Friday

September 19, 2014

September 19, 2014

Total # Posts: 9,097

**physics**

1. V^2 = Vo^2 + 2g*h h = (V^2-Vo)/2g = (0-6^2)/-19.6=1.84 m. 2. Zero. 3. Calculated in #1.
*February 11, 2014*

**physics**

V = 25km/h = 25000m/3600s = 6.94 m/s. KE = 0.5m*V^2 = 10^4 J. 0.5m*6.94^2 = 10000 24.08m = 10000 m = 415.3 kg.
*February 11, 2014*

**Math**

P = Po(1+r)^n. r = (5.6%/4) / 100% = 0.014 = Quarterly % rate expressed as a decimal. n = 4comp/yr. * 4yrs = 16 Compounding periods. Plug the above values into the given Eq and solve for P.
*February 11, 2014*

**physics**

h = Vo*t + 0.5g*t^2 = 1.75 m 0 + 4.9*t^2 = 1.75 Solve for t.
*February 11, 2014*

**Physics**

To get help, You will have to explain how the resistors are connected and identify Vx.
*February 11, 2014*

**Physics**

a. Fp = 518*sin25 = 218.9 N. = Force parallel to the incline. m*g = 518 N. m = 518/g = 518/9.8 = 52.86 kg. a = F/m = 218.9/52.86 = 4.14 m/s^2. b. V = Vo + a*t = 0 + 4.14*6=24.85 m/s.
*February 11, 2014*

**physics**

Correction: a = (0.75^2-0)/3.2 = 0.1758 m/s^2. b. Fp-Fk = m*a 10.77-Fk = 2.6*0.1758 = 0.4570 Fk = 10.77 - 0.4570 = 10.31 N u = Fk/Fn = 10.31/23.09 = 0.4466
*February 11, 2014*

**physics**

a. Wb = M*g = 2.6kg * 9.8N/kg=25.48 N. = Weight of block. Fp = 25.48*sin25 = 10.77 N. = Force parallel to the inclined plane. Fn = 25.48*cos25 = 23.09 N. = Normal Force = Force perpendicular to the incline. a=V^2-Vo^2)/2d a = (0.75^2-0)/2.6 = 0.2163 m/s^2. b. Fp-Fk = m*a 10.77...
*February 11, 2014*

**Physics**

F = mg*sin30 = 180 * sin30 = 90 N.
*February 11, 2014*

**Physics**

Use same procedure as previous problem.
*February 11, 2014*

**physics**

F1+F2+F3+F4+F5+F6 = 0 i57+40-i77-40+50*cos60+i50*sin60+F6=0 The student can finish this problem by using the same procedure as the previous problem.
*February 11, 2014*

**Physics**

F1 + F2 + F3 = 0 33N[215o] + 45N[315] + F3 = 0 33*cos215+i33*sin215+45*cos315+i45*sin315+F3 = 0 23.33 - i18.93 + 31.82 - i31.82 + F3=0 55.15 - i50.75 + F3 = 0 F3=-55.15 + i50.75=sqr(-55.15^2+50.75^2)= 74.95 N. = The equilibrant. Tan Ar = Y/X = 50.75/-55.15=-0.92022 Ar = -42....
*February 11, 2014*

**math**

(8,-5), (-6,2) m = (2-(-5))/(-6-8) = 7/-14 = -1/2. Y = mx + b = -5 (-1/2)*8 + b = -5 b = -5 + 4 = -1 Y = (-1/2)x -1 Y = -x/2 - 1 Multiply both sides by 2: 2y = -x - 2 X + 2Y = -2
*February 10, 2014*

**Physics**

1. V=62mi/h*1600m/mi*1h/3600s=27.56m/s a = (V-0)/t = (27.56-0)/2.5 = 11.02m/s^2 2. V=90mi/h * 1600m/mi * 1h/3600s=40m/s a = (V-0)/t = 11.02 m/s^2. Solve for t. 3. V = (180/90) * 40m/s = 80 m/s. a = (V-0)/t = 11,02 m/s^2. Solve for t. 4. Yes, with constant acceleration.
*February 9, 2014*

