Sunday

October 23, 2016
Total # Posts: 12,193

**science**

M*g = 2 * 9.8 = 19.6 N. d = 19.6N. * 1m/1500N. = 0.0130 m. = 1.30 cm.

*April 28, 2016*

**math**

a. Vb*t + Vc*t = 210. 60t + 80t = 210, t = ?. b. d = Vc*t.

*April 28, 2016*

**math**

A. V = 50mi/(45/60)h = 62.5 mph. d = V*t = 300. t = 300/62.5 = 4.8h. B. t = 4.8h - 48min. = 4.8h - 0.75h = 4.05h. d = V*t. d = 300 mi., t = 4.05h., V = ?.

*April 28, 2016*

**physics**

V^2 = Vo^2 + 2a*d. V = 45 m/s, a = -6.1 m/s^2, d = 59.7m+25m, Vo = ?. V = Vo + a*t. V = 45 m/s, Vo = previous calculation, a = -6.1 m/s^2, t = ?.

*April 28, 2016*

**Physics**

d = Vo*t, d = 18.3 m, Vo = 40 m/s, t = ?.

*April 28, 2016*

**Science**

Z = Sqrt(560^2+1200^2) = 1324.2 Ohms. I = E/Z, Vl = I*Xl. You didn't give the supply voltage, E.

*April 27, 2016*

**Algebra**

X^2 + Y^2 = 25^2, X^2 + (-7)^2 = 625, X^2 = 625-49 = 576, X = 24. Cos A = x/r = 24/25.

*April 27, 2016*

**Physics**

k = 0.8N/0.0050m = 160 N/m. L = 1.5 + 3.5N*1m/160N. = 1.5219 m.

*April 27, 2016*

**Physics**

40o E. to N. = 50o N. t0 E. D = 1000km[50o] + 500km[20o]. X = 1000*Cos50 + 500*Cos20o = Y = 100*sin50 + 500*sin20 = Tan A = Y/X, A = ? = Direction. X/Cos A = Magnitude.

*April 27, 2016*

**pre calc**

Correction: The decay rate is exponential. 50/e^x = 32, e^x = 50/32 = 1.5625, X = 0.446 = kt, K = 0.446/t = 0.446/18 = 0.0248. Mr = M/e^kt = M/e^(0.0248t) = Mass remaining.

*April 27, 2016*

**pre calc**

(50-32)grams/18yrs = 1 Gram/yr. Mr = M-1*T = M-T = 50 - 18 = 32 grams. = Mass remaining.

*April 27, 2016*

**Geometry**

x + 2x + 3x = 180, X = 30o = the Smallest.

*April 27, 2016*

**physics**

K = 2N./(2/100)m = 100 N/m. d = 4N. * 1m/100N = 0.04 m. Work = 2 * 0.04 = 0.08 J.

*April 27, 2016*

**physics**

1. KE = 0.5M*V^2 = 0.5*3*2^2 = 6 Joules. 2. PE = KE, M*g*h = 6, 3*9.8*h = 6, h = 0.204 m. sin30 = 0.204/d, d*sin30 = 0.204, d = 0.408 m. = Distance along the incline.

*April 27, 2016*

**math**

P Dollars @ 6%, 2P Dollars @ 3%, (50,000-3P) @ 5.5 0.06P + 0.03(2P) + 0.055(50,000-3P) = 2165. 0.06P + 0.06P + 2750 - 0.165P = 2165, -.045P = 2165-2750 = -585, P = $13,000 @ 6%. 2P = $26,000 @ 3%. (50,000-39,000) = $11,000 @ 5.5%.

*April 27, 2016*

**physics**

V = Vo + g*t = 0 + 9.8*6 = 58.8 m/s. KE = 0.5M*V^2, M = 0.05 kg.

*April 27, 2016*

**physics**

Range = Vo^2*sin(2A)/g. Vo = 80 m/s, A = 30o, g = 9.8 m/s^2.

