Thursday

July 24, 2014

July 24, 2014

Total # Posts: 8,898

**physics**

See previous post: Fri,11-29-13,8:15 PM.

**physics. again.**

V== Vo + g*t = 10 m/s. 37.8 + (-9.8)t = 10 -9.8t = 10-37.8 =-27.8 t = 2.84 s. h = Vo*t + 0.5g*t^2 h = 37.8*2.84 - 4.9*2.84^2 = 67.83 m.

**physics**

Fs = m*g = 22kg * 9.8N/kg = 215.6 N. = Force of the sled. Fp = 215.6*sin6 = 22.54 N. = Force parallel to the incline. Fn = 215.6*cos6 = 214.4 N. = Normal = Force perpendicular to the incline. Fk = u*Fn = 0.2 * 214.4 = 42.88 N. = Force of kinetic friction. V = 64km/h = 64000m/3...

**5th grade math**

I'm glad I could help, and thanks for your response.

**5th grade math**

4th Grade: 9 Left-handed students. Total = 3 * 9 = 27 Students. 9/27 = 1/3 Are left-handed. 5th Grade: 7 Left-handed students. Total = 30-2 = 28 Sudents. 7/28 = 1/4 Are left-handed. 6th Grade: 6 Left-handed students. Total = 27+3 = 30 Students. 6/30 = 1/5 Are left-handed. The ...

**Physics**

r2 = r1 + a*(T-To)r1 = 4.42 cm. 4.40 + 1.3*10^-4(T-20)4.40 = 4.42 4.40 + 5.72*10^-4(T-20) = 4.42 5.72*10^-4(T-20) = 4.42-4.40 = 0.02 5.72*10^-4T - 114.4*10^-4 = 0.02 5.72*10^-4T = 0.02 + 0.01144 = 0.03144 T = 314.4*10^-4/5.72*10^-4 = 54.97o

**Math**

Same procedure as previous post: Sun,12-1-13,7:39 PM.

**Math**

Given: A(-8,3), B(-6,1). m = -1 A(-8,3), P(x,y). m== -1. m = (y-3)/(x-(-8)) = -1 m = (y-3)/(x+8) = -1 Cross multiply: y-3 = -1(x+8) y-3 = -x-8 Eq: x + y = -5 Or x + y +5 = 0 Replace y with 0: x + 0 = -5 X = -5 = X-intercept. Replace X with 0: 0 + y = -5 Y = -5 = y-int.

**Physics**

Wr = m*g = 0.5kg * 9.8N/kg = 4.9 N = Wt. of the rat. Fp = 4.9*sin34 = 2.740 N. = Force to the plane. Fn = 4.9*cos34 = 4.062 N. Normal = Force perpendicular to the plane. Fk = u*Fn = 0.2 * 4.062 = 0.8125 N. Fc-Fp-Fk = m*a 0.4-2.74-0.8125 = m*a m*a = -3.15 a = -3.15/m = -3.15/0...

**Physics**

Fex = 15000 N. ? m = 500kg a = Fex/m = 15000/500 = 30 m/s^2.

**physics**

Change in L = Lo * a*(T-To) = 65.1 * 10^-5 * (-31.2-15.8) = -0.030597 m.

**physics**

Fap*cos45-u*mg = m*a Fap*cos45-0.02*588 = m*0 = 0 Fap * cos45 - 11.76 = 0 Fap*cos45 = 11.76 N. = Hor. component of Force applied. Work = 11.76 * 1000. = 11,760 Joules.

**physics**

a. Xl = 2pi*F*l = 6.28*50*0.405=127.2 Ohms Xc = 1/(6.28*50*4.43*10-6) = -718.9 Ohms tan A = (Xl-Xc)/R tan A = (127.2-718.9)/400 = -1.47925 A = -55.94o Z=R/cosA = 400/cos(-55.94) = 714.2 Ohms[-55.94o]= The Impedance. Vmax = Imax * Z=0.25 * 714.2 =178.6 Volts. b. The negative im...

