# Posts by Henry

Total # Posts: 13,729

**Algebra**

The freight travels r mi/h. The passenger train travels r+14 mi/h. Df = Dp. 5r = 3(r+14) 5r = 3r + 42 r = 21 mi/h. r+14 = 21 + 14 = 35 mi/h. Laura, Your Eq is correct, but you made an error when solving it.

**Math**

d1 + d2 = 200. 20mi/h * 2h + r*2 = 200 40 + 2r = 200 r = 80 mi/h.

**Mathematics**

1.*10^3. The positive "3" means move the decimal 3 places to the right to convert to standard form. (-3) means move the decimal 3 places to the left. 1.*10^3 = 1,000. 1.*10^-3 = 0.001.

**Physics**

Terry: d = Vo*t + 0.5g*t^2 = 29. 9t + 4.9t^2 = 29 4.9t^2 + 9t -29 = 0. Use Quadratic Formula: t = -9 +- Sqrt(9^2+4*4.9*29)/9.8 = 1.68 s. = Time to reach bottom of well. Sam: V = Vo + g*Tr = 0. 9 - 9.8Tr = 0 Tr = 0.918s = Rise time. Tf1 = Tr = 0.918s = Fall time to launching ...

**Math**

Smallest = X. Middle = x+1. Largest = x+2. 2x = (x+2) + 11. X = 13. x+1 = 13+1 = 14. x+2 = 13+2 = 15.

**Math**

V = Vo(1+r)^n. Vo = $420. r = 0.03/12 = 0.0025/mo. n = 1Comp/mo. * 2mo. = 2 compounding periods. V = ?.

**physcis**

V = Vo + a*t = 7. 2 + a*10 = 7, a = 0.5 rev/s^2. or a = 0.5rev/s^2 * 6.28rad/rev = 3.14 rad/s^2.

**algebra**

Yes, that is true. But when you divide both sides by (-2) to solve for x; you will have to reverse inequality sign. -2x - 20 >= 75. -2x >= 95 X <= -47.5. Therefore, all values of x that are less than or equal to (-47.5) will satisfy the given inequality.

**math**

Correction: Multiples of 40: 40, 80, 120, 160.

**math**

Multiples of 32: 32*1 = 32, 32*2 = 64. Therefore 32 and 64 are multiples of 32. Multiples of 32: 32, 64, 96, 128, 160. Multiples of 40: 40: 40, 80, 120, 160. LCM = 160.

**Algebra**

Frank is X years old. Gabriel is x-3 years old. When their ages are doubled: Frank is 2x years old. Gabriel is 2x-6 years old. x + (x-3) = 17. 2x-3 = 17 X = 10 years = Frank's age. x-3 = 10-3 = 7 years = Gabriel's age.

**Physics**

F = 1.8C + 32 = 107. C = 41.67o. Error = 42 - 41.67 =

**Math**

3.16*10^3 = 3160.

**Physics**

I'm assuming the cheetah is running at 0.029 km/s (29m/s). V = Vo + a*t = 29. 0 + 4.14*t = 29. t = ?.

**science**

a. Cos A = 0.3/0.5 = 0.6. A = 53.13o = B. T1*sin53.13 + T2*sin(180-53.13) = +15. T2 = T1: T1*sin53.13 + T1*sin126.9 = 15 0.8T1 + 0.8T1 = 15 T1 = 9.375 N. = Tens1on in the string. b. Cos A = 0.3/0.33 = 0.90909, A = 24.62o. T1*sin24.62 + T2*sin(180-24.62) = +15. T2 = T1 T1 = ?. ...

**physics HELP**

1. V^2 = Vo^2 + 2a*d. a. V^2 = 0 + 0.36*494, V = ?. b. d = 0.5a*t^2. 494 = 0.5*0.18*t^2. t = ?. 2. V = Vo + a*t = 0 + 1.4*4.1 = 5.74 m/s. V^2 = Vo^2 + 2a*d. 0 = (5.74)^2 - 3.6d. d = ?.

**Math**

(3/4)/(3/5) = x/1. 3/4*5/3 = x/1, X = 5/4 h.

