Monday

April 27, 2015

April 27, 2015

Total # Posts: 10,494

**Pre-Calc/Trig...**

Eq1: Y = x^2 + 5x - 2 h = -B/2A = -5/2 k = (-5/2)^2 + 5*(-5/2) - 2 = 25/4 - 25/2 - 2 = 25/4 - 50/4 - 8/4 = -33/4 V(-5/2, -33/4) Y = (x-3)^2 + 5(x-3) - 2 Eq2: Y = x^2 - x - 8 h = -B/2A = 1/2 k = (1/2)^2 - 1/2 - 8 = -8 1/4 = -33/4 V(1/2, -33/4). D. Shifted 3 units to the right.
*October 15, 2014*

**Physics/science**

See previous post: Wed,10-15-14, 6:23 AM
*October 15, 2014*

**Science**

Xo = 70mi/h * 1600m/mi + 1h/3600s = 31.1 m/s. h = 350 - 82 = 268 m Above the ledge. h = 0.5g*t^2 = 268 m. 4.9t^2 = 268 t^2 = 54.69 Tf = 7.4 s. = Fall time. Dx = Xo*Tf = 31.1m/s * 7.4s = 230 m. = Hor. distance.
*October 15, 2014*

**Physics**

a. Vpa = Vpg + Va = -228 km/h Vpg - 50i = -228 Vpg = -228 + 50i Tan Ar = Y/X = 50/-228 = -0.21930 Ar = -12.4o = Reference angle. A = -12.4 + 180 = 167.63oC CCW = 12.4o N. of W. = Heading. b. Vpg = X/CosA = -228/Cos167.63 = 233.4 km/h. = Plane's speed relative to gnd.
*October 15, 2014*

**Physics**

Vo = 31m/s[52o] Yo = 31*sin52 = 34.4 m/s. h = Yo*t + 0.5g*t^2 = 10 m. 34.4*t - 4.9t^2 = 10 -4.9t^2 + 34.4t - 10 = 0 Use Quadratic formula and get: t1 = 0.304 s. t2 = 6.71 s.
*October 14, 2014*

**physics**

h = L*sin A = 7.06*sin29 = 3.42 m. V^2 = Vo^2 + 2g*h = 4.03^2 + 19.6*3.42 = 83.3 V = 9.13 m/s.
*October 14, 2014*

**PHYSICS**

Fr = 10N[45o] + 10N[330] X = 10*Cos45 + 10*Cos330 = 15.73 m/s. Y = 10*sin45 + 10*sin330 = 2.071 m/s. Tan A = Y/X = 2.071/15.73 = 0.13166 A = 7.50o. Fr = X/Cos A = 15.73/Cos7.50 = 15.9 N. @ 7.50o.
*October 14, 2014*

**Physics**

Xo = 60 m/s. Yo = 20 m/s. Vo = ? m/s. Tan A = Yo/Xo = 20/60 = 0.33333 A = 18.43o = Direction. Vo = Xo/Cos A = 60/Cos18.43 = 63.2 m/s @ 18.43o
*October 14, 2014*

**Pre-Calc/Trig...**

Axis = h = Xv = -B/2A = 4/4 = 1. k = Y = 2*1^2 - 4*1 + 2 = 0 V(h,k) = V(1, 0).
*October 14, 2014*

**Physics**

h = 0.5g*t^2 = 6.14 m. 4.9t^2 = 6.14 t^2 = 1.253 Tf = 1.12 s. = Fall time.
*October 14, 2014*

**physics**

Incomplete.
*October 13, 2014*

**Algebra 2 Answer Check**

1. |3x-4|/(-5) = 6 (3x-4)/(-5) = 6 3x-4 = -30 3x = -26 X = -26/3 Does not satisfy Eq. (-3x+4)/(-5) = 6 -3x+4 = -30 -3x = -34 X = -34/-3 = 34/3 Does not satisfy Eq.
*October 13, 2014*

