# Posts by Henry

Total # Posts: 13,577

dynamics
V1 = 400m/20s = 20 m/s. V2 = 400m/30s = 13.33 m/s. a = (V2-V1)/(T2-T1) = (13.33-20)/(30-20) = -0.667 m/s^2. V2 = V1 + 2a*d. 13.33 = 20 - 2*0.667*d. d = ?.

physics
a. M1*V1 + M2*V2 = 2.9*5.4 - 1.5*1.4 = 13.6

physics
V = Vo + a*t. -1.33 = 0 + a*0.96, a = -1.33/0.96 = -1.39 m/s^2. F = M*a = 53.8 * (-1.39) = -74.5 N.

math
a. At =8*11= 88 in^2 = Total area. Ac = pi*r^2 = 3.14 * 1.5^2 = 7.07 in^2. = Area of each circle. As = 3 * 3 = 9 in^2. = Area of a 3 in square in which the circle can be inscribed. At/As = 88/9 = 9.78 or 9 = The number of squares = the number of circles that can be cut. b. 9Ac...

At beginning of year: X members in art club. 0.4X boys. 0.6X girls. In middle of year: 0.75 * 0.6X = 0.45X girls remaining. 0.4X+8 boys remains. 0.45x + 0.4x+8 = 42. X = 40 At beginning of year.

maths
Insufficient INFO.

MATH
200paces/4sides = 50 paces/side. 50paces/side * 40cm/pace = 2000 cm/side.

Math- fractions
So, we find a common denominator for the two fractions: 2/3 = 8/12, and 3/4 = 9/12.

math
I = Po*r*t = 8000*0.07*5 =

X members at first. 0.8 * x = 0.8x Male. x - 0.8x = 0.2x Female. After 450 members left: 0.75*0.8x + 0.5*0.2x = x-450. 0.6x + 0.1x - x = -450, X = 1500.

Physics
64.8o W of N = 154.8o CCW. 22.4o W of N. = 112.4o CCW. M1*V1 + M2*V2 = = M1*V3 + M2*V4. 0.4*3.57m/s[154.8o] + 0.45*5.46m/s[90o] = 0.4*4.28m/s[112.4o] + 0.45*V4. 1.43m/s[154.8] + 2.46m/s[90o] = 1.71m/s[112.4] + 045V4, -1.29+0.609i + 2.46i = -0.652+1.58i + 0.45V4, -1.29 + 3.07i...

Physics
L = V*T. 1.3 = 2.5*T, T = ?

algebra
Divide numerator and denominator by 5: (x-1)/(2x^2-5x+3). Factor the denominator: A*C = 2*3 = 6 = (-2)*(-3), 2x^2 - (2x+3x) + 3 = 0, (2x^2-2x) - (3x-3) = 0, 2x(x-1) - 3(x-1) = 0, (x-1)(2x-3) = 0, (x-1)/(x-1)(2x-3) = 1/(2x-3).

maths
Option 1: P = Po + Po*r*t. P = 12,000 + 12,000*(0.08/12)*9 = 12,000 + 720 = \$12,720. I = \$720. Option 2: Ar = Ab-Ab*r*t. Ar = 12,000-12,000*(0.07/12)*9 = 12,000 - 630 = \$11,370 = Amt. received. I = \$630. Gary should choose Option 2.

Physics
See previous post: Wed, 1-11-17, 12:49 PM.

Physics
F = M*g = (80+20)*9.8 = Work = F*d.

Physics
d = 0.5g*t^2 = 4.9*1^2 = 4.9 m.

Trig/PreCalc
Vr = 425mph[160o] + 75mph[200o]. X = 425*cos160+75*cos200 = -470 mph. Y = 425*sin160+75*sin200 = 120 mph. Tan A = Y/X = 120/-470 = -0.25532. A = -14.3o. = 14.3o N. of W. = The direction. Vr = -470/-Cos14.3 = 485 mph. = Resultant speed.

Science
F=M1*a1. M1 = F/a1 = 400/2 = 200 kg. M2 = F/a2 = 400/13 = 30.8 kg. a = F/(M1+M2).

Physics
The two numbers cannot be added directly, because they are 90o out of phase: V = 300 + 400i. You only want the magnitude: V = sqrt(300^2+400^2) = 500 m/s.