**physics**

k = 20N/(10.01-0.10) = 2.02 N/m = Force constant or spring constant.

**my success**

a, b, and d.

**Geometry**

A. 1/3 * 36 = 12 Boys. B. 36 - 11 = 25 Girls. C. p = 25/36 =

**Math**

No. 4 + 10 = 10 + 4 is commutative.

**Math**

sin60 = AD/CD = 2.54/CD. CD = ?.

**Math**

280 + 0.06(s-136-5000) = $328.54. 280 + 0.06s-308.16 = 328.54, 0.06s - 28.16 = 328.54, S = $5945. = Gross sales.

**Physics**

V = Vo + g*Tr = 0. 30 - 9.8Tr = 0, Tr = 3.06 s. = Rise time. Tf = Tr = 3.06 s. Tr+Tf = 3.06 + 3.06 = 6.12 s. = Time in air.

**math**

See previous post: Sun, 9-17-17, 12:42 PM.

**physic**

C = pi * Diameter = Circumference. We need to know the radius or diameter of the tire. Rev. = d/C. d = 50,000 Miles. d and C must be in the same unit(meters or miles).

**physic**

36o W. of N. = 90+36 = 126o CCW from E. (a+b) = 5.2 + 3.70[126o]. (a+b) = 5.2 + 3.70*Cos126+3.70*sin126, (a+b) = 5.2 - 2.17+2.99i, (a+b) = 3.03 + 2.99i = 4.26m[44.62o] A. Magnitude = 4.26 m. B. Direction = 44.62o. (b-a) = 3.70[126o] - 5.2. (b-a) = -2.17+2.99i - 5.2, (b-a) = -7...

**Math**

Wt. = 900Liters * 1oz/0.03Liters = 30,000 Ozs. = 1875 Lbs./min. Mass = 1875Lbs * 0.454kg/Lb. = 851.25 kg./min. P = M*g*d/t = 851.25/60s * 9.8 * 50 = 6952 J/s = 6952 Watts. h.p. = 6952/746 = 9.32.

**trigonometry**

See previous post: Sun, 9-17-17, 12:34 AM.

**trigonometry**

Tan18.16 = h1/105. h1 = 105*Tan18.16 = 34.44 m. = Height of Sky dome. h = h1 + h2. h = 34.44 + 105*Tan57.33 = 198.2 m. = Ht. of Trinoma.

**physics**

Displacement is the straight-line distance from the starting point to the end point. The minute hand returns to the starting point in one hour. Therefore the displacement is zero. V = d/t = 360o/h = 2pirad/h = 6.28 rad/h.

**Physics**

Incomplete.

**physics**

Tan A = Y/X = -7.00/-4.50 = 1.55555. A = 57.3o W. of S.

**physics**

d = d1 + d2 = 5m + 10m = 15 m. Disp. = Vector sum = Sqrt(5^2+10^2) =

**Algebra**

(-1,6), (5,2). m = (2-6)/(5-(-1)) = -4/6 = -2/3. Y = mx + b. 6 = (-2/3)(-1) + b, b = 6-2/3 = 18/3-2/3 = 16/3. y = -2x/3 + 16/3, 2x/3 + y = 16/3, Multiply Eq. by 3: 2x + 3y = 16. Std. form.

**math**

5 1/2/(3/4) = 5 1/2 * 4/3 = 11/2 * 4/3 = 44/6 = 22/3 = 7 1/3 servings. 2/3 of a serving needed: 2/3 * (3/4)cup = 6/12 = 1/2 cup needed.

**Physics**

Draw AB perpendicular to AC. Therefore, we have a right angle. Draw BC the hyp. of the rt. triangle formed. The displacement is the straight-line distance from the starting point to the final point which is the hyp. Disp. = hyp. = BC = Sqrt((AB)^2+(AC)^2). AB = 20km. AC = 13km...

**Physics**

30o E. of N. = 60o CCW. Fr = -1160 + 990[60]. Fr = -1160 + 990*Cos60+990*sin60, Fr = -1160 + 495+857.4i, Fr = -665 + 857.4i = 1085N[-52.2] = 1085N[127.8o] = Resultant force. Fr = M*a = 1085[127.8o]. 0.168a = 1085[127.8, a = 6458 m/s^2[127.8o].