**Algebra 2 Answer Check**

1. |3x-4}/( 2. |2x-5| = x + 3 2x-5 = x+3 X = 8. -2x+5 = x+3 -3x = -2 X = 2/3 3. |5x+15| > 20 5x+15 > 20 5x > 20-15 X > 1 -5x-15 = > 20 -5x > 20 + 15 X < -7 Or 1 < X < -7 4. |x-2|/4 => 5 (x-2)/4 => 5 x-2 => 20 X => 22. (-x+2)/4 => 5 -x...
*October 13, 2014*

**Business Math**

P = Po*r*t = 1000*(0.06/365)*192 = 31.56 = Penalty.
*October 13, 2014*

**Finance kennedy king**

See previous post: Sun, 10-12-14, 11:49 PM.
*October 13, 2014*

**physics**

a. ho + (V-Vo^2)/2g=13 + (0-(8^2)/-19.6 = 16.3 m. Above gnd. b. V^2 = Vo^2 + 2g*h Vo = 0 m/s, 2g = 19.6 m/s^2, h = 16.3 m. Calculate V. c. V = Vo + g*Tr = 0. Tr = -Vo/g = -8/-9.8 = 0.82 s=Rise time. h = 0.5g*t^2 = 16.3 m. 4.9t^2 = 16.3 t^2 = 3.33 Tf = 1.82 s. = Fall time. Tr+...
*October 13, 2014*

**8**

a. P = Po + Po*r*t = $9,500 2,000 + 2000*r*1 = 9,500 Solve for r. b. 9500 - 9500*r*t = 2000 9500 - 9500*r*1 = 2000 -9500r = 2000-9500 = -7500 r = 0.7895 = 78.95%
*October 12, 2014*

**5**

P = Po + Po*r*t = 5000 + 5000*0.08*4 = 5000 + 1600 = $6600 = Amt. paid. Int. = $1600
*October 12, 2014*

**F**

Growth rate = 5%/5yrs. = 1%/yr. A = Po + Po*r*t = 3 Million. 1.5 + 1.5*0.01*t = 3 1.5 + 0.015t = 3 0.015t = 1.5 t = 100 Years.
*October 12, 2014*

**physics**

h = ho + (V^2-(Vo^2))/2g h = 50 + (0-(20^2))/-19.6 = 70.4 m. Above gnd. V^2 = Vo^2 + 2g*h = 0 + 19.6*70.4 = 1380 V = 37.1 m/s.
*October 12, 2014*

**physics**

V^2 = Vo^2 + 2g*h Vo = 0 = Vertical component of initial velocity. g = 9.8 m/s^2 h = 0.70 m. Solve for V in m/s. Note: The mass of the ball does not matter.
*October 12, 2014*

**electrical**

Incomplete.
*October 12, 2014*

**physics**

30Rad/s * 1Rev/6.28Rad * 1s/10m = 0.478 Rev/m = 2.093 m/Rev = Circumference(C). pi*D = 2.093 3.14*D = 2.093 D = 0.67 m = Diameter.
*October 12, 2014*

**finance**

Sales (100 units) $200 Variable costs ($.80 ea) 80 Fixed Costs 20 EBIT 100 Interest Expense 30 EBT 70 Income tax 24 Net Income 46 Breakeven point in units
*October 12, 2014*

**Physics**

V = Vo + a*t a = (V-Vo)/t = (25-5)/40 = 0.5 m/s^2.
*October 12, 2014*

**engineering science N4**

Fp = mg*sin A = Force parallel to the incline. Fn = mg*Cos A = Normal = Force perpendicular to the incline. Fs = u*Fn = Force of static friction. Fp-Fs = 0 Fp = Fs mg*sin A = u*mg*Cos A Divide both sides by mg*Cos A: sin A/Cos A = u = 0.3 sin A/Cos A = Tan A Tan A = 0.30 A = ...
*October 12, 2014*

**trig**

Incomplete.
*October 12, 2014*

**physics**

V^2 = X^2 + Y^2 = 15.5^2 + 10.6^2 Solve for V.
*October 11, 2014*

**physics**

Vo = 78km/h = 78000m/3600s. = 21.7 m/s. V^2 = Vo^2 + 18g*d d = (V^2-Vo^2)/18g = 0-(21.7^2)/-176.4 = 2.67 m.
*October 11, 2014*

