Monday

January 23, 2017
Total # Posts: 13,051

**Maths Ratio and Proportion**

Q2. 30,000L = 3cm. L = 1*10^-4 cm. Q3. 10/30 * 510 = 170 words.

*November 24, 2016*

**Physics**

Correction: A. PE = M*g*h Joules.

*November 24, 2016*

**Physics**

B. PE = M*g*h Joules. B. KE = PE = C. V^2 = Vo^2 + 2g*h = 0 + 19.6*10 = 196, V = 14 m/s.

*November 24, 2016*

**Physics**

V^2 = Vo^2 + 2a*d = 0. 400^2 + 2a*0.12 = 0, 160,000 + 0.24a = 0, a = -666,667 m/s^2. F = M*a = 0.03 * (-666,667) = -20,000 N.

*November 24, 2016*

**Math grade 5, two-part problem**

Adeline has X pens. Lisa has 2x/3 pens. A. (2x/3 + 16)/x = 2/1. 2x/3 + 16 = 2x 2x + 48 = 6x, X = 12. B. 2/3 * 12 = 8 pens. (8+16)/(12-6) = 24/6 = 4/1.

*November 24, 2016*

**Science Physics**

Disp. = X/Cos25.6 = 34.7km[25.6o].

*November 23, 2016*

**Science Physics**

Disp. = 20km[150o]+40km[0o]+10km[30o]. X = 20*Cos150+40+10*Cos30 = 31.3 km. Y = 20*sin150+10*sin30 = 15 km. Tan A = Y/X = 15/31.3 = 0.47923. A = 25.6o = Direction.

*November 23, 2016*

**Physics**

r/2 + r/2 + r = 2r = 2 in parallel + 2 in parallel + 1 in series.

*November 23, 2016*

**Physics**

r/2 + 3r = r/2 + 6r/2 = 7r/2 = 2 in parallel and 3 in series. r/3 + 2r = r/3 + 6r/3 = 7r/3 = 3 in parallel and 2 in series.

*November 23, 2016*

**physics**

See previous post.

*November 23, 2016*

**physics**

10 to 15 m/s: KE1 = 0.5M*V1^2 = 0.5M*10^2 = 50M. KE2 = 0.5M*V2^2 = 0.5M*15^2 = 113M. KE2-KE1 = 113M - 50M = 63M. = Change in KE. 15 to 20 m/s: KE1 = 0.5M*15^2 = 113M. KE2 = 0.5M*20^2 = 200M. 200M - 113M = 87M. = Change in KE.

*November 23, 2016*

**Physics**

V = Vo + g*t. Vo = 20 m/s, g = 9.8 m/s^2, t = 5 s, V = ?.

*November 23, 2016*

**Physics**

V^2 = Vo^2 + 2a*d. 0 = 300^2 + 2a*0.05, a = -900,000 m/s^2. V = Vo + a*t. 0 = 300-900,000t, t = ?.

*November 23, 2016*

**Math**

An angle ? satisfies the relation csc ? cos ? = -1. A) Use the definition of the reciprocal trigonometric ratios to express the left side in terms of sin ? and cos ?. B) What is the relation between sin ? and cos ? for this angle? C) Determine two possible values for ?. - ...

*November 22, 2016*

**physics**

Fr = F1+F2 = 10N[80o] + 3.5N[10o]. X = 10*Cos80 + 3.5*Cos10 = 5.18 N. Y = 10*sin80 + 3.5*sin10 = 10.5 N. Fr = = sqrt(x^2+y^2) = (5.18^2+10.5^2) = 11.7 N, = Resultant force. Fr = M*a = 11.7, a = 11.7/M = 11.7/0.5 = 22.14 m/s^2.

*November 22, 2016*

**Math**

Rate no. 1 = r mi/h. Rate no. 2 = r+2 mi/h. r*t = 2, t = 2/r. (r+2)*t = 3 (r+2)2/r = 3, 2 + 4/r = 3, 4/r = 1, r = 4 mi/h. (r+2) = 4+2 = 6 mi/h.

*November 22, 2016*

**science**

Exp. = 0.5cm/m * 100m = 50 cm.

*November 22, 2016*

**physic**

L = 120 cm, W = 80 cm, h = 40 cm. V = 120*80*40 = 384,000 cm^3. M = V*D = 384,000cm^3 * 19.3g/cm^3 = 7.41*10^6 g = 7410 kg.

*November 22, 2016*

**physics**

Note: 39.48 = (2pi)^2.

*November 21, 2016*

**physics**

T^2 = 39.48 * L/g = 1^2 = 1. L/g = 1/39.48, L = g/39.48 = 9.8/39.48 = 0.248 m. On The Moon: T^2 = 39.48*L/g = 39.48*0.248/1.63 = 6.0, T = 2.45 s.

