Thursday
August 21, 2014

Posts by henry


Total # Posts: 8,916

dynamics
See 10:35am post.
July 22, 2013

Dynamics
Ek = 0.5m*V^2 *h - = 750 * 6^2 = 27,000 J. Wt. = Fg = 1500kg * 9.8N/kg = 14,700 N. Ep = Fg * h = 27000-Fk*d 14700*5*sin20 = 27000-Fk*5 25138.5 = 27000-5Fk 5Fk = 27000-25138.5 = 1861.5 Fk = 372 N.
July 22, 2013

dynamics
V^2 = Vo^2 + 2g*h h = (V^2-Vo^2)/2g h = (0-625)/-19.6 = 31.89 m. NOTE: V = 0 @ max. Ht.
July 22, 2013

general physics
Di + Db = Dsw 917 + Db = 1025 kg/m^3 Db = 108 kg/m^3 = Density of the bear. Mass of bear = 6.76m^3*108kg/m^3=730 kg Wt. of bear = 730kg * 9.8N/kg = 7154 N.
July 20, 2013

science
CORRECTION: Ek = 84.672 J.
July 20, 2013

science
V^2 = Vo^2 + 2g*d Vo^2 = V^2-2g*d Vo^2 = 0-(-19.6*1.2 = 23.52 Vo = 4.85 m/s. Ek = 0.5m*Vo^2 = 3.6*(4.85)^2 = 11.76 J. vo^2
July 20, 2013

MATH
h = 125-5t^2 = 0 -5t^2 + 125 = 0 t^2 - 25 = 0 (t+5)(t-5) = 0 t = -5 t = 5 s. V = g*t = 9.8 * 5 = 49 m/s.
July 19, 2013

physics
Vs = 25 m/s = Velocity of the source. F = 260 Hz(NOT 26Hz). Fo = 240 Hz. Vr = Velocity of the receiver(person) F = (V+Vr)/(V-Vs)*Fo = 260 Hz. (V+0)/(V-25)*240 = 260 240V/(V-25) = 260 240V = 260V - 6500 -20V = -6500 V = 325 m/s.
July 17, 2013

Math
P = (Po*r*t)/(1-(1+r)^-t) Po = $81,000. r = (9%/12)/100% = 0.0075 = Monthly % rate expressed as a decimal. t = 25yrs. * 12mo/yr. = 300 Months. Plug the above values into the given Eq and get: P = $203,924.72 Monthly Payments = P/t Monthly Int. = (P-Po)/t. Monthly Prin. = (P/t...
July 17, 2013

physics/science
See previous post.
July 17, 2013

physhcs
Xc = 1/W*C = 1/314.2*3*10^-6 = 1061 Ohms Z = R-jXc = 500 -j1061 = 1173[-64.8o]. 1. I = V/Z=12/1173[-64.8o]=0.01023[64.8] 2. Vc= I * Xc = 0.01023[64.8]*1061[-90o]= 10.85 Amps.[-25.2o] 3. A = -25.2o 4. P = I^2*R = (0.01023)^2 * 500= 0.0523 W. 5. Pf = cosA = cos(-64.8) = 0.426
July 17, 2013

phys ics
b. V = (0.243/0.335) * 28m/s = 20.3 m/s.
July 16, 2013

physics
Circumference=pi*2r=3.14*0.67=2.1=2.1 m. Va = 24.1m/s * 6.28rad/2.1m=72.1 rad/s.
July 16, 2013

physics
d = 0.5g*t^2 = 5.95 m. 4.9t^2 = 5.95 t^2 = 1.21 s. t = 1.10 s. 2.55rev/s * 1.1s = 2.8 revs.
July 16, 2013

physics
a. 28.9rad/s * 1rev/6.28rad = 4.60 rev/s. t = (13.6/4.60) * 1s = 3.0 s. b. V = Vo + at = 0 When @ rest. 28.9 + a*3 = 0 3a = -28.9 a = -9.63 rad/s^2.
July 16, 2013

physics
a. d = 2870rev * 6.28rad/rev = 18,024 rad. t = 18,024rad/131rad/s = 138 s. V = Vo + a*t = 131 rad/s Vo + 0.170*138 = 131 Vo = 131-23.4 = 108 rad/s. b. t = 138 s.
July 16, 2013

physics
V = Vo + at = 4.4 rad/s. 0 + 4.2t = 4.4 t = 4.4/4.2 = 1.05 s.
July 16, 2013

physics
d1 + d2 = 2pi rads = A complete circle. V1t + V2t = 2pi 2.46*10^-3 + 7.91*10^-3 = 6.28 10.37*10^-3t = 6.28 t = 606 s.
July 16, 2013

