Tuesday

June 30, 2015

June 30, 2015

Total # Posts: 10,677

**Physics**

db = 10*Log(I1/I2) = 10*Log(110/330) = -4.77 I1 = 4.77 db below I2.
*December 1, 2014*

**physics**

Vo = 0 V = 41 m/s. t = 5.3 s. M = 87 kg a = (V-Vo)/t Fx = M*a Fy = M*g F = Sqrt(Fx^2+Fy^2) = Total force.
*November 30, 2014*

**physics**

a = (V-Vo)/t = (0.37-0)/12 = 0.0308 (Fx-Fk) = M*a (127*Cos40-Fk) = 35 * 0.0308 97.3 - Fk = 1.079 -Fk = 1.079 - 97.3 = -96.2 Fk = 96.2 N. = Force of kinetic friction.
*November 30, 2014*

**Math**

1. P = Po + Po*r*t P = 100,000 + 100,000*0.1*5 = 150,000
*November 30, 2014*

**math**

Vo = 90Ft/s[60o] Xo = 90*cos60 = 45 Ft/s Yo = 90*sin60 = 77.9 Ft/s ho = 5 Ft. g = -32 Ft/s^2 t = 3 s. h = ho + Yo*t + 0.5g*t^2
*November 30, 2014*

**physics**

X = 10 km/h Y = 2 km/h V^2 = X^2 + Y^2 = 10^2 + 2^2 = 104 V = 10.20 m/s.
*November 30, 2014*

**physics**

h max = R/2 = 150m/2 = 75 m. h max = 0.5g*t^2 = 75 4.9*t^2 = 75 t^2 = 15.31 Tf = 3.91 s. = Fall time. Tr = Tf = 3.91 s. = Rise time. V = Vo + g*t = 0 @ max ht. Vo = -g*t = -(-9.8*3.91) = 38.34 m/s. = Initial velocity. R = Vo^2*sin(2A)/g = 100 m. 38.34^2*sin(2A)/9.8 = 100 150*...
*November 30, 2014*

**math**

Incomplete.
*November 30, 2014*

**physics**

See previous post: Sat, 11-29-14, 11:06 PM.
*November 30, 2014*

**physics**

d = Vo*t + 0.5a*t^2 = 40*15 + 8*15^2/2 = 1500 m.
*November 30, 2014*

**physics**

Vo = 50mi/h * 1600m/mi * 1h/3600s. = 22.22 m/s. V = Vo + a*t = 0 When stopped. t = -Vo/a = -22.22/-7=3.17 s. To stop.
*November 30, 2014*

**trigonometry**

1. Va=(1/2)rev/2min * 6.28rad/rev= 1.57 rad/min. 2 thru 6. Same procedure as #1.
*November 30, 2014*

**physics**

a = V-V0)/t = (60-0)/7.2 = 8.33 m/s^2. F = M*a
*November 29, 2014*

**Math (Expectation)**

Robyn: M = 2mi/day * d days = 2*d = 2d.
*November 29, 2014*

**physics**

M*g = 20 * 9.8 = 196 N.=Wt. of suitcase. a. a = Fx/M = 50*cos30/20 = 2.17 m/s^2. b. Fn = 196 - 50*sin30 = 171 N.=Normal force = Force exerted on the bag by the floor.
*November 29, 2014*

**physics**

Output = 0.9333 * 75kW
*November 29, 2014*

**two step equation-fraction**

(4+m)/3 = 5/6 Multiply both sides by 6: 2(4+m) = 5 Multiply both terms inside the parenthesis by 2: 8 + 2m = 5 Subtract 8 from both sides: 8-8 + 2m = 5-8 0 + 2m = -3 2m = -3 Divide both sides by 2: m = -3/2 = -1 1/2.
*November 29, 2014*

**math**

See Related Questions: Tue,11-12-13, 9:28 AM.
*November 29, 2014*

**physics**

d = 44 Ft. g = 32 Ft/s^2 u = 0.50? Vo = ? a = u*g = 0.50 * (-32) = -16 Ft/s^2 V^2 = Vo^2 + 2a*d = 0 Vo^2 = -2a*d = -(-32*44) = 1408 Vo = 37.5 Ft/s.
*November 29, 2014*