**algebra**

I = (240/540) * 12
*February 9, 2014*

**physical science**

a. Fap-Ff = m*a = m*0 Fap - Ff = 0 The velocity is constant. Therefore, the acceleration is zero. Fap = Force applied. Ff = Force of friction. b. Fap - Ff = 0 100 - Ff = 0 Ff = 100 N.
*February 9, 2014*

**Algebra**

Pitch = (Y/X) * 100% = (13/13.8) * 100%
*February 9, 2014*

**math**

cos52 = X/L = 100/L L = 100/cos52
*February 9, 2014*

**physics**

V = Vo + g*Tr = 0 10.5 - 9.8*Tr = 0 9.8t = 10.5 Tr = 1.07 s. = Rise time. hmax = ho + (V^2-Vo^2)/2g = 76 + (0-10.5^2)/-19.6 = 81.63 m. Above gnd. hmax = Vo*t + 0.5g*t^2 = 81.63 m. 0 + 9.8*t^2 = 81.63 t^2 = 8.33 Tf = 2.89 s. = Fall time. Tr+Tf = 1.07 + 2.89 = 3.96 s. To reach ...
*February 9, 2014*

**Physics**

h = Vo*t + 0.5g*t^2 = 115.7 m Vo*5.6 - 4.9*5.6^2 = 115.7 Vo*5.6 = 115.7+153.7 = 269.4 Vo = 48.1 m/s.
*February 9, 2014*

**Physics**

a. V = Vo + g*t = 0 + 9.8*2.04 = 20 m/s b. d = 0.5g*t^2 = 4.9*2.04^2 = 20.39 m. Downward.
*February 9, 2014*

**phys**

V = Vo + a*t = 12 + 4*3 = 24 m/s = Final velocity. d=(V^2-Vo^2)/2a = (24^2-12^2)/8 = 54 m.
*February 9, 2014*

**Physics**

41km/h[0o], 28min. 41km/h[37o], 15min. 41km/h[180o], 64min a. d1=41km/h[0o] * (28/60)h=19.13km[0o] d2=41km/h[37o] * (15/60)h=10.25km[37o]= 8.19 + i6.17 d3=41km/h[180o] * (64/60)h=43.73km[180o] V=(d1+d2+d3)/(t1+t2+t3)=(19.13+8.19+i6.17-43.73)/(28+15+64) = (-16.41 + i6.17)/107=...
*February 9, 2014*

**Physics**

a. d = 407km[0o] + 871km[270o] X = 407 + 871*cos270 = 407 km Y = 871*sin270 = -871 km. D = sqrt(407^2 + (-871^2)) = 961.4 km. b. Tan A = Y/X = -871/407 = -2.14005 A = -64.95o = 64.95o S of E. = Direction. c. V=D/T = 961.4/(1.9+0.7333)=2.63 km/h. d. 64.95o S of E.
*February 9, 2014*

**physic**

See previous post.
*February 9, 2014*

**physic**

X = 4 km Y = -6 km R = sqrt(4^2 + (-6)^2)
*February 9, 2014*

**Algebra 1**

P = 300 - 0.3*300
*February 9, 2014*

**Physics**

17.6m[43o] a. X = 17.6*cos43 b. Y = 17.6*sin43
*February 9, 2014*

**Physics**

10.2m[48o] + B = 15m[15o] 10.2*cos48+i10.2*sin48+B=15^cos22+i15*sin22. 6.83 + i7.58 + B = 13.91 + i5.62 B=13.91-6.83 + i5.62 - i7.58=7.08-i1.96 B = sqrt(7.08^2 + (-1.96)^2) = 7.35 m. b. Tan A = Y/X = -1.96/7.08 = -0.27684 A = -15.47o S of E = 344.5o, CCW.
*February 9, 2014*

**Physics**

Note: Xt = 7-(-3.82) = 10.82 km.
*February 9, 2014*

**Physics**

a. 22km[260o] + 34[90o]. X = 22*cos260 = -3.82 km. Xt = 7.0 (-3.820 = 10.82 km = Total hor distance to B. Y = 22*sin260 + 34*sin90 = 12.33 km. D = sqrt((11.82)^2 + 12.33^2)= 17.1 km b. Tan A = Y/Xt = 12.33/10.82 = 1.13956 A = 48.7o
*February 9, 2014*

