Saturday

August 1, 2015

August 1, 2015

Total # Posts: 10,787

**Physics**

P = (0.45m/3.6m) * 1s. = 0.125 s. = The period of the wave. Freq. = 1/P = 1/0.125 = 8 Cycles/s = 8 Hz.
*May 17, 2014*

**Physics**

d=V*T = 3*10^8 * (1.9*10^-3/2) = 2.85*10^5 m.
*May 17, 2014*

**Geometry**

As = 2*(W*h)) + 2*(L*h) + 2(L*W) a. As = Al + 2*(L*W) = 992 Ft^2 Al + 2*(20*12) = 992 Al = 992 - 480 = 512 Ft^2.=Lateral area. b. Al = 2(W*h) + 2(L*h) = 512 Ft^2 2(12*h) + 2(20*h) = 512 Solve for h.
*May 17, 2014*

**physics**

Circumference = pi*2r = 3.14 * 80 = 251.3 cm. = 2.513 m. V=300rev/min * 2.513m/rev * 1min/60s = 12.57 m/s. = Linear speed. Va = 12.57m/s * 6.28rad/2.513m=31.4rad/s = Angular speed.
*May 17, 2014*

**physics**

X = 100N Y = 100N Tan A = Y/X = 100p/100 = 1.0 A = 45o = Direction. Fr = X/Cos A = = 100/Cos45=141.4N[45o]= Resultant force. a=Fr/m=141.4[45o]/100kg=1.414m/s^2[45o].
*May 16, 2014*

**math**

Ans: D
*May 15, 2014*

**Pre cal**

1. AB+BC = 200km[110o] + 100km[37o] X = 200*cos110 + 100*cos37 = 11.46 km. Y = 200*sin110 + 100*sin37 = 248.1 km. D^2 = X^2 + Y^2 = (11.46)^2+(248.1)^2 = 61,685 D = 248.4 km 2. V = 530mph[N25oW] = 530mph[115o] CCW.
*May 15, 2014*

**Pre cal**

1. An airplane flies 200 km on course 110 degrees from point A to point B. At point B the pilot changes course to 37 degrees. The plane then flies 100 km to point C. Find the magnitude of the net displacement from A to C. 2. A plane is flying on a bearing of 25 degrees west of...
*May 15, 2014*

**Physic**

k = 50N/(25-20)cm = 10N/cm. L = 20cm + (100N/10N) * 1cm = 30 cm.
*May 15, 2014*

**algebra**

Po = $32,500 @ 69%? for 3 years. P1 = Po(1+r)^n. Compounded annually. P1 = 32,500(1+0.69)^3 = $156,871.29 P2 = 32,500(1+0.69/2)^6 = 192,405.32 P3 = 32,500(1+0.69/4)^12 = 219,400.48 P4 = 32,500(1+0.69/12)^36 = 243,207.46 P5 = 32,500(1+0.69/365)^1095=257,053.95 P6 = 32,500(1+0....
*May 14, 2014*

**math**

Assuming simple interest: A. Po = 2055.99-400 = 1655.99 P = Po + Po*r*t P = 1655.99 + 1655.99*0.0725*2 P = 1655.99 + 240.12 = $1896.11 1896.11/24mo = $79.00/Mo. B. P = 180/mo * 12mo = $2160. r = (p-Po)/Po = (2160-2055.99)/2055.99 = 0.0506 = 5.06% Per annum C. Option 1: $1896....
*May 14, 2014*

**Math**

(4/3)*Log(z+2) = Log 4 Log(z+2) = Log 4/(4/3) Log(z+2) = (3/4)*Log 4 = 0.4515 10^(0.4515) = z+2 z+2 = 2.828 Z = 0.828
*May 14, 2014*

**Math**

V(1,2), W(-2,-3) X = 1 + (-2) = -1. Y = 2 + (-3) = -1. (x,y) = (-1,-1).
*May 13, 2014*

**math**

A(-2,3),--B(4,3) C(-2,-2), D(4,y) AC = -2-3 = -5 BD = AC = -5 = y-3 y-3 = -5 Y = -2.
*May 13, 2014*

