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.

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