Tuesday

July 22, 2014

July 22, 2014

Total # Posts: 8,893

**Physics**

Fg=m*g = (66.2kg+5.3kg)*9.8N/kg=700.7 N. = Force of gravity = Combined wt. of person and sled. Ff = u*Fg = 0.12 * 700.7 = 84.1 N. = Force of friction. Fx-Ff = m*a Fx-84.1 = m*0 = 0 Fx = 84.1 N.

**math**

Y = 1.5x X = The # of bottles of water purchased. Y = Total cost in dollars. (x,y) (1,1.5) (2,3) (3,4.5) (4,6).

**Physics**

r = 225km/h = 225000/3600s = 62.5 m/s. = Average speed for full length. r1 = 205km/h = 205000m/3600s = 56.94 m/s.= Average speed for 1st half(700m). (r1+r2)/2 = r (56.94+r2)/2 = 62.5 m/s. 56.94 + r2 = 125 r2 = 125-56.94 = 68.06 m/s = Average speed for 2nd half of race.

**Physics**

Johnny: T1 = 4 min,57s = 240+57 = 297 s. Martha: T2 = 4 min,38s = 240+38 = 278 s. r2 = 400m/278s. = 1.439 m/s. d = r2*(T1-T2) = 1.439(297-278)=27.3 m.

**algebra**

Sum = 8 = 7+1 = 6+2 = 5+3 = 4+4 Select 5, and 3: Original #: 53. Reversed: 35. Difference = 53-35 = 18.

**algebra**

X Nickels. (16-X) Qtrs. 5x + 25(16-X) = 220 Cents. Solve for X.

**Algebra 2**

S1+S2+S3 = 5 Ft. S1 = S2 = S3 S1+S1+S1 = 5 3S1 = 5 S1 = 5/3 Ft. = 20 In. = S2 = S3. (s/2)^2 + h^2 = S^2 (20/2)^2 + h^2 = 20^2. Solve for h.

**Algebra 2**

N Large packages. (12-N) Small packages. Cost = 7n + 4.5(12-n) Cost = 7n + 54-4.5n = 2.5n + 54.

**physics**

h = 0.5g*t^2 = 1 m. 4.9t^2 = 1 t^2 = 0.204 t = o.452 s. = Fall time. d = Vo*t = 1.32 m. Vo*0.452 = 1.32 Vo = 2.92 m/s.

**physics**

V = 42.3mi/40min * 1600m/mi * 1min/60s = 28.2 m/s. V = 42.3mi/40min * 1.6km/mi * 60min/h = 101.5 km/h.

**physics**

V = 22.7[32o] Momentum=m*V = 537 * 22.7=12,190 kg-m/s.

**Physics**

Wt. = 1.8 Tonne. Vo = 3 m/s. d = 45 m. Fk = 80 N. Mass = 1.8 * 1000kg = 1800 kg. Fg = m*g = 1800 * 9.8 = 17,640 N. KE + PE = mg*h-Fk*d KE + PE = mg*h-80*45 0.5m*Vo^2 + 0 = mg*h-3600 900*9 + 3600 = 17640h 17,640h = 11,700 h = 0.6633 m. sinA = h/d = 0.6633/45 = 0.01474 A = 0.84o...

**physics**

99. If you drop an object: Vo = 0 = Initial velocity. a = g = 10 m/s^2. If you throw it down: Vo > 0 a = g = 10 m/s^2. So in both cases, the acceleration remains constant at 10 m/s^2.

**Algebra**

6x-72 = 0 6x = 72 X = 12

**Math**

y-6=> 12 Y =>12+6 Y => 18 This is the Eq of a hor. line in which Y => 18 for all values of X.

**calculus**

V = Vo + a*t = 2000 + (-3000)*0.03 = 1910 m/s.

**physics**

Momentum = m*V = 5 * 3 = 15 kg-rad/s.

