Monday

December 22, 2014

December 22, 2014

Total # Posts: 9,768

**math**

F(x) = 5x-1 F(-6) = 5*(-6) - 1 = -31. g(x) = -4x^2 - 3 g(5)=-4*5^2 - 3 = -100 - 3=-100 + (-3) = -103.
*June 22, 2014*

**math**

Eq1: D + C = 24kg Eq2: D + R = 20kg Eq3: C + R = 10kg Subtract Eq2 from Eq1: D + C = 24 D + R = 20 Diff: C-R = 4 R = C-4 In Eq3, replace R with C-4: C + C-4 = 10 2C = 14 C = 7 kg In Eq1, replace C with 7: D + 7 = 24 D = 17 kg R = C-4 = 7-4 = 3 kg C + D + R = 7 + 17 + 3 = 27 kg.
*June 22, 2014*

**Survey of Mathematics**

Jan. 5th thru Dec. 9th = 338 Days. a. I = Po*r*t = 6500*(0.085/360)*338 = $518.74 b. P=(6500 + 6500*(0.085/360)*118)-1500 = $6681.10 - 1500 = $5181.10 After May 3. P = 5181.10 + 5181.10*(0.085/360)*128 - 2500 = 5337.68 - 2500 = $2837.68 After Sept. 11 P = 2837.68 + 2837.68*(0....
*June 22, 2014*

**Physics**

Work = Fap*cosA * d=74.1*cos32.3 * 72.4 = 4535 J.
*June 22, 2014*

**physics**

V = Vo + a*t. Vo = Initial velocity.
*June 21, 2014*

**ap physics**

See previous post: Fri,6-20-14,11:33PM.
*June 21, 2014*

**ap physics**

d = d2-d1 = 120m[105o]-60m[15o] X = 120*cos105 - 60*cos15 = -89.0 m. Y = 120*sin105 - 60*sin15 = 100.4 m. Tan Ar = Y/X = 100.4/-89.0 = -1.12789 Ar = -48.44o = Reference angle. A = -48.44 + 180 = 131.6o = Direction. d = Y/sinA = 100.4/sin131.6 = 134.3 m. [131.6].
*June 20, 2014*

**math**

a ball is thrown down ward from a 320 ft building at a initial velocity of 32 ft per sec. How long would the ball take to reach a height of 48 feet?' 16t^2+32+320
*June 20, 2014*

**Please help! Urgent**

Po =(1-0.08) * 8500 = $7820. P = 243.07/mo. * 36mo. = $8750.52 P = Po + Po*r*t = 8750.52 7820 + 7820*r*3 = 8750.52 7820 + 23,460r = 8750.52 23,460r = 8750.52-7820 = 930.52 r = 3.97% or 4.0% = APR.
*June 20, 2014*

**Survey of mathematics**

Solved under a later post.
*June 20, 2014*

**Survey of Mathematics**

Correction: 100%-5% = 95% borrowed.
*June 20, 2014*

**Survey of Mathematics**

100% - 5% = 95% Down payment. Po = 0.95 * $289,000 = $274,550.=Amount of loan. P = (Po*r*t)/(1-(1+r)^-t) r = (6%/12)/100% = 0.005=Monthly % rate. t = 25yrs. * 12mo./yr. = 300 months. Plug the above values into the given Eq and get: P = $530,678.85 = Total cost of the house. 2 ...
*June 20, 2014*

**Survey of mathematics**

Po = P - 0.08P = 8500-(0.08*8500)= $7820 243.07/mo. * 36mo. = $8750.52 Paid back. I = Po*r*t = 8750.52-7820.00 = 930.52 7820*r*3yrs. = 930.52 23460r = 930.52 r = 0.0397 = 3.97% = APR.
*June 20, 2014*

**physics**

Vp+Vw = 275km[45o] Vp + 55km[90o] = 275[45o] Vp + 55i = 275*cos45 + i275sin45 Vp + 55i = 194.45 + 194.45i Vp = 194.45 + 194.45i - 55i Vp = 194.45 + 139.45i = 239.3km[35.6o] = Velocity and heading of plane. Check: 194.45+139.45i + 55i = 194.45 + 194.45i = 275[45o]
*June 19, 2014*