*April 27, 2016*

**physics**

V = Vo + a*t = 27.5, 25 + a*20 = 27.5, 20a = 2.5, a = 0.125 m/s^2. = Acceleration of car B. Vo*t + 0.5a*t^2 = Vo*t + o.5a*t^2 + 300, Vo*t-Vo*t + 0.5a*t^2 = 0.5*0.125*20^2 + 300, 0.5a*20^2 = 25 + 300 = 325, 200a = 325, a = 1.625 = Acceleration of car A. Va = Vo + a*t = 25 + 1....

*April 27, 2016*

**math**

I = Po*r*t = 100,000*0.06*30 =

*April 26, 2016*

**geometry**

or 2:48 = 1:24.

*April 26, 2016*

**geometry**

Scale Factor = 4Ft/2In = 2 Ft./In.

*April 26, 2016*

**Pre-Calculus**

A = Po(1+r)^c r = 0.03/n = 0.03/2 = 0.015 = Semi-annual % rate. c = 2Comp./yr. * 10yrs. = 20 Compounding periods(N*t). A = 1000(1+0.015)^20 = $1346.86. Repeat for the remaining values of N.

*April 26, 2016*

**Physics**

V = a*t, V = 57 m/s, t = 3.5 s, a = ?. d = 0.5a*t^2.

*April 25, 2016*

**science**

Work = F*d = 53,000 * 20 =

*April 25, 2016*

**Science- Density**

Density = Weigh per unit volume. Unit means one. Therefore, Density = Weight of one volume of a substance. One volume can be 1m^3, 1cm^3, or 1in^3 depending on which unit you are using. Water has a density of 1 gram per cm^3(1g/cm^3) which means that 1 cm^3 of water weighs 1 ...

*April 24, 2016*

**Physics2**

a. E = 3 * 500 = 1500 Volts. b. Ceq = 120/3 = 40 pF. Q = Ceq*E = 40 * 1500 = 60,000 Pico Coulombs. c. Energy = 0.5Ceq*E^2 = 0.5*40 * 1500^2 =

*April 24, 2016*

**math**

21 Ways to score 15 points.

*April 23, 2016*

**math**

1. 5 Long shots. 2. 4 Long shots, 1 field goal, 1 free throw. 3. 4 Long shots and 3 free throw. 4. 3 Long shots, 3 field goals. 5. 3 Long shots, 2 field goals, and 2 free throws. 6. 3 Long shots, 1 field goal, 4 free throws. 7. 3 Long shots, 6 free throws. 8. 2 long shots, 4 ...

*April 23, 2016*

**Physics**

V^2 = Vo^2 + 2a*d. V = 1.4 rad/s, Vo = 4.5 rad/s, a = -0.5 rad/s^2, d = ?. Note: d is angular distance in radians.

*April 22, 2016*

**Physics**

V^2 = Vo^2 + 2a*d. V = 0, Vo = 36 m/s, d = 414 m, a = ?. a will be negative. F = M*a. W = F*d Joules.

*April 21, 2016*

**Physics**

Po = F*d/t = M*g * V = 101 W. = 101 J/s, 121*9.8 * V = 101, V = 0.085 m/s.

*April 21, 2016*

**Physics**

V^2 = Vo^2 + 2g*h. Vo = 0.8 m/s, g = 9.8 m/s^2, h = 7.8 m, V = ?.

*April 21, 2016*

**Physics**

Work = Fx*d = 2.8*Cos26.8 * 8.3 =

*April 21, 2016*

**Physics**

V^2 = Vo^2 + 2a*d. V = 0, Vo = 9.5 m/s, d = 0.24 m, a = ? F = M*a, M = F/a.

*April 21, 2016*

**Physics**

Fn = M*g + Fap*sin64. g = 9.8 m/s^2, Fap = 11 N.

*April 21, 2016*

**Physics**

M*g = (2.5+4.4)*9.8 = 67.6 N. = Total wt. Fx-Fk = M*a, 19*Cos23.5-1.5 = 6.9*a, 6.9a = 15.9, a = 2.31 m/s^2.

