Friday
December 19, 2014

Posts by Henry


Total # Posts: 9,752

Algebra
V = 8*sqrt(h) = 8*sqrt(203) = 114 Ft/s.
November 5, 2014

physics
V^2 = Vo^2 + 2g*h = 0 + 19.6*(10-5) = 98 V = 9.90 m/s @ 5 m above the surface. V^2 = 0 + 19.6*10) = 196 V = 14 m. Just before striking the surface.
November 5, 2014

science
Incomplete.
November 5, 2014

physics
Vo = 10 m/s. V = 5 m/s. d = 150 m. a = ? a. V^2 = Vo^2 + 2a*d a = (V^2-Vo^2)/2d = b. d = (V^2-Vo^2)/2a. V = 0, Vo = 5 m/s.
November 5, 2014

Physics
Incomplete.
November 4, 2014

Algebra
F(x) = Y = -x^2 + 6x + 6 = 0 Use Quadratic Formula. (X, Y) = (-2, 0), (8, 0).
November 4, 2014

Precalculus
Do you mean e^2x - 1 = e^4 or e^(2x-1) = e^4. I will assume the 2nd Eq. (2x-1)*Ln e = 4*Ln e (2x-1)*1 = 4*1 2x-1 = 4 2x = 5 X = 5/2 = 2.5
November 4, 2014

physics
a. a = (V-Vo)/t. V = 510 m/s Vo = 0 t = 2.37 s. b. a = (V-Vo)/t V = 0 Vo = 510 m/s. t = 3.15 s. Note: Acceleration when braking will be negative.
November 4, 2014

physics
V^2 = Vo^2 + 2g*h. Vo = 0 @ top of hill. V^2 = 2g*h. Solve for V.
November 4, 2014

physics
V^2 = Vo^2 + 2g*h = 0 + 19.6*2000 = 3920 V = 62.6 m/s. KE = 0.5m*V^2 = 50*62.6^2 = 195,938 J.
November 4, 2014

physics
m*g = 180kg * 9.8N/kg = 1764 N. PE = mg*h = 8000 J @ top of hill. h = 8000/mg = 8000/1764 = 4.54 m.
November 4, 2014

Math
(40/360) * 2p1 = 2pi/9 Radians.
November 4, 2014

Science
a = (Fap-Ff)/m = (25-6)/1.5 =
November 4, 2014

Physics
A vector quantity shows magnitude and direction: 50 m/s @ 45o. Magnitude = 50 m/s. Direction = 45 Degrees.
November 4, 2014

physics
F1+F2+F3 = 72.7N[0o] + 79.9N[45o] + 103N[315o]. X = 72.7 + 79.9*Cos45 + 103*Cos315=202 N Y = 79.9*sin45 + 103*sin315 = -16.33 N. F^2 = X^2 + Y^2 = 202^2 + (-16.33) = 41,071 F = 203 N. = Resultant force. Tan A = Y/X = -16.33/202 = -0.08084 A = -4.62o = 4.62o S. of E. = Direction.
November 3, 2014

science
1. The DF increases: DF = PW/PRF. 2. The PRF increases: PRF = 1/PRP. 4. When WL decreases, the PRF increases. The increase in PRF decreases the DF. PRF = V/WL
November 3, 2014

physics
A = (27.1-9.1)*7.7*10^-4 * 5 = 0.0693 Gal.
November 3, 2014

science
incomplete.
November 3, 2014

Physics
D = 4.19*Cos10.4
November 3, 2014

Physics
D = 4.19*sin10.4 =
November 3, 2014

physics
a. m*g = 1.0*10^4 N. m = 1.0*10^4/g = 1.0*10^4/9.8 = 1020 kg. Fp = 1.0*10^4*sin34 = 5592 N. = Force parallel to the hill. a = Fp/m = 5592/1020 = 5.48 m/s^2. b. V^2 = Vo^2 + 2a*d = 0 + 10.96*28 = 307 V = 17.5 m/s.
November 2, 2014

