F*sin30 = Normal force. Fk = uk * Fn = uk*(M*g-F*sin30).

*October 26, 2016*

**science**

Density = 50g/20cm^3 = 2.5 g/cm^3. The substance will sink, because its' density is greater than the density of water.

*October 26, 2016*

**value**

See Related Questions: Mon, 12-21-15, 10:38 AM.

*October 25, 2016*

**bus math**

Ar = Ab - I. Ar = Ab - Ab*r*t. Ar = 2900 - 2900*(0.0625/360)*180 = Amt. received. Ab = Amt. borrowed.

*October 25, 2016*

**Physics**

See previous post: Sat., 10-22-16, 11:54 AM.

*October 24, 2016*

**Physics**

V^2 = 19.6, V = 4.43 m/s.

*October 24, 2016*

**Physics**

V^2 = Vo^2 + 2g*h. V^2 = 0 + 19.6*1 =

*October 24, 2016*

**physics projectile**

See previous post: Mon, 10-24-16, 5:42 PM.

*October 24, 2016*

**physics Projectiles**

1. See Previous post: Mon, 10-24-16, 5:42 PM. 2. Vo = 50m/s a. A = 45o for max. range. b. R = Vo^2*sin(2A)/g.

*October 24, 2016*

**Math**

Z = k * xy. 2.4 = k * 3*2, k = 0.4. Z = 0.4xy.

*October 24, 2016*

**physics projectiles**

Vo = 20m/s[30o]. Xo = 20*Cos30 = 17.32 m/s. Yo = 20*sin30 = 10 m/s. a. Y = Yo + g*Tr. 0 = 10 -9.8Tr, Tr = 1.02 s. = Rise time. Tf = Tr = 1.02 s. Tr+Tf = 1.02 + 1.02 = 2.04 s. = Time in flight. b. h = Yo*Tr + 0.5g*Tr^2. h = 10*1.02 - 4.9*1.02^2 = c. Range = Xo*(Tr+Tf)= 17.32*2....

*October 24, 2016*

**Physics**

Vo = 44rev/min. * 6.28rad/rev * 1min/60s. = 4.61 rad/s. V^2 = Vo^2 + 2a*D. 0 = 4.61^2 - 2.6D, D = ?.

*October 24, 2016*

**Science**

P = V*I = 120 * 6 = R = V/I = 120/6 =

*October 24, 2016*

**physics**

See Related Questions: Fri, 2-7-14, 2:59 AM.

*October 24, 2016*

**physics**

See Related Questions: Thu, 1-22-15, 6:20 PM.

*October 23, 2016*

**Math**

400mg = 0.400g = 4.00*10^-4 kg. 1 tonne = 1000kg. 1000/4*10^-4 = 2.5*10^6 = 2.5 Million buttons.

*October 23, 2016*

**Science**

Density = 85g/100cm^3 = 0.85g/cm^3.

*October 23, 2016*

**math**

Gordon: 4*t = 50, t = 12.5 s. Maria: d = 1m/s * 12.5s = 12.5 m. Difference = 50-12.5 = 37.5 m. Gordon beats her by 37.5 m.

*October 23, 2016*

**Physics**

Vo = 17rev/min. * 6.28rad/rev * 1min/60s = 1.78 rad/s. V = Vo + a*t. 0 = 1.78 - 2.2*t, t = ?.

*October 22, 2016*

**science**

a. Va = 120rev/min. * 6.28rad/rev * 1min./60s = 12.56 rad/s. b. C = pi*2r = 3.14 * 20cm = 62.8 cm = 0.628 m.= Circumference. V = 120rev/min * 0.628m/rev * 1min/60s = 1.256 m/s.

*October 22, 2016*

**Physical**

V = Vo + a*t = 14 - 7*1 = 7 m/s. V^2 = Vo^2 + 2a*d. 7^2 = 14^2 - 14*d, d = ?.

*October 22, 2016*

**PHYSIC**

a. Dx = Xo*t. t = Dx/Xo = 20/300 = 0.067 s. Dy = 0.5g*t^2 = 4.9*0.067^2 = 0.022 m. b. t = d/Vo = 40/300 = 0.133 s. Dy = 4.9*0.133^2 = 0.087 m. c. t = Dx/Vo = 80/300 = 0.267 s. Dy = 4.9*0.267^2 = 0.348 m. d. Dy = 4.9*1^2 = 4.9 m.

*October 22, 2016*

**Physics**

Yes. In fact, the resultant can be zero.

*October 22, 2016*

**Physics**

F1 = 100[30o] N. of E. = [30o]CCW. F1 + F2 = 0. 100[30] + F2 = 0. 100*Cos30 + (100*sin30)i + F2 =0. 86.6 + 50i + F2 = 0. F2 = -86.6-50i(Q3) = 100[30o] S. of W. = 100[210o] CCW from +x-axis. 210o - 30o = 180o. So the two vectors are 180o out of phase. Therefore, point in ...

*October 22, 2016*

**Physics**

See previous post: Fri, 10-21-16, 11:02 PM.

*October 22, 2016*

**Physics**

If F1 + F2 = 0, They must be equal in magnitude and opposite in direction. They cannot have different magnitudes(lengths). If F1 and F2 are unequal, a third force may be added to give a sum of zero. However, the third force must be equal to the sum of the first two and ...

*October 21, 2016*

**Math**

P = Po(1+r)^n. n = 1comp./yr * 3yrs = 3 Compounding periods. P = 2000(1+.03)^3 = $2,185.45.

*October 21, 2016*

**math**

a. Y = kx 72 = k*6, k = 12. Eq: Y = 12x. b. Y = 12 * 10 = 120.

