Monday
September 1, 2014

Posts by henry


Total # Posts: 8,968

Physics
At top of hill: KE + PE = mg*h 0 + PE = mg*h PE = mg*h At bottom of hill: KE + PE = mg*h KE + 0 = mg*h KE = mg*h = 0.5m*V^2 0.5m*V^2 = mg*h V^2 = 2g*h V = Sqrt(2g*h). V = Sqrt(19.6*h). Sqrt means Square root.
December 3, 2013

physics
See previous post.
December 3, 2013

physics
Fc = m*g = 29kg * 9.8N/kg = 284.2 N. = Force of crate. Fap-Fs = m*a 90-u*Fc = m*0 90 - u*284.2 = 0 u*284.2 = 90 us = 0.317
December 3, 2013

math
T = (2/5) * 2 = 4/5 or 0.8 h.
December 3, 2013

Physics
a. a=F/m = 3.34*10^7/2.77*10^6 = 12.06 m/s^2. b. t = 2.5min * 60s/min = 150 s. h = 0.5a(2t-1) h = 6.03*(300-1) = 1803 m.
December 3, 2013

Maths
100% - 40.25% - 30.76% = 28.99 % Greater than 5.5 Ft. People = 0.2899 * 120M=34.79 M Greater than 5.5 Ft.
December 3, 2013

science
P = 40.2hp * 746W/hp = 29,989 Watts. = 29,989 Joules/s. T = 5.9*10*5J/(2.9989*10^4J/s=19.67 s.
December 3, 2013

Physics
B. L = V/F = 343/239.7 1.43 When flying away.
December 2, 2013

Physics
A. L = V/F = 343/258 = 1.33 m. B. F = ((Vs+Vr)/(Vs-Vg))*Fo = 258 Hz ((343+0)/(343-12.6))*Fo = 258 (343/330.4) * Fo = 258 1.0381Fo = 258 Fo = 248.5 Hz=Initial Freq. of the goose F = ((343-0)/(343+12.6))*248.5 F = (343/355.6) * 248.5 = 239.7 Hz When flying away.
December 2, 2013

Physics
A. L = V*T =V*(1/F)=V/F L = 343/4.4*10^6 = 7.95*10^-5m. B. L = 1580/4.4*10^6 = 359*10^-6=3.59*10^-4 m.
December 2, 2013

math
what property is described in this equation: 24x5=(20x5)+(4x5)
December 2, 2013

Physics
Fs = m*g = 87.1kg * 9.8N/kg = 853.6 N. = Force of snowboarder. Fp = 853.6*sin36.7 = 510.1 N. = Force parallel to hill. Fn = 853.6*cos36.7 = 684.4 N = Normal = Force perpendicular to hill. Fk = u*Fn = 0.106 * 684.4 = 72.55 N. = Force of kinetic friction. a=(Fp-Fk)/m=(510.1-72....
December 2, 2013

Algebra
x^2 + y^2 + 8x + 2y + 8 = 0 x^2+8x+(8/2)^2+y^2+2y+(2/2)^2=-8+(8/2)^2 +(2/2)^2. x^2+8x+16 + y^2+2y+1 = -8+16+1 Eq: (x+4)^2 + (y+1)^2 = 9 C(-4,-1). r2 = 9 r = +-3
December 2, 2013

Geometry
See previous post: Mon,12-2-13,7:39 AM.
December 2, 2013

Geometry
See previous post:Mon,12-2-13,7:39 AM.
December 2, 2013

Geometry
The diagonals form 2 30o-60o rt. triangles. h = 24*sin30 = 12 In. W = 24*cos30 = 20.8 In. P = 2*(W+h) = 2*(20.8+12) = 65.6 In.
December 2, 2013

physics
v = Vmax*sinWt v = 100*sin(1000t) Vrms = 0.707 * 100 = 70.7 Volts. W = 2pi*F = 1000 6.28*F = 1000 F = 159 Hz. Xl = W*L = 1000 * 0.5 = 500 Ohms. Xc=1/W*C=1/(1000*4.6*10^-6)=-217.4 Ohms tan A = (Xl+Xc)/R tanA = (500+(-217.4))/400 = 0.7065 A = 35.2o Z = R/cos A = 400/cos35.2 = ...
December 2, 2013

