# Posts by Henry

Total # Posts: 13,500

physics
Radios and TV sets often use step-up transformers to increase the 120-volt line voltage. Step-up and step-down transformers are also used for impedance matching for maximum power transfer. For example, a step-down transformer would be used to match a high resistance source to ...

physics
The output voltage of a step-up transformer is greater than the input voltage. The output voltage of a step-down transformer is less than the input voltage. In each case, the input voltage is connected across the primary winding, and the output voltage is measured across the ...

physics
Do/Dw = 0.75. Do/1 = 0.75, Do = 0.75g/cm^3 = Density of the object. M*g = 48 N. M = 48/g = 48/9.8 = 4.90 kg. = 4900g = Wt. of object. Vo = 4900g/(0.75g/cm^3) = 6533.3 cm^3 = Vol. of object. 0.75 * 6533.3 = 4900 cm^3 immersed = Vol. of water displaced. 4900cm^3 * 1g/cm^3 = ...

PHYSICS HELP
b. V^2 = Vo^2 + 2g*hmax. 29^2 = 0 + 19.6*hmax, hmax = 42.9 m. = Max. ht. above gnd. ho + h1 = hmax. 31 + h1 = 42.9, h1 = 11.9 m. above the cliff. a. V^2 = Vo^2 + 2g*h1. 0 = Vo^2 -19.6*11.9, Vo^2 = 233.2, Vo = 15.3 m/s = Velocity at which the rock was released.

physics
d = r = 31.7m = Vertical distance traveled. V^2 = Vo^2 + 2g*d. V^2 = 0 + 19.6*31.7 = 621.32, V = 24.9 m/s.

Physics
V1 = 15m/s[45o E of N.] = 45o N. of E. V2 = 18m/s[5o N. of E.]. Vr = 15m/s[45o] + 18m/s[5o]. Vr = 15*Cos45+15*sin45 + 18*Cos5+18*sin5. Vr = (10.61+10.61i) + (17.93+1.57i) = 28.54 + 12.18i. Magnitude = sqrt(28.54^2 + 12.18^2) = Tan A = Y/X = 12.18/28.54 = 0.42887. A =

Algebra

physics question
Fc = M*g = 100 * 9.8 = 980 N. a. Work/s = F*d/t = 980 * 16/20 = 784 J./s. = 784 Watts. b. Po = Work/s = 784 J/s. c. Efficiency = Po/Pi = 784Watts/1000Watts = 0.784 = 78.4%.

physics
a. V^2 = Vo^2 + 2a*d. 0 = 20^2 + 2a*100, a = -2 m/s^2. b. F = M*a = 1000*(-2) = -2,000 N. c. W = F*d = -2000 * 100 = -200,000 Joules.

physics
Idc = 2Ipk/pi. 0.6 = 2Ipk/3.14, 2Ipk = 1.88, Ipk = 0.94 mA.

physics
Idc = Imax/pi = (1.414*150)/3.14 = 67.5 uA.

physic
Imax = I1max - I2min. Imax = (79+0.03*100) - (31-0.1) = 82 - 30.9 = 51.1 mA. Imin = I1min - I2max. Imin = (79-0.03*100) - (31+0.1) = 76 - 31.1 = 44.9 mA.

Maths
F(x) = (4x+7) + (x^2-2x). F(x) = Y = x^2 + 2x + 7. X = -B/2A = -2/2 = -1. Y = (-1)^2 + 2(-1) + 7 = 6. Min. point: (x,y) = (-1,6).

Math
2nd side = X yds. 1st. side = x-5 yds. 3rd. side = (x-5)-2 = x-7 yds. X + (X-5) + (X-7) = 42. 3x - 12 = 42, X = 18 Yds. X-5 = 18-5 = 13 Yds. X- 7 = 18 - 7 = 11 Yds.

