Thursday

October 23, 2014

October 23, 2014

Total # Posts: 9,329

**Physics**

Wt. = m*g = 69kg * 9.8N/kg = 676.2 N. F1 = 676.2*sin47 = 494.54 N. = Force parallel to the slope. F2 = 676.2*cos47 = 461.2 N. = Force perpendicular to the slope. 160-Fs = = m*a 160-u*F2 = m*0 = 0 u*461.2 = 160 u = 0.35 = Coefficient of static friction.
*September 16, 2013*

**Physics**

d1 = (9.5+0.9)t1 = 300 t1 = 300/(9.5+0.9) = d2 = (9.5-0.9)t2 = 300 t2 = 300/(9.5-0.9) = T = t1 + t2
*September 16, 2013*

**math**

d1 = 50mi/h * 1h + 50mi/h * 4h = 250 mi d2 = r*t = 250 mi r*4 = 250 r = 62.5 mi/h = Wife's speed.
*September 16, 2013*

**Physics**

a. D = -2 + 5i + 8 = 6 + 5i. D2 = 6^2 + 5^2 = 61 D = 7.81 Blocks. b. ta A = Y/X = 5/6 = 0.83333 A = 39.8o
*September 16, 2013*

**Physics**

V = Vo + a*t = o 9.6 + (-5.1)t = 0 -5.1t = -9.6 t = 1.88 s.
*September 16, 2013*

**Math**

6. 4 + 2(13-4)/3^2 = 4 + 2(9)/9 = 4 + 2 = 6.
*September 16, 2013*

**math**

a. TILE: L = 1/3 Ft. BOARD: L = 1/4 Yd. = 3/4 Ft. RATIO = (1/3)/(3/4) = 1/3 * 4/3 = 4/9. b. At = L*W = 1/3 * 1/3 = 1/9 Ft^2 Ab = 3/4 * 3/4 = 9/16 Ft^2. At/Ab = (1/9)/(9/16) = 1/9 * 16/9=16/81.
*September 16, 2013*

**Physics**

19t + 0.5a*t^2 = 49t + 49*0.6 19t + 0.5*6*t^2 = 49t + 29.4 3t^2 - 30t - 29.4 = 0 t = 10.9 s.
*September 16, 2013*

**physics**

a = (V^2-Vo^2)/2d a = (5.5^2-8^2)/14.8 = -2.28 m/s^2.
*September 16, 2013*

**Physics**

D = 1.2m/s * 10min *60s/min = 720 m.
*September 16, 2013*

**Math**

a. I = Po*r*t I=40,000*(0.13/365days)*160days = $2279.45 b. 40,000 + 2279.45 = $42,279.45 c. October 30.
*September 16, 2013*

**Algebra 2**

a. R = 0.00829s^2 = 5Lbs s^2 = 603.14 s = 24.6 mi/h. b. R = 0.008299*(2s)^2 = 4*0.00829s^2 The resistance increases by a factor of 4.
*September 15, 2013*

**Physics**

Vo = 9.4m/s[23o] Xo = 9.4*cos23 = 8.65 m/s. Yo = 9.4*sin23 = 3.67 m/s. c. X = Xo * t = 8.65t Y = Yo*t + 0.5g*t^2=3.67t+4.9t^2 e. h = 3.67t + 4.9t^2 h = Y = 3.67*6 + 4.9*6^2 = 198.4 m. Above gnd. f. 3.67t + 4.9t^2 = 10 m. 4.9t^2 + 3,67t _- 10 = 0 t = 1.10 s. (Use Quad. Formula).
*September 15, 2013*

**physics**

a. P = V^2/R = 24W. 120^2/R = 24 R = 600 Ohms. .
*September 15, 2013*

**Physics**

D=3.96m[90o] + 2.06m[45o] + 1.13m[240o] X=3.96*cos90+2.06*cos45+1.13*cos240 =0.892 m. Y = 3.96*sin90+2.06*sin45+1.13*sin240 = 4.44 m. tan A = Y/X = 4.44/0.892 = 4.98 A = 78.6o D = X/cos A = 0.892/cos78.6 = 4.51 m @ 78.6o N of E.
*September 15, 2013*

**algebra**

What does the "a" mean?
*September 15, 2013*

**Physics**

F = m*g = 30 N. 120*g = 30 g = 0.25 m/s^2
*September 15, 2013*

**Physics**

V^2 = Vo^2 + 2a.d a = (V^2-Vo^2)/2d a = (0-1.57^2)/2(6.25-1.83)=-0.279 m/s^2 Vo^2 = V^2-2a*d Vo^2= 0-2*(-0.279)*6.25 = 3.49 Vo = 1.87 m/s. Required.
*September 15, 2013*