Physics
M*g = 30 * 9.8 = 294 N. Fp = 294*sin30 = 147 N. = Force parallel with slide. Fn = 294*cos30 = 254.6 N. = Force perpendicular to the ride = Normal. Fk = u*Fn = 0.15 * 254.6 = 38.2 N. = Force of kinetic friction. Fap = 200 N. = Force applied. Fap-Fp-Fk = M*a. 200-147-38.2 = 30*a...

Physics
a,b. M1*V1 + M2*V2 = M1*V3 + M2*V4. 1*5 + 1*0 = 1*4[37o] + 1*V4. 5 = 4[37o] + V4, V4 = 5-4[37O], V4 = 5-4*Cos37-4*sin37 = 5-3.19-2.41i = 1.81 - 2.41i = 3.01m/s[-53.1o] = 3.01m/s[53.1o] S. of E. = Velocity and Direction. c. A1+A2 = 37 + 53.1 = 90.1o.

Math
D. 12/15 = 4/5, 30/50 = 3/5. The ratios must be equal to form a true proportion.

physics
M*g = 225, M = 225/g = 225/9.8 = 23 kg. F = M*a, a = F/M = 14.5/23 = 0.630 m/s^2.

physics
The system is in equilibrium: T1*sin15.4 + T2*sin A = +253. 459*sin15.4 + T2*sin A = 253, 121.9 + T2*sin A = 253. T2 = (253-121.9)/sin A = 131.1/sin A. -T1*Cos15.4 + T2*Cos A = 0, -459*Cos15.4 + T2*Cos A = 0. T2*Cos A = 459*Cos15.4 = 442.5, (131.1/sin A)Cos A = 442.5, 131.1*...

Science
M/W.

Physics
Density = 100g/150cm^3 = 0.667 g/cm^3.

Physics
Vb = 0.85 * 250 = 212.5 cm^3 = Vol. below surface. = Vol. of water displaced. V*D = 212.5cm^3 * 1g/cm^3 = 212.5 grams of water displaced. Upthrust = M*g = 0.2125 * 9.8 = 2.08 N.

Math
8/(2/3) = 8 * 3/2 = 12. pieces.

Science(physics)
V = (V1+V2)/2 = (15+25)/2 = 20 km/h.

Science(physics)
A boy while driving to his school covers at the average speed of 15km/h.On his return trip along the same route, covers at the average speed of 25km/h due to less traffic.What is the average speed for the whole trip

Finance
P = Po(1+r)^n = 83,190. r = APR expressed as a decimal. n = The number of compounding periods. 30,000(1+r)^9 = 83,190. (1+r)^9 = 83,190/30,000 = 2.773, 9*Log(1+r) = Log2.773, Log(1+r) = Log2.773/9 = 0.0492, 1+r = 10^(0.0492) = 1.12, r = 1.12-1 = 0.12 = 12%.

physics
M*g = Wt. of car. a. Fn = Mg*Cos17 = 0.956Mg. Fn/Mg = 0.956Mg/Mg = 0.956. b. Fn = Mg*Cos30 = 0.866Mg. Fn/Mg = 0.866Mg/Mg = 0.866.

physics
Car A: 0.5a*Ta^2 = 400 m. 0.5*11*t^2 = 400. Ta = ?. Car B: 0.5*11.8*Tb^2 = 400. Tb = ?. b. T = Ta-Tb.

math
Y = 1.0 + 0.06*180 Calories/min.

College Physics
Find?. F1+F2= M*a. Eq1: F1+F2 = 5.75 * 0.979 = 5.63 N. F1-F2 = M*a. Eq2: F1-F2 = 5.75*0.639 = 3.67 N. F1+F2 = 5.63 F1-F2 = 3.67 Sum: 2F1 = 9.30, F1 = 4.65 N. F1-F2 = 3.67, 4.65-F2 = 3.67, F2 = 0.98 N.

Science
Range = Vo^2*sin(2A)/g. Vo = 100 m/s, A = 45o, g = 9.8 m/s^2.

physics
a. 9.8 m/s^2. b. V*2 = Vo^2 + 2g*d. V = 0, Vo = 20 m/s, g = -9.8 m/s^2, d = ?. c. V = Vo + g*t. V= 0, Vo = 20 m/s, g = -9.8 m/s^2, t = ?. d. T = 2*t(part c).