**trig**

V(0,0), T(-12,5) X = -12 - 0 = -12. Y = 5- 0 = 5. r = Sqrt(X^2+Y^2) = Sqrt(144+25) = 13 Sin A = Y/r = 5/13. Cos A = X/r = Tan A = Y/X CSC A = r/Y Sec A = Cot A = NOTES: V = Vertex. T = Terminal side. Sqrt = Square root.
*June 19, 2014*

**Algebra**

(2b-2)/(2b^2-8) 2b^2-8 = 0 2b^2 = 8 b^2 = 4 b=+-2 Gives a denominator of zero which makes the expression Undefined. Domain: All real values of b except +2 and -2. Mathematically: -2 > b > 2.
*June 19, 2014*

**Physics**

1. See previous post:Tue,6-17-14,9:52 PM 2. Xo = 4.0 m/s. h = 0.5g*t^2 = 6.5 m. 4.9*t^2 = 6.5 t^2 = 1.327 Tf = 1.15 s. = Fall time. d = Xo * Tf = 4.0m/s * 1.15s = 4.60 m.
*June 18, 2014*

**Physics**

Glad I could help.
*June 18, 2014*

**Physics**

1. r1=d/t = 30m/5s = 6 m/s.=Speed of rabbit r2=30m/120s = 0.25 m/s.=Speed of turtle T1 = d/r1 = 96/6 = 16 s.=Rabbit's time. T2 = d/r2 = 96/0.25 = 384 s. = Turtle's time. T2 - T1 = 384 - 16 = 368 s. 2. T2 = d/r2 = 500/10 = 50 s. = Time of red bicycle. d = r1 * T1 = 500 ...
*June 18, 2014*

**math**

Incomplete.
*June 18, 2014*

**Physics**

T1 = d1/r1 = 800/6 = 133.3 s. T2 = d2/r2 = 800/8 = 100 s. a. T1+T2 = 133.3 + 100 = 233.3 s.=Total time of travel. b. r = d/T = 1600m/233.3s = 6.86 m/s.
*June 17, 2014*

**Physics**

Direction = 25.0o West of north? a. D = 290m[25.0o] t = D/V = 290[25.0]/2[25o] = 145 s. b. r = D/t = 290m/145s = 2m/s.
*June 17, 2014*

**physics**

d1 + d2 = 4-1 = 3 m. (0.5g*t^2) + (Vo*t+0.5g*t^2) = 3 m. 4.9t^2 + 6t+(-4.9t^2) = 3 6t = 3 t = 0.5 s. d1 = ho - 0.5g*t^2 d1 = 4 - 4.9*0.5^2 = 4 - 1.225=2.775 m. Above gnd. d2 = 1 + (6*0.5 + (-4.9)*0.5^2 d2 = 1 + (3 + (-1.225) = 1 + 1.775=2.775 m. Above gnd. Therefore, the ball ...
*June 17, 2014*

**Angles,Lines and Triangles**

A1 = A2 Eq: A1 + A2 + A3 = 180o A1 + A2 + (A1+18) = 180 Replace A2 with A1: A1 + A1 + (A1+18) = 180 3A1 + 18 = 180 3A1 = 180-18 = 162 A1 = A2 = 54o A3 = A1 + 18 = 54 + 18 = 72o.
*June 17, 2014*

**math apr**

See previous post: Tue,6-10-14, 10:55AM.
*June 17, 2014*

**math**

Jerry's number = n. Mike's number = n+2000 Barry's number = n+400. Larry's number = 443+1500 = 1943. Sam'2 number = 443. Barry's number = 443+60 = 503. n+400 = 503 n = 103 n+2000 = 103+2000 = 2103
*June 17, 2014*

**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.
*June 16, 2014*

**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).
*June 16, 2014*

**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.
*June 15, 2014*

**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.
*June 15, 2014*

**algebra**

Sum = 8 = 7+1 = 6+2 = 5+3 = 4+4 Select 5, and 3: Original #: 53. Reversed: 35. Difference = 53-35 = 18.
*June 15, 2014*