**physics**

2m/s * 33s/3.5rev = 18.857 m/rev = Circumference(C). C = pi*2r = 18.857 m. 6.28r = 18.857 r = 3 m.
*November 29, 2014*

**maths**

Tan A = Y/X = (22-1.5)/20.5 = 20.5/20.5 = 1. A = 45o.
*November 29, 2014*

**math**

5/2 - 3/8 * Log3 = 2.321
*November 29, 2014*

**Pyhsics**

A. M*1.17g = 34.9 N. M*1.17*9.8 = 34.9 M*11.47 = 34.9 M = 3.04 kg B. 3.04 * a = 19.2 N. a = 6.31 m/s^2 on planet X. Note: It is the free-fall acceleration that changes; the mass remains constant.
*November 28, 2014*

**math**

Post it.
*November 28, 2014*

**Physics**

a. W = F*d = 453*Cos37 * d = 4820 J. d = 13.3 m. b. Fx-Fk = M*a 453*Cos37-Fk = M*0 = 0 Fk = 453*Cos37 = 361.8 N. = Force of kinetic friction. c. W = Fk*d = 361.8 * 13.3 = 4812 J. d. W = M*V^2/2 = 4820 J. M*7.82^2/2 = 4820 M*30.58 = 4820 M = 157.6 kg = Mass of the crate. M*g = ...
*November 26, 2014*

**AP Physics**

What is the question?
*November 25, 2014*

**business math**

I=Po*r*t = 3600*(0.088/365)*207=$179.66 = Penalty.
*November 25, 2014*

**MAT201 Basic Statistics**

Incomplete.
*November 24, 2014*

**Pre algebra**

X = Minutes used. Y = T0tal cost in Dollars. (X,Y), (20,48), (35,54), (40,56). m = (Y2-Y1)/(X2-X1)=(54-48)/(35-20) = 0.40 = Slope. (20,48) Y = mX + b = 48 0.4*20 + b = 48 b = 40 Eq: Y = 0.4X + 40
*November 24, 2014*

**Math with business apps**

P = Po * (1+r)^n r = (3%/12)/100% = 0.0025 = Monthly % rate expressed as a decimal. n = 12Comp./yr * 15 yrs. = 180 Compounding periods. Solve for P. I = P-Po
*November 24, 2014*

**Math with business apps**

See previous post: Mon,11-24-14, 6:31 PM
*November 24, 2014*

**MATH!!**

P = Po * (1+r)^n r = (4%/4)/100% = 0.01 = Quarterly % rate expressed as a decimal. n = 4Comp./yr. * 5yrs. = 20 Compounding periods. Solve for P. 2nd investment = P + $500 @ 5% for 5 yrs.
*November 24, 2014*

**math**

Mr. Beach: X min. Ms. Johnson: 2x min. Mrs. Rodriguez: (X+10) min. x+10 = 35 min. X = 25 min. 2x = 50 min. Total = 35 + 25 + 50 = 110 Min.
*November 24, 2014*

**Math**

P = Po*(1+r)^n r = (3%/12)/100% = 0.0025 = Monthly % rate expressed as a decimal. n = 12Comp./yr. * 15yrs. = 180 Compounding periods. Solve for P. I = P-Po
*November 24, 2014*

**Math**

P = Po * (1+r)^n r = (6.5%/12)/100% = 0.00542 = Monthly % rate expressed as a decimal. n = 1Comp./mo * 18mo = 18 Compounding periods. Solve for P.
*November 24, 2014*

**math**

B: X min. A: (X+36) min. A/B = (x+36)/x = 6/5 5x + 180 = 6x 5x - 6x = -180 -X = -180 X = 180 min. X+36 = 180+36 = 216 min.
*November 24, 2014*

**physics**

See previous post.
*November 23, 2014*

**physics**

a = (V^2-Vo^2)/2d = (0-(22.9^2)/149.2 = -3.51 m/s^2. F = m*a =1949.1 * (-3.51) = -6851 N. Note: The negative sign means that the force opposes the motion.
*November 23, 2014*