**physics**

Fr = 5N[70o] + 8[35] + 4[20] + 7[245] X=5*Cos70 + 8*Cos35 + 4*Cos20 + 7*Cos245 = 9.1 N. Y=5*sin70 + 8*sin35 + 4*sin20 +7*sin245 = 4.31 N. Tan A = Y/X = 4.31/9.1 = 0.47583 A = 25.4o CCW = Direction. Fr = X/Cos A = 9.1/Cos25.4 = 10.0 N. @ 25.4o = Resultant force.
*October 11, 2014*

**physics**

See previous post: Fri, 10-10-14, 10:51 PM.
*October 11, 2014*

**physics**

V = 150km/h[20o] Vx = 150*cos20 = 141 km/h Vy = 150*sin20 = 51 km/h. a. T = 2min. * 1h/60min = 2/60=1/30 h. Altitude = Vy*T = 51 * 1/30 = 1.71 km. b. Dx = Vx*T = 141 * 1/30 = 4.7 km. c. Total Distance = V*T = 150 * 1/30 = 5 km/h.
*October 11, 2014*

**physics**

V = 150km/h[20o] Vx = 150*cos20 = 141 km/h Vy = 150*sin20 = 51 km/h. a. T = 2min. * 1h/60min = 2/60=1/30 h. Altitude = Vy*T = 51 * 1/30 = 1.71 km. b. Dx = Vx*T = 141 * 1/30 = 4.7 km.
*October 11, 2014*

**Physics**

Vr = 5 - 12i + 8[135o] Vr = 5 - 12i + 8*Cos135 + i8*sin135 Vr = 5 - 5.66-12i + 5.66i=-0.66 - 6.34i (Q3). Tan Ar = Y/X = -6.34/-0.66 = 9.61083 Ar = 84o = Reference angle. A = 84 + 180 = 264o CCW = 84o S. of W. Vr = Y/sin A = -6.34/sin264 = 6.37 mi/h. = Resultant velocity. Note...
*October 10, 2014*

**physics**

h = ho + -(Vo^2)/2g h = 17.1 + 6.93^2/19.6 = 19.6 m. Above gnd. a. V^2 = Vo^2 + 2g*h = 0 + 19.6*19.6 = 382.2 V = 19.6 m/s. b. Tr = -Vo/g = -6.93/-9.8 = 0.707 s. = Rise time. h = 0.5g*t^2 = 19.6 m. 4.9t^2 = 19.6 t^2 = 4 Tf = 2 s. = Fall time. Tr+Tf = 0.707 + 2 = 2.707 s = Time ...
*October 10, 2014*

**equation**

3.3a = 5.5b Divide both sides by b: 3.3a/b = 5.5 a/b = 1.67 a:b = 1.67
*October 10, 2014*

**Science Physics**

F = m*g = 175 * 9.8 = 1715 N. = Force of the boiler. Work = F*d = 1715 * 15 = 25,725 J. 4.5kw = 4500 W. = 4500J/s. t = 25,725J. * 1s/4500J = 5.72 s.
*October 10, 2014*

**math**

70t + 32t = 155 km 102t = 155 t = 1.52 h.
*October 10, 2014*

**Math Physics**

Correct.
*October 10, 2014*

**Physics**

Yes.
*October 10, 2014*

**Physics**

See current post: Sat, 10-11-14, 11:51AM
*October 10, 2014*

**physics**

a. D = Vo*t + 0.5g*t^2 D = 15*1 - 4.9*1^2 = 10.1 m. V = Vo + g*t = 15 - 9.8*1 = 5.2 m/s Tr = -Vo/g = -15/-9.8 = 1.53 s. = Rise time. h max = -(Vo^2)/2g = -(15^2)/-19.6 = 11.48 m. Above launching point. Tf = 4 - 1.53 = 2.47 s. D = 4.9*Tf^2 = 4.9*2.47^2 = 29.9 m After 4 s. V^2...
*October 10, 2014*