**Physics**

Correction: hi/h2 = 4.9*(2t)^2/4.9*t^2 h1/h2 = 4.9*4*t^2/4.9*t^2 = 4.
*September 15, 2013*

**Physics**

h1/h2 = 4.9*(2t^2)/4.9*t^2 h1/h2 = 4.9*4*t^2/4.9t^2= 4.
*September 15, 2013*

**physics**

See Related Questions: Sat,9-14-13,1:23 PM.
*September 15, 2013*

**Physical Science**

d = V * t = 381*10^6 m. 11,000 * t = 381*10^6. Solve for t.
*September 15, 2013*

**physics**

c. ER2/(R1+R2)
*September 15, 2013*

**Mechanics**

20in *0.0254m/in = 0.5084 m. P = F * d/T = mg * d/T P = 200*9.8 * 0.5084/60 = 16.6 J/s = 16.6 Watts. P = (16.6/746) * 1 hp = 0.0223 hp.
*September 15, 2013*

**Algebra**

Test Average = (72+80+65+78+60)/5 = 71 Test Points = 2/3 * 71 = 47.33 47.33 + S/3 = 76 142 + S = 228 S = 86 = Final Exam score.
*September 14, 2013*

**Math Homework HELP!**

(k,-8), (-3.-5). (9,7), (12,5). m1 = m2 = (5-7)/(12-9) = -2/3. m1 = (-5-(-8))/(-3-k) = -2/3 (-5+8)/(-3-k) = -2/3 3/(-3-k) = -2/3 6+2k = 9 2k = 3 k = 3/2.
*September 14, 2013*

**physics**

a=(V-Vo)/t=(13.9-16.90)/3.5=-0.769m/s^2 V = Vo _ a*t V = 13.9- 0.769*2 = 12.4 m/s.
*September 14, 2013*

**physics**

d2 = d1 + 26 m. r2*t = r1*t + 26 6t = 4.2t + 26 1.8t = 26 t = 14.44 s. d = d1 = 4.2*14.44 = 60.67 m..
*September 14, 2013*

**Math**

(1,4),(3,5). Slope = (5-4)/(3-1) = 1/2 (1,4). Y = mx + b = 4 (1/2)*1 + b = 4 b = 7/2 Eq: Y = x/2 + 7/2.
*September 13, 2013*

**physics**

CORRECTION: Change 2.31 io 2.51 m. Vo^2 = 49.2 Vo = 7.01 m/s, Up ward. a = (-7.01-9.2)/12.6 = -1.29 m/s^2.
*September 12, 2013*

**physics**

V1^2 = Vo^2 + 2g*d V1^2 = 0 + 19.6*4.31 = 84.48 V1 = 9.2 m/s. V^2 = Vo^2 + 2g*d = 0 Vo^2 + (-19.6)*2.31 = 0 Vo^2 = 45.3 Vo = 6.73 m/s. a =(Vo-V1)/t a=(6.73-9.2)/12,6=-0.196m/s^2
*September 12, 2013*

**physics**

a. d = Vo*t + 0.5g*t^2 = 98 m. 0 + 4.9t^2 = 98 t^2 = 20 Tf = 4.47 = Fall time. V = Vo + g*t = 0 + 9.8*4.47 = 43.8 m/s.= Velocity @ 98 m. b. d = Vo*t + 0.5g*t^2 = 98 m. 43.8*t + 4.9t^2 = 98 4.9t^2 + 43.8t - 98 = 0 Tf = 1.85 s.
*September 12, 2013*

**physics**

Correction: d1=0.5g*t^2=4.9*1.14^2=6.37 m Head start. V = Vo + g*t = 0 + 9.8*1.14=11.17m/s. = Velocity after falling 6.37 m. h1 = Vo*t + 0.5g.t^2 =45.4-6.37 11.17t + 4.9t^2 = 39 4.9t^2 + 11.17t - 39 = 0 Tf = 1.9 s. = Fall time of both stones. h2 = Vo*t + 0.5g*t^2 = 45.4 1.9Vo...
*September 12, 2013*