**Physics**

See previous post.
*February 9, 2014*

**Physics**

(Vb+Vr)2 = 26 km Eq1: 2Vb + 2Vr = 26 (Vb-Vr)6 = 26 km Eq2: 6Vb - 6Vr = 26 Add Eq1 and Eq2: 2Vb + 2Vr = 26 6Vb - 6Vr = 26 Multiply Eq1 by 3: 6Vb + 6Vr = 78 6Vb - 6Vr = 26 Sum: 12Vb = 104 Vb = 8.6667 km/h = Velocity of the boat. In Eq1, replace Vb with 8.6667: 2*8.6667 + 2Vr = ...
*February 9, 2014*

**Physics**

Vo = 0 V = 34.72 m/s. a = 5.6 m/s^2 A. V = Vo + a*t = 34.72 0 + 5.6t = 34.72 t = 6.2 s. Length = Vo*t + 0.5a*t^2 Length = 0 + 2.8*6.2^2 = 107.6 m. B. V^2 = Vo^2 + 2a*L = 34.72^2 = 1205.5 0 + 2a*75 = 1205.5 150a = 1205.5 a = 8.04 m/s^2. C. V = Vo + a*t = 34.72 m/s. 0 + 8.04t = ...
*February 8, 2014*

**Algebra 2**

(68-48sqrt2)^(1/4) = (68-67.882)^(1/4) = (0.118)^(1/4) = 0.5861
*February 8, 2014*

**Wave**

a. Period
*February 8, 2014*

**physics**

d. Reduced by a factor of 2: P = V^2/2R.
*February 7, 2014*

**physics**

1. False. 2. False. 3. False. 4. True. 5. True. 6. False. Note: The resistivity 0f both wires is the same, because they are made of the same material(copper).
*February 7, 2014*

**Physics**

d = Vo*t + (V^2-Vo^2)/2a d = 20*0.5 + (0-20^2)/-10 = 50 m. Note: Vo*t is the distance traveled during the reaction time. The 2nd Eq was derived from V^2 = Vo^2 + 2a*d. Solve for d.
*February 7, 2014*

**Physics**

Vc = Vo + a*(T-To)Vo Vc=3.5*10^-4 + 69*10^-6*(80-8)3.5*10^-4= 3.56*10^-4 m^3 = Vol. of can at 80oC. Vl = Vc + Vs = 3.56*10^-4 + 5.8*10^-6 = 3.618*10^-4 m^3=Vol. of liquid at 80oC. 3.618*10^-4 - 3.5*10^-4 = 1.18*10^-5 m^3 = The increase in vol. of the liquid. a*(T-To)Vo = 1.18*...
*February 7, 2014*

**Physics**

a. d = Vo*t + 0.5a*t^2 = 11.5 m. 0 + 0.5a*5.4^2 = 11.5 14.58a = 11.5 a = 0.789 m/s^2 m = F/a = 73/0.789 = 92.55 kg. b. V=Vo + a*t = 0 + 0.789*5.4=4.26 m/s. d = Vo*t = 4.26 m/s * 4.20s = 17.89 m.
*February 7, 2014*

**Physics**

m = 2.5 kg h = 1.7 m. Work=F*h = mg*h = 2.5*9.8*1.7=41.65 J. No work is done when can is stationary.
*February 7, 2014*

**physics**

X = 4.3 m/s. A = 44o V = X/cosA = 4.3/cos44 = 5.98 m/s = Total velocity.
*February 7, 2014*

**math**

9pages/15min = 0.6 Pages/min. 198pages * 1min./0.6pages = 330 min. reading. (330min/30min) * 5min = 55 min. on break. 330 + 55 = 385 min = 6 hours-25 min consumed. 8:00 AM + 6:25 = 14:25=2:25 PM.= Finish time.
*February 6, 2014*

**Science**

Ratio = 200/20 = 10/1. 10 Loops on Primary and 1 loop on Secondary. p
*February 6, 2014*

