Thursday

October 23, 2014

October 23, 2014

Total # Posts: 9,329

**Physics**

When t = 0, x = 0.
*September 27, 2013*

**dma040**

Do you mean V = (1/3)*ah? If so, V = ah/3 Multiply both sides by 3/a: h = 3V/a
*September 27, 2013*

**Physics**

L = (V^2-Vo^2)/2g a. L = (15^2-4.7^2)/19.6 = 10.4 m. b. h = L*sin10 h = 10.4*sin10 = 1.8 m. h = Vo*t + 0.5g*t^2 = 1.8 4.7t + 4.9t^2 = 1.8 4.9t^2 + 4.7t - 1.8 = 0 t = 0.293 s. Use Quadratic Formula.
*September 27, 2013*

**Crossing a River in min time**

TanA = (1km/h)/15km/h = 0.066666 A = 3.8o E. of N. d = 1.17/cos3.8 = 1.173km. = Distance boat must travel. Vb = 15/cos3.8 = 15.033 km/h d = V*t = 1.173 km 15.033t = 1.173 t = 0.078028 h = 4.68 Min.
*September 27, 2013*

**physics**

a. OA = 0.5a*t^2 = 25 m. 0.5a*7^2 = 25 0.5a*49 = 25 a = 1.02 m/s^2 b. V = a*t = 1.02 * 7 = 7.14 m/s. c. AB = (V^2-Vo^2)/2a AB = (15^2-7.14^2)/2.04 = 85.3 m.
*September 24, 2013*

**physics**

a. V = Vi + g*t b. d = Vi*t + 0.5g*t^2 c. V = -Vi + g*t. d = -Vi*t + g*t
*September 24, 2013*

**Phsyics**

Vo = 30m/s[80o] Yo = 30*sin80 = 29.54 m/s. hmax = (V^2-Vo^2)/2g hmax = (0-29.54^2)/-19.6 = 44.52 m Tr = -Vo/g = -29.54/-9.8 = 3.0 s = Rise time, Tf = 5-3 = 2 s. = Fall time. h = ho - 0.5g*t^2 h=44.52 - 4.9*2^2 = 24.92 m. after 5 s. 4.9*2^2 = 19.6
*September 24, 2013*

**physic**

V^2 = 30^2 + 5^2 = 925 V = 30.4 km/h.
*September 24, 2013*

**Physics**

Vo = 36km/h = 36000m/3600s = 10 m/s. V^2 = Vo^2 + 2g*h h = (V^2-Vo^2)/2g h = (0-10^2)/-19.6 = 5.0 m.
*September 23, 2013*

**Physics**

See previous post: Tue,1-18-11,6:56 PM.
*September 23, 2013*

**physics**

Correction: F2 = mg*cosA.
*September 23, 2013*

**physics**

mg = 667.5 N. F1 = mg*sinA = 667.5*sin38 = 411 N = Force parallel to the hill. F2 = mg*sinA= 667.5*cos38 = 526 N = Force perpendicular to the hill. Fs = u*F2 = 0.4 * 526 = 210.4 N = Force of static friction. Yes, because F1 is greater than the forceof s tatic friction, Fs.
*September 23, 2013*

**Physics**

a. V2 = T2/T1 * P1/P2 * V1.
*September 23, 2013*

**physics**

Vo = 18.9m/s[47o] Xo = 18.9*cos47 = 12.9 m/s. Range = Vo^2*sin(2A)/g Range = 18.9^2*sin94/9.8 = 36.4 m. Range = Xo * t = 36.4 m. 12.9 * t = 36.4 t = 2.82 s. in flight. d = 54.4-36.4 = 18 m To run in 2.82 s. Speed = d/t = 18m/2.82s = 6.38 m/s.
*September 23, 2013*

**Physics**

Vo = 15m/s[75o] Xo = 15*cos75 = 3.88 m/s. Range = Vo^2*sin(2A)/g Range = 15^2*sin(150)/9.81 = 11.47 m. d = 0.5a*t^2 = 11.47 m. 0.5a*1.03^2 = 11.47 0.53a = 11.47 a = 21.6 m/s^2.
*September 22, 2013*

**Physics**

0.4.9*t^2 = h t^2 = h/4.9 t = sqrt (h)/2.21 = Fall time. S = Vx * t
*September 22, 2013*