Math
5/6 = 10/12 = 15/18 = 20/24 = 25/30.

Science
P = F*d/t = 8000*75/30 J/s = Watts.

Math
V = Vo + a*t. V = 46.6 m/s, Vo = 0, t = 6.82 s, a = ?. F = M*a.

Maths
L*W = 680 m^2. L*20 = 680, L = 34 m. 2L + W = 2*34 + 20 = 88 m. needed.

Math
(17-(-28))/(14-5) = 5deg./h. T = 5deg./h * (6-5)h = 5 Degrees.

Physics
3a. L = V/F = 3*10*8/8.85*10^7 = 3.39 m = Wavelength. La = 1/4 * 3.39 = 0.85 m. = Length of antenna. b. L = V/F = 3*10^8/5.3*10^5 = Wavelength. 1/4 * wavelength = Length of antenna. 4. L = V/F = 347/1566 = 0.222 M.

Physics, math, algebra
V = Vo + a*t. V = 42300m/3600s = 11.75 m/s. Vo = 0, a = 5.60 m/s^2, t = ?.

Math
x/2 = -9/14. X = -18/14 = -9/7. Eq:(-9/7)/2 = -9/14.

biology
ok my question is asking for the percentage of thymine in the chicken DNA but I have asked google and all the sites say guanine

Physics
a. F1 = 110-4 = 106 Hz. = The difference freq. F2 = 110+4 = 114 Hz = The sum freq. b. Adjust strings until the notes cannot be heard.

Doppler Effect
Fo = (Vs+Vo)/(Vs-Vc) * Fc. Fo = (330+0)/(330-16) * 320 =

Doppler Effect
a. Moving away. b. Fo=(Vs-Vo)/(Vs+Vb) * Fb = 80. (343-0)/(343+Vb) * 85 = 80, 343/(343+Vb) = 80/85 = 0.941 322.8+0.941Vb = 343, Vb = 21.4 m/s. b.

Engineering
(y-2)^3 = (y+2)^3. (y-2)^2(y-2) = (y+2)^2(y+2). (y^2-4y+4)(y-2) = (y^2+4y+4)(y+2) y^3-4y^2+4y-2y^2+8y-8=y^3+4y^2+4y+2y^2+8y+8, -6y^2+12y-8 = 6y^2+12y+8, -12y^2 = 16, Y = 1.155i. No real solution, because y-2 cannot equal y+2.

Maths
V = Vo - Vo*r*t. V = 100,000 - 100,000*0.05*2 = 90,000.

Maths
V = Vo - Vo*r*t. V = 100,000 - 100,000*0.05*2 =

yes
h/L = 2/5, L = 2.5h. h/W = 4/5, W = 1.25h. 2(h*L) + 2(h*W) = 108 m^2. 2(h*2.5h) + 2(h*1.25h) = 108, 5h^2 + 2.5h^2 = 108, h = 3.79 m. A = L*W = 2.5h*1.25h = 2.5*3.79 * 1.25*3.79 = 45 m^2.

math
P = Po + Po*r*t. P = 9000 + 9000*(0.105/365)*270.

physics
d = 0.5g*t^2. g = 9.8 m/s^2, t = 5s. V = Vo + g*t. Vo = 0, g = 9.8, t = 5s.

Algebra
not anonymous.

Math
8+2+7 = 17.

MATH
Log10^a = 4. 10^a = 4, a = 4.

Math
240seats/5rows = 48 seats/row. 240seats/6rows = 40 seats/row. Repeat for 8, 10, 12, 15, 16, 20, 24, 30, and 40 rows.

algebra
(5z-2)(5z+2) = 25z^2 +10z - 10z - 4 = 25z^2 - 4. or (5z)^2 - 2^2 = 25z^2 - 4.

mystery
See previous problem.

mystery
See previous problem.

mystery
0.45N = 17.1, N = 38.

Maths
See previous post: Thu, 12-22-16, 11:14 PM.