**Algebra 1**

1.(15-5x)/(x^2-9x+18). -5(x-3)/(x-3)(x-6) = -5/(x-6). 2. T=T1*T2/(T1+T2) T = 40*60/(40+60)=24 min. 3. A*C = 2*(-20)-40 = 4*(-10) = 5*(-8) B = The sum of the pair of factors that are divisible by 2: B = 2+(-20) = -18 B = 4+(-10) = -6 Eq1: 2x^2-18x-20 = 0 Divide by 2: x^2-9x-10...

**Physics**

a. V=110km/h = 110000m/3600s.=30.56 m/s V^2 = Vo^2 + 2g*h h = (V^2-Vo^2)/2g = (0-(30.56)^2/-19.6 = 47.6 m.

**Physics**

d = (24.5N./2500N.)*1M = = 0.0098 M.

**math - APR**

a. (42,650-5100)/60 = %625.83/mo. b. P = (Po*r*t)/(1-(1+r)^-t) Po = 42,650-5100 = 37550 r = (2.5%/12)/100% = 0.00208 t = 60 Months. Plug the above values into the given Eq and get: P = $39,984.81 39984.81/60mo = $666.41/mo. = Monthly payments. c. I = (39984.81-37550)/5yrs = $4...

**math**

Use synthetic(long-hand) division: (2x^3-5x^2+x+2)/(x-2) = 2x^2-x-1 a = 2, and b = -1.

**physics**

Green = 0.99*200 = 198 White = 0.01*200 = 2 X green marbles removed. (200-x) Marbles remaining. 0.98(200-x) + 2 = 200-x 196-.98x + 2 = 200-x 0.02x = 200-198 = 2 X = 100 Green marbles removed. 198-100 = 98 Green marbles remaining. 200-100 = 100 total Marbles remaining. Check: G...

**Physics**

a. Fb = m*g = 76 * 9.8 = 744.8 N. = Force of barbell. Po = 20 * 744.8 * 2.6/90s = 430.3 J/s = 430.3 W. b. hp = 430.3/746 = 0.577

**physics**

See previous post.

**physics**

V^2 = Vo^2 + 2g*h = 0 + 20*10 = 200 V = 14.14 m/s. 0.5g*t^2 = 10 m. 5t^2 = 10 t^2 = 2 t = 1.414 s.

**physics**

Vo = 136km/h = 136,000m/3600s=37.78 m/s V^2 = Vo^2 + 2a*d d = (V^2-Vo^2)/2a d = (0-(37.78^2))/-500 = 2.85 m.

**Math Personal Finance**

See previous post.

**Math Personal Finance**

P = Po(1+r)^n = 2000 r = (6%/12)/100% = 0.005 n = 12comp/yr. * 5yrs. = 60 compounding periods. Po(1.005)^60 = 2000 Po = 2000/(1.005^60) = $1482.74=Initial deposit or present value.

**Math Personal Finance**

P=Po(1+r)^n. Calculate int. for 1 year. r = (5%/12)/100% = 0.00417 = Monthly % rate expressed as a decimal. n = 12comp./yr. * 1yr. = 12 Compounding periods. P = 7000(1.00417)^12 = $7358.13 I = P-Po = 7358.13 - 7000 = $358.13 APY = (I/Po)*100% = (358.13/7000)*100% = 5.116%

**Engg Mechanics**

Block A: 200*sin30 = 100 N. = Force parallel to the plane. Fn = 200*cos30 = 173.2 N. = Normal force Block B: 100*sin30 = 50 N. = Force parallel to the plane. Fn = 100*cos30 = 86.6 N. = Normal force. P = Wa+Wb = 200 + 100 = 300 N.

**electronics**

Given: i = 6 mA. t = ? 1. Locate 6 mA on the y-axis. 2. Draw a hor. line from 6 mA to the curve. 3. Draw a ver. line from the intersection of the hor. line and curve to the x-axis. 4.Read the time, t , at the intersection of the ver. line and x-axis. Note: When t is given, dra...

**physics**

a. The force of static friction decreases. b. The force of friction increases. The max. possible value of the force of friction increases. The max. angle at which block will slide decreases.

**Physics**

Upward: a = g = -9.8 m/s^2(slowing down) Highest point: a = g = -9.8 m/s^2. Downward: a = g = 9.8 m/s^2. The data shows that the acceleration due to gravity is present during the entire flight of the object. If g goes to zero, the object would not come down.

