# Posts by Henry

Total # Posts: 13,357

**MAth**

2^4 = 16. 2^-4 = 1/2^4 = 1/2^2*2^2 = 1/4*4 = 1/16.

*October 23, 2015*

**Physics**

h = 9.4*sin8.0 = 1.31 m. h = 0.5g*t^2 = 1.31 m. g = 9.8 m/s^2. t = ?

*October 22, 2015*

**Physics**

Vf = Vo + a*t = 20 + 2*4 = 28 m/s. Dc = 20*4 + 0.5*2*4^2 = 96 m. in 4 sec. Dc = 28m/s * 6s = 168 m. in 6 sec. Dc = 96 + 168 = 264 m. in 10 sec. Dt = 18m/s * 10s. = 180 m. in 10 sec. (264-8) - 180 = Distance in front of the truck.

*October 22, 2015*

**physics**

d = 2.06*sin28.8 = 0.992km, Due North.

*October 22, 2015*

**Science**

Vf = 100,000m/3600s. = 27.8 m/s. a = (Vf-Vo)/t = (27.8-0)/10 = 2.78 m/s^2

*October 22, 2015*

**Algebra**

Sun: X tickets were sold. Sat: 3x " " " Fri: 2x " " " $2(x + 3x + 2x) = $2160. X = ?

*October 22, 2015*

**math**

Assume 5 cm is measured on the drawing. d = 5cm * 3m/1cm = 15 m. = Actual distance.

*October 22, 2015*

**math**

(2/3)/6 = 2/3 * 1/6 = 2/18 = 1/9 cup.

*October 22, 2015*

**physics**

M*g = 1000 * 9.8 = 9800 N. Fp = 9800*sin33 = 5337 N. = Force parallel to the incline. a = Fp/M = 5337/1000 = 5.34 m/s^2.

*October 22, 2015*

**sri krishna**

3-4-5 triangle with each side multiplied by 4: hyp. = 20 = 5*4. 3*4 = 12. 4*4 = 16. So X = 4. so

*October 22, 2015*

**Math**

3/4 * M = 48. M = 4/3 * 48 = $64.

*October 22, 2015*

**Physics**

a. Vf = Vo + g*Tr = 0. Tr = -Vo/g = -15/-9.8 = 1.53 s. = Rise time. b. h1 = Vo*Tr + 0.5g*Tr^2 = Ht. above the roof. g = -9.8 m/s^2. h = h1 + 20. c. h = 0.5g*Tf^2. h = h1 + 20. g = 9.8 m/s^2. Tf = Fall time. Tf = ? Tr + Tf = Total flight time. d. Vf^2 = Vo^2 + 2g*h. Vo = 0. g...

*October 22, 2015*

**Physics**

Need more INFO.

*October 22, 2015*

**math**

d = 5days * 2(13/2)mi/day = 65 Miles. 65mi/4gal. = 16.25 mi/gal.

*October 21, 2015*

**math**

144/32 = 4 R16 = 4 Thirty-two inch pieces with 16 inches left.

*October 21, 2015*

**math**

(3 2/3)/2/3 = (11/3)/2/3 = 11/3 * 3/2 = 33/6 = 5 3/6 = 5 1/2 or 5 pieces.

*October 21, 2015*

**physics**

Yf^2 = Yo + 2g*h = 0. Yo = -2g*h = -2*(-9.8)*0.449 = 8.8 m/s. Yo = Vo*sin3.40 = 8.8 m/s. Vo = 8.8/sin3.4 = 148 m/s.

*October 21, 2015*

**math**

Sole X necklaces. Sold 3x watches. 4*x + 7*3x = $300. X = ?.

*October 21, 2015*

**Physics- PLEASE HELP!!**

Hannah and Tammy please show how you arrive at your answer.

*October 21, 2015*

**maths**

1 - (2/5 + 1/3) = 15/15 -(6/15 + 5/15)= 15/15 - 11/15 = 4/15 Left.

*October 21, 2015*

**physics**

D = 26km[90o] + 62km[60o]. X = 62*Cos60 = 31km. Y = 26 + 62*sin60 = 79.7 km. Q1. Tan A = Y/X = 79.7/31 = 2.57076. A = 68.7o = Direction. D = Y/sin A = 79.7/sin68.7 = 85.5 km[68.7o].

*October 21, 2015*

**Quick physics check**

Fr = 60[135o]CCW + 5[330o]CCW. X = 60*Cos135 + 5*Cos330 = -38.1 N. Y = 60*sin135 + 5*sin330 = 39.9 N. Q2. Tan A = Y/X = 39.9/-38.1 = -1.04794. A = -46.3o = 46.3o N. of W. = Direction. Fr=Sqrt(X^2 + Y^2)=Sqrt(38.1^2 + 39.9^2) = 55.2 N. = Resultant force.