*April 21, 2016*

**Physics**

Fo = ((Vs-Vo)/(Vs+Ve)) * Fe = 480 Hz. (345-0)/(345+Ve) * 560 = 480, 345/(345+Ve) * 560 = 480, 193,200/(345+Ve) = 480, 165,600 + 480Ve = 193,200, 480Ve = 27600, Ve = 57.5 m/s. = Velocity of the emitter or source. v

*April 21, 2016*

**Physics**

Change = 5.22*10^-5/oC*(52-14.4)oC = 1.96*10^-3 m. = 1.96 mm.

*April 21, 2016*

**algebra**

$X @ 9%, $Y @ 12%. Eq1: X + Y = $290,000. Eq2: 0.09x + 0.12y = $31,500. Multiply both sides of Eq1 by 0.12 and subtract Eq2 from Eq1.

*April 20, 2016*

**algebra**

1,2,3,4,5,6. 1,2,3,4. 2,3,4,5. 3,4,5,6. 4,5,6,1. 5,6,1,2. 6,1,2,3. 6 Ways.

*April 20, 2016*

**Math**

20,322*12/.004 = 60,966,000 Sheets. The answer is B.

*April 20, 2016*

**Physics**

Please proof-read your problem.

*April 20, 2016*

**classical mechanics**

A projectile is launched down ward from the top of inclined plane of angle alpha in the direction making an angle beta with the incline. assuming the projectile hits the incline, find the expression for the range and determine the maximum expression for the range down the ...

*April 19, 2016*

**calculus.can you help me on these as well@sir collins**

let sin^7x =(sin^2(x))^3sin(x) dx. sin^6x= (sin^2(x))^3 integral of(sin^2(x))^3sinx using identity sin^2x= 1-cos^2x integral of (1-cos^2x)^3sinx dx what if u=cosx du=-sinx. -integral(-u^6+3u^4-3u^2+1)du. =-(-u^7/7+3u^5/5-u^3+u)+k substituting for u give us the following -(-...

*April 19, 2016*

**Math**

Range = (1200)^2*sin(2A)/32 = 3000, 45,000*sin(2A) = 3000, sin(2A) = 0.0667, 2A = 3.82, A = 1.9 Degrees.

*April 18, 2016*

**math**

Train B travels X mi/h. Train A travels (x-6) mi/h. X*t/(x-6)t = 230/200, X/(x-6) = 230/200, 200x = 230x-1380, -30x = -1380, X = 46 mi/h, x-6 = 46-6 = 40 mi/h.

*April 18, 2016*

**Physcis- Energy**

KE = 0.5M*V^2.

*April 18, 2016*

**Math**

(4/11)/24 = (7/11)/L, (4/11)L = 24(7/11), L = 42 litres in tank.

*April 18, 2016*

**science**

W = F*d = M*g * d = 69*9.8 * 10 = 6762 Joules. P = W/t = 8762 J./12s. = 564 J./s = 564 Watts.

*April 17, 2016*

**physics**

a helium nuclide of mass M1 moving with initial velocity V is incident on a stationary of mass M1. After collision M1 was deflected through an angle x and M2 an angle y. If the velocities of the nuclides after collision were V1 and V2 respectively, show that for an elastic ...

*April 17, 2016*

**science**

a helium nuclide of mass M1 moving with a velocity Vo is incident on a stationary nuclide of mass M2. After collision M1 was deflected through an angle x and M2 an angle y. If the velocities of the nuclides after collision were V1 and V2 respectively show that for an elastic ...

*April 17, 2016*

**Algebra**

A. V = Vo + g*Tr = 0, Tr = -Vo/g = Rise time. T1 = Tr + Tf = Time to rise from launching point(90Ft.) to max ht. and return to launching point. Tr = Tf; Therefore, T1 = 2Tr = -2Vo/g. Vo*T2 - 16T2^2 = 90, 50T2-16*50^2 = 90, 50T2-40,000 = 90, 50T2 = 40,090, T2 = 802 Seconds To ...