**Physics**

P = mg*d/t = 600 * 1.2/1.5 = 480 J/s = 480 Watts.
*September 22, 2013*

**physics**

See previous post: Sun,9-22-13,8:57 PM.
*September 22, 2013*

**physics**

a = (V-Vo)/t = (34-10)/10 = 2.4 m/s^2. Fn = m*a = 1570 * 2.4 = 3768 N.
*September 22, 2013*

**physics**

See previous post: Tue,1-18-11,6:56 PM.
*September 22, 2013*

**Physics**

a = (V-Vo)/t = (10-(-50))/15 = 4 m/s^2.
*September 22, 2013*

**Physics**

A. h = 0.5g*t^2 = 4.9*15^2 = 1103 m. B. d = 290m/s * 15s = 4350 m. C. Over the island.
*September 22, 2013*

**physics**

See previous post: Sat,9-21-13,11:52 PM.
*September 22, 2013*

**physics**

Da = 204 + Db Da = 22.9t = 204 + 18.6t 22.9t-18.6t = 204 4.3t = 204 t = 47.44 s. To catch up.
*September 22, 2013*

**physics**

d = 0.5a*t^2 = 0.725 * 63.7^2 = 2942 Rad
*September 22, 2013*

**physics**

d1 + d2 = 5.16 m. (Vo*t+0.5g*t^2 ) + (Vo*t+0.5g*t^2=5.16 (8.67t-4.9t^2) + (8.67*t+4.9*t^2 = 5.16 8.67t + 8.67t = 5.16 17.34t = 5.16 t = 0.298 s. Note: 4.9t^2-4.9t^2 = 0 d1 = 8.67*0.298 - 4.9*0.298^2 = 2.14 m Above gnd. = The point where they meet.
*September 21, 2013*

**Physics**

Incomplete and unclear.
*September 21, 2013*

**Physics**

A = 45.6[51.2o]. B = 23.6[32.8o] C = 34[270o] A-B+C = 45.6[51.2o]-23.6[32.8o]+34[270] X = 45.6*cos51.2-23.6*cos32.8+34*cos270= 8.74. Y = 45.6*sin51.2-23.6*sin32.8+34*sin270= -11.2 tanAr = Y/X = -11.2/8.74 = -1.28146 Ar = -52o = Reference angle. A = -52 + 360 = 308o. = ...
*September 21, 2013*

**physics**

d = Xo * T = 2700 m. 520T = 2700 T = 5.19 s.
*September 21, 2013*

**math**

1. Real Numbers.
*September 20, 2013*

**maths**

5F = 250 F = 50 Females. F = 250 - 50 = 200 Females needed.
*September 20, 2013*

**maths**

Scale = 1:200,000? d = (200000/1) * 3cm = 600,000 cm. = 6000 m. = 6 km.
*September 20, 2013*

**Physics**

Y/X = 56/-25.5 = -2.19608 Ar = -65.5o = Rerence angle. A = -65.5 + 180 = 114.5o = Direction. Mag. = Y/sinA = 56/sin114.5 = 61.5 Units NOTE: If you draw the vector diagram showing 56 on the positive Y-axis and -25.5 on the negative X-axis, you can see that the Direction lies ...
*September 20, 2013*

**Physics**

See your previous post.
*September 20, 2013*

**Physics**

A + B = -15 29 + B = -15 B = -15-29 =-44 Units and points in negative Y direction.
*September 20, 2013*

**Physics**

B. d = 0.5a*t^2 = 2.27*8.43^2 = 161.3 m. C. V = a*t = 4.53*8.43 = 38.2 m/s. D. 3.62*8.43 = 30.5 m/s.
*September 20, 2013*

**Physics**

d1 = 0.5a*t^2 = 1.81*1.01^2 = 1.85 m. Head start. V1 = a*t = 3.62*1.01 = 3.66 m/s. d2 = 0.5a*t^2 = 1.85 + V1*t + 0.5a*t^2 2.27t^2 = 1.85 + 3.66*t + 1.81t^2 2.27t^2-1.81t^2 -3.66t - 1.85 = 0 0.46t^2 - 366t - 1.85 = 0 t = 8.43 s. To catch up.
*September 20, 2013*

**physics**

F = m*a a = F/m = 4.9*10^5/7 = 7*10^4 m/s^2 t = (V-Vo)/a = (4000-0)/70,000=0.0571 s.
*September 20, 2013*