**physics**

Vi = 62,000m/3600s = 17.22 m/s. d = Vi*t = 17.22m/s * 0.728s =

**PHYSICS**

Correction: V^2 = Vi^2 + 2a*d = 0. (26.4)^2 + 2a*0.8 = 0, a = 435.6 m/s^2. g's = 435.6m/s^2/(9.8m/s^2) = 44.4.

**PHYSICS**

Vi = 95,000m/3600s. = 26.4 m/s. V = Vi + 2a*d = 0. 26.4 + 2a*0.8 = 0, a = -16.5 m/s^2. g's = -16.5m/s^2/(9.80m/s^2) = -1.68.

**Math.... Anyone wanna help?**

c = (b/2)^2 = (-36/2)^2 = 324. x^2 - 36x + 324 = (x-18)^2.

**math**

44 - 21 = 23 yrs. = Her oldest daughter's age. 23 - 6 = 17 years = Her youngest son's age.

**Math**

Medium sized dogs eat X cups/day. Small dogs eat x-1/2 cups/day. Large dogs eat x+3/4 cups/day. Total = x + (x-1/2) + (x+3/4) = 3x-1/2+3/4 = 3x-2/4+3/4 = 3x + 1/4 cups/day.

**math**

2Log8^2 + 2Log8^3 = 2Log(8^2*8^3) = 2Log8^5.

**algrebra 1**

Sqrt(18x^2/50) = Sqrt(9*2x^2/(25*2) = 3x/5*Sqrt(2/2)= 3x/5.

**Science**

Incomplete.

**Math**

Multiples of 8 Multiples of 8: 8*1=8, 8*2=16, and etc: 8: 8, 16, 24, 32, 40, 48, 56, 64, 72,80, 88, 96. 12: 12, 24, 36, 48, 60, 72, 84, 96. Common Multiples: 24, 48, 72, 96. LCM = 24. 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36. 5: 5, 10, 15, 20, 25, 30, 35, 40. Common ...

**College Algebra**

3. Graph 2(3x-3) = 6, and 2(3x-4) = -8. 2(3x-3) = 6, X = 2. 2(3x-4) = -8, X = 0. 4. Sorry! but this one makes no sense to me.

**College Algebra**

2. Graph 4x-3 = -3, and 4x+2 = -14. 4x-3 = -3. X = 0. 4x+2 = -14. X = -4. Plotting points: X = -4, and X = 0. All points BETWEEN -4 and 0 should satisfy both inequalities. 3. Graph 2(3x-3) = 6, and 2 93x-4) = -8

**Math**

I = P*r*t = 0.125P. P*0.1*t = 0.125P, Divide both sides by P: 0.1t = 0.125, t = 1.25 Years.

**Math**

X years old today. Y years old 2 years ago. x = 6y, 0r 6y = x.

**Maths**

APR = 15/2% = 7.5% = 0.075. P = Po + Po*r*t = 3920. Po + Po*0.075*3 = 3920. Po = ?. = Sum(Amt. borrowed).

**Maths**

How many were sold at a 5% profit?

**AP Physics: shot projectile??**

The greatest horizontal distance occurs at 45o. Vo = 350m/s[45o]. Xo = 350*Cos45 = 247.5 m/s. Yo = 350*sin45 = 247.5 m/s. Y = Yo + g*Tr = 0, 350 - 9.8*Tr == 0, Tr = 35.7 s. = Rise time. Tf = Tr = 35.7 s. = Fall time. T = Tr+Tf = 35.7 + 35.7 = 71.4 s. = Time in flight. d = Xo*T...

**Maths**

<A + <B = 67o + 58 - 125o. <C = 180-125 = 55o. Using Law of Sine: Sin55/21 = Sin58/AC. AC = ?. Sin55/21 = Sin67/BC. BC = ?. <A and <B are the angles between the wires and gnd. <C is formed by the wires at the point of connection to the pole.