**physics**

Fn = 75N[40o] + 85N[340o] X = 75*cos40 + 85*cos340 = 137.3 N. Y = 75*sin40 + 85*sin340 = 19.14 N. tan A = Y/X = 19.14/137.3 = 0.13940 A = 7.94o Fn=X/cosA = 137.3/cos7.94=138.6 N[7.94o]

**PHYSICS**

a. Xc = 1/2pi*F*c Xc = 1/(6.28*60*4*10^-6) = 663.5 Ohms. I = V/Xc = 120/663.5 = 0.181A rms. b. Same procedure as "a".

**Physics**

We need to know the length of the hill. Length = 100 m? A = 30o m = 75 kg h = 100*sin30 = 50 m. = Ht. of hill. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*50 = 980 V = 31.3 m/s At bottom of hill. V^2 = Vo^2 + 2a*d a=(V^2-Vo^2)/2d=(31.3^2-0)/200=4.9 m/s^2 V = Vo + a*t = 31.3 0 + 4.9*t = 3...

**math**

CORRECTION: Cost = 2375*0.85*0.80*0.80 = $1292. Discount = 2375 - 1292 = $1083.

**math**

Discount = 2375*0.15*0.20*0.20 = $14.25

**Physics**

V1 = 6N[180o] X1 = -6N Y1 = 0 V2 = 4.5N[45o] X2 = 4.5*cos45 = 3.18 N. Y2 = 4.5*sin45 = 3.18 N. X = X1 + X2 = -6 + 3.18 = -2.82 N. Y = Y1 + Y2 = 0 + 3.18 = 3.18 N. tan Ar = Y/X = 3.18/-2.82 = -1.12766 Ar = -48.43o = Reference angle. A = -48.43 + 180 = 131.6o R=Y/sinA = 3.18/sin...

**Finance - Annuities**

P = Po*(1+r)^n P = $2250/mo. * 48mo. = $108,000 r = (3%/12)/100% = 0.0025 = Monthly % rate expressed as a decimal. n = 1comp./mo * 48mo = 48 Compounding periods. a. P = (Po-12000)*(1.0025)^48 = 108,000 (Po-12000)*1.12733 = 108000 Po-12000 = 95,801.75 Po = $107,801.75 = Initial...

**math**

A*(1-0.0653) = 1,225,000 A*0.9347 = 1225000 A = 1,310,580.94

**physics**

F1 = m*g = 1.6kg * 9.8N/kg = 15.68 N F2 = (0.05m/1m) * 400N = 20 N. F1-Fs = m*a 15.68-Fs = m*0 = 0 Fs = 15.68 = Force of static friction. Fs = u*F2 = 15.68 u*20 = 15.68 u = 0.784 = Coefficient of static friction.

**Physic: Projectile Motion**

Range = Vo^2*sin(2A)/g = 15 m. Vo^2*sin(40)/9.8 = 15 Vo^2*0.0656 = 15 Vo^2 = 228.7 Vo = 15.12 m/s.

**Math**

2. A cube has 6 edges. As = 6 * 3^2 = 6 * 9 = 54 Sq. In.

**finance**

1. P = (Po*r*t)/(1-(1+r)^-t) r = (9%/12)/100% = 0.0075 = Monthly % rate expressed as a decimal. t = 12mo/yr * 5yrs. = 60 Months. Plug th above values into the givenEq and get: P = $12,455.01 I = P-Po 2. Monthly = P/t 3. P = Po + Po*r*t Po = $10,000 r = 0.0075 t = 60 Months Plu...

**physics**

Fap-Fk = m*a 30-Fk = 2 * 10 = 20 Fk = 30-20 = 10 N. = Force of kinetic friction.

**geometry**

See Related Questions: Thu,5-25-11,11:28 AM.