**Algebra 1**

post it.
*May 13, 2014*

**Algebra 1**

See previous post: Tue,5-13-14, 1:15 PM.
*May 13, 2014*

**Algebra 1**

2x^2 + 7x + 8 = 0 B^2 = 7^2 = 49 4AC = 4*2*8 = 64. Since B^2 is less than 4AC, there are no real solution. But there are 2 imaginary solutions: X = (-B +-sqrt(B^2-4AC))/2A X =(-7 +-sqrt(49-64))/4 X = (-7+-sqrt(-15))/4 X = (-7+-sqrt(15*-1))/4 X = (-7+-(3.87i))/4 X = -1.75 + 0....
*May 13, 2014*

**Algebra 1 Answer Evaluation**

V = Vo + g*Tr = 0 Tr = (V-Vo)/g = (0-64)/-32 = 2 s. = Rise time. Tf = Tr = 2 s. = Fall time. Tr+Tf = 2 + 2 = 4 s. = Time it takes to return to gnd.
*May 13, 2014*

**Math - Proportion**

a. I = P^2/V b. I = (2P)^2/2V = 4P^2/2V = 2P^2/V. Therefore, I is doubled.
*May 13, 2014*

**Algebra 1**

(x+2)(x-5) = 60 x^2-5x +2x - 10 = 60 x^2 - 3x - 70 = 0 C = -70 = 7*(-10). B = 7 + (-10) = -3. (x+7)(x-10) = 0 x+7 = 0, X = -7. x-10 = 0, X = 10.
*May 13, 2014*

**Physical World Concepts**

Fn = 250 - 120 = 130 N.
*May 13, 2014*

**math**

Compounded Daily? Monthly? Annually?
*May 12, 2014*

**Algebra**

Width = W Ft. Length = (W+2) Ft. Area = (W+2)*W = 15Ft^2 W^2 + 2W - 15 = 0 C = -15 = -3*5 (W-3)(W+5) = 0 W-3 = 0 W = 3 W+5 = 0 W = -5. The width can't be negative. Therefore, W = 3 Ft. Length = W+2 = 3 + 2 = 5 Ft.
*May 12, 2014*

**Finance**

P = Po(1+r)^n P = $3,800 r = (8.9%/12)/100% = 0.00742 = Monthly % rate expressed as a decimal. n = 12comp./yr. * 5yrs.=60 Compounding periods. P = Po(1+0.00742)^60 = 3800 Po*(1.00742)^60 = 3800 Po = 3800/(1.00742)^60 = $2438.65 = Present value.
*May 12, 2014*

**Algebra 1 (Step-by-Step)**

1. -7 = X^2 x^2 + 7 = 0 X =( -B +- sqrt(B^2-4AC))/2A X = (0 +- sqrt(0-28))/2 = sqrt(28*(-1))/2 = 5.29i/2 = +-2.65i
*May 12, 2014*

**math**

10. P1 = Po(1+r)^n Po1 = $5,000 r = (6%/2)/100% = 0.03 n = 2comp/yr. * 2yrs. = 4 Compounding periods. P1 = 5000(1.03)^4 = $5627.54 in 2 yrs. P2 = P1(1+r)^n r = (8%/4)/100% = = 0.02 n = 4comp/yr. * 1.5yrs. = 6 Compounding periods. P2 = 5627.54(1.02)^=$6337.53 in 3.5 yrs.
*May 12, 2014*

**math**

a. Ar = Ab - Ab*r*t Ar = Ab - Ab*(0.055/360)*(60-15)=997.77 Ab - Ab*0.006875 = 997.77 0.993125Ab = 997.77 Ab = $1004.68 = Amt. borrowed. Ac = Ab-Ar = 1004.68 - 997.77 = $6.91 = Amt. charged. b. Face Value = Ab = $1004.68
*May 12, 2014*

**math**

5. Ar = Ab - Ab*r*t = 2,000 Ab - Ab*(0.08/360)*120 = 2,000 Ab - 0.02667Ab = 2000 0.97333Ab = 2000 Ab = $2,054.79 = Amount borrowed.
*May 12, 2014*

**math**

Correction: My calculations was based on a 4-day loan; it should be for 4 months: 2. Pr = Po - Po*r*t = 12,000 Po - Po*(0.095/12)*4 = 12,000 Po - Po*0.03167 = 12000 0.96833Po = 12,000 Po = $12,392.46
*May 12, 2014*