Math
See previous post.
July 16, 2013

Math
See previous post.
July 16, 2013

Math
Eq1: x^2 + y^2 = 34 Eq2: x + y = 2 x + y = 2 Y = 2 - x In Eq1, replace Y with 2 - x. x^2 + (2-x)^2 = 34 x^2 + 4 - 4x + x^2 = 34 2x^2 -4x + 4 = 34 2x^2 -4x - 30 = 0 Divide both sides by 2: x^2 - 2 - 15 = 0 (x+3)(x-5) = 0 x+3 = 0 X = -3. Y = 2- x = 2-(-3) = 5 x-5 = 0 X = 5. Y = ...
July 16, 2013

physics
Wt. = (6.0/1.0)^2 * 45.8 = 1649 N.
July 16, 2013

Elementary mechanics
My answer is the Rise Time or time to reach max. height. R = Vo*cosA * (Tr+Tf) Tr = Tf. Therefore, R = Vo*cosA * 2Tr. Tr = Rise time. Tf = Fall time. Vo*cosA = Hor. component of initial velocity.
July 15, 2013

Physics
Circumference=pi*D = 3.14 * 41=128.8 cm= 1.288 m. Vo = (86rev/min)*1min/60s*1.288m/rev = 1.85 m/s. V = (342/86) * 1.85 = 7.34 m/s a=(V-Vo)/t = (7.34-1.85)/3.4=1.61 m/s^2 d =Vo*t + 0.5*a*t^2 d=1.85*3.4 + 0.5*1.61*(3.4)^2= 15.6 m.
July 14, 2013

physics
Wt. = Fg = m*g = 60kg * 9.8N/kg=588 N.= Wt. of skier. Fp=588*sin35 = 337 N.=Force parallel to incline. Fv = 588*cos35 = 482 N. = Force perpendicular to incline. Fk = u*Fv = 0.08 * 482 = 38.5 N. = Force of kinetic friction. d =h/sinA = 2.5/sin35 = 4.36 m. Ek + Ep = Ekmax - Fk*d...
July 14, 2013

Physics
Wt. = m*g = 10kg * 9.8N/kg = 98 N. = Wt. of the luggage. F = 98N.[60o] = Force of luggage. Fp = 98*sin60 = 84.9 N. = Force parallel to incline. Fv=98*cos60 = 49 N.=Force perpendicular to incline = Normal. a. Work=mg * h = 98 * 6.5sin60= 552 J. b. Work = -98 * 6.5sin60 = -552 J...
July 14, 2013

physics
Density of water = 1000kg/m^3. V = 3m * 0.20m * 0.05m = 0.03 m^3=Vol. of board. 1 - (350/1000) = 0.65 = 13/20.
July 13, 2013

Physics
Impulse = m*V1-m*V2 Impulse = 2.4*2.5 - 2.4*1.5 = 2.4kgm/s
July 13, 2013

Elementary mechanics
F1 = 100[170o] F2 = 100[50o] X = 100*cos170+100*cos50o = -34.2 N. Y = 100*sin170+100*sin50 = 94 N. tan Ar = Y/X = 94/-34.2 = -2.74838 Ar = -70o = Reference angle. A = -70+180 = 110o Fr = X/cosA = -34.2/cos110 = 100N.[110o]
July 12, 2013

Trigonometry
Draw a picture of the situation: 1.Draw ver. line AC with A on the bottom. 2. Add point D on line AC. 3. Draw a hor. line from A to the left. Label it AB. Now we have a rt angle. 4. Draw hyp. BC. 5. Draw hyp. BD. <ABC = <ABD + <DBC = 61.5o 56.33 + <DBC = 61.5 <...
July 11, 2013