**Physics**

See previous post: Sun,11-23-14, 12:08 AM.
*November 23, 2014*

**Physics**

False.
*November 23, 2014*

**Physics**

Vo = 9.2m/s[47o] Xo = 9.2*Cos47 = 6.27 m/s. Yo = 9.2*sin47 = 6.73 m/s. a. Y = Yo + g*Tr = 0 @ max ht. Tr = -Yo/g = -6.73/-9.8 = 0.687 s. = Rise time or time to reach max ht. b. h max = ho + Yo*Tr + 0.5g*Tr^2 = 6.6 + 6.73*0.687 - 4.9*0.687^2 = 8.91 m. Above gnd. c. h = 0.5g*Tf^...
*November 23, 2014*

**Physics**

Vo = 215km/h = 215,000m/3600s.=59.72 m/s V = Vo + a*t = 0. Vo + a*t = 0 Solve for a; it should be negative.
*November 23, 2014*

**Physics**

Range = Vo^2*sin(2A)/g = 16 m. Vo^2*sin(110)/9.8 = 16 0.09589Vo^2 = 16 Vo^2 = 166.863 Vo = 12.92 m/s.
*November 23, 2014*

**capacitors**

Not enough INFO.
*November 23, 2014*

**physics**

Tf = 4/2 = 2 s. = Fall time. h = 0.5g*Tf^2 = 4.9 * 2^2 = 19.6 m.
*November 23, 2014*

**Physics**

V1 = a*t1 = 0.6rad/s^2 * 10s. = 6 rad/s. d1 = 0.5a*t1^2 = 0.3*10^2 = 30 Radians. d2=V1*t2 = 6rad/s. * 20s. = 120 Rad1ans V2 = V1 + a*t3 = 0 6 + a*10 = 0 10a = -6 a = -0.60 m/s^2 V2^2 = V1^2 + 2a*d = 0 d2 = -(V1^2)/2a = -(6^2)/-1.2 = 30 Rad. V=(d1+d2)/(t1+t2+t3)=(120+30)/(10+20...
*November 23, 2014*

**physics**

See Related Questions: Tue, 9-2-14, 11:13 AM.
*November 22, 2014*

**physics**

See previous post.
*November 22, 2014*

**physics**

M*g = 70.4kg * 9.8N/kg = 689.9 N. = Wt. of skier. Fp = 689.9*sin36.8 = 413.3 N. = Force parallel to the incline. Fn = 689.9*Cos36.8 = 552.4 N. = Normal force = Force perpendicular to the incline. Fk = u*Fn = 0.14 * 552.4 = 77.34 N. = Force of kinetic friction. a = (Fp-Fk)/M...
*November 22, 2014*

**physics**

a = (V-Vo)/t = (66-0)/4.5 = 14.67 m/s^2. F = M*a
*November 22, 2014*

**Physics**

A. X = 1.5 m/s Y = 2 m/s. TanA = Y/X = 2/1.5 = 1.33333 A = 53o, CCW = 90-53 = 37o E. of N. or [N37E].
*November 22, 2014*

**Physics**

M*g = 4kg * 9.8 N./kg = 39.2 N. = Wt. of the bundle. KE = M*Vo^2/2 = 128 J. 4*Vo^2/2 = 128 Vo^2 = 64 Vo = 8 m/s = Initial velocity. a = u*g = 0.3 * (-9.8) = -2.94 m/s^2. V^2 = Vo^2 + 2a*d = 0 @ max ht. Vo^2 + 2a*d = 0. Solve for d.
*November 22, 2014*

**physics**

The position versus time for a certain object moving along the x-axis is shown. The object’s initial position is −2 m. Find the instantaneous velocity at 6 s. Answer in units of m/s
*November 21, 2014*