**physics**

Xo = 180*cos34 = 149.2 m/s.
*September 20, 2013*

**physics**

sinA = 15%/100% = 0.15 A = 8.63o
*September 20, 2013*

**physics**

tanAr = Y/X = 325/-445 = -0.73034 Ar = -36o = Reference angle. A = -36 + 180 = 144o CCW = 54o W. of N.
*September 20, 2013*

**physics**

D = X^2 + Y^2 = 26.7^2 X^2 + 25^2 = 26.7^2 Solve for X.
*September 19, 2013*

**Physics**

a = (V^2-Vo^2)/2d a = (21^2-35^2/0.08 = -9800 m/s^2. V = Vo + a*t = 21 m/s. 35 + -9800t = 21 t = 0.001429 s. = 1.429 ms.
*September 19, 2013*

**Physics**

d = Vo*t + (V^2-Vo^2)/2a d = 24.4*1 + (0-24.4^2)/-16 = 61.6 m.
*September 19, 2013*

**Physics**

Incomplete.
*September 19, 2013*

**Mechanics**

Correction: a = (26-0)/0.008 = 3250m/s^2
*September 19, 2013*

**Mechanics**

a = (V-Vo)/t = (0-26)/0.008s = 3250m/s^2 F = m*a = 0.425 * 3250 = 1381.3 N.
*September 19, 2013*

**Mechanics**

Momentum = m*V = 0.058*51 = 2.96
*September 19, 2013*

**Physics**

See previous post: Wed,9-18-13,8:10 PM.
*September 19, 2013*

**physics**

V^2 = Vo^2 + 2a*h V^2 = 51.3^2 + 3.64*150 = 3177.69 V = 56.4 m/s. hmax = (V^2-Vo^2)/2g hmax = (0-56.4^2)/-19.6 = 162,3 m.
*September 19, 2013*

**physics**

a. Vo = 14m/s[45o] Xo = 14*cos45 = 9.9 m/s. Yo = 14*sin45 = 9.9 m/s. Y = Yo + g*t = 0 Tr=Yo/g = 9.9/9.8 = 1.01 s. = Rise time. hmax = ho + Yo*t + 0.5g*t^2 hmax=2.16 + 9.9*1.01 - 4.9*1.01^2=7.16m Above gnd. h = 0.5g*t^2 = 7.16 4.9t^2 = 7.16 t^2 = 1.46 Tf = 1.21 s. = Fall time. ...
*September 19, 2013*

**Physics**

2.80km[35o] X = 2.80*cos35 = 2.29 km Y = 2.80*sin35 = 1.61 km dmin = 2.29 + 1.61 = 3.9 km
*September 19, 2013*

**Physics**

1. Check calculations and have another person check it also. 2. Check Power supply voltage. 3. Remove all resistors from circuit and check them individually. 4. Make sure circuit is wired correctly.
*September 19, 2013*

**business math**

80 * 3.50 =
*September 19, 2013*

**business math**

0.75*P = 2484 P = $3312.
*September 19, 2013*

**Physics**

h = 0.5g*t1^2 = 20 m. 4.9*t1^2 = 20 t1^2 = 4.08 t1 = 2.02 s. d = r * t2 = 4.6 m. 1.6t2 = 4.6 t2 = 2.9 s. T = t1 + t2 = 2.02 + 2.9 = 4.92 s.
*September 19, 2013*

**Physics**

Vr = -10 + 20 = 10 km, East.
*September 18, 2013*

**physics**

See previous post.
*September 18, 2013*

**physics**

h1 = Vo*t + 0.5g*t^2 h1 = 16*0.65 - 4.9*0.65^2 = 8.33 m. Head start. V1 = Vo + g*t = 16 - 9.8*0.65=9.63 m/s. h2 = Vo*t + 0.5g*t^2=8.33+V1*t+0.5g*t^2 27*t - 4.9t^2 = 8.33 + 9.63t - 4.9t^2 27t - 9.63t - 4.9t^2 + 4.9t^2 = 8.33 17.37t = 8.33 t = 0.48 s. h = 27*0.48 - 4.9*0.48^2 = ...
*September 18, 2013*