**Science, Physics, math, calculus**

a. h = 0.5g*t^2 = 0.77 4.9t^2 = 0.77 t^2 = 0.1571 t = 0.396 s. = Fall time. Dx = Xo * t = 5.15 m. Xo * 0.396 = 5.15 Xo = 13 m/s = Break speed. b. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*0.77 = 15.09 V = 3.88 m/s

**Physics**

h = 0.5g*t^2 = 50 m. 4.9t^2 = 50 t^2 = 10.2 Tf = 3.19 s. = Fall time. d = V*Tf = 100m/s * 3.19s = 319 m.

**PHYSICS**

CORRECTION: T = 1.15 Milliseconds.

**PHYSICS**

CORRECTION: d. Vr = I*R = (0.8*0.857)*7 = 4.8 Volts Vi=6-4.8=1.2 Volts across the inductor. V/e^(T/0.714) = 1.2 6/e^(1.40T) = 1.2 e^1.40T = 6/1.2 = 5 1.40T*Ln e = Ln 5 1.40T = 1.609 T = 1.15 s. 7 =

**PHYSICS**

a. T.C.=L/R=5.0/7=0.714 Milliseconds b. T/TC = 0.25mS/0.714mS = 0.350 Vi = V/e^(T/TC) = 6/e^0.350 = 4.23 Volts after 250 uS. I=Vr/R = (V-Vi)/R = (6-4.23)/7= 0.253A. c. I=Vr/R = (V-Vi)/R = (6-0)/7 = 0.857A d. Vr=I*R = (0.8*0.857)*7 = 4.80 Volts. Vi = 6-4.8 = 1.2 Volts. = Voltag...

**Math**

Incomplete.

**physics**

Fr = 975N[0o] + 745N[60o] + 1175N[90o] X=975 + 745*cos60 + 1175*cos90=1347.5 N Y = 745*sin60 + 1175*sin90 = 1820.2 N. tan A = Y/X = 1820.2/1347.5 = 1.31079 A = 53.5o Fr = Y/sin A = 1820.2/sin53.5=2264.3 N. [53.5o].

**physics**

Ht. = 50 m.? a. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*50 = 980 V = 31.3 m/s. b. V = Vo + g*t = 31.3 m/s. 0 + 9.8t = 31.3 t = 3.19 s. c. m = 2.0Lb * 0.454kg/Lb = 0.908 kg. KE = m*V^2/2 = 0.908*31.3^2/2 = 444.8 J.

**physics**

Ws = m*g = 77.7kg * 9.8N/kg = 761.5 N = Wt. of skier. Fp = 761.5*sin35.7 = 444.3 N. = Force parallel to slope. Fn = 761.5*cos35.7 = 618.4 = Normal = Force perpendicular to slope. Fk = u*Fn = 0.08 * 618.4 = 49.47 N. = Force of kinetic friction. Fp-Fk = m*a a=(Fp-Fk)/m=(444.3-49...

**science**

KE = 0.5m*V^2 = 2.5*4^2 = 40 J.

**Please help!- Physics**

d = 483[180o ] + 347[106o] + 347[106o] d = 483[180 + 694[106o] X = 483*cos180 + 694*cos106 = -674.3 km Y = 483*sin180 + 694*sin106 = 667.1 km tan Ar = Y/X = 667.1/-674.3 = -0.98935 Ar = -44.69o = Reference angle. A = 180-44.69 = 135.3o d = X/cosA = -674.3/cos135.3 = 948.7 km [...

**Math**

Incomplete.

**physics**

3.2 cm from equilibrium position: KE + PE = mg*d 0 + PE = mg*d/2 Halfway to the equilibrium position: KE + PE = mg*d mg*d/2 + mg*d/2 = mg*d KE = mg*d/2 = 0.5m*V^2 0.5m*V^2 = mg*d/2 = 3.92*0.032/2 0.2*V^2 = 0.06272 V^2 = 0.3136 V = 0.56 m/s.