**algebra**

X Nickels. (16-X) Qtrs. 5x + 25(16-X) = 220 Cents. Solve for X.
*June 15, 2014*

**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.
*June 15, 2014*

**Algebra 2**

N Large packages. (12-N) Small packages. Cost = 7n + 4.5(12-n) Cost = 7n + 54-4.5n = 2.5n + 54.
*June 15, 2014*

**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.
*June 14, 2014*

**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.
*June 13, 2014*

**physics**

V = 22.7[32o] Momentum=m*V = 537 * 22.7=12,190 kg-m/s.
*June 13, 2014*

**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...
*June 11, 2014*

**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.
*June 11, 2014*

**Algebra**

6x-72 = 0 6x = 72 X = 12
*June 11, 2014*

**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.
*June 11, 2014*

**calculus**

V = Vo + a*t = 2000 + (-3000)*0.03 = 1910 m/s.
*June 11, 2014*

**physics**

Momentum = m*V = 5 * 3 = 15 kg-rad/s.
*June 10, 2014*

**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...
*June 10, 2014*

**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.
*June 10, 2014*

**Physics**

d = (24.5N./2500N.)*1M = = 0.0098 M.
*June 10, 2014*

**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 = $...
*June 10, 2014*

**math**

Use synthetic(long-hand) division: (2x^3-5x^2+x+2)/(x-2) = 2x^2-x-1 a = 2, and b = -1.
*June 10, 2014*

**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: ...
*June 10, 2014*

**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
*June 9, 2014*

**physics**

See previous post.
*June 9, 2014*

**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.
*June 9, 2014*

**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.
*June 8, 2014*

**Math Personal Finance**

See previous post.
*June 8, 2014*

**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.
*June 8, 2014*

**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%
*June 8, 2014*

**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.
*June 8, 2014*

**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, ...
*June 8, 2014*

**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.
*June 8, 2014*

**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.
*June 8, 2014*

**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.
*June 7, 2014*

**physics**

a. False.
*June 7, 2014*

**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.
*June 7, 2014*

**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.
*June 7, 2014*

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

post.
*June 6, 2014*

**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
*June 6, 2014*

**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
*June 6, 2014*

**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.
*June 6, 2014*

**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.
*June 5, 2014*

**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...
*June 5, 2014*

**math**

See previous post: Fri,5-23-14,12:35 PM.
*June 5, 2014*

**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 ...
*June 5, 2014*

**mechanical physics**

Incomplete.
*June 5, 2014*

**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.
*June 5, 2014*

**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.
*June 3, 2014*

**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
*June 3, 2014*

**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
*June 3, 2014*

**physics**

d1 = d2 25t = 0.5a*t^2 25 = 0.5a*t 0.002t = 25 t = 12,500 s. = 3.5 h.
*June 3, 2014*

**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 ...
*June 3, 2014*

**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.
*June 3, 2014*

**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
*June 3, 2014*

**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=...
*June 2, 2014*

**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...
*June 2, 2014*

**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.
*June 2, 2014*

**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.
*June 2, 2014*

**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
*June 2, 2014*

**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.
*June 2, 2014*

**algebra math!**

9pts/6wks = 1.5 Points/week.
*June 1, 2014*

**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.
*June 1, 2014*

**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.
*May 30, 2014*

**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.
*May 30, 2014*

**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.
*May 30, 2014*

**physics**

V^2 = Vo^2 + 2a*d V^2 = 0 + 10*10 = 100 V = 10 m/s.
*May 30, 2014*

**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.
*May 29, 2014*

**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. ...
*May 29, 2014*

**physics**

1. W = Fk*d 25 * 12 Joules. 2. W = 175 * 12 Joules. 3. Wn = (175*12)-(25*12)
*May 29, 2014*

**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.
*May 29, 2014*

**Physics! Help**

F1 + F2 = 96.2N.[55.4o] + 11.6N.[41.2o] X = 96.2*cos55.4 + 11.6*cos41.2=63.35 N
*May 29, 2014*

**ALGERBRA**

What are the "2 ways?" Perhaps some punctuation would help.
*May 29, 2014*

**Physics**

F = m*a = 1350 N. Impulse=m*V = m*(a*T) = 1350*6.2*10^-3= 8.37 kg-m/s.
*May 29, 2014*

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