physics
h = Vo*t + 0.5g*t^2 = 20 37.8t _ 4.9t^2 = 20 -4.9t^2 + 37.8t - 20 = 0 Use Quadratic Formula and get: t = 0.571, and 7.14 s. So, when the ball is rising; it reaches 20 m in 0.571 s. When it is falling, it reaches 20 m in 7.14 s.
December 1, 2013

physics
See your previous post: Sun,12-1-13,10:34 PM.
December 1, 2013

physics
See previous post: Fri,11-29-13,8:15 PM.
December 1, 2013

physics. again.
V== Vo + g*t = 10 m/s. 37.8 + (-9.8)t = 10 -9.8t = 10-37.8 =-27.8 t = 2.84 s. h = Vo*t + 0.5g*t^2 h = 37.8*2.84 - 4.9*2.84^2 = 67.83 m.
December 1, 2013

physics
Fs = m*g = 22kg * 9.8N/kg = 215.6 N. = Force of the sled. Fp = 215.6*sin6 = 22.54 N. = Force parallel to the incline. Fn = 215.6*cos6 = 214.4 N. = Normal = Force perpendicular to the incline. Fk = u*Fn = 0.2 * 214.4 = 42.88 N. = Force of kinetic friction. V = 64km/h = 64000m/...
December 1, 2013

5th grade math
I'm glad I could help, and thanks for your response.
December 1, 2013

5th grade math
4th Grade: 9 Left-handed students. Total = 3 * 9 = 27 Students. 9/27 = 1/3 Are left-handed. 5th Grade: 7 Left-handed students. Total = 30-2 = 28 Sudents. 7/28 = 1/4 Are left-handed. 6th Grade: 6 Left-handed students. Total = 27+3 = 30 Students. 6/30 = 1/5 Are left-handed. The ...
December 1, 2013

Physics
r2 = r1 + a*(T-To)r1 = 4.42 cm. 4.40 + 1.3*10^-4(T-20)4.40 = 4.42 4.40 + 5.72*10^-4(T-20) = 4.42 5.72*10^-4(T-20) = 4.42-4.40 = 0.02 5.72*10^-4T - 114.4*10^-4 = 0.02 5.72*10^-4T = 0.02 + 0.01144 = 0.03144 T = 314.4*10^-4/5.72*10^-4 = 54.97o
December 1, 2013

Math
Same procedure as previous post: Sun,12-1-13,7:39 PM.
December 1, 2013

Math
Given: A(-8,3), B(-6,1). m = -1 A(-8,3), P(x,y). m== -1. m = (y-3)/(x-(-8)) = -1 m = (y-3)/(x+8) = -1 Cross multiply: y-3 = -1(x+8) y-3 = -x-8 Eq: x + y = -5 Or x + y +5 = 0 Replace y with 0: x + 0 = -5 X = -5 = X-intercept. Replace X with 0: 0 + y = -5 Y = -5 = y-int.
December 1, 2013

Physics
Wr = m*g = 0.5kg * 9.8N/kg = 4.9 N = Wt. of the rat. Fp = 4.9*sin34 = 2.740 N. = Force to the plane. Fn = 4.9*cos34 = 4.062 N. Normal = Force perpendicular to the plane. Fk = u*Fn = 0.2 * 4.062 = 0.8125 N. Fc-Fp-Fk = m*a 0.4-2.74-0.8125 = m*a m*a = -3.15 a = -3.15/m = -3.15/0...
November 30, 2013