**physics**

d1 = 0.5g*t^2 = 4.9*1.14^2 = 6.37 m. head start. h = 0.5g*t^2 = 45.4 m. 4.9t^2 = 45.4 t^2 = 9.27 Tf = 3.04 s. = Fall time of both stones d2 = d1+ 6.37 m. Vo*t + 0.5g*t^2 = 0.5g*t^2 + 6.37 Vo*t + 0.5g*t^2 -0.5g*t^2 = 6.37 Vo*t = 6.37 Vo*3.04 = 6.37 Vo = 2.09 m/s. NOTE: The 2 ...
*September 12, 2013*

**Physics**

h = Vo*t + 0.5g*t^2 = 9.14 m. -2.27t + 4.9*t^2 = 9.14 4.9t^2 - 2.27t = 9.14 4.9t^2 - 2.27t - 9.14 = 0 t = 1.617 s. (Use Quad. Formula) NOTE: The initial velocity is negative, because its' movement is in a direction opposite to the falling object.
*September 10, 2013*

**Pre-calc**

Incomplete.
*September 10, 2013*

**physics**

Vo = 20.1m/2[36.4o] Xo = 20.1*cos36.4o = 16.18 m/s. Yo = 20.1*sin36.4o = 11.93 m/s. Y = Yo + g*t = 0 @ max. ht. 11.93 + (-9.8)*t = 0 -9.8t = -11.93 Tr = 1.22 s. = Rise time. d = Xo * Tr = 16.18m/s * 1.22s = 19.7 m.
*September 10, 2013*

**physics**

D = 29km[153o] - 42km[143o] a. X = 29*cos153 - 42*cos143 = 7.70 km. Y = 29*sin153 - 42*sin143 = -12.1 km. D^=X^2 + Y^2 = 7.7^2 + (-12.1)^2=205.94 D = 14.35 km. = The dist. between the 2 teams. b. tan A = Y/X = -12.1/7.70 -1.57142857 A = -57.53o = 57.53o South of East.
*September 10, 2013*

**Physics**

V = Vo +a*t = 18.1 m/s. 0 + 3*t = 18.1 t1 = 6.03 s. t2 = 24.5 s. t3 = 5.7 s. T = t1 + t2 + t3 T = 6.03 + 24.5 + 5.7 = 36.23 s.
*September 10, 2013*

**Algebra**

81-9t^2-6t-6t-4 = 81-9t^2-12t-4 = -9t^2-12t+77 Use AC Method of factoring: A*C = -9*77 = -693 = 3*-231 = 21*-33. Use the part whose sum equals -12, the coefficient of B: 21, and -33. -9t^2+(21t-33t)+77 Divide the 4 terms into 2 factorable binomials: (-9t^2+21t) + (-33t+77) = -...
*September 9, 2013*

**Algebra I**

X = The number. -X = The opposite of the number. X = -X + 96 2x = 96 X = 48
*September 9, 2013*

**physics**

a. D^2 = X^2 + Y^2 D^2 = 5.8^2 + 38.8^2 = 1539.1 D = 39.2 m. b. tan A = Y/X = 38.8/5.8 = 6.68966 A = 81.5o, CCW. A = 90-81.5 = 8.5o East of North.
*September 9, 2013*

**physics**

d = r * t = 2.65m/s * 4.5s = 11.9 m = Distance ran by Henrietta in 4.5s. h = 0.5g*t^2 = 54.8 m. 4.9t^2 = 54.8 t^2 = 11.18 Tf = 3.34 s. = Fall time. d = Vo*Tf = 11.9 m. Vo*3.34 = 11.9 Vo = 3.56 m/s.
*September 9, 2013*

**Physics**

V^2 = Vo^2 + 2a*d Vo = 60,000m/3600s = 16.7 m/s d = (V^2-Vo^2)/2a d = (0-16.7^2)/-500 = 0.56 m.
*September 9, 2013*

**Physics**

a. 38 * t1 = 44 mi. Solve for t1. 89*t2 = 44. Solve for t2. T = t1-t2 b. d = 38(14/60) = 8.9 mi.
*September 9, 2013*

**geometry**

Scale Factor = 8/6 = 4/3.
*September 9, 2013*

**geometry**

Your answers are correct.
*September 9, 2013*

**algerbra**

-3b + ac = c-4 ac-c = -4+3b c(a-1)=-4+3b Divide both sides by (a-1): C = (-4+3b)/(a-1).
*September 9, 2013*

**algebra**

Please clarify your problem.
*September 9, 2013*

**math**

V1 = X mi/h d1 = X * 3 = 3x miles head start. V2 = (X+15)mi/h (X+15)*T = X*T + 3x (X+15)*6 = 6x + 3x 6x + 90 = 9x 3x = 90 X = 30 mi/h X+15 = 30+15 = 45 mi/h.
*September 9, 2013*