*October 21, 2015*

**Physics**

M*g = 9990 N., M = 9990/9.8 = 1019 kg. V = 64.87 mi/h * 1600m/mi * 1h/3600s. = 28.83 m/s. KE = 0.5M*V^2 = 0.5*1019*(28.83)^2 = 423,481 J. PE = Mg*h = KE. 9990*h = 423,481. h = ?

*October 21, 2015*

**physics 11**

X = -2.7 m/s. Y = 1.3 m/s. Q2. a. Tan A = Y/X = 1.3/-2.7 = -0.48148. A = -25.7 m/s = 25.7o N. of W. = 64.3o W. of N. = Direction. Vr = Sqrt(X^2 + Y^2) = Sqrt(2.7^2+1.3^2)= 3.0 m/s = Resultant velocity. Dr = Sqrt(20^2 + 41.5^2) = 46.1 m. = Resultant distance. Dr = Vr*T = 46.1 m...

*October 20, 2015*

**Physics**

1. Vf^2 = Vo^2 + 2a*d Vo = 0. Vf = ?. 2. d = 0.5a*t^2.

*October 20, 2015*

**College Physics**

Wc = M*g = 1670 * 9.8 = 16,366 N. N/m = 16,366N./6.5m.

*October 20, 2015*

**physcial science**

D.

*October 20, 2015*

**Physics**

See previous post: Tue, 10-20-15, 11:26 AM.

*October 20, 2015*

**Physics**

See previous post: Tue,10-20-15, 11.26 AM.

*October 20, 2015*

**Physics. Appreciate the help I can get.**

a = (F-Fk)/M = (720-320)/400 = 1.0 m/s^2 A. d = Vo*t + 0.5a*t^2. Vo = 5 m/s. t = 6 s. d = ?. B. Work = F*d. C. Power = Work/t in J/s = Watts.

*October 20, 2015*

**NFCS**

Change = a*t = 0.219m/s^2 * 11.2s. =

*October 20, 2015*

**Physics 101**

Increase = (39-10)C*9.8*10^-6/C * 250 m. = 0.071 m.

*October 20, 2015*

**math**

Kim has X decals. 2x/3 on 5 cars. Remaining = x - 2x/3 = 1x/3. 2/5 * 1x/3 = 2x/15 decals on 2 bikes. Remaining = 6. 2x/3 + 2x/15 + 6 = X. 10x + 2x + 90 = 15x. 15x-12x = 90. 3x = 90. X = 30 = Total decals. 2x/3 = 60/3 = 20 Decals on 5 cars. 20decals/5cars = 4 decals/car.

*October 20, 2015*

**AP physics**

Vf^2 = Vo^2 + 2a*d = 0. a = -(Vo^2)/2d = -(10^2)/50 = -2.0 m/s^2 F = M*a = 60 * (-2.0)=-120 N. Retarding force.

*October 20, 2015*

**Physics 101 help (dumb it down please)**

M1*V1 + M2*V2 = M1*V + M2*V. M1 = 12,000 kg, V1 = 22 m/s. M2 = 1200 kg, V2 = 16 m/s. V = ?.

*October 20, 2015*

**PHYSICS**

Vf = 50.4km/h = 50400m/3600s = 14 m/s. a = (Vf-Vo)/t = (. Vo = 0. d = 0.5a*t^2.

*October 19, 2015*

**Physics**

M*g = 1600 * 9.8 = 15,680 N. Fp = 15,680*sin20 = 5363 N. Fn = 15,680*Cos20 = 14,734 N. Fk = u*Fn = 0.09 * 14,734 = 1326 N. Fw-Fp-Fk = M*a = M*0 = 0. Fw = Fp+Fk = 5363 + 1326 = 6689 N. = Force of the winch. Power = Fw * V = 6689 * 1.21 = 8094 J/s. = 8094 Watts.

*October 19, 2015*

**algebra**

-5(3-Q) + 4 = 5Q - 11. -15+5Q + 4 = 5Q - 11. 5Q - 5Q = -11 + 15 - 4. 0 = 0. Infinite solutions.

*October 19, 2015*

**Physics**

h = 0.5g*t^2 = 1.70 m. g = 9.8 m/s^2. t = ?.

*October 19, 2015*

**phPhysical Science**

Disp. = -16 + 20 = 4 km. V = 4km/(5+6)hrs. = 0.364 km/hr., East.

*October 19, 2015*

**AP physics**

h = 30*sin12 = 6.24 m. Vf^2 = Vo^2 + 2g*h = 0 + 19.6*6.24 = 122.3. Vf = 11.1 m/s.

