Tuesday

February 21, 2017
Total # Posts: 13,190

**Physics**

a. t = 1s/1.6rad * 6.28rad/rev * 30rev = 117.75 s. b. V = Vo + a*t = 1.6 + 0.32*117.75 = 39.28 rad/s.

*November 8, 2016*

**physics**

M*g = 25*9.8 = 245 N. = Wt. of block. Fp = 245*sin32 = 129.8 N. = Force parallel to the incline. Fn = 245*Cos32 = 207.8 N. = Normal force. Fs = u*Fn = 0.45 * 207.8 = 93.5 N. = Force of static friction. F-Fp-Fs = M*a. a = 0. F = Ma+Fp+Fs = 0 + 129.8 + 93.5 = 223.3 N.

*November 8, 2016*

**Physics**

F*V = 40,000 W. F*50 = 40,000, F = 800 N.

*November 8, 2016*

**phisics**

Correction: After the brakes were applied, V = Vo + a*t = 0. 12 + a*5 = 0, a = -2.4 m/s^2. d3 = Vo*t + 0.5a*t^2. d3 = 12*5 - 1.2*5^2 = 30 m. d = d1+d2+d3 = 36 + 360 + 30 = 426 m. = Total distance covered.

*November 8, 2016*

**phisics**

a. V = a*t = 2 * 6 = 12 m/s. V = 0.012km/s * 3600s/h = 43.2 km/h. b. d1 = 0.5a*t^2 = 0.5*2*6^2 = 36 m. d2 = V*t = 12 * 30 = 360 m. V = Vo + a*t = 0. 12 + a*6 = 0, a = -2 m/s^2 d3 = Vo*t + 0.5a*t^2. d3 = 12*6 - 1*5^2 = 47 m. d = d1+d2+d3 = Total distance.

*November 8, 2016*

**Physics**

b. KEb = 0.5M1*V1^2 + 0.5M2*V2^2 = Kinetic energy before collision. KEa = 0.5M1*V^2 + 0.5M2*v^2 = Kinetic energy after collision. KE Lost = KEb - KEa. %KE Lost = KE Lost/KEb.

*November 6, 2016*

**Physics**

M1 = 1200kg. V1 = 30km/h = 30,000m/3600s = 8.33 m/s[0o]. M2 = 1500 g. V2[90o] = ?. a. M1*V1 + M2*V2 = M1*V + M2*V. 1200*8.33 + 1500V2[90o] = 1200V[64o] + 1500V[64o]. 10,000 + 1500V2[90o] = 2700V[64o]. The hor. components before the collision = Hor. components after collision: ...

*November 6, 2016*

**math**

See previous post: Sun, 11-6-16, 4:19 AM.

*November 6, 2016*

**math**

Tan70 = 34/d1, d1 = 34/Tan70 = 12.4 m. = Jane's distance from the tower. Tan50 = 34/d2, d2 = 34/Tan50 = 28.5 m. = Bill's distance from the tower. d1+d2 = 12.4 + 28.5 = 40.9 m. Apart.

*November 6, 2016*

**Maths**

Tan35 = h/d, h = d*Tan35. Tan16 = h/(d+950), h = (d+950)Tan16. d*Tan35 = (d+950)*Tan16. 0.7d = 0.287d + 272.4, 0.413d = 272.4, d = 659.6 m. h = d*Tan35 = 659.6 * Tan35 = 461.8 m.

*November 6, 2016*

**physics**

h = 0.5g*t^2 = 4.9*10^2 = 490 m.

*November 6, 2016*

**physics**

V^2 = Vo^2 + 2g*h = 0 + 19.6*7000, V = 370 m/s. V = 0.370km/s * 3600s/h = 1333 km/h.

*November 6, 2016*

**physics**

a. V = 3 + 5i = 5.83km/h[59o]. b. d = 3km/h * 0.5h = 1.5 km. c. Width = 5km/h * 0.5h = 2.5 km.

*November 6, 2016*

**math**

Vo = 82m/s[13o]. Yo = 82*sin13 = 18.45 m/s. h = Yo*t = 18.45m/s * 420s. = 7747 m.

*November 6, 2016*

**math**

Tan A = h/d. Tan 6 = 27,000/d, d = ?.

*November 6, 2016*

**Business mathematics**

P = Po(1+r)^n. Po = 7000 - 2000 = $5000. r = 0.05/12mo. = 0.00417/mo. n = 1Comp./mo. * 15mo. = 15 Compounding periods. P/15 = Monthly payment.