*November 21, 2016*

**Maths**

1st number = X. 2nd number = X+1. (x+1) + x(x+1) = x+1 + x^2+x = x^2 + 2x + 1 = (x+1)(x+1) = (x+1)^2.

*November 21, 2016*

**Physics**

Fap = Force applied. Fap*d = 80 J. Fap*1 = 80, Fap = 80 N. Fap = M*a. a = Fap/M. = 80/2 = 40 m/s^2.

*November 21, 2016*

**Physics**

T = 136s/100cycles. = 1.36 s./cycle. T^2 = 39.48*L/g = (1.36)^2. L/g = 0.0468, g = 0.50/0.0468 = 10.7 m/s^2.

*November 21, 2016*

**Physics**

Ws = 1200 Lbs. Fp = 100*Cos30 = 86.6 Lbs. = Force parallel with the surface. Fn = 1200-100*sin30 = 1150 Lbs. = Normal force. Fk = u*Fn = u*1150 Lbs. Fp-u*Fn = Ws*a. u*Fn = Fp-Ws*0, u*Fn = Fp, u = Fp/Fn = 86.6/1150 = 0.075.

*November 21, 2016*

**Physics**

D = Vo*t + 0.5a*t^2. D = 1*10 + 0.05*10^2 = 15 rad. D = 15rad/(6.28rad/rev.) = 2.39 rev.

*November 21, 2016*

**Physics**

V^2 = Vo^2 + 2a*d. V = 0, Vo = 200 m/s, d = 0.045 m., a = ?.

*November 21, 2016*

**Physics**

C = pi*2r = 3.14 * 4 = 12.56 m. = circumference. Arc = (20/360) * 12.56m = 0.698 m.

*November 20, 2016*

**Physics**

F = M*a.

*November 20, 2016*

**Math**

P = Po(1+r)^n. First Year: Po = $100,000. r = 0.08/yr. * 0.5yrs. = 0.04. n = 2comp./yr. * 1yr. = 2 compounding periods. P = 100000(1.04)^2 = $108,160. Last Two Years: Po = 108,160. r = 0.12/yr. * 0.25yrs. = 0.03/qtr. n = 4comp./yr. * 2yrs. = 8 compounding periods. P = ?.

*November 20, 2016*

**physics**

M*g = 38.5, M = 38.5/g = 38.5/9.8 = 3.93 kg. = Wt. of fluid displaced. Density = M/V = 3.93kg/0.00735m^3 = 534.5 kg/m^3.

*November 20, 2016*

**Physics**

R = E/I = 40/5 = 8 Ohms. I = E/R = 120/8 = 15A.

*November 20, 2016*

**electronics and circuits**

I1 = Vs/(Rw1+RL1) = 4/(1+15) = 0.25A. = Current thru RL1. VL1 = I1*RL1 = 0.25 * 15 = I2 = (Vs/(Rw2+RL2) = VL2 = I2*RL2 =

*November 18, 2016*

**electronics and circuits**

I = V/r = 2/10 = 0.2A. Rbat = V/I = (4-2)/0.2 = 10 Ohms.

*November 18, 2016*

**physics**

See previous post: Thu, 11-17-16, 6:05 AM.

*November 18, 2016*

**math**

Salary = $X. X-x/4 = 3x/4. 3x/4-(1/4)3x/4 = 3x/4-3x/16 = 12x/16-3x/16 = 9x/16. 9x/16-(1/9)9x/16 9x/16-(1/9)9x/16 = 9x/16-x/16 = 8x/16 = x/2. x/2 = 3400, X = $6800.

*November 18, 2016*

**Physics**

See previous post: Fri, 11-18-16, 12:26 AM.

*November 18, 2016*

**Physics**

See previous post: Fri, 11-16-16, 12:26 AM.

*November 18, 2016*

**Physics**

See previous post.

*November 18, 2016*

**Physics**

V = (55-25)g * 1cm^3/g = 30 cm^3. Da = M/V = (48-25)g/30cm^3 = 0.767 g/cm^3 = Density of alcohol.

*November 18, 2016*

**Maths**

V = Vo + g*t. Vo = 0, g = 9.8 m/s^2, t is greater 0, but less than 1.5 s.

*November 17, 2016*

**Maths**

1. h = 0.5g*t^2 = 4.9*1.5^2 = 2. V^2 = Vo^2 + 2g*h. Vo = 0, g = 9.8 m/s^2, V = ?.

*November 17, 2016*

**Physics**

M*g = 40 * 9.8 = 392 N. = Wt. of child. Fp = 392*sin35 = 224.8 N. = Force parallel to the incline. V^2 = Vo^2 + 2a*d = 2.5^2. 0 + 2a*4 = 6.25, a = 0.781 m/s^2. Fp-Fk = M*a. Fk = Fp-M*a = 224.8-40*0.781 = 193.6 N.