Physics
Vo = 20m/s[50o] Xo = 20*cos50 = 12.9 m/s Yo = 20*sin50 = 15.3 m/s. V = Vo + g*Tr = 0 @ max Ht. Tr = -Yo/g = -15.3/-9.8 = 1.56 s. = Rise time. h = Yo*Tr + 0.5g*Tr^2 h max = 15.3*1.56 - 4.9*1.56^2=11.9 m. h = 0.5g*t^2 = 11.9-3.04 = 8.90 m. 4.9t^2 = 8.90 t^2 = 1.82 Tf = 1.35 s...
November 2, 2014

physics
Vo = 50m/s[30o] Xo = 50*Cos(30) = 43.3 m/s. Yo = 50*sin(30) = 25 m/s. h = Yo*t + 0.5g*t = 59 m. 25t + 4.9t^2 = 50 4.9t^2 + 25t - 50 = 0 Use Quadratic Formula. Tf = 1.54 s. = Fall time. Dx = Xo * Tf = 43.3m/s * 1.54s = 66.7 m. From the cliff. Y = Yo + g*t = 25 + 9.8*1.54 = 40.1...
November 2, 2014

Physics
a. Fr = 328N[35o] + 464N[13o] X = 328*Cos35 + 464*Cos13 = 721 N. Y = 328*sin35 + 464*sin13 = 293 N. Fr^2 = X^2 + Y^2 = 721^2 + 293^2 = 605,690. Fr = 778 N. = Resultant force. b. a = F/m = 778/2950 = 0.264
November 2, 2014

Physics
Maximum power transfer occurs when the resistance of the load is equal to the internal resistance of the source: R = r.
November 2, 2014

physics
Vo = 0 V = 6,000rad/min = 6,000rad/60s = 100 rad/s. a = (V-Vo)/t = (100-0)/4 = 25 rad/s^2
November 2, 2014

Physics
a. D = Vo*t = 190rad/s * 13s = 2470 rad b. D = 300rad/s * 13s = 3900 Rad. c. a = (V-Vo)/t = (300-190)/13 = 8.46 rad/s^2. D = Vo*t + 0.5a*t^2 D = 190*13 + 4.23*13^2 = 3185 Rad.
November 1, 2014

physics
Multiply your answer by 100 to convert to cm.
November 1, 2014

physics
d = 0.5g^t^2. g = 9.8 m/s^2, t = 0.29 s. Solve for d.
November 1, 2014

Physics
Momentum = m1*V1-m2*V2 = 0.062*9-0.006*4 = 0.558 - 0.024 = 0.534 m1*V = 0.534 0.062*V = 0.534 V = 8.61 m/s.
October 31, 2014

Physics
Fr = F1 + F2 + F3 + F4 = 0 100N[37o] + 200N[270] + 250N[200] + F4=0 X = 100*Cos37+200*Cos270+250*Cos200 = -155 N. Y = 100*sin37+200*sin270+250*sin200 = -225 N. Tan Ar = Y/X = -225/-155 = 1.45161 Ar = 55.44o = Reference angle. A = 55.44 + 180 = = 235.4o F1+F2+F3 = Y/sin A = -...
October 31, 2014

Physics
a.m2*V2-m1*V1 = 0.250*10[71o]-0.250*28.4[58.8o] = 2.50[71o] - 7.1[58.8o] X = 2.50*Cos71 - 7.1*Cos58.8 = -2.86 Y = 2.50*sin71 - 7.1*sin58.8 = -3.71 M^2=X^2 + Y^2 = (-2.86)^2 + (-3.71)^2 = 21.9 M = 4.68 = Magnitude of change in momentum. b. Tan Ar = Y/X = -3.71/-2.86 = 1.29720 ...
October 31, 2014

Physics
(m1+m2)*V = m1*V1 (1424+1424)*V = 1424*11 2848V = 15,664 V = 5.5 m/s.
October 31, 2014

Science Physics
a. Vw = L*W*h = 85 *30 * (15-3) = 30,600 Ft^3. b. 30,600Ft^3 * 62.4Lbs/Ft^3 = 1.909,440 Lbs. = 955 Tons = Wt. of water displaced. Load = 955 - 160 = 795 Tons.
October 31, 2014