Easy Maths QuestioPn
1. Y = 5.80n. 2. P = 5.80n - 0.8n - 1250, P = 5n - 1250. 3. P = 5n - 1250 = 0, n = 250.

electrical energy and power
Pi = E*I = 240 * 7.5 = 1800 W. 2hp * 746W/hp = 1492 W. Eff. = Po/Pi = 1492/1800 = 0.829 = 82.9%.

algebra
(2m-4)(m^2+2m+4) = 2m^3 + 4m^2 + 8m-4m^2-8m-16 = 2m^3-16 = 2(m^3-8).

Science: Physics
Cost = 0.0479/kW * 228.125kWh =

Science: Physics
1. P = E*I= 2500. 230I = 2500, I = 10.9A. 2. R = E/I. 3. T = 365 * 15/60 = 91.25 h/yr. 4. Energy = kW * h = 2.5 * 91.25 = 228.125 kWh.

physics
R = 1.02 + 0.0039*(60-20)= 1.176 Ohms.

math

maths
3.25x + 3.85(80-x) = 272. 3.25x - 3.85x + 308 = 272, X = ?.

Algebra 1
Multiply Eq1 by 3, and convert Eq2 to standard form: Eq1: 6x + 3y = 9. Eq2: 6x + 3y = 9. The 2 Eqs are identical. Therefore, we have an infinite number of solutions.

math
5F + 5S = 575. F = S+15. 5(S+15) + 5S = 575.

Physics
Are you sure the child is only 5 m ahead? Vo = 50km/h = 50,000m/3600s = 13.89 m/s. a. V = Vo + a*t = 0. 13.89 + a*5 = 0, a = -2.80 m/s^2. V^2 = Vo^2 + 2a*d. V = 0, Vo = 13.89 m/s, a = -2.80m/s^2, d = ?. b.

Math
Or 5/4 = 1.25 = 125%. 125% - 100% = 25%.

physics
See previous post: Thu, 12-15-16, 9:33 PM.

PHYSICS
What is the question?. Vo = 30m/s[60o]. Xo = 30*Cos60 = 15 m/s. Yo = 30*sin60 = 25.0 m/s. Range = Vo^2*sin(2A)/g. A = 60o. Y^2 = Yo^2 + 2g*h. Y = 0, Yo = 25 m/s, g = -9.8 m/s^2, h = ?.

p[hysics
See previous post: Thu, 12-15-16, 9:33 PM.

PHYSICS HELP!!!!!
Vo = 25m/s[20o]. Xo = 25*Cos20 = 23.5 m/s. Yo = 25*sin20 = 8.55 m/s. Y = Yo + g*Tr = 0. 8.55 - 9.8Tr = 0, Tr = 0.873 s. = Rise time. Y^2 = Yo^2 + 2g*h = 0. (8.55)^2 - 19.6h = 0, h = 3.73 m. Above the cliff. 0.5g*Tf^2 = 3.73+8.4 4.9Tf^2 = 12.13, Tf = 1.57 = Fall time. Dx = Xo(...

PHYSICS HELP
Tan A = Y/X = (-50)/400 = -0.125, A = -7.125o = 7.125o S. of E.

PHYSICS HELP
X = 400 km/h. Y = 50 km/h. V = sqrt(X^2+Y^2).

physics hw
Vo = 87km/h = 87,000m/3600s = 24.2 m/s. = Initial velocity. a. d1 = 24.2 * 2 = V^2 = Vo^2 + 2a*d2. V = 0, Vo = 24.2 m/s, a = -4.0 m/s^2, d2 = ?. d1+d2 = Stopping distance. b. V^2 = Vo^2 + 2a*d2. V = 0, Vo = 24.2 m/s^2, a = -8.0 m/s^2, d2 = ?. d1+d2 = stopping distance.

physics
V1 = a*t = 2.5 * 5 = 7.5 m/s. a. V2 = V1 + a*t = 7.5 -(3 * 2) = 1.5 m/s. After the braking period. b. d1 = 0.5a*t^2 = 0.5*2.5*5^2 = 31.25 m. d2 = V1*t + 0.5a*t^2. d2 = 7.5*2 - 0.5*3*2^2 = 9 m. d = d1+d2 = 31.25 + 9 = 40.25 m.

physics
V^2 = Vo^2 + 2g*h = 0 + 19.6*29 = 568.4, V = 23.8 m/s. Work = KE2-KE1 = KE2-0 = KE2. Work = KE2 = 0.5M*V^2 = 0.5*41,000*(23.8)^2 = 11.7*10^6 J. Work = F*d = F*29 = 11.7*10^6, F = 4.03*10^5 N. d = 1m/4.1*10^5N. * 4.03*10^5N. = = 0.983 m.

