Wednesday

November 26, 2014

November 26, 2014

Total # Posts: 9,597

**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 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**

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*

**physics**

See previous post: Sat,11-15-14, 5:29 PM.
*November 16, 2014*

**physics**

V^2 = V1^2 + 2g*h = 0 @ max ht. Vo^2 = -2g*h = 19.6*24.2 = 474.32 Vo = 21.8 m/s = Initial velocity. h = (V^2-Vo^2)/2g = (0-(21.8^2)/-3.2 = 148.3 m.
*November 15, 2014*

**physics**

See previous post: 5:29 PM.
*November 15, 2014*

**physics**

See previous post: 5:29 PM.
*November 15, 2014*

**physics**

1. V = (85,000/500,000) * 54,540,000 m^3 2. Dw = 1g/cm^3 = 1,000kg/m^3 = Density of water. Mass(kg) = V * 1000 3. h1 = 74 m, h2 = 221, h3 = 55 h = (h2-h1) + h3. 4. PE(gained) = mg*h - Mg*h1 PE/Mass = PE gained per kg of water.
*November 15, 2014*

**physics**

m*g = 4.3kg * 9.8N/kg = 42.14 N. = Wt. of block. b. a = u*g = 0.26 * (-9.8) = -2.548 m/s^2 V2^2 = V1^2 - 2*2.548*7.8 = 0 V1^2 = 39.75 V1 = 6.30 m/s = Initial velocity. KE = m*V1^2/2 = 42.14*39.75/2 = 838 J. c. = (1m/660N) * 42.14N = 0.0638 m.
*November 15, 2014*

**maths**

A1 = pi*r^2 A2 = pi*(r+6)^2 = 4A1 = 4*pi*r^2 pi*(r+6)^2 = 4*pi*r^2 Divide both sides by pi: (r+6)^2 = 4r^2 r^2 + 12r + 36 = 4r^2 r^2 - 4r^2 + 12r +36 = 0 -3r^2 + 12r + 36 = 0 Divide both sides by -3: r^2 - 4r - 12 = 0 (r-6)(r+2) = 0 r-6 = 0 r = 6. r+2 = 0 r = -2 Select ...
*November 15, 2014*

**Physical science**

a= 1.6 m/s^2 t = 10 s. V = a*t
*November 15, 2014*

**Physical science**

See previous post.
*November 15, 2014*

**Physical science**

AC = AB + BC = 50 + 120 = 170 m. t = d/V = 170/5 = 34 s.
*November 15, 2014*

**Physical science**

AC = AB + BC = 50 + 120 = 170 m.
*November 15, 2014*

**math**

See previous post: Sat, 11-15-14, 4:37 AM.
*November 15, 2014*

**math**

sqrt(N) = (N)^1/2. D^2 = (4*2^1/2-3^1/2)^2 + (6^1/2+2)^2 = 35.2 D = 5.933 cm.
*November 15, 2014*

**MATH**

The sqrt(N) = (N)^1/2. (m+3)^1/2 + (m-2)^1/2 = 5 m+3)^1/2 = 5 - (m-2)^1/2 Square both sides: m+3 = 25 - 2*5*(m-2)^1/2 + m-2 m+3 -m+2 = 25 - 10(m-2)^1/2 5 = 25 - 10(m-2)^1/2 Divide both sides by 5: 1 = 5 - 2(m-2)^1/2 2(m-2)^1/2 = 5-1 = 4 Square both sides: 4(m-2) = 16 4m - 8 = ...
*November 15, 2014*

**math**

TanA = Y/X = 5/6
*November 15, 2014*

**physical**

P2(-3,-4), P1(3,4). P1 - P2: X = 3-(-3) = 6 Meters. Y = 4-(-4) = 8 Meters. (X,Y) = (6,8).
*November 14, 2014*

**physics**

M =0.009 kg PE = Mg*h = 0.009*9.8*4.0 = 0.3528 J.
*November 14, 2014*

**math**

A = 11/16 * 256 = 176
*November 14, 2014*

**Physics**

m*g = 130kg * 9.8N./kg = 1274 N. Fn = m*g = 1274 N. Fk = u*Fn = 0.35 * 1274 = 446 N. = Force of kinetic friction. a = (Fap-Fk)/m = (-800-446)/130 = -9.58 m/s^2 V2^2 = V1^2 + 2a*d = 0 d = -V1^2/2a = -(10.2^2)/-19.17 = 5.43 m. = Stopping distance. Note: The force applied is ...
*November 13, 2014*

**6th grade math**

Baby eats X Lbs. Male eats 3x Lbs. Female eats 2x Lbs. x + 2x + 3x = 181.5 Lbs. Solve for x.
*November 13, 2014*