**Physics**

a. V^2 = Vo^2 + 2g*d V^2 = 4.9^2 + 19.6*21 = 435.61 V = 20.87 m/s. b. V = Vo + g*t t = (V-Vo)/g = (20.87-4.9)/9.8 = 1.63 s.

**physics**

a. False.

**Science**

2. Slower object: KE = 0.5m*V^2. Faster object: KE = 0.5m*(2V)^2 = 0.5m*4*V^2. 0.5m*4V^2/0.5m*V^2 = 4 Times. 3. KE = 0.5m*V^2 9. MA = 20/100 10. W = F*d. d = 0.

**Physics**

a. Vo=36mi/h * 1600m/mi * 1h/3600s=16 m/s. V^2 = Vo^2 + 2a*d d = (V^2-Vo^2)/2a d = (0-256)/-10 = 25.6 m. b. d = 0-1024)/-10 = 102.4 m.

**MULTIPLY. WRITE EACH PRODUCT IN SCIENTIFIC NOTATIO**

post.

**MULTIPLY. WRITE EACH PRODUCT IN SCIENTIFIC NOTATIO**

24. (3*10^6)(2*10^12) = 6*10^(6+12)=6*10^18 26. (6*10^9)(5*10^4) = 30*10^(9+4) = 30*10^13 = 3*10^14

**MULTIPLY. WRITE EACH PRODUCT IN SCIENTIFIC NOTATIO**

34. 5^10/5^7 = 5^(10-7) = 5^3 36. 76^11/76^5 = 76^(11-5) = 76^6

**electronics**

Rt = R2*R3/R1 = 2.11k R2*8.2k/2.2k = 2.11k 3.727R2 = 2.11k R2 = 0.566k = 566 ohms. NOTE: I'm assuming that Rt = 2.11k at 0oC.

**physics**

Yes, when an object is DROPPED, the initial velocity is 0. When an object is THROWN up or down, the initial velocity is not 0. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*7 = 137.2 V = 11.71 m/s.

**Math**

1. ) = 30 + 0.1(x-200) F(x) = 30 + 0.1x - 20 The above Eq is valid for all real values of X that are equal to or greater than 200: X => 200. When x = 200 minutes, the cost would be $30. None of the given choices meets this requirement. 2. Cost = 30 + 0.1x - 20 = $100 0.1x =...

**math**

See previous post: Fri,5-23-14,12:35 PM.

**electrical circuit instrumentation**

R1 = 6 ohms. R2 = 8 ohms. Re=R1*R2/(R1+R2) = 6*8/(6+8)=3.429 ohms = Equivalent resistor. I1 = E/R1 = 36/6 = 6 Amps. I2 = E/R2 = 36/8 = 4.5 Amps. I = I1+I2 = 6 + 4.5 = 10.5 Amps. P1 = E^2/R1 = 36^2/6 = 216 Watts. P2 = E^2/8 = 36^2/8 = 162 Watts. P = P1+P2 = 216 + 162 = 378 Watt...

**mechanical physics**

Incomplete.

**Physics**

1. h = 0.5g*t^2 = 6 m. 4.9t^2 = 6 t^2 = 1.224 Tf = 1.107 s. = Fall time. d = Xo * Tf = 24 m. Xo * 1.107 = 24 Xo = 21.7 m/s = Initial velocity. 2. Fg = m*g = Force of gravity = Wt. of car. Fk = u*Fg = Force of kinetic friction. Fn = Fap-Fk = Net force. Fap = Force applied.

**science**

1. V = Vo + g*t = 30 - 10*2 = 10 m/s. 2. hmax = (V^2-Vo^2)/2g hmax = (0-(30)^2)/-20 = 3. V = Vo + g*Tr = 0 @ hmax. Tr = -Vo/g = -30/-10 = 3 s. = Rise time.