**physics**

F1 = 100*Cos60 = 50 N. F2 = 100*sin60 = 87 N.
*October 10, 2014*

**Math**

C is correct.
*October 10, 2014*

**Physics**

Mass = 180Lb * 0.454kg/Lb = 81.72 kg. m*g = 81.72 * 9.8 = 801 N = Wt. of crate = Normal(Fn). Fs = u*Fn = 0.56 * 801 = 449 N. = Force of static friction. = Hor. component of applied force(Fx). Fk = u*Fn = 0.350 * 801 = 280 N. = Force of kinetic friction. a = (Fx-Fk)/m = (449-...
*October 9, 2014*

**physics**

L = 523 m. V = 4.6 km/s. = 4600 m/s. a. L = V*(1/F) = V/F = 523 m 4600/F = 523 523F = 4600 F = 8.8 c/s = 8.8 Hz. b. L = V/F = 7500/8.8 = 852.3 m.
*October 9, 2014*

**physics**

See previous post: Wed, 10-8-14, 7:55PM
*October 8, 2014*

**physics**

I = E/5R = 9.74 Amps E = 5R * 9.74 = 48.7R I = E/6R = 48.7R/6R = 8.12 Amps.
*October 8, 2014*

**physics**

D = 200yds[200o] + 300yds[130o] + 400yds [80o]. X = 200*Cos200 + 300*cos130o + 400*Cos80 = -311.3 Yds. Y = 200*sin200 + 300*sin130 + 400*sin80 = 555.3 Yds. Tan Ar = Y/X = 555.3/-311.3 = -1.78391 Ar = -60.73o = Reference angle. A = -60.73 + 180 = 119o CCW = 29o W. of N. = ...
*October 8, 2014*

**math**

X Bananas Ann ate X/3 Re = X - X/3 = 2X/3. Bob ate 1/3 * 2X/3 = 2X/9 Re = 2X/3 - 2X/9 = 4X/9. Carl ate 1/3 * 4X/9 = 4X/27 Re = 4X/9 - 4X/27 = 8X/27 Don ate 1/4 * 8X/27 = 8X/108 = 2X/27 Re = 8X/27 - 2X/27 = 6X/27 = 2X/9. 2X/9 = 12 2X = 108 X = 54 Bananas.
*October 8, 2014*

**Physics 203**

Let: m1 = 6 kg m2 = 1 kg KE1 = 0.5m1*V1^2 = 04 * (0.5m2*V2^2) 0.5*6*V1^2 = 0.4 * 0.5*1*V2^2 3V1^2 = 0.2V2^2 3V1^2/V2^2 = 0.2 V1^2/V2^2 = 0.2/3 V1/V2 = 0.258
*October 8, 2014*

**Engineering**

a. Vpg + Vw = 600km/h[-90o] = -600i Vpg + 125 = -600i Vpg = -125 - 600i Tan Ar = Y/X = -600/-125 = 4.80 Ar = 78.23o = Reference angle. A = 78.23 + 180 = 258.23o CCW = 11.8o W. of S. = Heading. b. Vpg = Y/sin A = -600/sin258.23 = 613 613 km/h. = Velocity of plane relative to gnd.
*October 8, 2014*

**Math**

Tan40 = h/L = h/24 h = 24*Tan40 = 20.14 cm V = L*W*h = 24 * 7 * 20.14 = 3383 cm^3.
*October 8, 2014*

**physics**

The distance is horizontal, but no hor. force is applied; therefore, no work is done. W = Fx*d = 0 * 50 = 0
*October 8, 2014*

**physics**

Work = Fx*d = 30*CosA * 50 = 1100 J. 1500CosA = 1100 CosA = 0.73333 A = 42.8o
*October 8, 2014*

**Math**

a. V = Vo + g*t = 320 - 32*5 = 160 Ft/s.
*October 7, 2014*

**Math**

a. V = Vo + g*t = 0 Vo - 32*2 = 0 Vo = 64 Ft/s. b. Tf1 = Tr = 2 s. = Fall time from hmax to top of cliff. Tf2 = 7-Tr-Tf1 = 7 - 2 - 2 = 3 s. = Fall time from top of cliff to gnd. h = Vo*Tf2 + 0.5g*Tf2^2 h = 64*3 + 16*3^2 = 336 Ft. = Ht. of cliff. c. What is time t? d. h max = ...
*October 7, 2014*