**math**

1. P = Po - Po*r*t P = 5000 - 5000*(0.085/360)*180 P = 5000 - 212.50 = $4787.50 = Amt. received by Joanne(Proceeds). 2. P = Po - Po*r*t = 12,000 Po - Po*(0.095/360)*4 = 12,000 Po - Po*0.00106 = 12000 0.99894Po = 12,000 Po = $12,012.68
*May 12, 2014*

**Math**

Y = -3x^2 + x. Yes.
*May 11, 2014*

**math**

Correction: Cross multiply: 3-6x = 276.71 -6x = 276.71-3 = 273.71 X = -45.62
*May 11, 2014*

**math**

Denominator = 4.13? 67 = (3-6x)/4.13 Cross multiply: 3x-6 = 276.71 3x = 276.71+6 = 282.71 X = 94.24
*May 11, 2014*

**math**

X = 686 cm Y = 438 cm D = X + Y = 686 + 438 = 1124 cm of denim
*May 11, 2014*

**Physics**

Correction: Change 127.2 J./s to 127.2 kJ/s = 127.2 KW.
*May 9, 2014*

**Physics**

V = 12.5km/h = 12500m/3600s. = 3.47 m/s. P = 55F*V = 55*mg*V = 55*68*9.8*3.47 = 127.2 Joules/s = 127.2 Watts.
*May 9, 2014*

**Math**

I1 = Po*r*t=20000*(0.025/365)*91=124.66 I2 = 20000*(0.0175/365)*80 = 76.71 I1-I2 = 124.66-76.71 = $47.95 More
*May 9, 2014*

**Physics**

1. I = V/R The voltage across each resistor is equal. Therefore, the lowest resistance (20)draws the greatest current. 2. V = I * R In a series circuit, the same current flows through each resistor. Therefore, the largest resistance(60) will have the greatest potential ...
*May 8, 2014*

**Physics**

Y^2 = Y0^2 + 2g*h Yo^2 = Y^2-2g*h = 0 + 19.6*10 = 196 Yo = 14 m/s = Ver. component of initial velocity. Yo = Vo*sin60 = 14 m/s. Vo = 14/sin60 = 16.2m/s[60o]
*May 8, 2014*

**Physics**

h = 0.5g*t^2 = 10 m. h = 4.9*t^2 = 10 t^2 = 2.04 Tf = 1.43 s Xo*1.43 = 10 m. Xo = 7.0 m/s
*May 8, 2014*

**Math 10**

V^2 = Vo^2 + 2g*h Vo^2 = V^2-2g*h = 0 + 20*(11-6) = 100 Vo = 10 m/s. To pass over tree. a. 0.5g*t^2 = 6 b. h max = 6 m. = Ht. of balcony.
*May 8, 2014*

**Physics**

Xo = 2.4 m/s h = 0.5g*t^2 = 2.5 m. 4.9*t^2 = 2.5 t^2 = 0.510 Tf = 0.714 s. = Fall time. D1 = Xo * Tf = 2.4m/s * 0.714s = 1.71 m. 4.9*t^2 = 5 m. t^2 = 1.02 Tf = 1.01 s. D2 = 2.4m/s * 1.01s = 2.42 m. D2-D1 = 2.42 - 1.71 = 0.714 m.
*May 8, 2014*

**Physics 270-1 Applied**

a. V = Vo + g*t = 30 + 32*3.5 = 135 Ft/s b. h = Vo*t + 0.5g*t^2 h = 30*3.5 + 16*3.5^2 = 301 Ft.
*May 8, 2014*

**Physics**

Correction: a = (Fap-Fp-Fk)/m = (50.09-17.69-2.56)/3 = 9.95 m/s^2. V^2 = Vo^2 + 2a*d = 0 + 2*9.95*2 = 39.8 V = 6.30 m/s. KE = 0.5m*V^2 = 0.5*3*39.8 = 59.7 J.
*May 7, 2014*