Algebra 1B
Width = W in. Length = (2W + 4) in. V = L * W * h = 2720 n^3. (2W+4) * W * 17 = 2720 2W^2+4W)*17 = 2720 34W^2 + 68W - 2720 = 0 W^2 + 2W - 80 = 0 -80 =-8*10. (W-8)(W+10) = 0 W-8 = 0 W= 8 W+10 = 0 W = -10 Use positive value of W: W = 8.
October 31, 2014

physics
T^2 = 4*pi^2*(L/g) T^2 = 39.48(0.65/9.8). Solve for T.
October 31, 2014

algebra 2
h = 16 - (16-12)/0.5h h = 16 - 8in/h Eq: h(t) = 16 - 8t
October 31, 2014

physics
a = 0 @ constant speed.
October 30, 2014

physics
Vo = 17 m/s V = 40 m/s t = 10.7 s. a = (V-Vo)/t. Solve for a.
October 30, 2014

physics
Vo = 0 a = 4.5 m/s^2 t = 7.9 s. d = ? V = Vo + a*t = 0 + 4.5*7.9 = 35.6 m/s. V^2 = Vo^2 + 2a*d = 35.6^2 Vo^2 + 2a*d = 35.6^2. Solve for d.
October 30, 2014

physics
V = ? Vo = 0 a = 0.557 m/s^2 d = 5.85 m. V^2 = Vo^2 + 2a*d. Solve for V.
October 30, 2014

physics
Vo = 0 V = ? t = 5.4 s. a = (V-Vo)/t = 2.57 m/s^2 (V-0)/5.4 = 2.57. Solve for V.
October 30, 2014

physics
D = Vo*t + 0.5g*t^2 D = 208*2.6 - 4.9*2.6^2 =
October 30, 2014

Fluid Mechanics
A flat-bottom river barge is 30.0 ft wide, 85.0 ft long, and 15.0 ft deep. (a) How many ft3 of water will it displace while the top stays 3.00 ft above the water? (b) What load in tons will the barge contain under these conditions if the empty barge weighs 160 tons in dry dock?
October 30, 2014

Physics
m*g = 0.5kg * 3.8N/kg = 1.9 N.
October 30, 2014

math
T = Time in seconds. h = Ht. in feet. (T, h) (0,100) Platform. (0.5,136) (1.0,164) (1.5,184) (2.0,196) V(2.5,200) Max. point. (3.0,196) (3.5,184) (4.0,164) (4.5,136) (5.0,100). Platform.
October 29, 2014

math
T = (d/2)/r1 + (d/2)/r2 = 35 min=2100 s. = (d/2)/4 + (d/2)/3 = 2100 = d/8 + d/6 = 2100 Multiply both sides by 24: 3d + 4d = 50,400 7d = 50,400 d = 7,200 m.
October 29, 2014

Physics
V^2 = Vo^2 + 2g*h = 0 @ max ht. h max = -(Vo^2)/2g = -(2.3^2)/-19.6 = 0.270 m. Since the max ht. is only 0.27 m, the ball cannot be spiked at o.8 m. Please check the numbers for accuracy.
October 29, 2014

physics
a. Balll #1: V = Vo + g*Tr = 0 @ max Ht. Tr = -Vo/g = -25/-9.8 = 2.55 s. = Rise time. Tf = Tr = 2.55 s. = Fall time. Tr+Tf = 2.55 + 2.55 = 5.10 s. = Time to hit gnd. Ball #2: h = 0.5g*t^2 = 20.0 m. 4.9*t^2 = 20 t^2 = 4.08 Tf = 2.02 s. = Fall time = time to hit gnd. b. Ball #1...
October 29, 2014

phy
Fs = m*g = 72.7kg * 9.8N/kg = 712.5 N. = Force of the student. P = F * d/t = 712.5 * 11.9/10.1 = 839.4 J./s = 839.4 Watts = 0.8394 Kilowatts.
October 29, 2014