**Physics**

CORRECTION: V = 81.6km/h[74.93o] D = 245 km[74.93o]

**Physics**

V = 100km/h[90o] + 30km/h[315o] X = 100*cos90 + 30*cos315 = 21.21 km/h Y = 100*sin90 + 30*sin315 = 78.79 km/h tan A = Y/X = 78.79/21.21 = 3.71461 A = 74.93o V=Y/sinA = 78.79/sin74.93=81.6 km/h [78.79] D=V*t = 81.6[78.79] * 3 = 245 km[78.8o]

**Math**

Parallel lines have equal slopes.

**Math**

Parallel lines have equal slopes.

**Math**

Parallel lines have equal slopes.

**Math**

2x - 3 = 4y Eq1: 2x - 4y = 3 m1 = -A/B = -2/-4 = 1/2 m2 = -(2/1) = -2 Y = mx + b Eq2: Y =-2x - 5/4.

**Math**

See previous post: Wed,11-20-13,6:18PM.

**Math**

Eq1: x + 2y = 10. m1 = -A/B = -1/2 The slope of the 2nd line = the negative reciprocal of m1: m2 = -(-2/1) = 2. Y = mx + b Eq2: Y = 2x - 10 or 2x - y = 10

**physics**

Energy = 120 * 5 *6h /1000=3.6 KWh Used Cost = 3.6kwh * 0.090/kwh = 0.324 or 32.4 Cents.

**Physics**

L = h/sin A = 2/sin 30 = 4 m. = Length of incline. KE = mg*h-Fk*L 0.5m*V^2 = mg*h-Fk*l 0.2*4.50^2 = 3.92*2 - Fk*4 4.05 = 7.84 - 4Fk 4Fk = 7.84-4.05 = 3.79 Fk = 0.948 N. = Force of kinetic friction.

**physics**

Fn = m * a =47 * 4.50

**Physics**

Yes. For a given initial velocity, the larger the angle the greater the vertical component of initial velocity. The increase in vertical velocity causes an increase in the max. ht.

**Physics - projectile**

V = Vo = 50 m/s.

**Physics**

b. h = Vo*t + 0.5g*t^2 = 3.05 8t + 4.9t^2 - 3.05 = 0 Use Quadratic Formula and get: t = 0.319 s. c. V^2 = Vo^2 + 2g*h V^2 = 8^2 + 19.6*3.05 = 123.78 V = 11.13 m/s.

**MATH**

A. Y = ho - 8X ho = The initial ht. B. When he got on the elevator, it was at the initial height(ho) and decreased at a rate of 8 feet per second for 12 seconds. C. Y = ho _ 8x = 240 Ft. ho - 8*12 = 240 ho = 240 + 96 = 336 Ft. above gnd. D. Y = 336 - 8x = 0 336 - 8x = 0 8x = 3...

**math**

N = 0.57 * 11

**Physics**

d = 0.5g*t^2 = 75 4.9t^2 = 75 t^2 = 15.31 Tf = 3.912 s. = Fall time. d = V*Tf = 7-4 = 3 m. V * 3.912 = 3 V = 0.769 m/s.

**math**

Did your book give the total # of Robinsons? Something is missing.

**physical science**

P = F * d/t = 96 * 2.8/4.6 = 58.43 J/s = 58.43 Watts.

**college algebra**

4^(x-3) = 3^(2x) (x-3)*Log4 = 2x*Log 3 Divide both sides by Log 4: x-3 = 2x * 0.79248 = 1.5850x x - 1.5850x = 3 -0.5850x = 3 X = -5.1282

**science**

Magnitude = 210 N. Direction = 30o South of West = 210o CCW.

**science**

Magnitude = 200 N. Direction = 60o North of East = 60o CCW.

**science**

Magnitude = 125 N. Direction = North(Positive Y-axis).

**math**

Sally has X postcards. Marta has X postcards. X = 4(X-18) Solve for X.