**physics**

85.4yds/300s * 70s. * 1m/1.1yd = 18.1 m.
*September 8, 2013*

**Math**

The freshman class at a major university contains 5840 students. This was a 27% decrease from the size of the freshman class the year before. What was the size of last year's freshman class?
*September 8, 2013*

**Physics**

1. d = r * t = 247 km 77 * t = 247 t = 2. 89 * t = 247
*September 8, 2013*

**geometry**

Day Cans 1-----7 2-----8 3-----10 4-----13 5-----17 6-----22 7-----28 Total-105.
*September 8, 2013*

**Physics**

Vo = 42.7m/s[33o] Xo = 42.7*cos33 = 35.81 m/s. Yo = 42.7*sin33 = 23.26 m/s. X = Xo * t = 41.8 m. 35.81t = 41.8 t = 1.17 s h = Yo*t - 4.9*t^2 h = 23.26*1.17 - 4.9*1.17^2 = 20.51 m.
*September 8, 2013*

**physics**

V^2 = Vo^2 + 2g*h h = (V^2-Vo^2)/2g hmax = (0-12.5^2)/-19.6 = 8 m. h = Vo*t + 0.5g*t^2 = 8/2 = 4 m 12.5*t + (-4.9)t^2 = 4 -4.9t^2 + 12.5t - 4 = 0 t = 0.375, and 2.18 s. (Use Quadratic Formula).
*September 8, 2013*

**PHYSICS**

P = V^2/R P = I^2 * R
*September 8, 2013*

**physics**

d = Vo*t + 0.5a*t^2 = 1900 m. 3t + 0.5*1.7*t^2 = 1900 0.85t^2 + 3t - 1900 = 0 t = 45s.(Use Quadratic Formula).
*September 8, 2013*

**physics**

d = 0.5a*t2^2 - 0.5a*t1^2 d = 0.5*0.5*4.4^2 - 0.5*0.5*1.2^2 d = 4.84 - 0.36 = 4.48 m.
*September 8, 2013*

**physics**

a. d1=42km/h*(40/60)h =28 km. t1 = 28/42+7/60 = 0.783 h d2 = 42km to school. t2 = d2/r = 42km/42km/h = 1 h. D = d1 + d2 = 28 + 42 = 70 km = Total driving distance. Speed=D/(t1+t2)=70/(0.783+1)=39.25 km/h
*September 8, 2013*

**Physics**

Ap/Ae = pi*(8.25r)^2/pi*r^2=68.1r^2/r^2= 68.1/1 Ap = 68.1*Ae. Ap = Area of the planet. Ae = Area of the earth.
*September 8, 2013*

**Physics**

See previous post: Sun,11:33 AM.
*September 8, 2013*

**Math**

Vo = 100Ft/s[60o] X = 4*100*cos60 = 200 Ft. Y = 4*100*sin60 = 346.4 Ft. a. (X,Y) = (200,346.4). b. Yo = Vo*sin O = 100^sin60 = 86.6 Ft/s Y = Yo + g*t = 0 @ max. Ht. 86.6 + (-32)t = 0 -32t = -86.6 Tr = 2.71 s. = Rise time. Tf = Tr = 2.71 s. = Fall time. T = Tr + Tf = 2.71 + 2....
*September 8, 2013*

**math**

Int. = 200,000-166,000 = $34,000 %Int = (34000/200000)*100% = 17%/13yrs. APR = 17%/13yrs. = 1.31%/yr.
*September 8, 2013*

**business math**

Gross Pay = 735 + 0.035(45,900-15,500)
*September 8, 2013*

**Physics**

CAR: V1 = 45mi/h * 1600m/mi * 1h/3600s=20 m/s a=8.5mi/h/s*1600m/mi*1h/3600s=3.78m/s^2 a*t = 20 m/s 3.78t = 20 t = 5.29 s. to reach max velocity. d1 = 0.5a*t^2 d1 = 0.5*3.78*5.29^2 = 52.9 m = Dist.@ which max. velocity is reached. BIKE: V2 = (15/45)*20 m/s = 6.67 m/s = max. ...
*September 7, 2013*

**college essay**

something beautiful
*September 7, 2013*

**algebra 2**

A=A1+A2=(150*65) + (150*225)=43,500 Ft^2 43,500Ft^2 * 1bag/5000Ft^2=8.7 or 9 Bags to cover both yards. (150*225)Ft^2 * 1bag/5000Ft^2 = 6.75 or 7 Bags to cover back yard.
*September 6, 2013*