*April 17, 2016*

**science**

M1*V1 + M2*V2 = M1*V3 + M2*V4. 8*10 - 12*2 = 8*3 + 12*V4. 80-24 = 24 + 12V4. 12V4 = 32, V4 = 2.67 m/s, East.

*April 16, 2016*

**Personal Finance**

I chose C.

*April 15, 2016*

**Reverse math confused**

C = (p-2)1.2 = 9.00, p = $9.50.

*April 15, 2016*

**Polynomials**

6t+2 + 9t-6 = 15t - 4. = Total earnings.

*April 14, 2016*

**phy**

d = 2844rev * 6.28rad/rev = 17,860 radians. a. V^2 = Vo^2 + 2a*d. V = 136 rad/s, a = 0.130 rad/s, Vo = ?. b. V = Vo + a*t. V = 136 rad/s, a = 0.130 rad/s^2, t = ?. 2

*April 14, 2016*

**Science**

V = Vo + a*t = 15 m/s, Vo = 25 m/s, a = -2 m/s^2, t = ?.

*April 14, 2016*

**Math help**

a. C = 4.70d. b. C = 4.70d - 1 = 4.70*4 - 1 = $17.80. C = 4.70*7 = $32.90.

*April 13, 2016*

**Math help!**

d = 66t.

*April 13, 2016*

**maths**

Vo = 40.000m/3600s = 11.11 m/s. V = Vo + a*t = 0, 11.11 - 0.5t = 0, -0.5t = -11.11, t = 22.22 s.

*April 13, 2016*

**Find the area of the segment of a circle of radious 21 cm and corresponding central angle 30**

As = 30/360 * Ac = 30/360 * 3.14*21^2 = 115.4 cm^2.

*April 13, 2016*

**math**

-16x^2 + 24x + 16 = 0. A. Divide by 8: -2x^2 + 3x + 2 = 0, A*C = -2*2 = -4 = -1 * 4. Sum = -1 + 4 = 3 = B, -2x^2 + (-x+4x) + 2 = 0, (-2x^2-x) + (4x+2) = 0, -x(2x+1) + 2(2x+1) = 0, (2x+1)(-x+2) = 0, 2x+1 = 0, X = -1/2. -x+2 = 0, X = 2. X-intercepts: (-1/2,0), (2,0). B. Since ...

*April 12, 2016*

**Math**

V = 390mi/h[28o]N of W. D = 390mi/h[28o] * 3h = 1170 mi[28o]N. of W. Dn = 1170*Cos28 = Dw = 1170*sin28 =

*April 11, 2016*

**pre algebra**

Width = W cm. Length = W+6 cm. ((W+6)-3)(W+3) = 64 cm^2. (W+3)(W+3) = 64, W^2+6W+9 = 64, W^2+6W-55 = 0, -55 = -5*11, -5+11 = 6 = B, (W-5)(W+11) = 0, W-5 = 0, W = 5. W+11 = 0, W = -11. Original Dimensions: W = 5 cm, L = 5+6 = 11 cm.

*April 11, 2016*

**PHY 1004**

Range = Vo^2*sin(2A/g. A = 30o, g = 9.8 m/s^2.

*April 9, 2016*

**Physics**

1. Basically, a loudspeaker converts electrical energy to sound.

*April 9, 2016*

**Math**

P = Po(1+r)n = 100,000. r = 0.072/2 = 0.036 = Semi-annual % rate expressed as a decimal. n = 2Comp./yr. * t yrs. = 2t Compounding periods. 73,000(1.036)^2t = 100,000. (1.036)^2t = 100,000/73,000 = 1.370, 2t*Log1.036 = Log1.370, 2t = Log1.370/Log1.036 = 8.90, t = 4.45 Years.

*April 9, 2016*

**math**

See previous post.