**Math**

2 * 48 = 96 Ounces 96/8 = 12- Eight oz. classes.
*November 13, 2014*

**physics**

F = m*a
*November 13, 2014*

**Physics-Atwood's Machine**

m*g = 5kg * 9.8N./kg = 49 N. Fk = u*mg = 0.5 * 49 = 24.5 N. = Force of kinetic friction. Fx-Fk = m*a Fx-24.5 = 5 * 3 = 15 Fx = 15 + 24.5 = 39.5 N.
*November 13, 2014*

**science**

m*g = 40 N. 4.20g = 40 g = 9.52 m/s^2 a = F/m = 45.5/4.20 = 10.83 m/s^2.
*November 13, 2014*

**Math help please!!!!!!**

C is correct.
*November 13, 2014*

**physics**

Yo = 141*sin45 = 99.7 m/s.
*November 13, 2014*

**physics**

Momentum = m*V = 0.1 * 500
*November 13, 2014*

**physics**

M = 4.5 kg h = 1500cm = 15 m. F = 1861N/m * 0.12m = 223.32 N. a = F/m = 223.32/4.5 = 49.63 m/s^2 V2^2 = V1^2 + 2a*h=0 + 99.25*15=1488.8 V2 = 38.6 m/s = Speed of block.
*November 12, 2014*

**Freshman Algebra**

Private plane: 500km/h * 1h = 500km Head-start. d1 + d2 = 2100 km 500+500t + 700t = 2100 1200t = 2100-500 = 1600 t = 4/3 = 1 1/3 Hours(1:20 PM).
*November 12, 2014*

**Physics (Work Problem)**

a. Work = Fx * d = 50*Cos30 * 10 = 433 J
*November 12, 2014*

**physics**

Correct!
*November 12, 2014*

**Physics**

g/2^2 = g/4.
*November 12, 2014*

**Physics**

F = 110N[45o] Fx = 110*Cos45 = 77.78 N.
*November 12, 2014*

**Science**

T = 1/F = 1/0.5 = 2 s. = Period = Time between crests. WL = V*T = 6 m. V * 2 = 6 V = 3 m/s.
*November 12, 2014*

**Physics**

a. d1 = 0.5a*t^2 = 0.5*1.3*5.9^2=22.63 m V1 = a*t = 1.3 * 5.9 = 7.67 m/s. V = V1 + a*t = 7.67 - 1.7*1.6 = 4.95 m/s b. d1 = 0.5a*t^2 = 0.5*1.3*5.9^2=22.63 m d2 = (V^2-V1^2/2a = (4.95^2-(7.67^2))/-3.4 = 10.1 m. d = d1+d2 = 22.63 + 10.1 = 32.73 m
*November 12, 2014*

**physics**

d = 4.3*10^-6cm/s * 3600s/h * 8760h/yr. * 6.4yrs. = 868 cm.
*November 11, 2014*

**math**

Your problem would be easier to under- stand if you proof-read it and show punctuations.
*November 11, 2014*

**Math**

Log2(x+4) = Log2(x^2+2) x + 4 = x^2 + 2 x - x^2 = 2 - 4 -x^2 + x = -2 -x^2 + x + 2 = 0 Multiply both sides by -1: x^2 - x - 2 = 0 -2 = -2*1. Sum = -2 + 1 = -1 = B. x+(-2)) = 0 x-2 = 0 X = 2 x+1 = 0 X = -1 Solution: X = -1, and 2.
*November 11, 2014*

**physics**

Work = Fx*d = 148*Cos35 * 2 = 242.5 N.
*November 11, 2014*

**physics**

Wt. = (1.61/9.8) * 54.3N. = 8.92 N.
*November 11, 2014*

**physics**

KE = m*V^2/2 2KE = m*V^2 m = 2KE/V^2 m*V^2 = 2KE V^2 = 2KE/m V = Sqrt(2KE/m)
*November 11, 2014*

**physics**

d = 0.5a*t^2 = 122.1 m. 2.4*t^2 = 122.1 t^2 = 50.875 t = 7.13 s. V = a*t = 4.8 * 7.13 = 34.2 m/s.
*November 10, 2014*

**physics**

h = 0.5*t^2 = 125 m. 4.9t^2 = 125 t^2 = 25.51 Tf = 5.05 s. = Fall time. Dx = Xo * Tf = 144m/s * 5.05s = 727 m. From the cliff.
*November 10, 2014*

**Math**

10yds * 36in/yd. = 360 In. 360in * 1ribbon/6in. = 60 Ribbons.
*November 10, 2014*

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