**Physics**

Wb = m*g = 3kg * 9.8N/kg = 29.4 N. = Weight of block. Fp = 29.4*sin37 = 17.69 N. = Force parallel to the incline. Fn = 29.4*cos37 = 25.61 N. = Normal force = Force perpendicular to the incline. Fk = u*Fn = 0.1 * 25.61 = 2.56 N = Fap = 40/cos37 = 50.09 N. Parallel to incline. a...
*May 7, 2014*

**Math**

A = X Ft^2 B = (X+200) Ft^2 C = (X+200) +400 Ft^2 D = (X+200)+400 + 800 AREA = 4x + 600 + 800 + 800 = 4x + 2200 = 4A + 2200 Answer: She must measure Region A, multiply the results by 4, and add 2200 Ft^2.
*May 7, 2014*

**physics**

Mass = 150Lbs * 0.454kg/Lb = 68.1 kg. d = 75Ft * 1m/3.3Ft = 22.73 m. Work = F*d = F * 22.73 = 3813.75 Fn = 3813.75/22.73 = 167.8 N = Net force a = Fn/mass = 167.8/68.1 = 2.46 m/s^2 Vo = 1Ft/s * 1m/3.3Ft = 0.303 m/s = Initial velocity. V^2=Vo^2 + 2a*d=0.303^2 + 2*2.46*22.73 = ...
*May 7, 2014*

**Science**

Ct = 10uF/3 = 3.33 uF. Qt = Q1 = Q2 = Q3 = Ct*V = 3.33 * 100 = 333 Micro coulombs.
*May 7, 2014*

**science**

Wt = m * g. So the wt. decreases with distance.
*May 7, 2014*

**Physics**

See 10:24 PM post.
*May 6, 2014*

**Physics**

a = F/m = 65/0.075 = 867 m/s^2. V^2 = Vo^2 + 2a*d = 0 + 2*867*.9 = 1560 V = 39.5 m/s.
*May 6, 2014*

**Math!!**

-3(-9)+(3 + (2*5^2)) = 27 + (3 + (2*25)) = 27 + (3 + 50) = 27 + 53 = 80.
*May 6, 2014*

**algebra**

Glad I could help.
*May 6, 2014*

**algebra**

25 = (1/5)^-2 25 = 1/(1/5)^2 25 = 1/(1/25) 25 = 1 * 25/1 25 = 25
*May 6, 2014*

**math**

1. V = L*W*h = 3 1/2 * 1 1/2 * 2 = 7/2 * 3/2 * 2/1 = 42/4=10.5 cubic units. 2. 8 Cubes. 4. V = 1 * 1 * 1 = 1 Gubic units. 3.
*May 6, 2014*

**physics**

Work = F * d. Therefore,increasing the force or distance increases the amount of work done.
*May 5, 2014*

**Physics URGENT!!!!!!!!!!!!**

See previous post: 5-5-14, 11:42 AM.
*May 5, 2014*

**Physics URGENT!!!!!!!!!!!!**

Fr = ((Vs-Vr)/(Vs+Vb))*Fb Fr = ((343-0)/(343+Vb))*80 = 76 kHz (343/(343+Vb))*80 = 76 27,440/(343+Vb) = 76 26,068+76Vb = 27,440 76Vb = 27440 - 26,068 = 1372 Vb = 18 m/s. = Velocity of the bat. The bat is receding, because the freq. heard is lower than the freq. emitted by the ...
*May 5, 2014*

**physics**

Vt=120000m/h = 120000m/3600s = 33.33 m/s Fp = ((Vs+Vp)/(Vs-Vt))*Ft Fp = ((343+0)/(343-33.33))*600 Hz Fp = (343/309.7)*600 = 664.6 Hz = Freq. heard by the person. L = Vs/Fp = 343/664.6 = 0.516 m. = Wave- length.
*May 5, 2014*

**MATHS - FRACTION**

To add or subtract fractions, they must have the same denominator. The fraction that is being subtracted must be smaller than the other fraction. Given: 3 1/3 - 1 3/4 Step 1. Find a common denominator: 3 4/12 - 1 9/12 Step 2. Subtract 1(1=12/12) from 3 and add it to 4/12: 2 16...
*May 5, 2014*