Physics
Fex = 15000 N. ? m = 500kg a = Fex/m = 15000/500 = 30 m/s^2.
November 30, 2013

physics
Change in L = Lo * a*(T-To) = 65.1 * 10^-5 * (-31.2-15.8) = -0.030597 m.
November 30, 2013

physics
Fap*cos45-u*mg = m*a Fap*cos45-0.02*588 = m*0 = 0 Fap * cos45 - 11.76 = 0 Fap*cos45 = 11.76 N. = Hor. component of Force applied. Work = 11.76 * 1000. = 11,760 Joules.
November 29, 2013

physics
a. Xl = 2pi*F*l = 6.28*50*0.405=127.2 Ohms Xc = 1/(6.28*50*4.43*10-6) = -718.9 Ohms tan A = (Xl-Xc)/R tan A = (127.2-718.9)/400 = -1.47925 A = -55.94o Z=R/cosA = 400/cos(-55.94) = 714.2 Ohms[-55.94o]= The Impedance. Vmax = Imax * Z=0.25 * 714.2 =178.6 Volts. b. The negative ...
November 29, 2013

physics
Fn = 75N[40o] + 85N[340o] X = 75*cos40 + 85*cos340 = 137.3 N. Y = 75*sin40 + 85*sin340 = 19.14 N. tan A = Y/X = 19.14/137.3 = 0.13940 A = 7.94o Fn=X/cosA = 137.3/cos7.94=138.6 N[7.94o]
November 29, 2013

PHYSICS
a. Xc = 1/2pi*F*c Xc = 1/(6.28*60*4*10^-6) = 663.5 Ohms. I = V/Xc = 120/663.5 = 0.181A rms. b. Same procedure as "a".
November 29, 2013

Physics
We need to know the length of the hill. Length = 100 m? A = 30o m = 75 kg h = 100*sin30 = 50 m. = Ht. of hill. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*50 = 980 V = 31.3 m/s At bottom of hill. V^2 = Vo^2 + 2a*d a=(V^2-Vo^2)/2d=(31.3^2-0)/200=4.9 m/s^2 V = Vo + a*t = 31.3 0 + 4.9*t = ...
November 28, 2013

math
CORRECTION: Cost = 2375*0.85*0.80*0.80 = $1292. Discount = 2375 - 1292 = $1083.
November 27, 2013

math
Discount = 2375*0.15*0.20*0.20 = $14.25
November 27, 2013

Physics
V1 = 6N[180o] X1 = -6N Y1 = 0 V2 = 4.5N[45o] X2 = 4.5*cos45 = 3.18 N. Y2 = 4.5*sin45 = 3.18 N. X = X1 + X2 = -6 + 3.18 = -2.82 N. Y = Y1 + Y2 = 0 + 3.18 = 3.18 N. tan Ar = Y/X = 3.18/-2.82 = -1.12766 Ar = -48.43o = Reference angle. A = -48.43 + 180 = 131.6o R=Y/sinA = 3.18/...
November 26, 2013

Finance - Annuities
P = Po*(1+r)^n P = $2250/mo. * 48mo. = $108,000 r = (3%/12)/100% = 0.0025 = Monthly % rate expressed as a decimal. n = 1comp./mo * 48mo = 48 Compounding periods. a. P = (Po-12000)*(1.0025)^48 = 108,000 (Po-12000)*1.12733 = 108000 Po-12000 = 95,801.75 Po = $107,801.75 = Initial...
November 26, 2013

math
A*(1-0.0653) = 1,225,000 A*0.9347 = 1225000 A = 1,310,580.94
November 26, 2013

physics
F1 = m*g = 1.6kg * 9.8N/kg = 15.68 N F2 = (0.05m/1m) * 400N = 20 N. F1-Fs = m*a 15.68-Fs = m*0 = 0 Fs = 15.68 = Force of static friction. Fs = u*F2 = 15.68 u*20 = 15.68 u = 0.784 = Coefficient of static friction.
November 26, 2013

Physic: Projectile Motion
Range = Vo^2*sin(2A)/g = 15 m. Vo^2*sin(40)/9.8 = 15 Vo^2*0.0656 = 15 Vo^2 = 228.7 Vo = 15.12 m/s.
November 26, 2013