**Math**

P1 = Po*(1+r)^n. Compounded annually. r = 12%/100% = 0.12 = Annual % rate expressed as a decimal. n = 1Comp./yr. * 4yrs. = 4 Compounding periods. P1 = 6,000*(1.12)^4 = $9441.12 P2 = Po*(1+r)^n. Compounded quarterly. r = (12%/4)/100% = 0.03 = Quarterly % rate. n = 4Comp./yr. * ...
*November 21, 2014*

**physic**

Vo = 55m/s[30o] Xo = 55*Cos30 = 47.63 m/s Yo = 55*sin30 = 27.5 m/s. a. Y = Yo + g*Tr = 0 @ max ht. Tr=-Yo/g = -27.5/-9.8 = 2.806 s.=Rise time. Tf = Tr = 2.806 s. = Fall time. Tr+Tf = 2.806 + 2.806 = 5.61 = Time in air. b. Dx = Xo*(Tr+Tf) = 47.63m/s * 5.61s = 267.3 m. from base...
*November 21, 2014*

**physics**

a. Correct The last sentence in your problem is incomplete.
*November 21, 2014*

**MATH**

2AB + AB1 = 2AB + 1AB = 3AB.
*November 21, 2014*

**math**

Incomplete.
*November 21, 2014*

**physics**

Mass = 200kg? Vo = 15 m/s. V = 25 m/s. t = 10 s. a = (V-Vo)/t = (25-15)/10 = 1 m/s^2. F = m*a = 200 * 1 = 200 N. d = Vo*t + 0.5g*t^2=15*10 + 4.9*10^2 = 640 m. W = F*d = 200 * 640 = 128,000 Joules.
*November 21, 2014*

**math**

Correction: T = 10/3-6/5 = 50/15 - 18/15 = 32/15 = 2.1333 h Vp+Vw = 900/2.1333 = 421.875 mi/h Vp = (270+421.875)/2 = 346 mi/h = Velocity of the plane without wind.
*November 21, 2014*

**math**

Vp-Vw=900/(10/3) = 900 * 3/10 = 270 mi/h Vp+Vw=900/(50/60)=900 * 60/50=1080 mi/h Vp - Vw = 270 Vp + Vw = 1080 Sum: 2Vp = 1350 Vp = 675 mi/h. = Velocity of plane without the wind.
*November 21, 2014*

**Physics**

M*g = 310kg * 9.8N/kg = 3,038 N. = Wt. of the crate = Normal force(Fn). Fap-Fk = M*a (440+230)-Fk = M*0 = 0 670 - Fk = 0 Fk = 670 N. = Force of kinetic friction uk = Fk/Fn = 670/3038 = 0.221
*November 21, 2014*

**physics**

d = 0.5a*t^2 = 200 m. 0.5a*19.5^2 = 200 190.125a = 200 a = 1.052 m/s^2. V = a*t = 1.052m/s^2 * 1.7s = 1.788 m/s.
*November 20, 2014*

**physics**

Vo = 1000m/s[24o] Xo = 1000*Cos24 = 913.5 m/s. Yo = 1000*sin24 = 406.7 m/s. h1=Yo*t + 0.5a*t^2=406.7*2 + 7.5*2^2 = 843.4 m Y1 = Yo + a*t = 406.7 + 15*2=436.7 m/s. Y2 = Y1 + g*t = 0 @ max ht. t = -Y1/g = -436.7/-9.8 = 44.56 s. Tr = t+2 = 44.56 + 2 = 46.56 s. = Rise time or time...
*November 20, 2014*

**ap physics**

See Related Questions: Sun, 9-2-14, 11:13 AM.
*November 20, 2014*

**physics**

Range = Vo^2*sin(2A)/g = 10.1 m. Vo^2*sin(90.8)/9.8 = 10.1 0.102Vo^2 = 10.1 Vo^2 = 98.99 Vo = 9.95 m/s.
*November 20, 2014*

**Math**

A different Method: X Grams per apple. Y Grams = Wt. of basket. Eq1: 12x + Y = 3105 Eq2: 7x + Y = 1980 Diff: 5x = 1125 X = 225 In Eq1, replace X with 225: 12*225 + Y = 3105 Y = 3105 - 2700 = 405.
*November 20, 2014*