*November 6, 2016*

**Physics**

M*V1 + M*V2 = M*V3[45o] + M*V4[30o]. V1 + 0 = V3[45o] + V4[30o]. 44 = V3*Cos45 + V4*Cos30. Eq1: 0.707V3 + 0.866V4 = 44, V3 = 62.2-1.22V4. V3*sin45 + V4*sin30 = 0. Eq2: 0.707V3 + 0.5V4 = 0, 1.414V3 + V4 = 0, V4 = -1.414V3. V3 = 62.2 - 1.22*(-1.414V3), V3 = 62.2 + 1.73V3, V3 = -...

*November 5, 2016*

**Physics**

Northwest = 45o N. of W. = 135o CCW from +x-axis. Disp. = 18km[135o] - 9. Disp. = 18*Cos135-9 + 18*sin135 = -12.73-9 + 12.73i = -21.73 + 12.73i = 25.2km[-30.4o] = 25.2km[30.4o] N. of W.

*November 5, 2016*

**Physics**

See previous post: Wed, 11-2-16, 9:11 PM.

*November 4, 2016*

**Physics**

9/9 - 1/9 = 8/9 of its' volume below water. Dw = 1 g/cm^3. Vb = Di/Dw * Vi. 8/9 = Di/1 * 1, Di = 0.889 g/cm^3.

*November 4, 2016*

**PHYSICS (REALLY DIFFICULT PLEASE HELP)**

Fp = Force parallel to the surface.

*November 4, 2016*

**PHYSICS (REALLY DIFFICULT PLEASE HELP)**

Fp = Mg*sin 0 = 0. Fn = Mg*Cos 0 = Mg = Normal force. Fk = u*Fn = 0.50*Mg. Fp-Fk = M*a. 0-0.5Mg = M*a, Divide by Mg: -0.5 = a/g = a/-10, a = 5 m/s^2. V^2 = 60^2 - 10d. 0 = 3600 -10d, d = 360 m.

*November 4, 2016*

**Physics**

a. V1^2 = Vo^2 + 2g*h. V1^2 = 0 + 20*8, V1 = 12.65 m/s. V^2 = V2^2 + 2g*h. 0 = V2^2 - 20*2, V2 = 6.32 m/s. M*V1-M*V2 = 0.1*12.65 - 0.1*6.32 = 0.633 = Change in momentum. b. V = V2 + a*t. 0 = 6.32 - a*0.1, a = 63.2 m/s^2. F = M*a = 0.1 * 63.2 = 6.32 N.

*November 4, 2016*

**Physics**

a. M = 21 kg on earth and the planet. b. M*g = 21*9.8 = 205.8 N. = Wt. on earth. 21*12 = 252 N. = Wt. on the planet.

*November 4, 2016*

**Science**

1st stone: V = Vo + g*Tr. 0 = 20 - 10Tr, Tr = 2 s. = Rise time. 1. 2nd stone: V = Vo + g*t. 10 = 20 - 10t, t = 1 s. in motion. 2. 1st stone: V = Vo + g*t. = 0 + 10*1 = 10 m/s. When they meet.

*November 3, 2016*

**Biophysics**

Po = 0.15*Pi = 0.15 * 450 = 67.5 Watts.

*November 3, 2016*

**maths**

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

*November 3, 2016*

**physics -damon help**

1. The resistance of the inductor is assumed to be zero. P = Vr*I = 40 * 2 = 80 Watts. 2. pf = Cos A = Vr/E = 40/50 = 0.8.

*November 3, 2016*

**Physics**

See previous post: Wed, 11-2-16, 8:37 PM.

*November 3, 2016*

**Physics**

F2 = 2F1 = 2 * 192 = 384N.[25o] W. of N.

*November 2, 2016*

**Physics**

F1 + 2F1[115o] = 350i. F1 + 2F1*Cos115 + (2F1*sin115)i = 350i, F1 - 0.845F1 + (1.81F1)i = 350i, 0.155F1 + (1.81F1)i = 350i. F1(0.155+1.81i) = 350i, F1(1.82[85.1] = 350[90o], F1 = 192N.[4.9o]. F2 ====

*November 2, 2016*

**Physics Urgent!**

M*g = 60 * 9.8 = 588 N. Fp = 588*sin A. = Force parallel to the incline. Fn = 588*Cos A = Normal force. Fs = us*Fn = 0.55*(588*Cos A = 323.4*Cos A. Fp-Fs = M*a. 588*sin A-323.4*Cos A = 60*0 = 0, 588*sin A = 323.4*Cos A, Divide by 588: sin A = 0.55*Cos A, Divide by Cos A: sin A...

*November 2, 2016*

**Physics**

Fp = Force parallel to the incline. Fn = Normal force.

*November 2, 2016*

**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*