Math
2. A cube has 6 edges. As = 6 * 3^2 = 6 * 9 = 54 Sq. In.
November 25, 2013

finance
1. P = (Po*r*t)/(1-(1+r)^-t) r = (9%/12)/100% = 0.0075 = Monthly % rate expressed as a decimal. t = 12mo/yr * 5yrs. = 60 Months. Plug th above values into the givenEq and get: P = $12,455.01 I = P-Po 2. Monthly = P/t 3. P = Po + Po*r*t Po = $10,000 r = 0.0075 t = 60 Months ...
November 25, 2013

physics
Fap-Fk = m*a 30-Fk = 2 * 10 = 20 Fk = 30-20 = 10 N. = Force of kinetic friction.
November 25, 2013

geometry
See Related Questions: Thu,5-25-11,11:28 AM.
November 24, 2013

Science, Physics, math, calculus
a. h = 0.5g*t^2 = 0.77 4.9t^2 = 0.77 t^2 = 0.1571 t = 0.396 s. = Fall time. Dx = Xo * t = 5.15 m. Xo * 0.396 = 5.15 Xo = 13 m/s = Break speed. b. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*0.77 = 15.09 V = 3.88 m/s
November 24, 2013

Physics
h = 0.5g*t^2 = 50 m. 4.9t^2 = 50 t^2 = 10.2 Tf = 3.19 s. = Fall time. d = V*Tf = 100m/s * 3.19s = 319 m.
November 24, 2013

PHYSICS
CORRECTION: T = 1.15 Milliseconds.
November 24, 2013

PHYSICS
CORRECTION: d. Vr = I*R = (0.8*0.857)*7 = 4.8 Volts Vi=6-4.8=1.2 Volts across the inductor. V/e^(T/0.714) = 1.2 6/e^(1.40T) = 1.2 e^1.40T = 6/1.2 = 5 1.40T*Ln e = Ln 5 1.40T = 1.609 T = 1.15 s. 7 =
November 24, 2013

PHYSICS
a. T.C.=L/R=5.0/7=0.714 Milliseconds b. T/TC = 0.25mS/0.714mS = 0.350 Vi = V/e^(T/TC) = 6/e^0.350 = 4.23 Volts after 250 uS. I=Vr/R = (V-Vi)/R = (6-4.23)/7= 0.253A. c. I=Vr/R = (V-Vi)/R = (6-0)/7 = 0.857A d. Vr=I*R = (0.8*0.857)*7 = 4.80 Volts. Vi = 6-4.8 = 1.2 Volts. = ...
November 24, 2013

Math
Incomplete.
November 24, 2013

physics
Fr = 975N[0o] + 745N[60o] + 1175N[90o] X=975 + 745*cos60 + 1175*cos90=1347.5 N Y = 745*sin60 + 1175*sin90 = 1820.2 N. tan A = Y/X = 1820.2/1347.5 = 1.31079 A = 53.5o Fr = Y/sin A = 1820.2/sin53.5=2264.3 N. [53.5o].
November 24, 2013

physics
Ht. = 50 m.? a. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*50 = 980 V = 31.3 m/s. b. V = Vo + g*t = 31.3 m/s. 0 + 9.8t = 31.3 t = 3.19 s. c. m = 2.0Lb * 0.454kg/Lb = 0.908 kg. KE = m*V^2/2 = 0.908*31.3^2/2 = 444.8 J.
November 24, 2013

physics
Ws = m*g = 77.7kg * 9.8N/kg = 761.5 N = Wt. of skier. Fp = 761.5*sin35.7 = 444.3 N. = Force parallel to slope. Fn = 761.5*cos35.7 = 618.4 = Normal = Force perpendicular to slope. Fk = u*Fn = 0.08 * 618.4 = 49.47 N. = Force of kinetic friction. Fp-Fk = m*a a=(Fp-Fk)/m=(444.3-49...
November 22, 2013

science
KE = 0.5m*V^2 = 2.5*4^2 = 40 J.
November 22, 2013

Please help!- Physics
d = 483[180o ] + 347[106o] + 347[106o] d = 483[180 + 694[106o] X = 483*cos180 + 694*cos106 = -674.3 km Y = 483*sin180 + 694*sin106 = 667.1 km tan Ar = Y/X = 667.1/-674.3 = -0.98935 Ar = -44.69o = Reference angle. A = 180-44.69 = 135.3o d = X/cosA = -674.3/cos135.3 = 948.7 km [...
November 22, 2013