**math**

I=2.37*10^-5 watts/cm^2=Sound Intensity level. Io =10^-16 W/cm^2 = Reference sound Intensity level. db = 10*Log(I/Io) db = 10*Log(2.37*10^-5/10^-16) = 114

**physics**

Fx = 100*Cos37 = 79.86 N. Wb = m*g = 10kg * 9.8N/kg = 98 N. = Weight of buggy. a=(Fx-Fk)/m = (79.86-60)/10=1.99 m/s^2

**physics**

d1 = d2 25t = 0.5a*t^2 25 = 0.5a*t 0.002t = 25 t = 12,500 s. = 3.5 h.

**physics**

d = 300km[135o] V1 = 300km[135o]/0.75h = 400 km/h[135o] without wind. Vp + Vw = 400o[135] Vp + 80[-90o] = 400[135] Vp = 400[135] - 80[-90] Vp=400*cos135+i400*sin135 - (80*Cos(-90)+i80*sin(-90)) Vp = -282.84+i282.84 - (0-i80) Vp = -282.84 + i362.84 = 460km[128o] = Velocity and ...

**Algebra 1 (Reiny)**

1. T = T1*T2/(T1+T2) = 2*3/(2+3)=1.2 h. 2. H = 0.4 * 300 = 120 mL in current solution. W = 0.6 * 300 = 180 mL of water in current solution. W/(W+H) = 0.7 W/(W+120) = 0.7 W = 0.7W + 84 0.3W = 84 W = 280 mL of water in new solution. 280-180 = 100 mL of water added to new solution.

**geometry**

A1 = 150o = Minor Arc. A2 = 360-150 = 210o = Major Arc. X = (A2-A1)/2 = (210-150)/2 = 30o=Angle formed by 2 tangents. a

**College Algebra**

Length = L units. Width = (2L-2) units. A = L(2L-2) = 82cm^2 2L^2 - 2L - 82 = 0 L^2 - L - 41 = 0 Use Quadratic formula: L = 6.92 cm. Width = 2L - 2 = 2*6.92 - 2 = 11.84 cm. The diagonal divides the rectangle into 2 congruent rt. triangles. D^2 = L^2 + W^2 = 6.92^2 + 11.84^2=18...

**College Algebra ..Please help**

1. Width = W ft. Length = (W+20) ft. A = W*(W+20) = 8,000 Ft^2 W^2 + 20W - 8000 = 0 C=-8,000 = -80*100. Sum = -80+100=20=B. (w+100)(w-80) = 0 w+100 = 0, W = -100 w-80 = 0, W = 80 Ft = Width. w+20 = 80+20 = 100 Ft = Length. 2. A = L*W = 16, L = 16/W. Eq2: L^2 + W^2 = 68 In Eq2,...

**LOOK AT THE GIVEN TRIANGLES??**

a. P1 = (4x+2) + (7x+7) + (5x-4)=16x + 5 P2 = (x+3) + (x+7) + (2x-5) = 4x+5 b. P1-P2 = (16x+5) - (4x+5) = 16x+5 - 4x-5 = 12x.

**physics**

d = 3.6 + 0.5 = 4.1 miles. T1 = 3.6/9 + 12/60 = 0.6 hr. To travel 4.1 miles from starting point. V1 = d/T1 = 4.1/0.6 = 6.83 mi/h. V2=9.0 mi/h. when returning to starting point. V = (V1+V2)/2 = (6.83+9.0)/2 = 7.92 mi/h = Average velocity for entire trip.

**physics**

T^2 = 4pi^2(L/g) = 3.4^2 39.48(2.87/g) = 11.56 113.3/g = 11.56 11.56g = 113.3 g = 9.80 m/s^2

**Kirr**

P = Po(1+r)^n = $25,000 r = (1.825%/365)/100% = 5*10^-5 = Daily % rate expressed as a decimal. n = 365Comp./yr. * 4yrs. = 1460 Compounding periods. Po(1.00005)^1460 = 25000 Po = 25,000/1.00005^1460 = $23,240.

**algebra math!**

9pts/6wks = 1.5 Points/week.

**physics**

Wb = m*g = 40kg * 9.8N/kg = 392 N. = Weight of box. Fk=u*(Wb-F*sin31)=0.45(392-173*sin31) = 136.3 N.= Force of kinetic friction. Fn=F*CosA-Fk = 173*cos31 - 136.3 = 12 N. = Net force. a = Fn/m = 12/40 = 0.30 m/s^2.