Math, slope
C = 5 + 0.75/0.5KM. C = 5 + 1.50/km Eq: C = 1.5x + 5. C = Cost. Slope = 1.5. X = Distance traveled. Y-Intercept = 5.

Calculus
Tan(A) = Y/X = -7/2 r^2 = X^2 + Y^2 = 2^2 + (-7)^2 = 53, r = sqrt(53). a. sin(A) = Y/r = (-7)/sqrt(53) = (-7)*sqrt(53)/53. b. Cos(A) = X/r = 2/sqrt(53) = 2*sqrt(53)/53. c. sec(A) = 1/Cos(A) = qrt(53)/2. d. csc(A) = sqrt(53)/(-7). e. cot(A) = 1/Tan(A) = 2//(-7). = - 2/7.

Calculus
V^2 = Vo^2 = 2a*d. 0 = Vo^2 - 32*200, Vo^2 = 6400, Vo = 80 Ft/s. Vo = 80FT/s * 1m1/5280Ft. * 3600s/h = 54.5 mi/h. = Initial velocity.

Physics 12
a. Fr = F1 + F2 = 360 + 360 = 720 N. b. Fr = 360[0o] + 360[60o]. Fr = 360 + (180+312i) = 540 + 312i = 624N.[30o]. c. Fr = 360[0o] + 360[120o]. Fr = 360 + (-180+312i) = 180 + 312i = 360N.[60o]. d. Fr = 360[0o] + 360[180o]. Fr = 360 + (-360+0l) = 0.

algebra
Incomplete.

physics
V^2 = Vo^2 + 2a*d. 1.12^2 = 0 + 2a*5.4, a = 0.116 m/s^2. M*g = 6.8*9.8 = 66.64 N. = Wt. of bats. = Normal force(Fn). Fk = u*Fn = 66.64u. Fe-Fk = M*a. 20-66.64u = 6.8*0.116 = 0.789, 66.64u = 20-0.789 = 19.2, u = 0.288.

math
u(8,-3), v(-3,-8). Tan A = (-8-(-3))/(-3-8) = -5/-11 = 0.45455, A = 24.4o. S. of W.

mechanics
M*a = -30. a = -30/M = -30/0.54 = -55.6 M/S^2. V = Vo + a*t = 15 - 55.6*0.25 = 1.11 m/s.

mechanics
V = Vo + a*t. 12 = 15 + a*0.25, a = -12 m/s^2. a. Fe = M*a = 1200*(-12). b. M1*V1 + M2*V2 = M1*V3 + M2*V4. 1200*15 + 800*10 = 1200*12 + 800V4, 18,000 + 8000 = 14,400 + 800V4, -14,400 + 26,000 = 800V4, 800V4 = 11,600, V4 = 14.5 m/s. = Velocity of the car.

Phyisics
Vs = Vo + 0.6m/s/Co. Vs = 340 + 0.6*127 = 416 m/s.

math
1. S = 5000. 2. S = 5000 + 1500 = 6500. 3. S = 6500 + 1500 = 8,000. 4. S = 8000 + 1500 = 9,500. S = 5000 + 5000*0.3*(n-1). Factor out 5000: Eq: S = 5000(1 + 0.3*(n-1)). 2. S = 5000(1+0.3*(2-1)) = 6500. 3. S = 5000(1+0.3*(3-1)) = 8000. 4. S = 5000(1+0.3*(4-1)) = 9500.

Physics
1-0.8 = 0.2 N. lost. M*g = 0.2, M = 0.2/9.8 = 0.0204 kg = 20.4 grams lost

Math Fractions
6cups * 8oz/cup = 48 oz. of sports drink concentrate. 48oz + 9*48oz. = 480 oz. 480oz./(128oz/gal) = 3.75 Gal.