**Math term definitions**

See your previous post.
*September 18, 2013*

**physics**

m*g = 15,400 N. m = 15400/g = 15400/9.8 = 1540.4 kg Fr = -2000 + 4000[120o] X = -2000 + 4000*cos120 = -4000 N. Y = 4000*sin120 = 3464 N. tan Ar = Y/X = 3464/-4000 = -0.86603 Ar = -40.9o = Reference angle. A = -40.9 + 180 = 139.1o CCW = 49.1o W. of N. Fr = Y/sinA = 3464/sin139...
*September 18, 2013*

**Math Definitions**

See previous post.
*September 18, 2013*

**Math Please Urgent**

See your previous post: Wed,9-18-13,8:04 PM.
*September 18, 2013*

**Math definitions**

1. A perfect cube. Example: 125 = 5*5*5. 2. A perfect square. Example: 36 = 6*6. 3. 1*sqrt (4) 4. 8*sqrt(4)
*September 18, 2013*

**Math**

((1/4)^-3/(1/4)^2)^-2 = ((1/4)^-5)^-2 = (1/4)^10 = 9.54*10^-7 (3^1/2)^3 = 3^(3/2) = 5.196. -56r^2/-7r^2 = 8. x*y*x*2y = 2X^2Y^2 3600X^4Y^6. sqrt(16*10^4) = 4*10^2 = 400. sqrt means Square root. sqrt(0.04) = sqrt(4*10^-2) = 2*10^-1 = 0.20 3*sqrt(81) = 3*9 = 27 sqrt(900) = sqrt(...
*September 18, 2013*

**Physics**

F = m*a
*September 18, 2013*

**physics**

a. d = Xo * t = 2.75m/s * 0.866s=2.38 m. b, d=0.5g*t^2 = 4.9*(0.866)^2 = 3.67 m. c. d = 0.5g*t^2 = 10 m. 4.9t^2 = 10 t^2 = 2.04 Tf = 1.428 s. = Fall time. D = Xo * Tf = 2.75 * 1.428 = 3.93 m.
*September 18, 2013*

**pressure**

To = (2.7/1.75) * 25C = 38.57oC
*September 18, 2013*

**Physics**

h = 0.5g*t^2 = 44 m. 4.9t^2 = 44 t^2 = 8.98 t = 3 s. = Time in flight. Range = Vo*cos10 * t = 109 m. Vo*cos10 * 3 = 109 Vo = 109/3*cos10 = 36.9 m/s[10o]
*September 18, 2013*

**Business Math**

I = 2600-2000 = $600 I = Po*(0.06/360)*t = 600 2000*(0.06/360)*t = 600 0.333t = 600 t = 1800 Days = 5 yrs(Assuming 360 days/yr)
*September 18, 2013*

**physics**

See previous post.
*September 18, 2013*

**physics**

Xo = 75 m/s. Y^2 = Yo^2 + 2g*h Y^2 = 0 + 19.6*50 = 980 Y = 31.3 m/s. V = 75 + 31.3i tan A = Y/Xo = 31.3/75 = 0.41740 A = 22.7o
*September 18, 2013*

**physics**

I = 10*Log 105 = 20.2 db.
*September 18, 2013*

**math**

N(-2,-3), O(0,0), P(6,p). m1 = (0-(-3))/(0-(-2)) = 3/2 m2 = (p-0)/(6-0) = 3/2 p/6 = 3/2 2p = 18 p = 9.
*September 18, 2013*

**Physics**

d = 0.5a*t^2 = 2.5*3.9^2 = 38 m.
*September 18, 2013*

**Physics**

See previous post.
*September 18, 2013*

**Physics**

P = V^2/R = 120^2/15 = 960 Watts. Energy = P * t = 960 * 60s = 57,600 Watt-seconds.
*September 18, 2013*

**Physics**

Correction: R + 11=(11A/6.6A)*R= 1.666R.
*September 18, 2013*

**Physics**

R + 11 = (11A/6.6A)R 1.666R 1.666R - 1R = 11 0.666R = 11 R = 16.5 Ohms. = Original Resistance.
*September 18, 2013*

**Physics**

h1=a*t^2 = 28.3*5.5^2=856.1 m Above gnd. V1 = a*t = 28.3 * 5.5 = 155.7 m/s. V = V1 + g*t = 0 155.7 - 9.8t = 0 -9.8t = -155.7 t = 15.9 s. To reach max ht. h2 = V1*t + 0.5g*t^2 h2 = 155.7*15.9 - 4.9*15.9^2 = 1236 m Above h1. h = h1 + h2 = 856 + 1236 = 2092 m. Above gnd.
*September 17, 2013*