Physics
Vo = 60km/h = 60,000m/3600s = 16.67 m/s. V = 15km/h = 15,000m/3600s = 4.17 m/s. a = (V^2-Vo^2)/2d = (4.17^2-(16.67^2))/900 = -0.289 m/s^2. d = (Vf^2-Vo^2)/2a d = (0-(16.67^2)/-0.579 = 480 m. To stop. 480-450 = 30 m. Further before coming to rest.
October 28, 2014

Physics
I believe there is an error in the problem. The problem should read: The speed of a train is reduced from 60km/h to 15km/h(for example) at the same time as it travels a distance of 450 m. If the retardation is uniform, find how much further it will travel before coming to rest...
October 28, 2014

Physics
V = I*R = 0.0015A * 20 = 0.03 Volts.
October 28, 2014

Physics
See previous post: Tue, 10-28-14, 12:16 AM.
October 28, 2014

Math
V = Vo + g*Tr = 0 @ max Ht. Tr = -Vo/g = -55/-32 = 1.72 s. = Rise time. Tf = Tr = 1.72 s. = Fall time. Tr+Tf = 1.72 + 1.72 = 3.44 s. To hit gnd
October 28, 2014

Math HELP!
Yes!
October 28, 2014

Math
(x+72/2)^2 = (x+36)^2 = x^2 + 72x + 1296 k = 1296
October 28, 2014

Physic
Vo = 26.7 m/s V = 0 u = 0.70 a. u = a/g a = g*u = (-9.8) * 0.70 = -6.86 m/s^2. V^2 = Vo^2 + 2a*d = 0 @ max distance. d = -(Vo^2)/2a = -(26.7^2)/-13.72 = 52 m
October 28, 2014

Physics
u = a/g = 0.8 a = 0.8*g = 0.8 * (-9.8) = -7.84 m/s^2 d = (V^2-Vo^2)/2a = (0-(20^2)/-15.68 = 25.5 m. To stop. 75-25.5 = 49.5 m. from deer.
October 28, 2014

Physics
See previous post.
October 28, 2014

Physics
Fb = m*g = 3kg * 9.8N/kg = 29.4 N. = Force of the brick. Fp = 29.4*sin34 = 16.44 N. = Force parallel to the incline. d = (16.44/120) * 1m = 0.137 m.
October 28, 2014

Physics
a. Work = F*d = 80 * 5 = 400 J. b. h = 5*sin29 = 2.424 m. Work = F*h = mg*h = 98*2.424 = 237.6 J. c. Work = 20 * 5 = 100 J.
October 27, 2014

physics
You haven't given all of the INFO: 1. Is the skier coasting down hill? 2. Is she being pulled up hill at constant speed?
October 27, 2014

Physics
h = 11.2km = 11,200 m. h = 0.5g*t^2 = 11,200 4.9*t^2 = 11,200 t^2 = 2286 Tf = 47.8 s. = Fall time.
October 27, 2014

Pre-Algebra
2. X Tubas. 2x Trombones. 4x Trumpets. X = 2 Tubas 2x = 2 * 2 = 4 Trombones. 4x = 4 * 2 = 8 Trumpets. Total players = 2 + 4 + 8 = 14. 3. Cost = (2.88/2) * 6Dozens = $8.64 for 6 dozens. Profit = Sale price - Cost. 4. From 6:50AM to 10:15AM = 3h and 25 min = 205 Min. 205Min * ...
October 27, 2014

science
P^2 = 4*pi^2(L/g) Since g is in the denominator, a smaller g means a longer period or lower frequency(1/P). Therefore, the clock will run slower on the moon.
October 27, 2014

physics
Fw = m*g = 35.2 * 9.8 = 345 N. = Force of the wagon. Fp = 345*sin18.3 = 108.3 N. = Force parallel to the hill. a = (Fex-Fp)/m = (125-108)/35.2 = 0.474 m/s^2. V^2 = Vo^2 + 2a*d = 0 + 0.949*75.4 = 71.54 V = 8.46 m/s.
October 27, 2014

physics
h = 1.150 m. Dx = 0.410 m. a. h = 0.5g*t^2 = 1.150 4.9*t^2 = 1.150 t^2 = 0.235 Tf = 0.484 s. = Fall time. b. Dx = Xo*Tf = 0.410 m. Xo * 0.484 = 0.410 Xo = 0.846 m/s. = Speed across table.
October 27, 2014