*October 21, 2016*

**Physics**

F2 = (Vs_Vr)/(Vs+Vg) * F1. F2 = (340-0)/340+2.3) * 74 = 73.5 Hz. Fb = F1-F2 = 74 - 73.5 = 0.5 Hz.

*October 21, 2016*

**Physics**

V = 100km/h = 100,000m/3600s = 27.78 m/s. KE = 0.5M*V^2 = 500 * 27.78^2 = 385,802 J. = KE of the auto. 0.5M*V^2 = 385,802. 25*V^2 = 385,802, V = ?.

*October 20, 2016*

**Math**

P = Po*r*t/(1-(1+r)^-t). Po = 07 * 49,500 = $34,650 Financed. r = 0.12/12 = 0.01/mo. t = 2.5yrs * 12mo/yr. = 30 mo. P = (34,650*0.01*30)/(1-(1.01)^-30) = 10,395/0.25807708 = $40,278.66 = Total amt. paid. 40,278.66/30mo. = $1342.62 /mo. 0

*October 20, 2016*

**math**

Correction: The plane is not a free-fall object. a. d = Yo*t. 10,000 = 140*t, t = ?. b. 16,000 = 140*t, t = ?.

*October 20, 2016*

**math**

Vo = 345Ft/s[24o]. Xo = 345*Cos24 = 315 Ft/s. Yo = 345*sin24 = 140 Ft/s. Y^2 = Yo^2 + 2g*h. 0 = 140^2 - 64*h. h = 306.25 Ft., max. Based on the information given, the plane can reach a maximum ht. of only 306 Ft.

*October 20, 2016*

**science**

Efficiency = Output/Input. High friction lowers the output and causes mechanical efficiency to be lowered.

*October 20, 2016*

**physics**

Vo = 80m/s[30o]. Xo = 80*Cos30 = 69.3 m/s. Yo = 80*sin30 = 40 m/s. a. Y = Yo + g*Tr. 0 = 40 - 9.8Tr, Tr = 4.08 s. = Rise time. h = Yo*Tr + 0.5g*Tr^2. h = 40*4.08 -4.9*4.08^2 = 81.6 m. b. Tf = Tr = 4.08 m/s. = Fall time. Tr+Tf = 4.08 + 4.08 = 8.16 s. = Time in air. c. Range = ...

*October 20, 2016*

**Math**

Sign: W = 22/36 * 52 = 32. Ab/As = (36*52)/(22*32) = 2.68. Or Ab/As = (36/22)^2 = 2.68.

*October 20, 2016*

**Physics**

See previous post: Tue, 10-18-16, 8:27 AM.

*October 20, 2016*

**Physics**

M*g = 12*9.8 = 117.6 N. = Wt. of the object. Fp = 117.6*sin56 = 97.5 N. = Force parallel to the slope. a. Work = Fp*d = 97.5 * 34 = 3315 J.

*October 20, 2016*

**Physics**

1. M1*V1 + M2*V2 = M1*V + M2*V. 600*30 + 900*0 = 600V * 900V, 18000 = 1500V, V = 12 m/s. 2. V = Vo + a*t. 12 = 30 + a*0.15, a = -120 m/s^2. F = M*a = (M1+M2)*a = 1500 * (-120) = -180,000 N. The negative sign means the force opposed the motion. 3. a = -120 m/s^2.

*October 20, 2016*

**Maths**

X = Smaller number. x+4x = 5x = Larger number. 5x-x = 24. X = 6, 5x = 30.

*October 19, 2016*

**physic**

Density = (80-25)g/500mL = 0.11g/mL.

*October 19, 2016*

**math**

X adults. 4x children. x + 4x = 300. X = 60 Adult seats. 4x = 4*60 = 240 Children seats.

*October 19, 2016*

**Math**

Cathy had $X. x - x/5 - x/4 - 120 = 540. x - 4x/20 - 5x/20 - 120 = 540, 20x - 4x - 5x - 2400 = 10,800, 11x = 13,200, X = $1200.

*October 18, 2016*

**Math**

The opposite angles are equal: A = C = 2x+25, B = D = 3x-5. 2(2x+25) + 2(3x-5) = 360. 4x+50 + 6x-10 = 360, X = 32. A = C = 64+25 = 89o, B = D = 96-5 = 91.

*October 18, 2016*

**physics**

a. M*g = 50 * 9.8 = 490 N. = Wt. of sled = Normal force(Fn). Fs = us*Fn = 0.3 * 490 = 147 N. Fap-Fs = M*a. Fap = M*0 + 147 = 147 N. b. Fk = uk*Fn = 0.10 * 490 = 49 N. Fap = M*0 + 49 = 49N.

*October 18, 2016*

**Physics**

V = Vo + a*t. 78 = 0 + a*0.04, a = 1950 m/s^2, F = M*a = 0.145 * 1950 = 283 N.

*October 18, 2016*

**Physics**

See previous post: Tue, 10-18-16, 4:43 AM.

*October 18, 2016*

**Physics**

M1V1 + M2V2 = M1V + M2V. 14866*5-14866*5 = 14866V+14866V, V = 0.

*October 18, 2016*

**Math**

a. L = 120yds * 3ft./yd = 360 Ft. W = 53 1/3yd * 3ft/yd = 160 Ft. b. Length = 2L + 2W = 2*360 + 2*160 = 1040 Ft. = Perimeter. c. 5,280Ft/mi * 1Lap/1040Ft = 5.1 Laps/m1. or 5.1 Laps = 1 mile.

*October 18, 2016*