**12**

cot E = -9/12 = X/Y. r^2 = X^2 + Y^2 = (-9)^2 + 12^2 = 225 r = 15 sin E = Y/r = 12/15.
*September 17, 2013*

**Physics**

D = 9.6-2.59i D^2 = 9.6^2 + (-2.59)^2 = 98.89 D = 9.94 m. tan A = Y/X = -2.59/9.6 = -.26979 A = -15.1o = 15.1o S of E.
*September 17, 2013*

**Physics**

h = 0.5g*t^2 = 4.9*1.7^2 = 14.2 m.
*September 17, 2013*

**finance**

P = Po(1+r)^n. P = 1000(1.02)^n = 2000 1.02^n = 2 n*Log 1.02 = Log 2 n = Log 2/Log 1.02 = 35 Compounding periods. 35Comp / 1Comp/yr = 35 Yrs. To double.
*September 17, 2013*

**algebra 2**

1. $40/7.50 = 5.33 Or 5 tickets. 2. $40/7.50 = 8 Tickets.
*September 17, 2013*

**math**

N - 0.25N = sqrt(576) = 24 = Length of each side of the square. 0.75N = 24 N = 32 = Length of long sides of rectangle. A = L * W = 32 * 24 = 768 = Area of rectangle.
*September 17, 2013*

**Geometry**

Radius of R = r units. Radius of Q = (4/5)*r = 4r/5 units. Ar/Aq = pi*r^2/pi*(4r/5)^2 Ar/Aq = r^2/(4r/5)^2 = r^2/(16r^2/25) Ar/Aq = r^2*25/16r^2 25/16 = 25/16 = 1.5625 = 156.25% Ar = 156.25% - 100% = 56.25% > Aq.
*September 17, 2013*

**physics**

See previous post: Tue,9-17-13,6:20PM.
*September 17, 2013*

**physical science**

V = (575/950) * 1*10^6 =
*September 17, 2013*

**math**

r1*t + r2*t = 3 Mi. 4t + 5t = 3 9t = 3 t = 3/9 = 1/3 h. = 20 min.
*September 17, 2013*

**physics**

d = Xo * t d = 327*cos37.2 * 7.83 =
*September 17, 2013*

**PHYSICS**

D = 5.2i - 3.6 - 2.6i = -3.6+2.6i D^2 = -3.6^2 + 2.6^2 = 19.72 D = 4.44 km.
*September 17, 2013*

**Physics**

V^2 = Vo^2 + 2g*d Vo^2 = V^2 - 2g*d Vo^2 = 10^2 - (-19.6)98*5 Vo^2 = 100 + 98 = 198 Vo = 14.1 m/s. = Speed at which ball was thrown.
*September 17, 2013*

**Physics**

Xo = 12.2 m/s. Range = 21 m. Range = Xo * Tf = 21 m. 12.2 Tf = 21 Tf = 1.72 = Fall time. h = 0.5g*Tf^2 = 4.9 * 1.72^2 = 14.5 m.
*September 17, 2013*

**Physics**

d = 0.5g*t^2 = 490 m 0.5g*10^2 = 490 0.5g*100 = 490 100g = 980 g = 9.8 m/s^2.
*September 17, 2013*

**finance**

See previous post.
*September 16, 2013*

**finance**

P = Po(1+r)^n r = (2%/365)/100% = 0.00005479 = Daily % rate expressed as a decimal. n = 365Comp./yr * 20yrs. = 7300 Compounding periods. P = !000(1.00005479)^7300 = $1491.76
*September 16, 2013*

**physics**

a. Speed=1mi/4min * 1min/60s * 3600s/h = 15 mi/h. b. S=15mi/h * 5280Ft/mi * 1h/3600s = 22 Ft./s. c. S = 15mi/h * 1600m/mi * 1h/3600s=
*September 16, 2013*

**Physics**

h = 117*sin 31 = 60.26 m. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*60.26 = 1181.09 V = 34.37 m/s
*September 16, 2013*

**Physics**

d = 0.5a*t^2 = 200 m. 2*t^2 = 200 t^2 = 100 t = 10 s.
*September 16, 2013*

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