Physics
T^2 = 4*pi^2(L/g) 1a. Longer. A smaller g increases the ratio of L/g which increases the period. 1b. Unchanged. The mass is not included in the Eq. 1c. Shorter. The ratio of L/g decreases which decreases the period. 1d. Unchanged. The ratio of L/g remains the same. Therefore, ...
July 10, 2013

science
The 100W bulb.
July 10, 2013

Physics
Wc = m*g = 1650kg * 9.8N/kg = 16,170 N.= Wt. of car. k = 16,170N./3.5m. = 4620 N/m.
July 8, 2013

Physics
Wc = m*g = 1840kg * 9.8N/kg = 18032 N. = Wt. of car. Fc = 18,032N[12.5o] = Force of the car. Fp = 18,032*sin12.5 = 3903 N. = Force parallel to incline. F-Fp = m*a = m*0 = 0 F-3903 = 0 F = 3903 N. Parallel to the incline Work = F*d = 3903 * 14 = 54,642 J.
July 8, 2013

physics
g = 9.8/6 = 1.633333 m/s^2 on moon. d = o.5g*t^2 = 50 m. 0.5*1.63333*t^2 = 50 0.81666t^2 = 50 t^2 = 61.22 t = 7.82 s.
July 8, 2013

physics
b. Fn = m*a a = Fn/m = (940-521)/95.9 = 4.37m/s^2. V = Vo + a*t = 0 Vo = -a*t = -(-4.37*1.63) = 7.1 m/s.
July 8, 2013

physics
Wp = m*g = 95.9kg * 9.8N/kg = 940 N. = Wt. of player. a. Fk = 0.554 * 940 = 520.7 N.
July 8, 2013

physics
CORRECTION: b. hmax = 3 + 0.141 = 3.141 m.
July 8, 2013

physics
a. V^2 = Vo^2 + 2g*h h(up) = (V^2-Vo^2)/2g. h(up) = (0-2.76)/-19.6 = 0.141 m. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6(0.141+3) = 61.6 V = 7.85 m/s. b. 0.141 m.
July 8, 2013

math
See previous post: 7:09pm.
July 8, 2013

Physics
d = 0.5g*t^2 = 122.5 m. 4.9t^2 = 122.5 t^2 = 25 t = 5 s. = Fall time. d = r*t = 122.5 m. 343t = 122.5 t = 0.357 s. T = 5 + 0.357 = 5.357 s.
July 8, 2013

physics
a. Y^2 = Yo^2 + 2g*h = 0 @ max. ht. Yo^2 = -2g*h = 19.6 * 21.8 = 427.28 Yo = 20.7 m/s. = Ver. component of initial velocity. Yo = 51.2*sin A = 20.7 m/s. sinA = 20.7/51.2 = 0.40373 A = 23.8o. Vo = 51.2[23.8o] Xo = 51.2*cos23.8 = 46.8 m/s. = Hor. component of initial velocity. V...
July 8, 2013

physics
F = m*g = 0.662 * 9.8 = 6.49 N. a. Work=F*d=6.49 * (6.32-1.82)=29.2 J. b. PE = mg*h = 6.49 * 6.32 = 41.0 J. c. PE = 6.49 * 1.82 = 11.81 J. d. 11.81 - 41 = -29.2 J.
July 8, 2013

physics
V^2 = Vo^2 + 2g.h Vo^2 = V^2-2g.h Vo^2 = 0-(-19.6)*190sin13 = 837.7 Vo = 28.9 m/s
July 8, 2013

physics
CORRECTION: Vo^2 = 9.8*190/sin26 = 4247.54 Vo = 65.2 m/s.
July 8, 2013

physics
D = Vo^2*sin(2A)/g = 190 m. Vo^2*sin(26)/9.8 = 190 Vo^2 = 190/sin26 = 433.4 Vo = 20.8 m/s.
July 8, 2013