Physics
M*g = Wt. of box = Normal force(Fn). Fp = Mg*sin o = 0. = Force parallel to the surface. Fk = u*Fn = u*M*g. V^2 = Vo^2 + 2a*d = (3.3)^2. (4.56)^2 + 2a*0.7 = 10.9, a = -7.07 m/s^2. Fp-Fk = M*a. 0-u*Mg = M*(-7.07), 0-u*M*9.8 = -7.07M, Divide both sides by -9.8M: u = 0.722.

Physics
Vo = 17.7 m/s[39.8o]. Yo = 17.7*sin(39.8) = 11.33 m/s. = Vert. component of Vo. Y = Yo + g*Tr = 0. 11.33 - 9.8Tr = 0, Tr = 1.16 s. = Rise time. T = Tr+Tf. Tf = Tr. T = Tr+Tr = 1.16 + 1.16 = 2.32 s.

Physics
A. F = M*g*30 = 71*9.8*30 = 20,874 N. = 2.09*10^4 N. B. Vo = 95km/h = 95,000m/3600s = 26.4 m/s. F = M*a = -20,874. a = -20,873/71 = -294 m/s^2. V^2 = Vo^2 + 2a*d. V = 0, Vo = 26.4 m/s, a = -294 m/s^2, d = ?.

P = Po - Po*r*t. P = 9500-9500*(0.10/365)*95 = \$9252.74. = Proceeds.

Math
db = 10*Log(Po/75) = 12. Log(Po/75) = 1.2, Po/75 = 10^1.2, Po = 1189 W.

Physics
a. Vo = 20m/s[45o]. Xo = 20*Cos45 = 14.14 m/s. Yo = 20*sin45 = 14.14 m/s. Y = Yo + g*t = 0. 14.14 - 9.8t = 0, t = 1.44 s. b. Y^2 = Yo^2 + 2g*h = 0. (14.14)^2 - 19.6h = 0, h = ?. c. Range = Vo^2*sin(2A)/g. A = 45o. d. T = Tr+Tf. Tf = Tr, T = Tr+Tr = 1.44 + 1.44 = 2.88 s. d.

Math
Invested: Po @ 2%. (2Po+2300) @ 9%. t = 1 yr.? I = Po*r*t + (2Po+2300)*r*t = 647. Po*0.02*1 + (2Po+2300)*0.09*1 = 647, 0.02Po + 0.18Po + 207 = 647, 0.20Po = 440, Po = \$2200. 2Po+2300 = 2*2200 + 2300 = \$6700.

Mathematics
1. (8,11). y/x = 11/8, Y = 1.375x. 2. correct. 3. y/x = 232/4 = 58/1. 4. (2,5), (8,3). m = (3-5)/(8-2) = -2/6 = -1/3.

math
Correction: 360cm^3/2^3 = 45 Cubes.

physics
Work = KE2-KE1 = KE2-0 = KE2. KE2 = 0.5M*V^2 = 10,000 J. 500*V^2 = 10,000, V = ?.

Physics
a. M*g = 1.35 * 9.8 = 13.2 N. = Wt. of book. = Normal force(Fn). Fs = us*Fn = 0.45 * 13.2 = 5.95 N. F-Fs = M*a. F = Fs+M*a = 5.95+M*0 = 5.95 N. b. Fk = uk*Fn = 0.30 * 13.2 = 3.96 N. F-Fk = M*a. a = (F-Fk)/M. c. Fap-Fk = M*a. Fap = Fk+M*a = 3.96 + M*0 = 3.96 N. = Force applied...

Physics
e. Fnet = M*a. a = Fnet/M.

Physics
a. M*g = 475 * 9.8 = 4655 N. = Wt. of sleigh. = Normal force(Fn). b. Fs = u*Fn = 0.20 * 4655 = c. Fk = uk*Fn = 0.15 * 4655 = d. Fnet = Fh-Fk = 150,000-4655 =

Science
F = M*a. = 20. a = 20/M = 20/60 = 0.333 m/s^2.

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