Math
Incomplete.
November 21, 2013

physics
3.2 cm from equilibrium position: KE + PE = mg*d 0 + PE = mg*d/2 Halfway to the equilibrium position: KE + PE = mg*d mg*d/2 + mg*d/2 = mg*d KE = mg*d/2 = 0.5m*V^2 0.5m*V^2 = mg*d/2 = 3.92*0.032/2 0.2*V^2 = 0.06272 V^2 = 0.3136 V = 0.56 m/s.
November 21, 2013

Physics
CORRECTION: V = 81.6km/h[74.93o] D = 245 km[74.93o]
November 20, 2013

Physics
V = 100km/h[90o] + 30km/h[315o] X = 100*cos90 + 30*cos315 = 21.21 km/h Y = 100*sin90 + 30*sin315 = 78.79 km/h tan A = Y/X = 78.79/21.21 = 3.71461 A = 74.93o V=Y/sinA = 78.79/sin74.93=81.6 km/h [78.79] D=V*t = 81.6[78.79] * 3 = 245 km[78.8o]
November 20, 2013

Math
Parallel lines have equal slopes.
November 20, 2013

Math
Parallel lines have equal slopes.
November 20, 2013

Math
Parallel lines have equal slopes.
November 20, 2013

Math
2x - 3 = 4y Eq1: 2x - 4y = 3 m1 = -A/B = -2/-4 = 1/2 m2 = -(2/1) = -2 Y = mx + b Eq2: Y =-2x - 5/4.
November 20, 2013

Math
See previous post: Wed,11-20-13,6:18PM.
November 20, 2013

Math
Eq1: x + 2y = 10. m1 = -A/B = -1/2 The slope of the 2nd line = the negative reciprocal of m1: m2 = -(-2/1) = 2. Y = mx + b Eq2: Y = 2x - 10 or 2x - y = 10
November 20, 2013

physics
Energy = 120 * 5 *6h /1000=3.6 KWh Used Cost = 3.6kwh * 0.090/kwh = 0.324 or 32.4 Cents.
November 20, 2013

Physics
L = h/sin A = 2/sin 30 = 4 m. = Length of incline. KE = mg*h-Fk*L 0.5m*V^2 = mg*h-Fk*l 0.2*4.50^2 = 3.92*2 - Fk*4 4.05 = 7.84 - 4Fk 4Fk = 7.84-4.05 = 3.79 Fk = 0.948 N. = Force of kinetic friction.
November 19, 2013

physics
Fn = m * a =47 * 4.50
November 19, 2013

Physics
Yes. For a given initial velocity, the larger the angle the greater the vertical component of initial velocity. The increase in vertical velocity causes an increase in the max. ht.
November 19, 2013

Physics - projectile
V = Vo = 50 m/s.
November 19, 2013

Physics
b. h = Vo*t + 0.5g*t^2 = 3.05 8t + 4.9t^2 - 3.05 = 0 Use Quadratic Formula and get: t = 0.319 s. c. V^2 = Vo^2 + 2g*h V^2 = 8^2 + 19.6*3.05 = 123.78 V = 11.13 m/s.
November 19, 2013

MATH
A. Y = ho - 8X ho = The initial ht. B. When he got on the elevator, it was at the initial height(ho) and decreased at a rate of 8 feet per second for 12 seconds. C. Y = ho _ 8x = 240 Ft. ho - 8*12 = 240 ho = 240 + 96 = 336 Ft. above gnd. D. Y = 336 - 8x = 0 336 - 8x = 0 8x = ...
November 19, 2013

math
N = 0.57 * 11
November 19, 2013

Physics
d = 0.5g*t^2 = 75 4.9t^2 = 75 t^2 = 15.31 Tf = 3.912 s. = Fall time. d = V*Tf = 7-4 = 3 m. V * 3.912 = 3 V = 0.769 m/s.
November 19, 2013

math
Did your book give the total # of Robinsons? Something is missing.
November 18, 2013

physical science
P = F * d/t = 96 * 2.8/4.6 = 58.43 J/s = 58.43 Watts.
November 18, 2013