MATH
P(t) = 20(4t+3)/(2t+5) a. Population in 1990: Let t =0. Solve for P and get 12,000. Population in 2000: Let t = 10. P = 34,400. Population in 2010: Let t = 20. P=36,889. Therefore the population is growing. b. Replace P with 50 and solve for t. You should get -9.5 years. The ...
July 8, 2013

physics
V^2 = Vo^2 + 2a*d a=(V^2-Vo^2)/2 a = ((2.1)^2-0)/19.2=0.230 m/s^2 Fn = m*a (Fap-Fk) = m*a (29-Fk) = 17*0.230 29-Fk = 3.91 Fk = 29-3.91 = 25.1 N. Ws = m*g = 17kg * 9.8N/kg = 167 N. = Wt. of sled. u = Fk/Ws = 25.1/167 = 0.150 = Coefficient of kinetic friction.
July 8, 2013

physics
Wc = m * g = 1310kg * 9.8N/kg = 12838 N. Fp = 12338*sin9.12o = 2035 N. = Force parallel to road. Fv = 12838*cos9.12 = 12676 N. = Force perpendicular to road. = The normal. Work = Fn * D = 155,00 J. Fn * 337 = 155000 Fn = 460 N. = Net force. Fn = F-Fp-Fk = 460 N. F-2035-541 = ...
July 8, 2013

physics
a. F*cos23.2-48.5 = m*a = m*0 = 0 Fcos23.2 = 48.5 F = 48.5/cos23.2 = 52.8 N. b. Work = F*d = 52.8 * 34 = 1795 Joules. c. Work = Fk * d = 48.5 * 34 = 1649 J.
July 8, 2013

math
-16x^2 + 160t The max. point on the parabola is the vertex: t = Xv = -B/2A = -160/-32 5 s hmax. = Yv = -16*5^2 + 160*5 = 400 Ft. V(5,400).
July 8, 2013

Geometry
1. A = 400cm * 2cm = 800 cm^2. 2. A = (3.5^2) = 3. A = pi*r^2 = 3.14 * (9/2)^2 =
July 8, 2013

algebra1 HELP PLEASE
Let y = 0. x^2-7 = 0 x^2 = 7 X = =+-sqrt 7
July 8, 2013

algebra1 HELP PLEASE
h1(t) = 100 - 0.5*32*t^2. h1 = 100 - 16t^2 = 0 @ gnd. level. 16t^2 = 100 t^2 = 6.25 t = 2.50 s. h2(t) = 210 - 0.5*32*t^2 h2 = 210 - 16t^2 = 0 @ gnd. level. 16t^2 = 210 t^2 = 13.125 t = 3.62 s.
July 8, 2013

physics
See previous post,4:21 PM.
July 7, 2013

Finance
2. Increases with every payment and completely repays the loan with the last payment.
July 7, 2013

physics
Vo = 17m/s[25o] Xo = 17*cos25 = 15.4 m/s. Yo = 17*sin25 = 7.2 m/s. Y = Yo + g*t = 0 @ max. Ht. Tr = -Yo/ g = -7.2/-9.8 = 0.73 s. = Rise time. Tf = Tr = 0.73 s. = Fall time. D = Xo*(Tr+Tf) = 15.4 * 1.46 = 22.5 m. V=(D-12)/(Tr+Tf)=(22.5-12)/1.46=7.19m/s
July 7, 2013

physics
F = m*a V^2 = Vo^2 + 2a*d a = (V^2-Vo^2)/2d a = ((350)^2-0)/1.7 = 72,059 m/s^2 F = 0.004 * 72059 = 288 N.
July 6, 2013

physics
Please clarify your problem.
July 6, 2013

phy
1. Fn = m*a 40*cos37-Fk = 5 * 3 31.9-Fk = 15 Fk = 31.9-15 = 17 N. 3. a = Fn/m a = (250*cos37-8)/20 = 9.58 m/s^2.
July 6, 2013

math
The bar means the 2nd 89 REPEATS continuously.
July 5, 2013

physics
A = 5.0km[135o] B = 7.0km[315o] D = A+B D=(5.0*cos135+7.0*cos315)+i(5.0*sin135+ 7.0*sin315 D = (-3.54+4.95) + i(3.54-4.95) D = 1.41 - i1.41 = 2km[-45o]=2km[45o S of E]. NOTE: The cosine function was used to find the hor. components; the sine function was used to find the ver. ...
July 4, 2013

physics
A = 100m[0o] B = 200m[270o] C = 50m[3i5o] D = A+B+C D=(100+200*cos270+50*cos315+i(sin270+50*sin315) D = (100+0+35.4) + i(-200-35.4) D = 135.4 - i235.4 = 272m[-60o] = 272m [60o S. of E.].
July 4, 2013