*April 9, 2016*

**math**

2x^2 + 6x - 5 = 0. Use Quadratic Formula: X = (-6 +- Sqrt(36+40))/4 = (-6 +-(8.72)/4 = 0.679, and -3.68.

*April 9, 2016*

**physics**

P = E^2/R = 120^2/29 = 497 Watts = 0.497 kW. Cost = 0.497 * 5.6 * 7.35cents/kWh.

*April 8, 2016*

**physics**

1. P = E*I = 120 * 15 = 1800 W. 1800/1500 = 1.2 or 1 Dryer. 2. 1500W. = 1.5kW. Cost = 1.5 * 6.3 * 0.078 =

*April 8, 2016*

**Physics**

T = 2pi*Sqrt(L/g) = 6.28*Sqrt(1/1.63) = 4.92 s.

*April 8, 2016*

**physics**

M*g = 20 N., g = 20/M = 20/6.5 = 3.08 m/s^2.

*April 7, 2016*

**Physics**

Vo = 217km[26.9o], a. Xo = 217*Cos26.9 = b. Yo = 217*sin26.9 =

*April 7, 2016*

**Algebra**

Sqrt(363) - 3Sqrt(27) = Sqrt(121*3) - 3Sqrt(3*9) = 11Sqrt(3) - 3*3Sqrt(3) = 11Sqrt(3) - 9Sqrt(3) = 2Sqrt(3).

*April 7, 2016*

**math**

4c =< 9, C =< #2.25 Per doz.

*April 7, 2016*

**Math**

Grandfather: X years old. Father: x-26 years old. Son: (x-26)-29 = x-55. x + x-26 + x-55 = 135, 3x - 81 = 135, 3x = 216, X = 72, x-26 = 46, x-55 = 17.

*April 7, 2016*

**Sarah**

Can you explain your problem in words instead of drawing a diagram? I understand electrical circuits, but I don't understand your diagram.

*April 7, 2016*

**Math**

Beginning bal. = 1761.

*April 5, 2016*

**algebra**

V1 = X km/h, V2 = x + 18 km/h. d1 + d2 = 150 km. 3x + 3(x+18) = 150, 6x + 54 = 150, 6x = 96, X = 16 km/h, x+18 = 16 + 18 = 34 km/h = V2 = Speed of the faster car.

*April 5, 2016*

**science**

Vo = 180m/s[55o]. a. Range = Vo^2*sin(2A)/g = 180^2*sin(110)/9.8 = 3107 m. b. Same procedure as "a" except g = 1.6 m/s^2.

*April 5, 2016*

**physics**

Xc = 1/WC = -1/(314.2*20*10^-6) = -159.2 Ohms. Z(Ohms) = 30 -j159.2 = 162[-79.3o]. I = E/Z = 100[0o]/162[-79.3] = 0.617A[79.3o].

*April 4, 2016*

**physics**

a. Xl = E/I = 3.6/2.5*10^-4 = 1.44*10^4 Ohms. b. Xl = 2pi*F*L = 14,400, L = 14,400/(6.28*1.6*10^6) = Henrys.

*April 4, 2016*

**Science**

V1 = 15 + 3 = 18 km/h. V2 = 15 - 3 = 12 km/h.

*April 4, 2016*

**MATH**

P = Po + Po*r*t = 2200 + 2200*(0.07/360)*100 = P = 2200 + 2200*(0.07/365)*100 =

*April 4, 2016*

**math**

Correction: 4- 1 1/2 = 2 1/2 Pizza without pepperoni. 1 1/2 - 5/6 = 3/2 - 5/6 = 9/6 - 5/6 = 4/6 = 2/3 Pizza with pepperoni remaining. 4 - 5/6 = 24/6 - 5/6 = 19/6 = 3 1/6 Pizza left. (2/3)/(19/6) = 2/3 * 6/19 = 12/57 = 4/19 Of total pizza left has pepperoni.