Math
P = (Po*r*t)/(1-(1+r)^-t). Po = \$20,300. r = 0.0975/12 = 0.008125/mo. t = 4yrs. * 12mo./yr. = 48 mo. P = (20,300*0.008125*48)/(1-1.008125^-48). P = 7917/(1-1.008125^(-48)), P = 7917/0.32187535 = \$24,596.48. M.P. = P/48. = 24,596.48/48 = \$512.43.

Physics
A. V2^2 = V1^2 + 2g*h. V2^2 = 0 + 19.6*1.25 = 24.5, V2 = 4.95 m/s.

physics
Avg. Speed = (20+60+120)/3 = 66.67 km/h.

physical sciences
V2 = a*t = 4 * 40 = 160 m/s = Take-off speed. V2 = V1 + a*t. 160 = V1 + 4*40, V1 = 0.

Physics
Vr = 25 + 100i = 103m/s[76o].

Physics
output = 0.8 * Input =

Physics
V1 = 610rev/min * 6.28rad/rev * 1min/60s = 63.85 rad/s. V2 = V1 + a*t. = 63.85 + 5.9*3.2 = 82.73 m/s.

Math
kids ticket = \$X each. Adult tickets = \$2X each. 9x + 2*2x = 72. X = ?.

math
Width = X ft. Length = 2x+3 Ft. A = L*W = (2x+3)x = 65. 2x^2+3x = 65, 2x^2 + 3x - 65 = 0, Use Quadratic Formula: X = (-3 +- sqrt(9 + 520))/4 X = (-3 +- 23)/4 = 5, and -6.5. X = 5 Ft. = Width. Length = 2*5 + 3 = 13 Ft. P = 2L + 2W.

physics
F = M*g = 0.50 * 9.8 = 4.9 N. X = (1m/175N)*4.9N. + (1m/270N)*4.9N = 0.028 + 0.0181 = 0.0461 m.

Physicd
a. Fap = M*a. 10 = 2a, a = 5 m/s^2. b. V = Vo + a*t = 10 + 5*5 = 35 m/s.

MATH
d = 15mi/h*(40/60)h + 10mi/h*(20/60)h = 13.33 miles. - Total dist. traveled. r = 13.33mi/1h = 13.33 mi/h.

3 + 6*(5+4/2)-7 = 38.

physics
V^2 = Vo^2 + 2g*h. V = 0, Vo = 10 m/s, g = -9.8 m/s^2, h = ?.

Physics
M*g = 85*9.8 = 833 N. = Force of load. Effort = 833/0.85 =

eec115 electrical and electronic engineering science
C1 = 10uF, C2 = 5uF. C = C1*C2/(C1+C2) = (10*5)/(10+5) = 3.33 uF. a. Q1 = Q2 = C*V = 3.33 * 20 = 66.6 Micro Coulombs. b. V1 + V2 = 20 V2 = 10uF/5uF * V1 = 2V1, V1 + 2V1 = 20, V1 = 6.66 Volts.

Pre-calculus
Disp. = 4km[30o] + 10km[160o]. X = 4*Cos30 + 10*Cos160 = -5.93km. Y = 4*sin30 + 10*sin160 = 5.42km. Tan A = Y/X = 5.42/(-5.93) = -0.91403, A = -42.43o N. of W.137.6o CCW from + x-axis. Disp. = X/Cos A = (-5.93)/Cos137.6 = 8.03 km[137.6]

Physics - Voltage across a wire of unknown length
p = 1.68*10^-8 Ohm m = 1.68*10^-6 Ohm cm. R1 = pL/A = (1.68*10^-6)L/1cm^2 = (1.68*10^-6)L Ohm. R2 = (1.68*10^-6)L/2cm^2 = (0.84*10^-6)L Ohm. R3 = (0.56*10^-6)L Ohm. R4 = (0.42*10^-6)L Ohms. R = R1 + R2 + R3 + R4. R = (1.68L+0.84L+0.56L+0.42L)10^-6 = (3.5*10^-6)L Ohms. I = E/R...