**Math**

When the ball returns to the roof, its velocity will be 80 Ft/s. V^2 = Vo^2 + 2g*h = 80^2 + 64*48 = 9472 V = 97.32 Ft/s.
*October 7, 2014*

**Physics**

X = -40 m/s. Y = 5m/s^2 * 6s. = 30 m/s. A. Tan Ar = Y/X = 30/-40 = -0.750 Ar = -36.9o = Reference angle. A = -36.9 + 180 = 143.1o CCW = 53.1o W. of N. V = X/Cos A = -40/Cos143.1 = 50 m/s @ 143.1o CCW or 53.1o W. of N.
*October 7, 2014*

**physics**

a = 22,000 - 800*12 =
*October 7, 2014*

**Math**

Eleanor and Max used two rectangular wooden boards to make a set for the school play. 1 board was 6 ft long, the other was 5 1/2 ft long. The 2 boards had equal widths. The total area of the set was 60 3/8 square ft. What was the width?
*October 7, 2014*

**Physics**

What are the units for #30?
*October 7, 2014*

**math**

Perimeter = 4 * 6m = 24.0 m. = Amt. of fencing needed.
*October 7, 2014*

**physics**

m*g = 1.75 * 9.8 = 17.15 N. = Wt. of block. Fn = 17.15 + 53.5*sin32 = 45.5 N. = Normal = Force perpendicular to the floor. Fk = u*Fn = 0.343 * 45.5 = 15.61 N. = Force of kinetic friction. a = (Fx-Fk)/m = (53.5*Cos32-15.61)/1.75 = 17 m/s^2.
*October 7, 2014*

**physics**

A. m1*V-m2*V2 = 10,000*5-1,500*14=29,000 m1*V+m2*V = 29,000 10,000*V + 1500*V = 29000 11,500V = 29000 V = 2.52 m/s. In the direction of the truck. B. KE1 = 0.5m1*V1^2 = 0.5*10,000*5^2 = 125,000 J. = 125 kJ. Before collision. KE1 = 0.5*m1*V^2 = 0.5*10,000*2.52^2 = 31,752 J. = ...
*October 6, 2014*

**physics**

d = 0.5m/s * 195s = 97.5 m. Head-start. d2 = d1 + 195 m. 0.5*a*t^2 = r*t + 195 0.5*3*t^2 = 0.5*t + 195 1.5t^2 - 0.5t - 195 = 0 Use Quadratic formula. t = 11.6 s.
*October 6, 2014*

**physical science**

Conclusion: m1*V1 = m2*V2. 2*V1 = 1*V2 V2 = 2V1
*October 6, 2014*

**Physics**

X = 25 m/s. Y = 200 m/s. Tan A = Y/X = 200/25 = 8.00 A = 82.9o Vp = Y/sin A = 200/sin82.9 = 202 m/s. = Velocity of the plane. d = 202m/s[82.9] * 3600s = 728,147 m. @ 82.9o
*October 6, 2014*

**Physics**

a. D=1.10km - 0.624i km + 1.09km[161.8o] X = 1.10 + 1.09*cos161.8 = 0.0645 km. = 64.5 m. Y = - 0.645 + 1.09*sin161.8 = -0.305 km. = -305 m. Tan A = Y/X = -305/64.5 = -4.72868 A = -78.06o CW = 78.06o S. of E. D = Y/Sin(-78.06) = -305/Sin(-78.06) = 312 m.[-78.06]. b. V = D/t = ...
*October 5, 2014*

**physics**

Xo = 3.76 m/s. 0.5g*t^2 = 6 m. 4.9t^2 = 6 t^2 = 1.22 Tf = 1.11 s.= Fall time. Dx = Xo*Tf = 3.76m/s * 1.11s. = 4.16 m.
*October 5, 2014*

**Algebra 1 Check**

2. 2*Sqrt(43x) = 14*Sqrt(43) Square both sides: 4*43x = 196*43 4x = 196 X = 49
*October 5, 2014*