**Math**

1. No. After the first prime factorization, no further factoring can be done. 2. Yes. Prime numbers(2, 3, 5, 7) have no prime factors; because they have already gone through "Prime factorization".

**AP Physics Springs - very confusing question**

A, and C.

**physics**

R = pL/A. A = pi*r^2 = 3.14*(1/2)^2 = 0.7854 mm^2 4 = 1.78*10^-4*L/0.7854. 4 = 2.2664*10^-4L, L = 1.765*10^4 mm = 17.65 m.

**College Algebra**

(5+12)/2 = 8.5%.

**Physics**

Work = F*Cos A * d = 19.4*Cos61 * 2.7 =

**Algebra**

Sum = 13*sqrt(64*2) + 6*13 - 7*11 - 11*sqrt(81*2), Sum = 13*8*sqrt2 + 78 - 77 - 11*9*sqrt2 Sum = 104*sqrt2 + 1 - 99*sqrt2, Sum = 5*Sqrt2 + 1 = 8.071.

**Algebra**

3.25/3.30 = 0.985 = 98.5%. %Change = 98.5% - 100% = -1.5% = 1.5% Decrease.

**Algebra**

Po*r*t = 1650. 11,000*r*5 = 1650. r = 0.03/yr. = 3%/yr. So APR = 3%.

**math**

The cost of the shovels(4172.50) makes no sense!

**geometry**

Incomplete.

**math**

d = 45 + 20 = 65 km. t = 3 + 1.5 + 1.5 = 6.0 Hours. V = d/t = 65km/6h = 10.83 km/h.

**Physics - conservation of momentum**

The kayak is initially stationary(V2 = 0). I'm assuming their velocities are equal after landing. M1*V1 + M2*V2 = M1*V + M2*V. 80.8*5.5 + 29.9*0 = 80.8V + 29.9V. 444.4 = 110.7V, V = 4.01 m/s.

**AP Physics 1 Momentum**

I agree with all of your selections.

**Math**

(3x^2y)^2 = 9x^4y^2.

**Algbra**

I = Po*r*t. I = 12,000*0.12*(120/360). = $480. r = (I/Po) = 480/12,000 = 0.04 = 4% = effective interest rate.

**Algebra**

3x^-2 * y^-5 = 3/x^2 * 1/y^5 = 3/x^2y^5.

**Physics**

Note: Fp = Force parallel with the incline. Fn = Normal force. = Force perpendicular to the incline.

**Physics**

Fp = Mg*sin25 = 0.423Mg. Fn = Mg*Cos25 = 0.906Mg. Fk = u*Fn = 0.2 * 0.906Mg = 0.181Mg. Fp-Fk = M*a. 0.423Mg-0.181Mg = M*a. Divide both sides by M: 0.423g-0.181g = a, a = 0.242g = 0.242 * 9.8 = 2.37 m/s^2. V^2 = Vo^2 + 2a*d. V^2 = 0 + 4.74*10.4 = 49.3, V = 7.02 m/s. V^2 = Vo^2...

**Algebra II**

d1 + d2 = 400. 40*T + 35*T = 400, T = 5 1/3 Hours.

**Algebra II**

Width = X feet. Length = x+6 feet. x + (x+6) + x = 164. X = 52 2/3 Ft. x+6 = 52 2/3 + 6 = 58 2/3 Ft.

**Maths**

Do w you mean "How many blue balloons?" Blue = 27/4 * 9 =

**physics**

Fn = 87-60*sin15 = Normal force. Fk = u*Fn = 0.35 * Fn. = Force of kinetic friction.

**Math**

1. (12*W) + (11*n) = 12W + 11n. 2. (42*c) + (47*e) = 42c + 47e.

**science**

B is my answer.

**Science**

r = 4,000m/3min *100cm/m = 133,333 cm/min.

**Math**

<COA = 90o: Given. <DOA = 135o: Given. <DOC = <DOA - <COA = 135 - 90 = 45o.

