# Posts by Henry

Total # Posts: 13,500

**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.

**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 = ?.

**physics**

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

**Physics**

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

**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).

**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.

**Science**

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

**science**

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

**science**

The answer is A.

**physics**

Cos30 = d/1780, d = ?.

**Math**

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

**Solid Mensuration**

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

**Solid Mensuration**

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

**Maths**

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

**7th grade math**

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

**7th Grade Matj**

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

**math**

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

**science**

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

**math**

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

**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 = ?.

**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 = ?.

**Physics**

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

**Science**

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

**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.

**Physics**

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

**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.

**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.

**pre calc**

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

**Geometry**

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

**physics**

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

**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.

**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%.

**physics**

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

**physics**

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

**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....

**math**

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

**geometry**

or 2:48 = 1:24.

**geometry**

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

**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.

**Physics**

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

**science**

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

**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 ...

**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 =

**math**

21 Ways to score 15 points.

**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 ...

**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.

**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.

**Physics**

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

**Physics**

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

**Physics**

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

**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.

**Physics**

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

**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.

**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

**Physics**

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

**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.

**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.

**Math**

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

**Physics**

Please proof-read your problem.

**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 ...

**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 -(-...

**Math**

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

**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.

**Physcis- Energy**

KE = 0.5M*V^2.

**Math**

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

**science**

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

**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 ...

**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 ...

**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 ...

**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.

**Personal Finance**

I chose C.

**Reverse math confused**

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

**Polynomials**

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

**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

**Science**

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

**Math help**

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

**Math help!**

d = 66t.

**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.

**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.

**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 ...

**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 =

**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.

**PHY 1004**

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

**Physics**

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

**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.

**math**

See previous post.

**math**

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

**physics**

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

**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 =

**Physics**

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

**physics**

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

**Physics**

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

**Algebra**

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

**math**

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

**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.

**Sarah**

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

**Math**

Beginning bal. = 1761.

**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.

**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.

**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].