Algebra
P = Po*e^(r*t). r*t = 0.05*6 = 0.3. P = 1200 * e^0.3 = \$1619.83.

P = (Po*r*t)/(1-(1+r)^-t). Po = 0.7*200,000 = 140,000. r = 0.115/12 = 0.009583/mo. = Monthly % rate. t = 30yrs. * 12mo./yr. = 360 mo. P = (140,000*0.009583*360)/(1-(1.009583)^-360) = 499,091.50. M.P. = P/360.

physics
Circumference = pi*D = 3.14 * 150 = 471.2 m. V = 471.2m/30min * 1min/60s = m/s.

Maths
P = Po + Po*r*t. P = \$24,200, r = 0.07, t = 3 yrs. Po = ?.

Physics 2
T1 = 20oC. T2 = 140oC. D = Do + Do*a*(T2-T1) Density = 19.3 + 19.3*14.3*10^-6/oC*(140-20)oC = 19.333 g/cm^3.

Physics
M*g = 10 * 9.8 = 98 N. = Wt. of mass. The system is in equilibrium: T1*Cos60 = -T2. T1 = -T2/Cos60 = -2T2. T1*sin60 = 98 N. T1 = 98/sin60 = 113.2 N. -2T2 = T1 = 113.2, T2 = -56.6 N. = Tension in horizontal string.

Math
State A: 23rep./13.5mil. = 1.70 reps/mil. State B: 16reps/12.4mil = 1.29 reps/mil. State B has the least number of reps per mil; therefore, the last rep should be assigned to state B.

Geometry
The diagonals bisect each other. Therefore, DO = 0C = 20/2 = 10 in. CD = AB = 13 in. P = DO + OC + CD = 10 + 10 + 13 = 33 in.

math-consumer arithmentic
APR = (1567/37,536)*100 = 4.17%.

math-consumer arithmentic
Po = \$25,000. t = 8yrs. * 12mo./yr. = 96 mo. P = 391/mo. * 96mo. = \$37,536. Int./yr. = (P-Po)/t = (37,536-25,000)/8yrs. = \$1567. APR

Math
a. D.P. = 0.05 * 20,800 = \$1,040. b. Po = 20,800 - 1040 = \$19,760 = Amt. borrowed. c. P = Po*r*t/(1-(1+r)^-t). r = 0.0325/12 = 0.0027/mo. t = 4yrs. * 12mo./yr. = 48 mo. P = (19,760*0.0027*48)/(1-1.0027^-48) = \$21,034.03. 21,034.03/48mo. = \$438.21/mo. d. \$21,034.03 + 1040 = \$...

Math
a. 0.05 * 17,900 = Down payment(D.P.). b. Amt. = 17,900 - D.P. =

math
L = 15 * 5cm =75 cm. Breath = 15 * 3cm = 45 cm.

Trig
AB = sqrt((2-0)^2+(7-2)^2 = 5.39. BC = sqrt((0-2)^2+(10-7)^2 = 3.61. AC = sqrt(10-2)^2 = 8. P = 5.39 + 3.61 + 8 = 17. A^2 = (P*AB*BC*AC)/16. a^2 = (17*5.39*3.61*8)/16 = 165.4. A = sqrt(165.4) = 12.86.

Trig
(AB)^2 = (2-0)^2 + (7-2)^2 = 29, AB = 5.39. (BC)^2 = (6-2)^2 + (10-7)^2 = 25, BC = 5. (CD)^2 = (9-6)^2 + -2-6)^2 = 73, CD = 8.54. (AD)^2 = ((9-0)^2 + (-2-2)^2 = AD = P = AB + BC + CD + AD = A^2 = (P*AB*BC*CD*AD)/16 = A =

Maths
100-23-9-20 = 48% That voted for A and B in ratio of 1:2. A/B = 1/2. B = 2A. A + B = 48%. A + 2A = 48, A = 16%, B = 2A = 32%. A = 23 + 16 = 39% Total. B = 9 + 32 = 41% Total.

angular accleration
t = 50rev. * 1s/10rev = 5 s. acc. = (V2-V1)/t = (10-0)/5 = 2 rev/s^2. 2rev/s^2 * 6.28rad/rev = 12.56 rad/s^2.