**Physics**

hmax = L*sin A = 5*sin40 = 3.21 m. At top of incline: KE + PE = mg*hmax-Fk*L 0 + PE = mg*3.21-10*5 PE = mg*3.21-50. At bottom of incline: KE + PE = mg*3.21-50 KE + 0 = mg*3.21-50 KE = mg*3.21-50 = 35 J. m*9.8*3.21-50 = 35 31.5m-50 = 35 31.5m = 85 m = 2.7 kg. = Mass of box.

**physics**

V = Vo + g*Tr = 0 at max. ht. Tr = -Vo/g = -40/-9.8 = 4.08 s. = Rise time. T = 4.08-1 = 3.08 s. h1 = Vo*t + 0.5g*t^2 h1 = 40*3.08 - 4.9*3.08^2 = 76.7 m. h2 = 40*4.08 - 4.9*4.08^2 = 81.6 m. h2-h1 = 81.6-76.7 = 4.93 m. = Distance traveled in the last second.

**physics**

h = Vo*t + 0.5g*t^2 h = 0 + 5*3^2 = 45 m. = Height of object above gnd. (45-1)/4m = 11th floor.

**physics**

V^2 = Vo^2 + 2a*d V^2 = 0 + 10*10 = 100 V = 10 m/s.

**algebra**

I = 2.42*10^-5 Watts/cm^2. = Sound intensity. Io = 10^-16 Watts/cm^2 = Reference sound intensity. dB = 10^Log(2.42*10^-5/10^-16) = 114.

**physics**

h = L*sin A = 5.5*sin30 = 2.75 m. Fn = mg*Cos A = 66*Cos 30 = 57.16 N. = Normal force = Force perpendicular to the ramp. Fk = u*Fn = 0.22 * 57.16 = 12.57 N. = Force of kinetic friction. KE + PE = mg*hmax-Fk*L KE + PE = 66*2.75-12.57*5.5 = 112.4 J. 0 + PE = 112.4 PE = 112.4 J. ...

**physics**

1. W = Fk*d 25 * 12 Joules. 2. W = 175 * 12 Joules. 3. Wn = (175*12)-(25*12)

**Physics**

a. X = 45 N. Y = -22 N. F^2 = 45^2 + (-22)^2 = 2,509 F = 50.09 N. b. d = 22m/s * 3s = 66 m. Work = F*d = 50.09 * 66 = 3306 Joules.

**Physics! Help**

F1 + F2 = 96.2N.[55.4o] + 11.6N.[41.2o] X = 96.2*cos55.4 + 11.6*cos41.2=63.35 N

**ALGERBRA**

What are the "2 ways?" Perhaps some punctuation would help.

**Physics**

F = m*a = 1350 N. Impulse=m*V = m*(a*T) = 1350*6.2*10^-3= 8.37 kg-m/s.

**Physics**

D=2m[270o] + 16m[180o] + 24m[90o]+36m[180o]. Add the two 180o vectors directly: D = 2[270o] + 52[180o] + 24[90o] X = 2*cos270+52*cos180+24*cos90 = -52 m. Y = 2*sin270+52*sin180+24*sin90 = 22 m. D^2 = (-52)^2 + 22^2 = 3188 D = 56.5 m.

**Physics**

a. d = V*T = 420 m. (12.5-2.70) * T1 = 420 T1 = 420/(12.5-2.70) = 42.9 s. b. T2 = 420/(12.5+2.7) = 27.6 s. T = T1+T2 = 42.9 + 27.6 = 70.5 s. c. T1 = 420/12.5 = 33.6 s. T2 = T1 = 33.6 s. T = 33.6 + 33.6 = 67.2 s.

**physics**

V=100mi/h * 1600m/mi * 1h/3600s = 44.44m/s V = Vo + a*t = 0 a = -Vo/t = -44.444/10^-3=-44,444 m/s^2 F = m*a = 0.145 * (-44,444) = - 6444 N.