**Physics question**

Yes.
*May 4, 2014*

**Physics**

a.KE = 0.5m*V^2 = 0.5*1.4*8.5^2=50.6 J. b. V^2 = Vo^2 + 2g*d V^2 = 8.5^2 + 19.6*37 = 725.2 V = 26.9 m/s. c. 0.5m*V^2 = 3600 J. .5*1.4*V^2 = 3600 0.7V^2 = 3600 V^2 = 5143 V = 71.7 m/s. When it hits the gnd. V^2 = Vo^2 + 2g*h Vo^2 = V^2-2g*h Vo^2 = (71.7)^2 - 19.6*37 = 4416 Vo...
*May 4, 2014*

**Physical science**

V = 25 * 10 * 1.5 = 375 m^3 375m^3 * 1000kg/m^3 = 375,000 kg.
*May 4, 2014*

**physics**

R1 = 9.0 ohms R2 = 53 ohms I1 = 1.41 Amps = current thru R1. V = I1 * R1 = 1.41 * 9 = 12.69 Volts. = voltage across battery.
*May 3, 2014*

**Math**

To find y-intercepts, let x = 0 and solve for Y. 1. 2x = 3y+4 2x-3y = 4 m = -A/B = -2/-3 = 2/3. 2*0-3y = 4 -3y = 4 Y = -4/3 = y-int. 2. 8x-2y-3 = 0 8x-2y = 3 Use same procedure as #1.
*May 3, 2014*

**math**

The following INFO is needed: h = ? W = ?
*May 3, 2014*

**math**

10-5c = 20c-40-18c-6 -5c-20c+18c = -40-6-10 -7c = -56 C = 8. 1.25y-.5y = -11.5+20.5 0.75y = 9 Y = 12 Divide both sides by 3: 7p-3q = 23.
*May 3, 2014*

**math**

NOTE: Disregard the last expression. The answer is 241i.
*May 3, 2014*

**math**

1. 5[19+(5^2-16)^2]^2 5[19+(9)^2]^2 5[100]^2 = 50,000 2. (7m^3-6m^2+10)-(5m^3-9+3m-2m^2) = 7m^3-6m^2+10-5m^3+9-3m+2m^2 = Combine like-terms: 2m^3-4m^2-3m+19 3. 3(a-2)(4a+1)-5(2a+3)(a-7) = 3(4a^2+1-8a-2)-5(2a^2-14a+3a-21) = 12a^2+3-24a-6-10a^2+70a-15a+105 = Combine like-terms: ...
*May 3, 2014*

**Science**

1b. 2c.
*May 3, 2014*

**MATH(markup and markdown )**

Po = $7,000 = Original price. P1 = 100% - 8% = 92% of Po P1 = 0.92 * 7000 = $6,440 = Resale price P2 = 100% + 18% = 118% 0f P1. P2 = 1.18 * 6440 = $7599.20=List price.
*May 2, 2014*

**MATH(markup and markdown )**

P1 = 100%-19% = 81% of original price. P1 = 0.81 * 15 = $12.15. = Sale price. P2 = 100%-5% = 95% of P1. P2 = .95 * P1 = .95 * 12.15 = $11.54 = Final sale price.
*May 2, 2014*

**Physics**

F1 = 512 - 20/4 = 507 Hz. F2 = 512 + 20/4 = 517 Hz.
*May 2, 2014*

**Physics (URGENT!!!)**

See previous post: Fri,5-2-14,2:37 AM.
*May 2, 2014*

**Calculus/Physics**

W = F*d = F * (5-2) = 1800 Joules. 3F = 1800 F = 600 N. k = 600N./3m = 200N/m
*May 2, 2014*

**Physics**

TYPO: Change Y = Yo*g*Tr = 0 to Y = Yo + g*Tr = 0
*May 2, 2014*

**Physics**

Vo = 120m/s[30o] Xo = 120*cos30 = 103.9 m/s. Yo = 120*sin30 = 60 m/s. a. Y = Yo * g*Tr = 0 Tr=-Yo/g = -60/-9.8 = 6.12 s. = Rise time. h = ho + (Y^2-Yo^2)/2g h = 35 + (0-(60^2))/-19.6 = 218.7 m. Above gnd. h = 0.5g*t^2 = 218.7 4.9t^2 = 218.7 t^2 = 44.63 Tf = 6.68 s. = Fall time...
*May 2, 2014*

