Thursday

October 27, 2016
Total # Posts: 12,223

**Maths**

2. V = Vo(1-r)^n. a. V = 1500(1-0.21)^6 = $364.63 b. V = 1500(1-0.21)^n = 60. 1500(0.79)^n = 60, 0.79^n = 60/1500 = 0.04, n*Log0.79 = Log0.04, n = Log0.04/Log0.79 = 13.7 Years.

*May 6, 2016*

**math**

Ar = Ab - Ad. Ar = 15000 - 15000*(0.075/360)*120 = $14,625 = Amt. received(proceeds). Ar = Amount received. Ab = Amount borrowed. Ad = Amount discounted.

*May 6, 2016*

**math 5th grade**

L = 5/6 yds. = 2 1/2 Ft. W = 3*2 1/2 = 15/2 = 7 1/2 Ft. Area = L*W = 2 1/2 * 7 1/2 = 5/2 * 15/2 = 75/4 = 18 3/4 square Ft. Or Area = L*W = 5/6 * 2 1/2 =[ 5/6 * 5/2 = 25/12 = 2 1/12 sq. yds. 1yd = 3ft, 1sq yd. = 3^2 = 9 sq. Ft. A = 2 1/12sq yds * 9sq ft/sq yd = 25/12 * 9 = 225/...

*May 5, 2016*

**physics**

Vo = 2 m/s[30o]. Xo = 2*Cos30 = 1.73 m/s. Yo = 2*sin30 = 1.0 m/s. Y = Yo + g*Tr. Y = 1 -9.8*Tr = 0, -9.8Tr = -1, Tr = 0.102 s. = Rise time or time to reach max ht. Tf = Tr = 0.102 s. = Fall time. Tr+Tf = 0.102 + 0.102 = 0.204 s. = Time in air. Y = 1 - 9.8*0.2 = -0.96 m/s. Y = ...

*May 5, 2016*

**physics**

Cos30 = V/10. V = ?.

*May 5, 2016*

**physics**

Correction: B. Impulse = F*t.

*May 5, 2016*

**physics**

a = (V-Vo)/t. V = 50 m/s, Vo = 0, a = ?. A. F = M*a. B. Impulse = M*t. C. Momentum ch. = M*V-M*Vo. C.

*May 5, 2016*

**Science (PhYsics)**

C = pi*2r = 3.14 * 1 = 3.14 m. Vo = 200rev/min * 3.14m/rev. * 1min/60s = 10.5 m/s. Since the velocity is constant, the acceleration is zero: a = (V-Vo)/t = (10.5-10.5)/t = 0/t = 0.

*May 5, 2016*

**Mathematics**

P1/P2 = 2/5, A1/A2 = (2/5)^2 = 4/25.

*May 5, 2016*

**physics**

b. Fk = u*Mg = 0.25 * 1.5*9.8 = 3.675 N. PE = KE - Fk*d = 19-3.675*d = 1.5*9.8*d, 19-3.675d = 14.7d, -18.375d = -19, d = 1.03 m.

*May 4, 2016*

**physics**

V = 75000m/h * 1h/3600s = 20.83 m/s. a. KE = 0.5M*V^2. b. PE = Mg*h = KE(Part "a"). g = 9.8 m/s^2, h = ?.

*May 4, 2016*

**Physics**

d = r*t =

*May 4, 2016*

**math**

Vb = 40km/2h = 20 km/h. Downstream. Vb = 40km/4h = 10 km/h. Upstream. Vb = (20+10)/2 = 15 km/h. In still water. Vs = 20 - 15 = 5 km/h. = Velocity of the stream.

*May 4, 2016*

**physics**

A. Work = F*d = 75 * 2 = 150 J. B. Work also = Change in kinetic energy = 0.5M*V^2 = 150, M = 65 kg, V = ?.

*May 4, 2016*

**physics**

A. k = 15N/0.450m = 33.3 N/m. B. F = 0.75m * 33.3N/m = 25 N.

*May 4, 2016*

**Physics**

D = 2.5 + 5i = 5.24 km[63.43o].

*May 4, 2016*

**HELP MATH ASAP**

Your problems are written in a very unconventional manner which makes them difficult to read and understand. Normal format: (x,y) = (3,4), (6,7).

*May 4, 2016*

**phy**

V = 45rev/min * 6.28rad/rev * 1min/60s = 4.71 rad/s. V = Vo + a*t = 4.71. 0 + a*4.5 = 4.71, a = 1.05 rad/s^2. D = Vo*t + 0.5a*t^2. D = 0 + 0.5*1.05*3^2 = 4.73 rad. V = Vo + a*t = 0 + 1.05*3 = 3.15 rad/s.

*May 4, 2016*

**Science**

E = 40 Volts, r = 5 Ohms, R = 15 Ohms. I = E//(r+R) = 40/20 = 2A. Vt = I*R = 2 * 15 = 30 Volts.

*May 2, 2016*

**science**

Q1. Matter. Q3. Density = 9g/45mL = 0.2 g/mL.

*May 2, 2016*

**science**

The answer is A.

*May 2, 2016*

**physics**

Cos30 = d/1780, d = ?.

*May 2, 2016*

**Math**

8W = 3F, 1W = 3/8F, 4W = 12/8F = 3/2F, 1D = 3/2F, 8D = 12F.

*May 1, 2016*

**Solid Mensuration**

There are 6 identical circles; the radius of each circle is 2 in.

*April 30, 2016*

**Solid Mensuration**

Diameter = 2/6 = 1/3 Ft. = 4 in. Radius = 1/2 * 4 = 2 In.

*April 30, 2016*

**Maths**

2^n = 50. n*Log2 = Log50, n = Log50/Log2 = 5.64 or 6 10-day periods to reach 50 times current populat5ion.

*April 29, 2016*

**7th grade math**

See previous post: Thu, 4-28-16, 8:26 PM.

*April 28, 2016*

**7th Grade Matj**

The number 25 should be 24. K = 27/24 = 9/8 = 1.125. Eq: Y = kx, or Y = 1.125x.

*April 28, 2016*

**math**

sin55 = Y/82, Y = 82*sin55 = 67.2 Ft., h = 67.2 + 3 = 70.2 Ft.

*April 28, 2016*

**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*