*April 3, 2016*

**math**

4- 1/1/2 = 2 1/2 Pizzas without pepperoni. 2 1/2 - 5/6 = 5/2 - 5/6 = 15/6 - 5/6 = 10/6 = 5/3 = 1 2/3 pizzas with pepperoni remaining. 4 - 5/6 = 24/6 - 5/6 = 19/6 = 3 1/6 Pizzas left. (5/3)/(19/6) = 5/3 * 6/19 = 30/57 = 10/19 Of total pizza left has pepperoni.

*April 3, 2016*

**math**

g = C/5 + J/5 + S/5. C = Classic CDs, J = Jazz CDs, and S = Soft rock CDs.

*April 3, 2016*

**Physics**

Vo = 2.19m/s[25.1o]. Yo = 2.19*sin25.1 = 0.93 m/s. a. Y^2 = Yo^2 + 2g*h = 0, 0.93^2 - 19.6h = 0, -19.6h = -0.865, h = 0.0441 m. b. Y = Yo + g*t = 0, 0.93 - 9.8t = 0, -9.8t = -0.93, t = 0.095 s. c. V = Vo = 2.19 m/s.

*March 31, 2016*

**Physics**

F = 32N[30o] + 56N[0o]? + 38N[60o] = 27.7+16i + 56 + 19+32.9i = 102.7 + 48.9i = 118N{25.5o]. F = M*a, a = F/M = 118[25.5o]/118 = 1 m/s^2[25.5o].

*March 31, 2016*

**Mechanics**

Wb = M*g = 6 * 9.8 = 58.8 N. = Wt. of block = Normal(Fn). Fap-Fk = M*a, 22.5-Fk = 6*1.25 = 7.5, Fk = 15 N. = Force of kinetic friction. u = Fk/Fn = 15/58.8 = 0.255.

*March 30, 2016*

**Physics- Circuits Current & Voltage Problem**

The above note does not apply to R2.

*March 29, 2016*

**Physics- Circuits Current & Voltage Problem**

E1 = 40V., R1 = 80 Ohms. E2 = -360V., R2 = 20 Ohms. E3 = 80V., R3 = 70 Ohms. Ro = 200 Ohms. Convert the 3 voltage sources to a single current source: Is = E1/R1+E2/R2+E3/R3 = 40/80 - 360/20 + 80/70 = -16.9A., Downward. Determine current through Ro: 1/Rs = 1/R1+1/R2+1/R3 = 1/80...

*March 29, 2016*

**math**

Adult: $X each. Student: $Y each. Eq1: 7x + 16y = 120. Eq2: 13x + 9y = 140. Multiply Eq1 by 13, Eq2 by 7, and subtract: 91x + 208y = 1560 91x + 63y = 980 Diff.:145y = 580. Y = $4.00.

*March 29, 2016*

**Physics**

V = Vo + a*t = 0 + 2*2 = 4 m/s. a. d1 = v*t = 4 * 4 = 16 m. V = Vo + a*t = 0, 4 + a*10 = 0, a = -0.4 m/s^2. V^2 = Vo^2 + 2a*d2 = 0, 4^2 - 0.8*d = 0, -0.8d2 = -16, d2 = 20 m. b. Vavg = (d1+d2)/(t1+t2) = (16+20)/(4+10) = 2.57 m/s.

*March 29, 2016*

**Physics**

Vo = 108,000m/3600s = 30 m/s. V = Vo + a*t = 0, a = -Vo/t = -30/5 = -6.0 m/s^2.

*March 29, 2016*

**PHYSICS**

Add a resistor in series with the coil: R+12 = E/I = 10/0.0025 = 4,000, R = 4,000-12 = 3,988 Ohms.

*March 29, 2016*

**College Algebra**

a. Y = 2^w + 7.

*March 28, 2016*

**math\**

Po*0.03*1 + (Po+750)*0.05*1 = 157.50. 0.03Po + 0.05Po + 37.50 = 157.50, 0.08Po = 120, Po = $1500 @ 3%. 1500 + 750 = $2250 @ 5%.

*March 28, 2016*