*November 17, 2016*

**physics**

c. F = 24.5N/m * 0.05m = 1.23 N.

*November 17, 2016*

**physics**

M*g = 0.5 * 9.8 = 4.9 N. = Wt. of object. a. k = F/d = 4.9N./(0.45-0.25)m = 24.5 N/m. b. 24.5N./m * (0.50-0.25)m = 6.125 N. 6.125 - 4.9 = 1.23 N. addition wt.

*November 17, 2016*

**Algebra**

Eq1: 5x - 4y = 10. Eq2: 2x + 8y = 4. Multiply Eq1 by 2 and add the Eqs: 10x - 8y = 20. +2x + 8y = 4. Sum: 12x = 24,m X = 2. In Eq2, replace x with 2: 2*2 + 8y = 4. Y = 0. M1 = -A/B = -5/-4 = 1.25. M2 = -2/8 = -0.25.

*November 16, 2016*

**science**

Incomplete.

*November 16, 2016*

**science**

V^2 = Vo^2 + 2g*h = 0 + 19.6*2 = 39.2, V = 6.26 m/s. PE = Mg*h = 0.98*1 = 0.98 J. KE = 0.5M*V^2 = 0.05*39.2 = 1.96 J.

*November 16, 2016*

**maths**

7/8-1/2 = 7/8-4/8 = 3/8 added. (3/8)/(7/8) = 3/8 * 8/7 = 24/56 = 3/7 of the bottle.

*November 16, 2016*

**Physics**

Dia. = 2 * 20 = 40 cm. hb = height below the surface. Dw = 1g/cm^3 = The density of water. hb = Dl/Dw * h = 40-8 = 32 cm. Dl/1 * 40 = 32, Dl = 0.8g/cm^3.

*November 16, 2016*

**math**

c = 10x + 1200 = 40x. X = 40 rides.

*November 15, 2016*

**math**

(2/7)/(3/4) * 1h = 2/7 * 4/3 * 1 =

*November 15, 2016*

**Math**

P = 0.85g + 0.07*0.85g = 0.91g.

*November 15, 2016*

**Mathe: NEEDHELP!**

6 oz./202.5mg * 52.5mg = 1.56 oz.

*November 15, 2016*

**math**

Correct.

*November 15, 2016*

**Math grade 6, Fractions**

Phillip had $X at 1st. X - 2x/5 = 5x/5-2x/5 = $3x/5 Left. = Jenny's amount. 3x/5 + 3x/5 = 360, 6x/5 = 360, X = $300.

*November 15, 2016*

**physics**

F1+F2+F3 = 0. F3 = -(F1+F2), F3 = -(8N[0o]+5N.[60o]), F3 = -((8+5*Cos60) + 5*sin60), F3 = -10.5 - 4.33i = 11.4N[20.9o] S. of W.

*November 15, 2016*

**PHYSICS**

k = 0.65N./0.053m = 12.3 N/m.

*November 14, 2016*

**math**

7*5 + 3 = 38 Oranges, initially. 38 - 5 = 33 Left.

*November 14, 2016*

**PHYSICS**

M*g = 3.5 * 9.8 = 34.3 N. = Wt. of block = Normal force(Fn). Fp = 15*Cos40 = 11.5 N. = Force parallel with the surface. 1. Fk = u*Fn = 0.25 * 34.3 = 8.58 N. 2. Fp-Fk = M*a. a = ?.

*November 14, 2016*

**math**

M = 0.454kg/Lb. * 80Lbs. = 36.3 kg. M*g = 36.3 * 9.8 = 356.0 N. Fp = 356*sin13.8 = 84.9 N. = Force parallel to the incline. F = Fp = 84.9 N.

*November 14, 2016*

**math**

Fr = 18.4[0o] + 13.1[16.5o]. X = 18.4 + 13.1*Cos16.5 = Y = 13.1*sin16.5 = Fr = Sqrt(x^2+Y^2).

*November 14, 2016*

**physics**

X = 1350-745 = 605 N. Y = 6300-3200 = 3100 N. Fn = Sqrt(X^2+Y^2) = Sqrt(605^2+3100^2) = 3158.5 N. Tan A = Y/X = 3100/605 = 5.12397. A = 79o N. of E. = Direction.

*November 13, 2016*

**Physics**

a. V = Vo + a*t. 1.6 = 0 + a*0.3, a = 5.33 m/s^2. F = M*a = 65 * 5.33 = 346.7 N.

*November 13, 2016*

**Math**

1760Ft/8.625 = 204 posts.