**PHYSICS**

a. I=E/(Ri+Rb) = (12.6/(0.05+5.60)=2.23A V = I*Rb = 2.23 * 5.60 = 12.49 Volts. b. Vb=E-I*Ri=12.6 - (35+2.23)0.05=10.74 Volts.
*September 6, 2013*

**Physics**

D, and F.
*September 6, 2013*

**physics**

Vo = 120km/h = 120000m/3600s=33.33 m/s. d1 = Vo*t + 0.5a*t^2 d1 = 33.33*2 + (-3)*2^2 = 54.66 m Traveled by policeman in 2 s. d2 = Vo * t = 33.33 * 2 = 66.66 m/s. = Distance traveled by me in 2 s. d3 = Do - (d2-d1) d3=25 - (66.66-54.66)=13 m = Separation between me and the ...
*September 5, 2013*

**physics**

Vo = 74km/h = 74000m/3600s = 20.56 m/s. V = Vo + a*t t1 = (V-Vo)/a = (0-20.56)/-1.3 = 15.8 s. t2 = 3 min = 180 s. t3 = 20.56-0)/0.7 = 29.37 s T=t1 + t2 + t3=15.8 + 180 + 29.37=225.2s = 3.75 min. = Time lost.
*September 5, 2013*

**physics**

a. See previous post: 9-5-13,12:33 AM. b. 1784 Watts = 1784 J/s. Energy=1784J/s * 2.9h*3600s/h=18,625 J. c. (1.784*2.9)kWh*0.160/kWh = $0.83
*September 5, 2013*

**physics**

See 11:25 Am post.
*September 5, 2013*

**physics**

Vo = 10.8m/s[24.9o] Xo = 10,8*cos24.9 = 9.8 m/s Yo = 10.8*sin24.9 = 4.55 m/s a. Y = Yo + g*t Y = 4.55 + (-9.8)*0.310 = 1.51 m/s. V^2 = Xo^2 + Y^2 V^2 = 9.8^2 + 1.51^2 = 98.3 V = 9.9 m/s. b. = tan A = Y/Xo = 1.51/9.8 = 0.15408 A = 8.76o = The direction. c. Y = Yo + g*t Y = 4.55...
*September 5, 2013*

**physics**

Po = 2.20hp * 746w./hp = 1641.2 Watts Pi = Po/0.92 = 1641.2/0.92 = 1784 Watts Pi = 120*I = 1784 W. I = 1784/120 = 14.9A.
*September 5, 2013*

**Physics**

P=(Vrms)^2/R = (0.707*169)^2/506=28.2 Watts.
*September 4, 2013*

**physics**

V^2 = Vo^2 + 2a*d d = (V^2-Vo^2)/2a d = (7^2-0)/2.4
*September 4, 2013*

**physics**

d1 = 0.5a*t^2 = 0.6*5.3^2 = 16.85 m. V1 = a*t = 1.2m/s^2 * 5.3s = 6.36 m/s. a. V = Vo + a.t V = 6.36m/s - 2.3m/s^2*1.60s = 2.68 m/s. b. V^2 = V0^2 + 2a*d d2 = V^2-Vo^2)/2a d2 = (2.68^2-6.36^2)/-4.6 = 7.23 m. D = d1 + d2 = 16.85 + 7.23 = 24.1 m.
*September 4, 2013*

**Math**

(150,80), (50,30). m =(30-80)/(50-150) = -50/-100 = 0.5 Y = mx + b Y = 0.5*150 + b = 80 b = 80-75 = 5 Eq: Y = 0.5x + 5 Error: The student interchanged the slope and Y-intercept.
*September 4, 2013*

**jru-physics**

PE = mg*h = 50*9.8*2m = 980 Joules
*September 4, 2013*

**Math**

Another Approach: %Decrease = ((15%-10%)/15%)*100% = (5/15)*100% = 33.33%
*September 3, 2013*

**Math**

(10%/15%)*100%=(10/15)*100%= 66.67%. 66.67% - 100%=-33.33% or 33.33% Decrease
*September 3, 2013*

**Physics**

See your 5:59 pm post.
*September 3, 2013*

**Physics**

a. Fa = ((V-Va)/(V+Vb))*Fb Fa = ((343-0)/(343+68.6))*960 = 800 Hz b. Fc=((343+114.33)/(343-0))*480=640 Hz. c. Fb = ((343+68.6)/(343-114.33))*1550 Fb = 2790 Hz.
*September 3, 2013*