**Physics Resistance**

R/4 Ohms/wire. Rb = 1/4 * R/4 = R/16 or 1/16R = Resistance of the bundle.
*October 5, 2014*

**physics**

EFF. = (Wo/Wi)*100% = (91/224)*100% = 40.6 %.
*October 4, 2014*

**physics**

Work = The change in kinetic energy. Work = KE2-KE1 = 0.5*m*V2^2-0.5*m*V1^2 = 0.5*550*3.2^2-0.5*550*1.5^2 = 2197 J.
*October 4, 2014*

**Physics**

Y^2 = Yo^2 + 2g*h = 0 Yo^2 - 19.6*1.1 = 0 Yo^2 = 21.56 Yo = 4.64 m/s. Vo = Yo/Sin A = 4.64/sin45 = 6.57 m/s @ 45o.
*October 4, 2014*

**Science**

a = F/m F = 420 N. m = 0.15 kg a in m/s^2
*October 4, 2014*

**Intro to Physical Science**

V = Vo = 6 m/s.
*October 4, 2014*

**Physics**

R1 = 61.5 Ohms. R2 = 146.6 Ohms. R3 = 16 Ohms. V = 13.6 Volts. a. Rt = R1*R2/(R1+R2) + R3 Rt = (61.5*146.6)/(61.5+146.6) + 16 = 59.32 Ohms. = Total resistance. I = V/Rt = 13.6/59.32 = 0.229 Amps. b. V2 = I*(R1*R2)/(R1+R2)=0.229 * 43.32 = 9.92 Volts. = Voltage across R2. P2 = ...
*October 3, 2014*

**Physics**

m*g = 36 * 9.8 = 352.8 N. KE+PE = 460 J. 185 + PE = 460 PE = 275 J. = mg*h mg*h = 275 352.8h = 275 h = 0.779 m.
*October 3, 2014*

**physics**

Fap = 340 N.[20o] Above the hor. Mass = 54 kg. u(k) = 0.4 m*g = 54 * 9.8 = 529.2 N. = Wt. of object. Fn = m*g+Fap*sin20=529.2 N. + 340*Sin20 = 645.5 N. = Normal = Force perpendicular to the surface. Fk = u*Fn = 0.4 * 645.5 = 258.2 N. a = (Fap*Cos20-Fk)/m = (319.5-258.2)/54= 1....
*October 3, 2014*

**physics help**

Based on the information given, 245 N. is too low. Please check all of the given INFO for accuracy.
*October 3, 2014*

**physics**

a. d = 0.5g*t^2 = 0.095 m. 4.9t^2 = 0.095 t^2 = 0.0194 Tf = 0.139 s. = Fall time or time in air. b. Dx = Xo*Tf = 20.6 Xo * 0.139 = 20.6 Xo = 148 m/s.
*October 3, 2014*

**AC DC Circuit fundamentals**

V = 12 Volts. R1 = 10k Ohms. R2 = 5k Ohms. I = V/(R1+R2) = 12/(10k+5k) = 0.8 mA. V1 = I*R1 = 0.8mA * 10k = 8 Volts. V2 = I*R2 = 0.8mA * 5k = 4 Volts.
*October 2, 2014*

**physics**

a = F/m = 7950/0.040 = 198,750 m/s^2. V^2 = Vo^2 + 2a*d Vo^2 = V^2 - 2a*d = 0 + 2*198750*0.011 = 4373 Vo = 66.1 m/s.
*October 2, 2014*

**Physics**

a. m*g = 0.6 * 9.8 = 5.88 N. = Wt. of the ball. Work = F*d = 5.88 * (6.1-1.2) = 28.8 J. b. PE = mg*h = 5.88 * 6.1 = 35.87 J. c. PE = mg*h = 5.88 * 1.2 = 7.06 J. d. (PEo-PEf) = 35.87 - 7.06 = 28.81 J. = The work done on the ball.
*October 2, 2014*

**Physics**

a. Box 1 V^2 = Vo^2+2g*h = 0 + 19.6*(4.8-1.2) = 70.56 V = 8.4 m/s. b. Box 2. V^2 = Vo^2+2g*h = 0 + 19.6*(4.8-1.2) = 70.56 V = 8.4 m/s. c. KE2/KE1 = 0.5m2*V^2/0.5m1*V^2 = 24*70.56/4.5*70.56 = 5.33 = m2/m1.
*October 2, 2014*