**math**

Now: X years old. 5 yrs. ago: x-5 yrs. old. 5 yrs. from now: x+5 years old. x+5 = 2*(x-5)^2. x+5 = 2(x^2-10x+25). x+5 = 2x^2-20x+50, -45 = 2x^2-21x, 2x^2-21x+45 = 0. Use Quadratic Formula: X = (21 +- sqrt(441-360))/4 = 30/4 = 15/2, and 3. Use the larger number: X = 15/2 = 7.5 ...

**physics**

1. M*V1 + M*V2 + M*V3 = M*V + M*V + M*V. M*10[30o] + M*20[30] + M*30[30] = 3MV. Divide both sides by M: 10[30o] + 20[30] + 30[30] = 3V, 60[30o] = 3V, V = 20m/s[30o].

**Math**

5km/(1.6km/mi) = 3.125 Miles = 3 1/8 Miles.

**Math**

1 * 12. 2 * 6. 3 * 4. Total = 3 different stands.

**PreCal**

44Ft/0.5s * 1mi/5280Ft * 3600s/h = 60 mi/h.

**Physics**

d = V*t + 0.5g*t^2. 20 = V*1 + 0.5*10*1^2, V = 15 m/s = Velocity at top of pole. V^2 = Vo^2 + 2g*d. 15^2 = 0 + 20d, d = 11.25 m.

**Science Help Practice**

1. 0.5M*V^2 = KE. 0.5 * 90,000 * V^2 = 1*10^9 J. V = ?. V = 149.07 J. 2. Use same formula as #1: 0.5M*V^2 = KE. 0.5M * 23^2 = 4.32*10^6 J. M = ?.

**Science**

M*g = 50 * 9.8 = 490 N. = Wt. of block. = Normal force(Fn). Fp = 490*sin30 = 245 N. = Force parallel with the incline. Fs = u*Fn = u * 490 = 490u. Fap-Fp-uFn = M*a. 250 - 245 - 490u = M*0 = 0, u = 0.010.

**science**

Volume.

**Physics**

Vb = Do/Dl * Vo. 3/4 = Do/1.2 * 1. 4Do = 3.6, Do = 0.9kg/m^3. = Density of the object.

**HELP plz**

I would use C.

**Math**

Another Method: L = 2*(3+40+3) + 30 + 30 = 152 Ft. = Length of walkway. A = L*W = 152 * 3 = 456 Ft^2.

**Math**

All dimensions are assumed to be in feet. Lo = 3 + 40 + 3 = 46 Ft. = Length of outer rectangle. Wo = 3 + 30 + 3 36 Ft. = Width of o = uter rectangle. Ao = Lo * Wo = 46 * 36 = 1656 Ft^2. Ap = 40 * 30 = 1200 Ft^2. Ao - Ap = 1656 - 1200 = 456 Ft^2. = Area of walkway.

**math**

Velocity in the morning = V mi/h. Velocity in the evening = V-6 mi/h. d = V*t = V * 20/60. d = (V-6) * 31/60. V * 20/60 = (V-6) * 31/60. V = 16.91 mi/h. d = V * 20/60 = 16.91 * 20/60 = 5.64 Miles.

**math**

d1 + d2 = L. d1 = Distance covered by cyclist #1. d2 = Distance covered by cyclist #2. d1 = L-200. d2 = L-100. (L-200) + (L-100) = L. L = 300 m. = Length of road.

**Precalculus 11**

Plane takes T hours. Train takes T+1 hours. Velocity of train = V km/h. Velocity of plane = 2V km/h. Plane: 2V*T = 240 km. Train: V*T = 240 km. Therefore, 2V*T = V*(T+1). T = 1 h. T+1 = 1 + 1 = 2 h. 2V*T = 240. 2V * 1 = 240, 2V = 240 km/h = Velocity of the plane.

**ALGEBRA HELP #2**

A. V = Vo + a*t. V = The velocity in km/h at any time where t is in hours. a is the acceleration in km/h^2.

**trigonometry(height and distance)**

The distance should be 5m LONGER at 45o. Tan 45 = h/(d+5). h = (d+5)*Tan45 = d+5. Tan60 = h/d. h = d*Tan60 = 1.73d d+5 = 1.73d. d = 6.83 m. h = d + 5 = 6.83+5 = 11.83 m.