Physics
a = 0.0235 m/s^2. t = 67.8 s. d = 1km = 1,000 m. d = Vo*t + 0.5a*t^2 = 1,000 m. Vo*67.8 + 0.5*0.0235*67.8^2 = 1000 67.8Vo + 54 = 1000 67.8Vo = 1000-54 = 945.99 Vo = 14 m/s.
October 27, 2014

Physics
Vo = 3.01 m/s. t = 3.89 s. a = 3.63 m/s^2. V = Vo + a*t. Solve for V.
October 27, 2014

Physics
Energy = KE2-KE1 = 0.5m*V2^2-0.5m*V1^2 = 800*40^2 - 800*15^2 = 1,100,000 J.
October 27, 2014

physics
a = 3.7 m/s^2. d = 67 m. Vo = 0 V = ? t = ? a. V^2 = Vo^2 + 2a*d. Solve for V. b. d = 0.5a*t^2 = 67 m. Solve for t.
October 27, 2014

physics
Incomplete.
October 27, 2014

physics
Vo = 17.9 m/s. V = 31.8 m/s. d = 188 m. V^2 = Vo^2 + 2a*d a = (V^2-Vo^2)/2d = (31,8^2-17.9^2)/376 = 1.84 m/s^2.
October 27, 2014

Science Physics
V^2 = Vo^2 + 2g*h = 0 + 19.6*1.75 = 34.3 V = 5.86 m/s. Note: Always show your Eq before plugging in the values.
October 27, 2014

physics intro
V^2 = Vo^2 + 2g*h = 0 @ max ht. h = -(Vo^2)/2g = -(75^2)/-64 = 87.9 Ft.
October 27, 2014

Physics
See previous post: Mon, 10-27-14, 2:13 PM.
October 27, 2014

physics
Work = Fap*Cos A * d = 555 J. Fap*Cos36 * 15 = 555 12.14*Fap = 555 Fap = 45.7 N. = Force applied. = Tension in the strap.
October 27, 2014

physics
Fap-Fk = m*a = m*0 = 0 Fk = Fap = 62.9 N. = Force of kinetic friction.
October 27, 2014

physics
F = 1.35 N. a = 1.5 m/s^2 F = m*a m = F/a
October 27, 2014

Physical Science
m1 = 0.16 kg m2 = 80kg V1 = 28 m/s. (m1+m2)*V = m1*V1 (0.16+80)V = 0.16*28 V = 4.48/(0.16+80) = 0.056 m/s.
October 27, 2014

Physics
a = F/m = (5.5-2.5)/15 = 0.20 m/s^2. V = Vo + a*t = 0 + 0.2*4 = 0.8 m/s.
October 26, 2014

Physics
uk = a/g = 0.1372 a = 0.1372 * g = 0.1372 * (-9.8) =-1.34 m/s^2. V^2 = Vo^2 + 2a*d = 0 @ max. ht. d = -(Vo^2)/2a = -(16.8^2)/-1.34 = 210 m
October 26, 2014

Physics
h = 17.6 m. g = 9.8 m/s^2 h = 0.5g*t^2 = 17.6 m Solve for t.
October 26, 2014

algebra
a. $30/4gueest = $7.5 per guest Y = 7.5x b. Slope = 7.5 c. Y = 7.5x = 7.5 * 10 = $75 (x, y) = (10,75). (2,15), (4,30), (0,0).
October 26, 2014

physics
X = m1*V1 = 2165 * 17 = 36,805 Y = m2*V2 = 1300 * 27 = 35,100 Tan A = Y/X = 35,100/36,805 = 0.95367 A = 43.64o m*V = X/Cos A = 36,805/Cos43.64 = 50,859 (m1+m2)V = 50,859 (2165+1300)V = 50,859 V = 50,859/(2165+1300) = 14.7 m/s. @ 43.64o
October 26, 2014

physics
Vo = 100km/h = 100,000m/3600s. = 27.8 m/s. a = F/m = -4800/730 = -6.58 m/s^2. V = Vo + a*t = 27.8 - 6.58*1.9 = 15.3 m/s. Momentum = m*V = 730 * 15.3 = 11,174
October 26, 2014