Physics
a. a = 0. b. Fp-Fk = M*a. a = (Fp-Fk)/M =

Physics
M*g = 2.5 * 9.8 = 24.5 N. = Wt. of block. Fp = 24.5*sin53 = 19.6 N. = Force parallel to the incline. Fn = 24.5*Cos53 = 14.7 N. = Normal force. Fs = us*Fn = 0.5 * 14.7 = 7.37 N. Fk = uk*Fn = 0.25 * 14.7 = 3.69 N.

Math1
S = 285 + 285*0.75(1994-1985). S= 285 + 1924 = 2209 Subscribers.

Math
t = 9:00 - 6:50 = 2 h, and 10 min. = 2 1/6 h. = 13/6 h. t1 + t2 = 13/6. 3t1 + 30t2 = 20. Multiply Eq1 by -30 and add: -30t1 - 30t2 = -65. +3t1 + 30t2 = 20, Sum: -27t1 = -45, t1 = -45/-27 = 5/3 h = The girl's walking time. d = r*t = 3 * 5/3 = 5 Miles.

Physics
b. V^2 = Vo^2 + 2g*h. V^2 - 0 + 19.6*19.5 = 382.2, V = 19.5 m/s.

Physics
h = 0.5g*Tf^2 = 21.3-1.8 = 19.5 m 4.9*Tf^2 = 19.5, Tf^2 = 3.98, Tf = 1.99 s. = Fall time. a. d = Xo * Tf = Xo * 1.99 = 61, Xo = 30.6 m/s = Hor. velocity at time it leaves the road.

Math
P = Po(1+r)^n. r = 0.03/365 = 8.22*10^-5/day = Daily % rate. n = 365 Compounding/yr. Let Po = \$1.00 for this calculation. P = 1(1.00008.22)^365 = 1.03045. APY = 1.03045 - 1 = 0.03045 = 3.05%.

Science
Vw = 500g * 1cm^3/g = 500 cm^3. = 500 mL. We have 500 cm^3 of water which = 500 mL.

V = Vo + Vo*r*t. V = 30,000 + 30,000*(0.05/12)*4.

Physics
V = Vi + a*t = 20 + 2*7 = 34 m/s.

Algebra
2. Iguana food: V = pi*r^2*h = 3.14 * 3^2 * 8 = 226.1 in^3. Hamster food: V = 3.14 * 2.5^2 * 10 = 196.3 in^3.

Algebra
1. Vt = 187*89*77 = 1,281,511 in^3 per truck. Vb = 24*14*27 = 9,072 in^3 per box. 9,072in^3/box * 200boxes = 1,814,400 in^3 of space needed. 1,281.511*N = 1,814,400. N = 1,814,400/1,281,511 = 1.4 or 2 trucks.

math
As = 2(W*h) + 2(L*h) + 2(L*W). As = 2(6*3) + 2(11*3) + 2(11*6) = 234 m^2. Does W = 6mm or 6 m ?.

physics
Connect a resistor in series with lamp.

Physics/Mechanics
M1 = 150g = 0.150 kg. M2 = 100g = 0.10kg. M1*V1 + M2*u = M1*4 + M2*4. 0.150*0 + 0.10*u = 0.15*4 + 0.10*4. 0.1u = 1.0, u = 10 m/s. KE1 = 0.5M*u^2 = 0.5*0.1 * 10^2 = 5 Joules = Total kinetic energy before collision. KE2 = 0.5M1*V1^2 + 0.5*M2*V2. KE2 = 0.5*0.15*4^2 + 0.5*0.10*4^2...

physics
Connect a resistor in series with it.