*November 13, 2016*

**English**

sample research paper about business

*November 13, 2016*

**Math**

a.Peaches = 0.2x. b. Apples = 0.25x. c. Lemons = 0.05x. d. Plums =

*November 12, 2016*

**Math**

X pieces of fruit. .2x + 0.25x + 0.05x + 0.1x + 0.2x + 0.15x = 0.95x. x - 0.95x = 0.05x = Remaining pieces. 0.05x = 8+4 = 12, X = 240 Pieces of fruit.

*November 12, 2016*

**Math**

I = Po*r*t = 275,000*0.03*1 = $8,250.

*November 12, 2016*

**Geometry**

(x+y)+7x+(3x-20)+(5y-10) = 360o. The opposite angles are equal: R = (x+y) = P = 7x. K = (5y-10) = A = (3x-20). (7x)+(7x)+(3x-20)+(3x-20) = 360, 20x = 400, X = 20. x+y = 7x = 7*20 = 140o.

*November 12, 2016*

**Physics**

PE = Mg*h = 98 J. 0.04*9.8*h = 98, h = 250 m. V^2 = Vo^2 + 19.6*h. V^2 = 0 + 19.6*250, V = ?. KE = 0.5M*V^2.

*November 11, 2016*

**Physics**

V = Vo + a*t = 130 rad/s. 30 + a*5 = 130, a = 20 rad/s^2. d = Vo*t + 0.5a*t^2. d = 30*5 + 10*5^2 = 400 rad.

*November 10, 2016*

**Pyhsics**

Correction: Y = 35*sin57 =

*November 10, 2016*

**Pyhsics**

35m/s[57o]. X = 35*Cos57 = Y = 35*sin7 =

*November 10, 2016*

**Physics**

a. M1*V1 + M2*V2 = M1*V + M2*V. 10*2 - 5*1 = 10V + 5V. V = ?. b. KE2 = 0.5M1*V^2 + 0.5M2*V^2. = KE after collision. c. KE1 = 0.5M1*V1^2 - 0.5M2*V2 = KE before collision.

*November 10, 2016*

**Math**

The number = N. sqrt(2N) = N/3. Square both sides: 2N = N^2/9, 18N = N^2, N^2 - 18N = 0, N(N-18) = 0, N = 0, and 18.

*November 10, 2016*

**Physics**

D = 30g/(60-50) = 30g/10cm^3 = 3g/cm^3.

*November 10, 2016*

**maths**

V2 = pi*r2^2 * h = 476,187 in^3. 3.14*(17.5)^2 * h = 476,187. h = ?.

*November 10, 2016*

**maths**

42barrels * 42gal/barrel = 1764 gal. 1764gal. * 1barrel/55gal. = 32 - 55 gal barrels. V1 = pi*r^2 * h = 3.14*(11.65)^2 * 34.9 = 14,881 in^3. = Vol. of a 55 gal. container. V2 = 32*V1 = 32 * 476,187 in^3 = Vol. of the 1764 gal container. Let r2 = 1.5r1 = 1.5 * 11.65 = 17.5 in. 8

*November 10, 2016*

**maths**

P = Po(1+r)^n. T = 7.5yr. * 12mo./yr. = 90 mo. P = 9230/mo. * 90mo. = $830,700. r = 0.0615. n = 1comp./yr. * 7.5yrs. = 7.5 compounding periods. Po = ?. I = P-Po.

*November 9, 2016*

**physics**

M*g = 1500 * 9.8 = 14,700 N. = Wt. of car. = Normal(Fn). V = Vo + a*t = 18. 0 + a*12 = 18, a = 1.5 m/s^2. d = 0.5a*t^2 = 0.75*12^2 = 108 m. Fr = 400 N. Fe-Fr = M*a. Fe = M*a+Fr = 2250 + 400 = 2650 N. = Force of engine. P = Fe*d/t = 2650 * 108/12 = 23,850 J/s = 23,850 Watts.

*November 9, 2016*

**Physics**

d = (30Lbs/12Lbs) * 3in. = 7.5 In.

*November 9, 2016*

**physics**

M1*g = 0.4 * 9.8 = 3.92 N. = Wt. of pkg.= Normal force(Fn). Fp = 3.92*sin 0 = 0 = Force parallel to the surface. Fap = M2*g = 0.2 * 9.8 = 1.96 N. = Force applied. Fs = us*Fn. = 3.92us. Fap-Fp-Fs = M*a. 1.96-0-3.92us = M*0 = 0, us = 0.50.

*November 9, 2016*

**Physics**

d = 15-10 = 5 cm = 0.05 m. F = 150N/m * 0.05m = 7.5 N. Work = F*d = 7.5 * 0.05 = 0.375 Joules.

*November 9, 2016*

**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*