**Math**

Y = 5 For all values of X. (0,5),(5,5),(2,5),(-3,5).

**science**

500+(65-47)sk/wk*105days*1wk/7days=770 Skunks.

**Phyics**

d1 = 0.5a*t^2 = 15 m. 0.5*t^2 = 15 t^2 = 30 T1 = 5.477 s. V = a*t = 1m/s^2 * 5.477s = 5.477 m/s. d2 = V * t = 5.477m/s * 15s = 82.2 m. D = d1 + d2 = 15 + 82.2 = 97.2 m. = Distance at which he was caught. T = T1 + T2 = 5.477 + 15 = 20.48 s To catch up.

**math**

(25%/15%/10% = (1-0.25)(1-0.15)(1-0.10)= 0.75 * 0.85 * 0.90 = 0.57375

**math**

a. X + 27.80*20 = 914 X = $358. b. C = 358 + 27.80x X = The number of years since 1981. c. 2000-1981 = 19 years. C = 358 + 17.80*19 = $528.20

**Check my answers please- Physics**

1. A force that makes the net force on an object 0. 2. It is equal in magnitude and opposite in direction. 3. An object in equilibrium must not be in motion. 7. 90 N.

**algebra2**

See previous post: Mon,11-18-13,11:59 AM.

**algebra2**

CD: $X Savings: $4X Mutual: $(15,000-5X) 0.02X + 0.01*4X + 0.1(15000-5x) = 210 0.06X + 1500 - 0.5X = 210 -0.44X = 210-1500 = -1290 X = 2931.82 4X = 4*2931.82 = $11,727.27 = Savings.

**math**

Bal. = 423.78 + 123.42 - 100 = 447.20 Int. = 447.20 *(0.15/12) * 1 = $5.59

**Physics**

Incomplete.

**Business math**

P = Po*(1+r)^n r = (0.75%/365)/100% = 2.055*10^-5 = Daily % rate expressed as a decimal. n = 1comp./day * 21days = 21 compounding periods. Plug the above values into the given Eq and get: $9,0003.88

**physic**

Vo=36mi/h * 1600m/mi * 1h/3600s=16 m/s. V = Vo + a*t = 0 16 + a*2.4 = 0 2.4a = -16 a = -6.67 m/s^2. F = m*a = 58 * (-6.67) = -386.7 N. The negative sign means that the force was in the opposite direction of the motion.

**Math**

P = 350hp * 746W/hp = 261,100 Watts.

**physics**

Wb = m*g = 7.6kg * 9.8N/kg = 74.48 N. = Wt. of block. Fs = 8 N ? Fs = us*Fv = 8 N. us*74.48 = 6 us = 0.081

**geometry**

See previous post: Sat, 11-16-13, 7:13 PM.

**GEOMETRY**

1. Triangle #1 a = 8 b = 15 c = 18 Triangle #2: d = 10 e = ? f = ?. a/d = b/e = c/f = 8/10 15/e = 8/10 e = 18.75 18/f = 8/10 f = 22.5 2. Scale Factor=5/4 = 15/12=25/20 = 1.25 3. x/r = y/p = z/n.

**physics**

Fn = m*a m = Fn/a = 50/25 = 2 kg

**Trig**

V1 + V2 = 1200[70o] + 900[205o] X = 1200*cos70 + 900*cos205 = -405.3 Y = 1200*sin70 + 900*sin205 = 747.3 tanAr = Y/X = 747,3/-405.3 = -1.84376 Ar = -61.53o = Reference angle. A = -61.53 + 180 = 118.5o Vr = Y/sinA = 747.3/sin118.5 = 850.3[118.5o] = Resultant vector.

**nature of science**

A. The speed and direction.

**Math**

V1 = 1.5 *1.5 * 0.25 = 0.5625 in^3. V2 = 3.25 * 3.50 * 0.25 = 2.844 in^3. V2/V1 = 2.844/0.5625 = 5.056 = 505.6%. % Increase = 505.6% - 100% = 405.6 %.