**Physics**

Fr = ((Vs+Vr)/(Vs-Vo))*Fo = 205 Hz ((336+0)/(336-Vo))*200 = 205 ((336)/(336-Vo))*200 = 205 67,200)/(336-Vo) = 205 205(336-Vo) = 67200 68,880-205Vo = 67200 -205Vo = 67200-68880 = -1680 Vo = 8.2 m/s. = Speed of the train.
*September 3, 2013*

**Physics**

CORRECTION: b. Fr = 638.33 Hz.
*September 3, 2013*

**Physics**

Vo=120km/h = 120,000m/3600s = 33.33 m/s. a. Fr = ((Vs+Vr)/(Vs-Vo))*Fo Fr=(345+0)/(345-33.33)*700Hz = 774.9 Hz b. Fr = ((345-0)/(345+33.33))*700=356 Hz = Freq. heard by the receiver(person).
*September 3, 2013*

**Physical Science**

Yes, the answer is C, because KE + PE = A constant.
*September 3, 2013*

**Physics**

a. d = 115-160 = -45 miles. The negative sign means the number decreased. b A decreasing marker number means you are traveling South or West. Therefore, John is 45 miles South or West of town.
*September 2, 2013*

**Math**

((-3)^2+(-3)*(-2))/4*(-2) = (9+6)/-8 = 15/-8 = -15/8 = -1 7/8.
*September 2, 2013*

**science**

d1 = 0.5*3.5*5.9^2 = 60.9 m V1=a*t = 3.5*5.9 = 20.65 m/s. = Velocity after 3.5 s. d2 = Vo*t + 0.5a*t^2 d2 = 20.65*5.98 + 2.98*5.98^2 = 176.8 m. V2 = a*t = 2.98*5.98 = 17.82 m/s. = Velocity @ 176.8 m. d3 = (V^2-Vo^2)/2g d3 = (0-17.82^2)/-19.6 = 16.2 m. = Free fall distance up. ...
*September 2, 2013*

**optical circuits**

Total loss = -5 + -5 + -1 = -11 db 10*Log(Po/Pi) = -11 db. 10*Log(Po/2) = -11 Log(Po/2) = -1.1 Po = 2*10^-1.1 = 0.159 mW.
*August 31, 2013*

**Physics**

d1 + d2 = 5.3+4.2 = 9.5 km = Distance between the runners. 8.8t + 7.9t = 9.5 16.7t = 9.5 t = 0.569 h. to cross paths. d1 = 5.3 - 8.8*0.569 = 0.293 km West of flagpole. d2 = 4.2 - 7.9*0.569 = -0.295 km West of Flagpole. So they meet at approximately 0.294 km west of flagpole.
*August 31, 2013*

**Algebra**

Steve, that was an excellent explanation.
*August 31, 2013*

**math**

a. V = Vo + g*t Tr = (V-Vo)/g = (0-15)/-32 = 0.469 s. To reach max. Ht. = Rise time. b. h = ho + Vo*t + 0.5g*t^2 h = 4 + 15*0.469 - 16*(0.469)^2=7.52Ft. Above Gnd. c. h = Vo*t + 0.5g*t^2 = 7.52 Ft. 0 + 16*T^2 = 7.52 T^2 = 0.469 Tf = 0.685 s. = Fall time. T = Tr + Tf = 0.469 + ...
*August 31, 2013*

**US History**

True or False Check. 1. During the Starving Time of 1609-10, some of the colonists turned to cannibalism as a means of survival. True 2. Early settlers of Jamestown spent many of their waking hours bowling. True 3. The location of Jamestown was selected partially out of fear ...
*August 28, 2013*

**phiycics**

t = 144km * 1h/48km = 3 h.
*August 28, 2013*

**Physic**

Correction: The speed of the car does not have to be reduced to zero, because the truck is moving forward. It must be reduced to 50 km/h(13.9m/s). a = (V^2-Vo^2)/2d a = (13.9^2-27.8^2)/400 = -1.45 m/s^2.
*August 28, 2013*

**Physic**

Car Speed=100km/h=100000m/3600s=27.8m/s Truck Speed =(50/100) * 27.8=13.9 m/s. V^2 = Vo^2 + 2a*d a = (V^2-Vo^2)/2d a = (0-(27.8-13.9)^2)/400 = -0.483 m/s^2 NOTE: The effective speed of the car is less than the actual speed, because the truck is moving forward.
*August 28, 2013*

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