Physics
A = 3m/s * 20s = 60m[180o]. B = 100m[270o]. C = 2m/s * 20s = 40 m[0o]. D = (A+B)-C A+B = (60*cos180+100*cos270)i(60*sin180+ 100*sin270) A+B = (-60+0) + i(0-100) A+B = -60 - i100 = -116.5[59o] A+B = 116.5[59+180] = 116.5m[239o]. D = (A+B)-C = 116.5[239] - 40 D = -60 - i100 - 40...
July 4, 2013

math 2
m1 = -A/B = 6/2 = 3. m2 = -12/-4 = 3. The Eqs have equal slopes. Therefore, they are parallel and do not intersect. So there are NO solutions.
July 4, 2013

contemporary math
P = Po(1+r)^n. P = $50,000 r = (8%/4)/100% = 0.02 = Quarterly % rate expressed as a decimal. n = 4comp./yr * 5.5yrs. = 22 Compounding periods. Plug the above values into the given Eq and solve for Po.
July 4, 2013

Math
Substitution.
July 4, 2013

Math
Substitution.
July 4, 2013

math
See previous post: Mon,7-1-13,10:49 PM.
July 3, 2013

math
Correction: A =(8/4)^2 * 18 = 72 Ft^2 = Area of the base. V = A*h = 72 * 8 = 576 Ft^3. OR V = (8/4)^3 * 72Ft^3 = 576 Ft^3.
July 3, 2013

math
18Ft^2*h1 = 72Ft^3 h1 = 72Ft^3/18Ft^2 = 4 Ft. A = (8Ft/4Ft) * 18Ft^2 = 36 Ft^2 = Area of the base. V = A*h = 36Ft^2 * 8Ft = 288 Ft^3.
July 3, 2013

Gen. physics
V^2 = Vo^2 + 2ad = 0 a = -Vo^2/2d = -(6.4)^2/29 = -1.41 m/s^2
July 2, 2013

physics
a. V = Vo + g*t = 17 m/s. Vo = 17-g*t = 17-(-9.8*2.2) = 38.56 m/s. b. V = 38.56 -9.8*4.4 = -4.56 m/s. The negative sign means the rock is on its' way down.
July 2, 2013

gen physics
See Related Questions: Thu,6-27-13,6:00am.
July 2, 2013

gen physics
A = 71[180o]. B = 71[270o]. a. A+B=(71*cos180+71*cos270)+i(71*sin180+71*sin270) A+B = (-71+0) + i(0-71) A+B = -71 - i71 = -100.4]45o] or 100.4[45o+180o] = 100.4[225o]. Since the resultant is in Q3, 45o is the reference angle. b. A-B=(71*cos180-71*cos270)-i(71sin180-71sin270) A...
July 2, 2013

Algebra
x(3y) = y(3x) = 3(xy) = 3*y*x.
July 2, 2013

49PM.ath
See Related Questions: Mon,7-1-13,10:
July 1, 2013

math
P = Po(1+r)^n. Po = $42,000 r = 11%/100% = 0.11 n = 1comp./yr. * 19yrs = 19 Compounding periods. Plug the above values into the given Eq and solve for P.
July 1, 2013

algebra 1 NEED NOW!!! PLEASE HELPPP
Since the parabola opens downward, the vertex is the max. point on the curve. Y = -12x^2 + 48x 1. h = Xv = -B/2A = -48/-24 = 2 Seconds. 2. k = Yv = -12*2^2 + 48*2 = 48 Ft. V(x,y)= (2,48). 3. Tr = Tf = 2 s. T = 2 + 2 = 4 s. Tr = Rise time. Tf = Fall time.
July 1, 2013

business math
See Mon,7-1-13,10:49PM post.
July 1, 2013

Mathematics
What is 72ten?
July 1, 2013

finance
D = 10000-0.15*10000 = $8500.
June 30, 2013

Physics
F = m*a a = V-Vo)/t = (34.4-0)/42 = 0.819 m/s^2. F = 3.6*0.819 = 2.95 N.
June 30, 2013