**physics**

h = 9.7*sin30 = 4.85 m. V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*4.85 = 95.06 V = 9.75 m/s.

**Physics**

F1=m*g = 0.151[26.2o]*9.8=1.480N[26.2o] F2 = 0.215[281o]*9.8 = 2.107N[281o] F3[Ao] F = F1 + F2 + F3 F=1.480N[26.2o] + 2.107N[281] + F3[Ao] X = 1.480*cos26.2+2.107*cos281+F3*cosA=0 X = 1.328 + 0.4020 + F3*cosA = 0 F3*cosA = -1.73 cosA = -1.73/F3. Y = 1.480*sin26.2+2.107*sin281+...

**MATH**

P = Po + Po*r*t P = 15,000 + 15,000*0.045*(8/12) Solve for P.

**Math**

6w + 20 = 60 6w = 40 W = 6 4/6 or 7 Weeks.

**4th grade math**

1. a/7 = 20 Multiply both sides by 7: a = 7 * 20 = 140. Check: 140/7 = 20 2. Same procedure as #1. 3. Same procedure as #1.

**Physics**

a. F*cos20-Fk = m*a = m*0 = 0. F*cos20-u(Fn+F*sin20) = 0 300*cos20 - u(1000+300*sin20) = 0 281.9 - 1102.6u = 0 1102.6u = 281.9 u = 0.256 = Coefficient of kinetic friction. b. m*g = 1000N. m = 1000/g = 1000/9.8 = 102 kg. 300*cos20 - 0.256(1000-300*sin20)=m*a 281.9 - 229.7 = m*a...

**math**

Scott ate X Fries Mike ate (2x+1) Fries. Holly ate (x-5) Fries. Total fries ordered = Fries ate + 6: ORDER = X + (2x+1) + (x-5) + 6 = 4x + 2.

**physics**

Tr + Tf = 4.8s. = Rise time + Fall time = Time in air. Tr = Tf = 4.8/2 = 2.4 s. Dx = 60yds * 3Ft/yd * 1m/3.3Ft=54.55 m. Dx = Xo * (Tr+Tf) = 54.55 m. Xo * 4.8 = 54.55 Xo = 11.36 m/s. = Hor. component of initial velocity. Y = Yo + g*Tr = 0 @ max ht. Yo - 9.8*2.4 = 0 Yo = 23.52 m...

**physics**

See your 6:11 PM post.

**physics**

Work = F*d = 1 * 2000 = 2000 Joules. Calories = 2000J * 1cal/4.184J = 478

**Physics**

V = 90km/h = 90000m/3600s = 25 m/s. a = (V-Vo)/t = (25-0)/6 = 4.167 m/s^2 d = 0.5a*t^2 = 0.5*4.167*6^2 = 75 m. P = F*d/t = mg * d/t P = 13720 * 75/6 = 171,500 J/s.

**Math-Algebra**

1. F = m*a = 25 * 3 = 75 N.

**Fly Ball Lab - Projectile Motion Please HELP FAST!**

Dx = Xo * T = 48.9 m. Xo * 3.60 = 48.9 Xo = 13.58 m/s = Hor. component of initial velocity. Tr = Tf = T/2 = 3.60/2 = 1.80 s. = Rise and fall times. Y = Yo + g*Tr = 0 @ hmax. Yo - 9.8*1.8 = 0 Yo = 17.64 m/s = Ver. component of initial velocity. tan A = Yo/Xo = 17.64/13.58 = 1.2...

**math**

0.25 - (-1.5) = 0.25 + 1.5 = 1.75

**math**

1 1/2 - 2 = 3/2 - 4/2 = -1/2.

**Physics**

1. F = 250*2 + 25 = 525 N. Work = F*d = 525 * 2 = 1050 Joules. 2. P = F*d/t = 525 * 2/3 = 350 J/s. = 350 Watts.

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