Algebra
a. V^2 = Vo^2 + 2g*hc. hc = (Vf^2-Vo^2)/2g = Ht. above the cliff. b. h max = ho + (Vf^2-Vo^2)/2g h max = 58.8 + (0-49^2)/(-19.6) = 181.3 m. Above gnd. c. V = Vo + g*Tr = 0. 49 -9.8Tr = 0, Tr = 5 s. = Rise time. h max = 0.5g*Tf^2 = 181.3. 4.9Tf^2 = 181.3, Tf = 6.08 s. = Fall ...

math
F(x) = 7 - 2x. F(x+5) = 7-2(x+5). F(x+5) = 7 - 2x - 10, F(x+5) = -3 - 2x. After you multiply the terms inside the parenthesis by (-2), you move the parenthesis.

Science
V = (1.8m)^3 = 5.83 m^3. Density = 0.070kg/5.83m^3 = 0.012 kg/m^3.

Physics
M1*V1 + M2*V2 = -6.10*10^5i + 7.20*10^5. Tan A = Y/X = (-6.10*10^5)/7.20*10^5 = -0.84722, A = -40.3o = 40.3o S. of E. Resulting momentum = X/Cos A = 7.20^10^5/Cos(-40.3) =

Physics
Remember that the total momentum before the collision = The total momentum after the collision.

Physics
Resulting momentum: M1*V1 + M2*V2 = 4.60*10^4i + 6.25*10^4. Tan A = Y/X =4.60*10^4/6.25*10^4 = 0.736, A = 36.4o Res. Momentum = X/Cos36.4 = 6.25*10^4/Cos36.4 = 7.76*10^4 kg km/h.

math
P = Po(1+r)^n. Po = 25 * 12 = \$300. r = 0.105/12 = 0.00875/mo. n = 1Comp/mo. * 12mo. = 12 Compounding periods. P = ?.

physical science
P = E*I = 12*0.25 = 3.0 Watts.

Math
P = Po + Po*r*t. P = 3200 + 3200*0.05*4 =

physics
0 = 5^2 - 2*10*h, 20h = 25, h = 1.25 m. A 2nd method: V = Vo + g*t 0 = 5 -10t, t = 0.5 s. h = Vo*t + 0.5g*t^2, h = 5*0.5 - 5*0.5^2, h = 2.5 - 1.25 = 1.25 m. A 3rd Method: KE = PE. 0.5M*Vo^2 = Mg*h 1.4*5^2 = 2.8*10*h 35 = 28h, h = 1.25 m. Based on the information given, your ...

physics
Vo = 5 m/s = Initial velocity. V = 0 = Final velocity = Velocity at max. ht. g = -10 m/s. V^2 = Vo^2 + 2g*h. h = ?.

math
P = Po + Po*r*t. r = 1.14/12 = 0.095/mo. = Monthly % rate. 12,150 = Po + Po*0.095*25, Po = ?.

science
The ball is considered a free fall after reaching it's max. ht.

science
Vo = 25 m/s. V = 35 m/s. d = 500 m. Fk = 800 N. V^2 = Vo^2 + 2a*d. 35^2 = 25^2 + 2a*500. a = ?. 35^2-25^2 = 1000a, a = 0.6 m/s^2. F-Fk = M*a. F = ?.

Science
Oops! Not anonymous.

Math! Help Hurry!
post.

Math! Help Hurry!
Cubes = Vp/Vc. 96 = Vp/(1/2)^3, Vp = (1/2)^3 * 96 =

Math! Help Hurry!
Vr = L*W*h = 8 * 4 * 2.25 = 14.22 in^3 = Vol. of rectangle. Vc = L*W*h = 0.25 * 0.25 * 0.25 = (0.25)^3 = 0.0156 in^3 Vr/Vc = 14.22in^3/0.0156in^3 = 910 Cubes.