**Science**

Work = 200*cos37 * 10 = 1597 Joules.
*May 1, 2014*

**math**

P = Po(1+r)^n Po = $3250. r = 6%/100% = 0.06 n = 1Comp./yr * 3.5yr. = 3.5 Compounding periods. Plug the above values into the given Eq and solve for P.
*May 1, 2014*

**physics**

Correction: R1 = R2 = R3 = 27/3 = 9 Ohms, each. When connected in parallel: Re = 9/3 = 3 Ohms.
*May 1, 2014*

**physics**

R = 27Ohm/3 = 9 Ohms. r =
*May 1, 2014*

**4th Grade Math**

6/8 = 3/4 (3/4) * 32 = 24 Teeth had cavities. 32 - 24 = 8 Healthy teeth.
*May 1, 2014*

**4th Grade Math**

2/8 = 1/4 (1/4)*64 = 16 Blue shirts. 64-16 = 48 Shirts not blue.
*May 1, 2014*

**Physics**

R1 = 16 Ohms R2 = 8 Ohms Re = R1*R2/(R1+R2)
*April 30, 2014*

**Math**

P = Po - Po*r*t P = 300 - 300*(0.17/12)*8 = $266.
*April 30, 2014*

**Math**

P = Po + Po*r*t = 500 Po + Po*(0.08/12)*9 = 500 Po + 0.06Po = 500 1.06Po = 500 Po = $471.70
*April 30, 2014*

**Geometry**

A(x,y), B(-24,15), C(-18,10). -18-x = 2(-24-x) -18-x = -48-2x 2x-x = -48+18 X = -30 10-y = 2(15-y) 10-y = 30-2y 2y-y = 30-10 Y = 20.
*April 30, 2014*

**Algebra**

15x^2 + 31x + 2 A*C = 15*2 = 30 = 1*30. Sum = 1+30=31=B. 15x^2 + (x+30x) + 2 Form 2 factorable binomials: (15x^2+x) + (30x+2) = x(15x+1) + 2(15x+1) = (15x+1)(x+2).
*April 30, 2014*

**Math**

The numerator: Are you sure that's a +2 ? Perhaps it should be -2. Please check.
*April 30, 2014*

**physics**

V = Vo + a*Tr = 0 @ max. ht. Tr = -Vo/a = -5/-10 = 0.5 s. = Rise time or time to reach max. ht. h = Vo*t + 0.5a*Tr^2 = 5*0.5 - 5*0.5^2 = 1.25 m.
*April 30, 2014*

**Science**

F = m*a
*April 30, 2014*

**Math**

V = (L*W) * h = (650)Ft^2 * 0.25Ft = 162.5 Ft^3. V = 162.5Ft^3 * 1yd^3/27Ft^3 = 6 yds^3
*April 30, 2014*

**Math**

V = L*W*h = 36 * 18 * 0.25 = 162 Ft^3 V = 162Ft^3 * 1yd^3/27Ft^3 = 6 Yds^3.
*April 30, 2014*

**Math**

V = pi*r^2 * L = pi * (0.5/12)^2 * 12 = 5.45*10^-3 Ft^3. = Vol. of rod. Wt.=490Lbs/Ft^3 * 5.45*10^-3Ft^3 = 2.67 Lbs.
*April 30, 2014*

**physics**

d = V*t = 343m/s * (1.6s/2) = 274.4 m.
*April 30, 2014*

**Science**

g on Jupiter is 2.5 times g on earth. 100/2.5 = 40 Lbs.
*April 30, 2014*

**physics**

What direction is the airplane flying?
*April 30, 2014*

**Science**

F = m*a = 5 * 7 = 35 N.
*April 29, 2014*

**Engineering**

Was the current given?
*April 29, 2014*

**Physics**

100 Cars: db = 10*Log(I/Io) db = 10*Log(I/10^-12) = 80 Log(I/10^-12) = 8 10^8 = I/10^-12 I = 10^-4 W/m^2. 5 Cars: I = (5/100) * 10^-4 = 5*10^-6 W/m^2. db = 10*Log(5*10^-6/10^-12) db = 10*Log(5*10^6) = 67.
*April 29, 2014*