**physics**

Series: Ct = 4.98*8.98/(4.98+8.98) = 3.20 uF. Parallel: Ct = 4.98 + 8.98 = 13.96 uF.
*February 6, 2014*

**math**

2/9/(3/5) = X/1 X = 2/9 * 5/3 = 10/27 gal.
*February 6, 2014*

**Physics**

x^2 + 2x - 35 = 0 -35 = -1*35 = -5*7. Choose the pair of factors whose sum = 2, the coefficient of X. (x-5)(x+7) = 0 x-5 = 0 X = 5. x+7 = 0 X = -7. Solution Set: X = -7, and 5.
*February 6, 2014*

**Physics**

See Related Questions: Mon,9-5-11,11:19 PM.
*February 6, 2014*

**trig**

h = 80*sin40
*February 5, 2014*

**Physics**

See Related Questions: Fri, 9-9-11,11:20 AM.
*February 5, 2014*

**Physics**

What is the question?
*February 5, 2014*

**Physics**

a. a = (V^2-Vo^2)/2d a = (30.9^2-21^2)/382 = 1.35 m/s^2. b. 21 + 1.35t = 30.9 1.35t = 9.9 t = 7.33 s.
*February 5, 2014*

**physics**

a. h1 = 0.5a*t^2 = 7.5*21^2 = 3308 m V = a*t = 15 * 21 = 315 m/s. hmax = h1 + (V^2-Vo^2)/2g = 3308 + (0-315^2)/-19.6 = 8371 m.
*February 5, 2014*

**Physics**

Vo = 17.9m/s[39o] Xo = 17.9*cos39 = 13.91 m/s. Yo = 17.9*sin39 = 11.26 m/s. Y = Yo + g*Tr = 0 @ max ht. 11.26 - 9.8Tr = 0 9.8Tr = 11.26 Tr = 1.15 s. = Rise time. Tf = Tr = 1.15 s. = Fall time. Tr+Tf = 1.15 + 1.15 = 2.30 s. = Time to hit gnd.
*February 5, 2014*

**physics**

Incomplete.
*February 5, 2014*

**physics**

Fn = mg*cos45 = 15 * 9.8 * cos45=104 N. = Normal force = Force perpendicular to the incline. Fk = u*Fn = 0.2 * 104 = 20.8 N.
*February 5, 2014*

**physics**

See Related Questions: Mon,2-3-13,12:14 PM.
*February 5, 2014*

**science**

d = 0.5g*t^2 = 4.9*2^2 = 19.6 m.
*February 5, 2014*

**physics**

X = -3.0km Y = 2km Tan Ar = Y/X = 2/-3 = -0.66667 Ar = -33.69o = Reference angle. A = -33.69 + 180 = 146.3o, CCW. D=X/cos A = -3/cos146.3=3.61km[146.3o]
*February 3, 2014*

**physics**

X = -200 N. Y = -150 N. Fn = sqrt((-200)^2 + (-150)^2) = 250 N.
*February 3, 2014*

**Math**

X nickels. (18-X) dimes. 5x + 10(18-X) = 125 Cents. 5x + 180 - 10x = 125 5x = 180-125 = 55 X = 11 (18-X) = 18-11 = 7.
*February 3, 2014*

**Physics**

Vo = 15m/s[35o] Yo = 15*sin35 = 8.60 m/s.
*February 3, 2014*

**physics**

d = 5050m/s * 0.0944s = 476.7 m. 476.7/91.4 = 5.22 Football fields.
*February 3, 2014*

**phsyics**

a. a = (V-Vo)/t = (3.65-0)/3.46 = 1.055 m/s^2 = Acceleration of the jogger. d1 = 0.5a*t^2 = 0.5*1.055*3.46^2=6.31 m b. a = (40.1-24)/3.46 = 4.65 m/s^2 d2 = Vo*t + 0.5a*t^2 d2=24*3.46 + 0.5*4.65*3.46^2 = 110.9 m. c. d2-d1 = 110.9-6.31 = 104.6 m. farther
*February 3, 2014*