MATH
A(-1,-2),P(x,y),B(9,3). x-(-1) = 4(9-x) x+1 = 36-4x 5x = 35 X = 7. y-(-2) = 4(3-y) y+2 = 12-4y 5y = 10 Y = 2. P(7,2).
June 30, 2013

Physics
V = 6.48*cos9.54 = 6.39 m/s.
June 30, 2013

Physics
See previous post.
June 30, 2013

Physics
a=(V-Vo)/t = (26.5-0)/0.55 = 48.2 m/s^2. F = m*a = 929.4 * 48.2 = 44,780 N.
June 30, 2013

Discrete Math
CORRECTION:BCD should be BCDA
June 30, 2013

Discrete Math
8 different passwords were formed: ABCD BCD CDAB DABC. DCBA CBAD BADC ADCB
June 30, 2013

math
Move the decimal 8 places to the right. 7.5*10^8 = 750,000,000
June 30, 2013

math
1. P = Po(1+r)^n. Po = $500,000. r = (6%/4)/100% = 0.015 = Quarterly % rate expressed as a decimal. n = 4comp./yr. * 5yrs. = 20 Compounding periods. Plug the above values into the given Eq. and solve for P. 2. P = Po(1+r)^n. r = APR = (8%/100% = 0.08 n = 1comp./yr. * 5yrs. = 5...
June 29, 2013

trig
X ^5 - 11 = 0 X^5 = 11 (X^5)^(1/5) = (11)^(1/5) X = 1.615.
June 28, 2013

physics
See Related Questions: Thu,6-27-13,6:ooAM.
June 28, 2013

Business Math
P = Po(1+r)^n. Po = 50000 r = (1.6%/2)/100% = 0.008 = Semi-APR. n = 2comp./yr. * 5yrs = 5yrs = 10 Compounding periods. Plug the above values into the given Eq and solve for P.
June 27, 2013

Business Math
P = Po(1+r)^n P = $27,500 Po = Initial investment. r = (6%/12)/100% = 0.005 = Monthly % rate expressed as a decimal. n = 12comp/yr. * 3yrs = 36 Compounding periods. P = Po(1.005)^36 = 27500 Po = 27500/(1.005)^36 = $22,980.
June 27, 2013

Business Math
APY = The interest for 1 year divided by the initial investment: APY = (I/Po)*100%.
June 27, 2013

Business Math
CORRECTION: n = 4Comp./yr. * 1yr. = 4 Compounding periods.
June 27, 2013

Business Math
P = Po(1+r)^n. Po = $1,000,000. r = (8%/4)/100% = 0.02 = Quarterly % .rate expressed as a decimal. n 4Comp./yr. * 8trs = 32 Compounding periods. Plug the above values into the given Eq and solve for P. I = P-Po.
June 27, 2013

Business Math
P = Po(1+r)^n. Po = $7700. r = (6%/4)/100% = 0.015 = Quarterly % rate expressed as a decimal. n = 4Comp./yr. * 5yrs = 20 Compounding periods. Plug the above values into the given Eq and get: P = $10,370.78
June 27, 2013

physics
Vo = 85m/s[45o]. Xo = 85*cos45 = 60.1 m/s. Yo = 85*sin45 = 60.1 m/s. Tr = (Y-Yo)/g = (o-60.1)/-9.8 = 6.1 s. = Rise time. h = Yo*t + 0.5g*t^2 h = 60.1*6.1 - 4.9*(6.1)^2 = 184.3 m. d = Yo*t + 0.5g*t^2=184.3 + 120=304.3m 0 + 4.9t^2 = 304.3 t^2 = 62.1 Tf = 7.9 s. = Fall time. d =...
June 27, 2013

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