**physics**

h max = (V^2-Vo^2)/2g = (0-(20)^2/-19.6 = 20.41 m. V^2 = Vo^2 + 2g*h = 0 + 19.6*(20.41-5) = 302. V = 17.4 m/s
*October 1, 2014*

**Physics**

X = 1 km. Y = 1 km. Tan A = Y/X = 1 A = 45o D = X/Cos A = 1/Cos45 = 1.414 km[45o]
*October 1, 2014*

**Physics**

Fth = 1.250*10^7 N. = Force of thrust. Ra = 4.50*10^6 N. = Air resistance. m = 5.00*10^5 kg = Mass of the rocket. a = (Fth-Ra)/m
*October 1, 2014*

**physics**

Vo = 80km/h = 80000m/3600s = 22.22 m/s. V = 55km/h = 55000m/3600s = 15.28 m/s. Work = KE1-KE2 = o.5m*Vo^2-0.5m*V^2 = 935*22.22^2 - 935*15.28^2 = 461,636 - 218,302 = 243,334 J.
*October 1, 2014*

**Physics**

Xo = 39.0 m/s. h = 0.5g*t^2 = 16 m. 4.9t^2 = 16 t^2 = 3.27 Tf = 1.81 s. = Fall time. Dx = Xo*Tf = 39m/s * 1.81s = 70.5 m.
*October 1, 2014*

**physics**

m*g = 220kg * 9.8N/kg = 2156 n. = Wt. of the log. Fp = 2156*sin26.6 = 965.4 N. = Force parallel to the incline. Fn = 2156*Cos26.6 = 1928 N. = Normal. = Force perpendicular to the incline. Fk = u*Fn = 0.863 * 1928 = 1664 N. = Force of kinetic friction. Fex-Fp-Fk = m*a Fex-965.4...
*October 1, 2014*

**physics**

a1=(V-Vo)/t = (0.4-0.1)/5.5=0.055 m/s^2 a2 = (V-Vo)/t = (1.05-0)/15 = 0.07 m/s^2 F2=(a2/a1)*5N. = (0.07/0.055)*5N. = 6.36 N.
*September 30, 2014*

**physics**

What is a slug?
*September 30, 2014*

**physics**

a. Fn = (m1+m2)*g = (10+20)*9.8 = 294 N. b. Fn = m1*g = 10 * 9.8 = 98 N.
*September 30, 2014*

**Physics**

kg or kilograms.
*September 30, 2014*

**Physics**

m*g = 12kg * 9.8N/kg = 117.6 N. = Wt. of box. Fp = 117.6*Sin30 = 58.8 N. = Force parallel to the incline. Fn = 117.6*Cos30 = 101.8 N. = Normal = Force perpendicular to the incline. Fk = u*Fn = 0.29 * 101.8 = 29.53 N. = Force of kinetic friction. Fex-Fp-Fk = m*a Fex-58.8-29.53...
*September 30, 2014*

**physics**

A. h = 0.5g*t^2 = 0.7 m. 4.9t^2 = 0.7 t^2 = 0.1429 Tf = 0.378 s. = Fall time. B. Dx = Xo*Tf = 1 m Xo * 0.378 = 1 Xo = 1/0.378 = 2.65 m/s. = Initial hor. velocity.
*September 29, 2014*

**physics**

Tan5 = Y1/X = Y1/1.8 Y1 = 1.8*Tan5 = 0.157 km = Ht. of hill. Tan6.8 = (Y1+Y2)/X = (Y1+Y2)/1.8 Y1+Y2 = 1.8*Tan6.8 = 0.215 km Y2 = 0.215-Y1 = 0.215-0.157 = 0.058 km. = 58 m. = Ht. of tower.
*September 29, 2014*

**physics**

KE+PE = 520 J. 250 + PE = 520 PE = 520-250 = 270 J. mg*h = 270 h = 270/m*g = 270/(42*9.8) = 0.656 m.
*September 29, 2014*