**physics**

Da = 69.5*T Db = 84.3*T B will have to travel 394 m(0.394km) farther than A to catch up: Db = Da + 0.394km 84.3 * T = 69.5 * T + 0.394 84.3T-69.5T = 0.394 14.8T = 0.394 T = 0.02662 h. = 1.60 Min. to catch up.

**math**

Slope = Tan A = Y/X = 1/6 A = 9.46o

**math**

Slope = Y/x = 16 Y/3 = 16 Y = 48 m.

**physics**

W = F*d*cos A = 457 * 6.2 * Cos 8 = 2806 J.

**college physics**

mgh2 - mgh1 = mg(h2-h1) = mg(3.1) = 64.7*9.8(3.1) = 1966 Joules.

**college physics**

a. Always negative.

**Physics**

The force of the golf club acts in parallel with the motion of the ball which is 28o. So my answer is 1650 N. @ 28o. Since they did not ask for the direction of the force, I did not include the angle. Your answer is not the full force acting on the ball; it is the hor. compone...

**Physics**

a=(V-Vo)/t a = (55-0)/1.5*10^-3=36670 m/s^2 F = m*a = 0.045 * 36,670 = 1650 N.

**Business mat**

7x + 3 = 7x + b b = 7x-7x+3 = 3

**Math**

Eq1: Y = x^2+3x-4 Eq2: Y = 2x+2 In Eq1, replace Y with 2x+2 and solve for X: 2x+2 = x^2+3x-4 x^2+3x-2x = 2+4 x^2+x = 6 x^2+x-6 = 0 C = -6 = -2*3. (x-2)(x+3) = 0 x-2 = 0, X = 2. x+3 = 0, X = -3. Solution: X = -3, and 2.

**math**

1. Y = 4x + 12 = $44. 4x = 44-12 = 32 X = 8 Months = Oct. of same yr. 2.C 3. 8 < x + 3 X > 8-3 X > 5. 7 > 5 Answer = b = 7.

**Math**

Bought X boxes. Sold (x-5) boxes. Cost = $Y per box Selling price = $(y+0.1) per box. P = $6 * 1.25 = 7.50 = Sale price. (x-5)(y+0.1) = 7.50 xy + 0.1x - 5y - 0.5 = 7.5 Eq1: xy + 0.1x - 5y = 8 Eq2: xy = $6.00 Y = 6/x In Eq1, replace Y with 6/x: 6 + 0.1x - 30/x = 8 0.1x - 30/x =...

**math**

Martin is X yrs. old. Joan is (x-3) yrs. old. 4x/5 = x-3 Multiply both sides by 5: 4x = 5x-15 X = 15 (4/5) * 15 = 12 yrs. = Joan's age.

**math**

Answer = b.

**math**

I = 2.42*10^-5 watts/cm^2 = Intensity. Io = 1*10^-16 watts/cm2 = Reference. db = 10*Log(I/Io) db = 10*Log(2.42*10^-5/1*10^-16) db = 10*Log(2.42*10^11) = 114.

**math**

Thu sales = $X Sat sales = $2X Other 4 days = $X/2 X/(x+2X+X/2) = X/(3 1/2)x = X/(7x/2) = x * 2/7x = 2/7.

**physics**

KE = 0.5m*V^2 = 900,000 J. 0.5*2000*V^2 = 900,000. Solve for V in m/s.

**Algerbra 2**

V = Vo - Vo*r*T V = 16,400 - 16,400*0.24*2 = $8528

**Math**

Do you mean: A(7,3.-4), B(-3,1,0). If so, X = (7+(-3))/2 = 2. Y = (3+1)/2 = 2. Z = (-4+0)/2 = -2. (x,y,z) = (2,2,-2).

**Math**

See previous post.

**Math**

C(h,k), P(x,y). x - h = x+5 x-x-h = 5 -h = 5 h = -5 y-k = y-2 y-y-k = -2 -k = -2 k = 2 C(-5,2). r = sqrt(9) = 3 Units.

**math**

-15-(-4) + (-12) + -8 -9 = -15 + 4 -12 -17 = -44 + 4 = -40.

**Science**

B. 1.

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