Math
P = Po + Po*r*t P = 3,000 + 3000*(0.10/12)*3 = $3,075.
October 26, 2014

physics
Vo = 20 m/s[0o] V = 20 m/s[30o] a = (V-Vo)/t = (20[30o]-20[0o])/5 = (20*cos30+i20*sin30-20)/5 = (17.32+10i-20)/5 = (-2.68+10i)/5 = -0.536 + 2i,(Q2). Tan Ar = Y/X = 2/-0.536 = -3.73134 Ar = -75o = Reference angle. A = -75 + 180 = 105o,CCW = 15o W. of N. a = 2/sin105 = 2.07 m/s^...
October 26, 2014

Power Transmission
rpm = (24/60) * 120rpm = 48.
October 25, 2014

Physics
Xo = 15 m/s. h = 90 m. g = 9.8 m/s^2 a. h = 0.5g*t^2 = 90 m. Solve for t. b. Dx = Xo * t
October 25, 2014

physics
Vo = 50km/h = 50,000m/3600s = 13.89 m/s. a = (V-Vo)/t = (0-13.89)/5 = -2.78 m/s^2 F = m*a = 1000 * (-2.78) = -2780 N. The negative sign means the force is against the motion.
October 25, 2014

Calculus/pre-trig
D = B^2 - 4AC 1. If B^2 is less than 4AC(B^2 < 4AC), the Determinant is negative and we have 2 imaginary solutions and no real solutions. 2. If B^2 = 4AC, we have one real solution and no imaginary solutions. 3.If B^2 > 4AC, we have 2 real solutions and no imaginary ...
October 25, 2014

Physics
Fb = m*g = 11.2kg * 9.8N/kg = 109.8 N. = Force of block. Fp = 109.8*sin24 = 44.64 N. = Force parallel to the incline. d = (1m/31,300N) * Fp d = (1m/31,300N) * 44.64N = 0.0014262 m. = 0.143 cm.
October 25, 2014

physics
Xo = 13 m/s. Dx = 60 m. h = ? Dx = Xo * Tf = 60 Tf = 60/Xo = 60/13 = 4.62 s. = Fall time. h = 0.5g*Tf^2 = 4.9*4.62^2 = 105 m.
October 25, 2014

intermidiate algebra
Eq1: 3x + 300y = 111 Eq2: 5x + 600y = 198 Multiply Eq1 by -5 and Eq2 by 3 : -15x - 1500y = -555 +15x + 1800y = +594 Sum: 300y = 39 Y = $0.13 per mile. In Eq1, replace Y with 0.13 and solve for X: 3x + 300*0.13 = 111 3x = 111 - 39 = 72 X = $24 per day.
October 25, 2014

physis
W = 750N/6 = 125 N. on the moon.
October 24, 2014

Math, Trig/Pre Calc
See previous post: Fri, 10-24-14, 5:38 PM.
October 24, 2014

Pre-Calc/Trig...
Y = x^2 - 2x - 3 Vertex Form: Y = a(x-h)^2 + k h = -b/2a = 2/2 = 1 K = 1^2 - 2*1 - 3 = -4 Vertex Form: Y = 1(x-1)^2 - 4 Y = x^2 - 2x - 3 = 0 -3 = 1*(-3). Sum = 1 + (-3) = -2 = b. Factored or Intercept form:(x+1)(x-3) = 0
October 24, 2014

math
Tan13 = h/200 h = 200*Tan13 = 46 Ft. Cos13 = 200/r r = 200/Cos13 = 205 Ft = hypotenuse.
October 24, 2014

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