**Physics**

a=(V-Vo)/t = (6.20-12.2)/6.70=-0.896 m/s^2.
*February 3, 2014*

**math**

See previous post.
*February 3, 2014*

**mah**

P = Po + Po*r*t P = 8000 + 8000*0.09*18. Solve for P.
*February 3, 2014*

**physics**

See previous post.
*February 3, 2014*

**physics**

I need to know the angles.
*February 3, 2014*

**physics**

See previous post.
*February 3, 2014*

**Physics**

See previous post: Mon,2-3-14,5:42 PM.
*February 3, 2014*

**Physics 1**

Vox = 5710 m/s Voy = 7490 m/s a. Hor. acceleration: Vo*t + 0.5a*t^2 = 5.78*10^6 m. 5710*910 + 0.5a*910^2 = 5.78*10^6 5.196*10^6 + 4.14*10^5a = 5.78*10^6 4.14*10^5a = 5.84*10^5 a = 1.41 m/s^2. b. Ver. acceleration: 7490*910 + 0.5a*910^2 = 6.17*10^6 6.816*10^6 + 4.14*10^5a = 6....
*February 3, 2014*

**physics**

PE = F*h = mg*h = 98*10 = 980 Joules.
*February 3, 2014*

**Physics 1**

d = Vo*t + 0.5g*t^2 = 2 m. 0 + 4.9t^2 = 2 t^2 = 0.408 Tf = 0.639 s. = Fall time. D = 5.0m/s * 0.639s = 3.19 m.
*February 3, 2014*

**Physics**

Correction: 4 Ft = 1.21 m. Not 13.2 m. hmax=1.21+8.22*0.84 - 4.9*0.84^2=4.66 m Above gnd. 0.5g*t^2 = 4.66 m. 4.9t^2 = 4.66 t^2 = 0.95 Tf = 0.97 s. = Fall time. d = 3.36m/s * (0.84+0.97) = 6.1 m.
*February 3, 2014*

**Physics**

V = Vo + g*Tr = 0 at max ht. 8.22 - 9.8Tr = 0 9.8Tr = 8.22 Tr = 0.84 s. = Rise time or time to reach max ht. hmax = ho + Vo*t + 0.5g*t^2 hmax=13.2 + 8.22*0.84 - 4.9*0.84^2=16.7 m. Above gnd. 0.5g*t^2 = 16.7 m. 4.9t^2 = 16.7 t^2 = 3.40 Tf = 1.84 s. = Fall time. d = 3.36m/s * (0...
*February 3, 2014*

**physics**

50N[50o] X = 50*cos50 Y = 50*sin50
*February 3, 2014*

**Physical sciences**

F = 10 + 30 = 40 N.
*February 3, 2014*

**physics**

V^2 = Vo^2 + 2a*d V^2 = Vo^2 - 6*24 = 0 Vo^2 = 144 Vo = 7 m/s = Initial velocity of the block = Speed of the truck.
*February 3, 2014*

**PHYSICS**

Please check your problem for errors.
*February 3, 2014*

**science**

L min. = 10.26 cm W min. = 4.91 cm H min. = 1.52 cm V nom. = 10.27 * 4.92 * 1.53=77.308 cm^3 V min. = 10.26 * 4.91 * 1.52=76.728cm^3 Error = 77.308 - 76.728 = 0.5796 cm^3 NOTE: The fractional error has no units; they cancel. Fractional Error = 0.58cm^3/77.308cm^3 = 0.0075
*February 3, 2014*

**Physics**

V^2 = Vo^2 + 2g*d = 0 + 19.6*10.1 = 198 V = 14.1 m/s.
*February 2, 2014*

**Physics**

X = -7 m/s Y = -8 m/s tan Ar = -8/-7 = 1.14286 Ar = 48.8o = Reference angle. A = 48.8 + 180 = 228.8o, CCW V = -8/sin228.8 = 10.63 m/s[228.8o].
*February 2, 2014*

**physics**

31m/s[44o] X = 31*cos44 = Y = 31*sin44 =
*February 2, 2014*

**Physýcs**

V = Vo + a*t = 17 m/s. 3 + a*5 = 17 5a = 17-3 = 14 a = 2.8 m/s^2.
*February 2, 2014*