**Math**

Correction: After removing 5 apples, we took the reduction in Wt.(1125grams) and divided by the # of apples removed(5). That gave us the wt. per apple.
*November 20, 2014*

**Math**

(3105-1980)/(12-7) = 225 grams/apple 3105 - (12*225) = 405 grams = Wt. of the basket. 1980 - (7*225) = 405 grams = Wt. of basket. Note: After removing 7 apples, we took the remaining wt(1125grams) and divided by the remaining # of apples(5). That gave us the Wt. per apple.
*November 20, 2014*

**physics**

M*g = 13 * 9.8 = 127.4 N. = Wt. of box = Normal force(Fn). Fap-Fs = M*a 47 - Fs = M*0 = 0 Fs = 47 N. = Force of static friction. us = Fs/Fn = 47/127.4 = 0.369
*November 20, 2014*

**physics**

V8y^2=X^2 + Y^2 = 3.98^2 + (-3.16)^2=25.83 V = 5.08 m/s. Momentum = M*V = 4.53 * 5.08 = 23 kg.m/s
*November 20, 2014*

**Physics**

KE = M*V^2/2 = 3.54*596^2/2 = 628,732 J
*November 20, 2014*

**Science**

M*g = 32kg * 9.8m/kg = 313.6 N. = Wt. of crate. = Normal force(Fn). Fk = u*Fn = 0.57 * 313.6 = 178.8 N. = Force of kinetic friction. F-Fk = M*a F-178.8 = 32 * 1.8 = 57.6 F = 57.6 + 178.8 = 236.4 N.
*November 20, 2014*

**physics**

h = 0.5g*t^2 = 40 m 4.9t^2 = 40 t^2 = 8.16 Tf = 2.86 s. = Fall time. Dx = V*Tf = 1.2m/s * 2.86s = 3.43 m.
*November 20, 2014*

**physics**

a = u*g = 0.8 * (-9.8) = -7.84 m/s^2 V = Vo + a*t = 0 27 - 7.84*t = 0 -7.84t = -27 t = 3.44 s.
*November 20, 2014*

**physics**

Incomplete.
*November 20, 2014*

**Physics**

F = m*g = 1*10^4kg * 9.8N/kg = 9.8*10^4N P = F*d/t = 9.8*10^4 * 20/5 = 3.92*10^5 J/s = 3.92*10^5 Watts. = 3.92e5 Watts. Note: Your Eq should have been m*g * d/t You omitted g(9.8m/s^2).
*November 19, 2014*

**physics**

V^2 = Vo^2 + 2a*d V = 561 m/s Vo = 0 d = 0.976 m. a = ?
*November 19, 2014*

**physics**

V = Vo + a*t
*November 19, 2014*

**physics**

Y^2 = Yo^2 + 2g*h = 0 @ max ht. Yo^2 = - 2(-9.8)*45 = 882 Yo = 29.7 m/s = Vertical component of initial velocity. Vo*sin50 = Yo = 29.7 Vo = 38.8 m/s.
*November 19, 2014*

**Math**

P = Po*(1+r)^n r = (7%/4)/100% = 0.0175 = Quarterly % rate expressed as a decimal. n = 4 Comp./yr. * 7yrs. = 28 Compounding periods. P = Po*(1.0175)^28 = 30,000 Po = 30,000/(1.0175)^28 = $18,456.85 = Initial deposit.
*November 19, 2014*

**Math**

Find the value of b, if any, that will make the function differentiable at x = 0 g(x)= { x+b, x<0 cos(x), x≥0 can you help, I got 0 but I don't know if that will make the function differential at x=0.
*November 18, 2014*

**Math**

Find the value of b, if any, that will make the function differentiable at x = 0 g(x)= { x+b, x<0 cos(x), x≥0 can you help, I got 0 but I don't know if that will make the function differential at x=0.
*November 18, 2014*