college algebra
4^(x-3) = 3^(2x) (x-3)*Log4 = 2x*Log 3 Divide both sides by Log 4: x-3 = 2x * 0.79248 = 1.5850x x - 1.5850x = 3 -0.5850x = 3 X = -5.1282
November 18, 2013

science
Magnitude = 210 N. Direction = 30o South of West = 210o CCW.
November 18, 2013

science
Magnitude = 200 N. Direction = 60o North of East = 60o CCW.
November 18, 2013

science
Magnitude = 125 N. Direction = North(Positive Y-axis).
November 18, 2013

math
Sally has X postcards. Marta has X postcards. X = 4(X-18) Solve for X.
November 18, 2013

Math
Y = 5 For all values of X. (0,5),(5,5),(2,5),(-3,5).
November 18, 2013

science
500+(65-47)sk/wk*105days*1wk/7days=770 Skunks.
November 18, 2013

Phyics
d1 = 0.5a*t^2 = 15 m. 0.5*t^2 = 15 t^2 = 30 T1 = 5.477 s. V = a*t = 1m/s^2 * 5.477s = 5.477 m/s. d2 = V * t = 5.477m/s * 15s = 82.2 m. D = d1 + d2 = 15 + 82.2 = 97.2 m. = Distance at which he was caught. T = T1 + T2 = 5.477 + 15 = 20.48 s To catch up.
November 18, 2013

math
(25%/15%/10% = (1-0.25)(1-0.15)(1-0.10)= 0.75 * 0.85 * 0.90 = 0.57375
November 18, 2013

math
a. X + 27.80*20 = 914 X = $358. b. C = 358 + 27.80x X = The number of years since 1981. c. 2000-1981 = 19 years. C = 358 + 17.80*19 = $528.20
November 18, 2013

Check my answers please- Physics
1. A force that makes the net force on an object 0. 2. It is equal in magnitude and opposite in direction. 3. An object in equilibrium must not be in motion. 7. 90 N.
November 18, 2013

algebra2
See previous post: Mon,11-18-13,11:59 AM.
November 18, 2013

algebra2
CD: $X Savings: $4X Mutual: $(15,000-5X) 0.02X + 0.01*4X + 0.1(15000-5x) = 210 0.06X + 1500 - 0.5X = 210 -0.44X = 210-1500 = -1290 X = 2931.82 4X = 4*2931.82 = $11,727.27 = Savings.
November 18, 2013

math
Bal. = 423.78 + 123.42 - 100 = 447.20 Int. = 447.20 *(0.15/12) * 1 = $5.59
November 18, 2013

Physics
Incomplete.
November 18, 2013

Business math
P = Po*(1+r)^n r = (0.75%/365)/100% = 2.055*10^-5 = Daily % rate expressed as a decimal. n = 1comp./day * 21days = 21 compounding periods. Plug the above values into the given Eq and get: $9,0003.88
November 17, 2013

physic
Vo=36mi/h * 1600m/mi * 1h/3600s=16 m/s. V = Vo + a*t = 0 16 + a*2.4 = 0 2.4a = -16 a = -6.67 m/s^2. F = m*a = 58 * (-6.67) = -386.7 N. The negative sign means that the force was in the opposite direction of the motion.
November 17, 2013

Math
P = 350hp * 746W/hp = 261,100 Watts.
November 17, 2013

physics
Wb = m*g = 7.6kg * 9.8N/kg = 74.48 N. = Wt. of block. Fs = 8 N ? Fs = us*Fv = 8 N. us*74.48 = 6 us = 0.081
November 17, 2013

geometry
See previous post: Sat, 11-16-13, 7:13 PM.
November 17, 2013

GEOMETRY
1. Triangle #1 a = 8 b = 15 c = 18 Triangle #2: d = 10 e = ? f = ?. a/d = b/e = c/f = 8/10 15/e = 8/10 e = 18.75 18/f = 8/10 f = 22.5 2. Scale Factor=5/4 = 15/12=25/20 = 1.25 3. x/r = y/p = z/n.
November 16, 2013

physics
Fn = m*a m = Fn/a = 50/25 = 2 kg
November 16, 2013

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