**Physýcs**

F = m*a a = acceleration. m=mass of the object being accelerated.
*February 2, 2014*

**physics..**

V^2 = Vo^2 + 2g*h = 0 at max. ht. 40^2 - 19.6*h = 0 19.6h = 1600 h = 81.6 m.
*February 1, 2014*

**physics**

45m[90o] + 60m[180o] + 75m[270o] + 50m[0o]. X = -60 + 50 = -10 m. Y = 45 -75 = -30 m. d^2 = (-10)^2 + (-30)^2 = 1000 d = 31.62 m. Speed=d/t = 31.62m/7.433min.=4.25 m/min
*February 1, 2014*

**physics**

Vo = 37m/s[30.6o] Xo = 37*cos30.6 = 31.8 m/s. Yo = 37*sin30.6 = 18.8 m/s. a. Yo*t + 0.5g*t^2 = 8.9 m. 18.8t - 4.9t^2 = 8.9 -4.9t^2 + 18.8t - 8.9 = 0 t = 3.28 s. and heading downward. (Used Quad. formula). b. Y = Yo - g*Tr = 0 at max ht. 18.8 - 9.8*Tr = 0 9.8Tr = 18.8 Tr = 1.92...
*February 1, 2014*

**physics**

Y^2 = Yo^2 + 2g*h Y^2 = 0 + 19.6*24.93 = 488.6 Y = 22.1 m/s. Xo = 22.1/3 = 7.37 m/s.=Initial velocity
*February 1, 2014*

**physics**

V = 26m/s[-37o] A. Xo = 26*cos(-37) = 20.76 m/s. B. Xo * T = 53 m. 20.76 * T = 53 T = 2.55 s. = Fall time. Y = 26*sin(-37) = -15.65 m/s. Y = Yo + g*T = -15.65 Yo + 9.8*2.55 = -15.65 Yo = -15.65 - 24.99 = -40.64 m/s.=Vert. component of initial velocity. tan A = Yo/Xo = -40.64/...
*January 31, 2014*

**physics**

Fn = -4100 + 8000 + 1200 = 5100 N., Due East. = Net force. a = Fn/m = 5100/6800 = 0.75 m/s^2, Due East.
*January 31, 2014*

**Math**

Correct.
*January 31, 2014*

**Physics**

V = Vo + a*t = 0 43 + a*0.28 = 0 0.28a = -43 a = -153.6 m/s^2
*January 31, 2014*

**science**

a. F = m * a. Newtons .
*January 31, 2014*

**physics**

Vo*t + 0.5g*t^2 = 100-50 = 50 0 + 4.9t^2 = 50 t^2 = 10.20 t = 3.19 s. V = Vo + g*t = 0 + 9.8*3.19 = 31.3 m/s = The velocity after the 1st 50 m drop = The initial velocity (Vo) for the 2nd 50 m drop. 31.3*t + 4.9t^2 = 50 4.9t^2 + 31.3t - 50 = 0 t = 1.32 s.(Use Quad. Formula).
*January 31, 2014*

**physics**

a=(V^2-Vo^2)/2d = (640^2-0)/2.4=170,667 m/s^2. V = Vo + a*t t=(V-Vo)/a = (640-0)/170,667=0.00375 s. = 3.75 ms.
*January 31, 2014*

**physics**

Dc = Dt 0.5a*t^2 = 9.5*t 1.1t^2 = 9.5t 1.1t^2 - 9.5t = 0 t = 8.64 s. (Use Quad. formula). D = 9.5 * 8.64 = 82.1 m. V = Vo + a*t = 0 + 2.2*8.64 = 19.0 m/s.
*January 31, 2014*

**science**

Ws = 0.08m^3 * 7840kg/m^3 * 9.8=6147 N. = Wt. of the steel in air. Ww=0.08m^3 * 1000kg/m^3 * 9.8 = 784 N. = Wt. of the water displaced. Ws in water = 6147 - 784 = 5363 N.
*January 30, 2014*

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