**5th grade math**

X = Total # of flowers. Pink = X/4 Flowers. Bal. = X - X/4 = 3x/4 Red = 2/5 * 3x/4 = 6x/20=3x/10 Flower. Yellow = 18 X/4 + 3x/10 + 18 = X Multiply both sides by 20: 5x + 6x + 360 = 20x 11x - 20x = -360 -9x = -360 X = 40
*November 18, 2014*

**physics**

Momentum = M*(V-Vo) = 2*(8-0) = 16 J/s.
*November 18, 2014*

**Physics**

M1*V1 + M2*V2[90o] = 2.59m/s[23.9o] 8.34*2.4 + 0.170*V2[90o] = 2.59[23.9o] 20.02 + 0.170*V2[90] = 2.37 + 1.05i 0.170V2[90] = 2.37-20.02 + 1.05i 0.170V2[90] = -19 + 1.05i 0.170V2{90] = 19.03[176.8o] V2 = 112m/s[86.8o] = Velocity of the puck.
*November 18, 2014*

**math**

Compounded Int. P1 = Po(1+r)^n r = 4.8%/100 = 0.048 = Annual % rate expressed as a decimal. n = 1Comp./yr. * 10Yrs. = 10 Compounding periods. P1 = 850(1.048)^10 = $1358.41 Simple Int. P2 = Po + Po*r*t = 850 + 850*0.048*10 = $1258.00 P1-P2 = 1358.41 - 1258 = $100.41
*November 17, 2014*

**science**

M*g = 2000kg * 9.8N./kg = 19,600 N. = Wt of car. = Normal Force(Fn). a = u*g = 0.2 * (-9.8) = -1.96 m/s^2. d = -Vo^2/2a = -(27^2)/-3.92 = 186 m. = Stopping distance.
*November 17, 2014*

**math**

See previous post
*November 17, 2014*

**math**

See previous post.
*November 17, 2014*

**algebra**

L(x) = 100*e^-1.5 = 100*0.22313=22.313 %
*November 17, 2014*

**algebra**

I(30) = 81,000 - 45,000e^-0.005t = 81,000 - 45,000*e^(-0.15) = $42,268.14 I(130) = 81,000 - 45,000*e^(-0.65) = b. I(approach): 81,000 - 0 = $81,000
*November 17, 2014*

**MATH**

X = # heads to begin the day. (X-24) = Bal. after morning sale. (2/7)*(X-24) sold during afternoon. Bal. = (5/7)*(X-24) = X/2 (10/7)(X-24) = X (10x-240)/7 = X 10x - 240 = 7x 10x - 7x = 240 3x = 240 X = 80
*November 17, 2014*

**physical**

Fk = u*Fn = 40. Solve for Fn
*November 17, 2014*

**physics**

I agree with your answer.
*November 17, 2014*

**physics**

M = 70.3 kg = Mass of the person. Dj = Density of the jacket. Vj = 0.0307 m^3 = Vol. of the jacket. Dp = Density of the person. Vp = 0.0649 m^3 = Vol. of the person. Dw = 1000kg/m^3 = Density of water. Mj+Mp = (Vj+Vp) * Dw Mj+Mp = 0.0956m^3 * 1000kg/m^3=95.6 kg Mj = 95.6 - Mp...
*November 16, 2014*

**Physics**

M*g = 25kg * 9.8N./kg = 245 N. = Wt. of the box = Normal force. Fk = u*Fn = 0.55 * 245 = 134.75 N. = Force of kinetic friction. a. Fp-Fk = M*a Fp - 134.75 = M*0 = 0 Fp = 134.75 N. = Pulling force. b. F(net) = Fp-Fk = 350 - 134.75 = 215.3 N. c. a = (Fp-Fk)/M = 215.3/25 = 8.61 m...
*November 16, 2014*

**physics grade 11**

See previous post.
*November 16, 2014*

**physical education**

KE = M*Vo^2/2 = 196 J. 1*Vo^2/2 = 196 Solve for Vo. V^2 = Vo^2 + 2g*h = 0 @ max ht. h = -Vo^2/2g. g = -9.8 m/s^2 Solve for h.
*November 16, 2014*

**physics**

They are asking for the PE at A only: PE = m*g*h1
*November 16, 2014*