*October 18, 2015*

**physics**

Yf = Yo + g*t = 12 - 10*2.4 = -12 m/s. Vf = sqrt(9^2 + 12^2) = 15 m/s.

*October 18, 2015*

**Physics**

Distance = 10 + 15 = 25 m. X = -10 m. Y = -15 m. Q3. Tan A = Y/X = -15/-10 = 1.50. A = 56.3o S. of W. = 236.3o CCW. Displacement = -15/sin236.3 = 18 m[236.3o] CCW.

*October 18, 2015*

**math**

b. 36cookies/2hr. = 18 Cookies/hr. T = 120Cookies * 1hr/18Cookies = 6.67 hrs.

*October 18, 2015*

**Physics**

Wb = M*g = 10 * 9.8 = 98 N. = Normal force, Fn. Fs = Force of static friction. Fap-Fs = M*a. 8 - Fs = M*a = M*0 = 0. Fs = 8 N. Fs = u*Fn = 8 N. u = 8/Fn = 8/98 = 0.082.

*October 18, 2015*

**physics**

Wc = M*g = 1.3 * 9.8 = 12.74 N. Fp = 12.74*sin25 = 5.38 N. = Force parallel to the incline. a. Fap-Fp = M*a. Fap-5.38 = M*0 = 0. Fap = 5.38 N. = Force applied.

*October 18, 2015*

**Physics**

M*g = 2.9 * 9.8 = 28.4 N. = Wt. of the brick = Normal force, Fn. Fk = u*Fn = 0.33 * 28.4 = 9.38 n. = Force of kinetic friction. Fap-Fk = M*a. Fap-9.38 = M*0 = 0. Fap = 9.38 N.

*October 17, 2015*

**maths**

5 yrs. ago: Amreen was X yrs. old. Juhi was 3x yrs. old. 10 years later: Amreen is x+10 yrs. old. Juhi is 3x+10 yrs. old. (3x+10) = 2(x+10). 3x + 10 = 2x + 20. X = 10. Amreen = x+10 = 10 + 10 = 20 yrs. old. Juhi = 3x+10 = 3*10 + 10 = 40 yrs. 0ld.

*October 17, 2015*

**Science**

1. False. The forces are balanced. 2. Air resistance. 7. Size of an object.

*October 17, 2015*

**physics**

M*g = 82 * 9.8 = 803.6 N. = Wt. of crate. = Normal force, Fn. Fk = u*Fn = 0.3 * 803.6 = 241 N. = Force of kinetic friction. F-Fk = M*a. 314-241 = 82*a. 82a = 73. a = 0.890 m/s^2. Vf^2 = Vo^2 + 2a*d. Vo = 0. Vf = ?.

*October 16, 2015*

**PHYSICS**

See previous post: Fri, 10-16-15, 12:41 AM.

*October 16, 2015*

**physics**

a. h = 0.5g*Tf^2. h = 414.1 m. g = 9.8 m/s^2. Tf = ? = Fall Time. Dx = Xo*Tf. Dx = 95.3 m. Xo = ? = Initial hor. speed. b. Y = Yo + g*Tf. Yo = 0. Y = ? = Ver. component of total velocity. Speed = Sqrt(Xo^2 + Y^2).

*October 16, 2015*

**physics**

Fo = (340+Vo)/(340-Vs1)*Fs1. Fo = (340+0)/(340-20) * 500 = 531.25 Hz. = The freq. heard by the observer. Fo = (340+0)/(340-23) * 500 = 536.28 Hz. Fb = 536.28 - 531.25 = 5.028 Hz = Beat freq. Note: The Freq. of S1 and S2 are equal, but their velocities are different. Therefore...

*October 16, 2015*

**Physics**

Dx = Vo^2*sin(2A)/g. Vo = 11 m/s. A = 30o g = 9.8 m/s^2. Dx = ?

*October 16, 2015*

**Physics**

a. h = 0.5g*t^2. g = 9.8 m/s^2. h = 1.05 m. t = ? b. Dx = Xo*t. Xo = 1.90 m/s. t = Value calculated in part a.

*October 15, 2015*

**physics**

Dx = Vo^2*sin(2A)/g = 44. m. Vo^2*sin(68)/9.8 = 44. Vo^2*0.0946 = 44. Vo^2 = 465.1. Vo = 21.6 m/s. at 34o below the hor. Xo = Vo*Cos A = 21.6*Cos34 = 17.9 m/s. Dx = 17.9*T = 44. T = 2.46 s. = Time in air.

*October 15, 2015*

**physics**

Vo = 15 m/s. Yf^2 = Yo^2 + 2g*h. Yf = 0. g = -9.8 m/s^2. h = 2 m. Yo = ?. sin A = Yo/Vo. A = ?

*October 15, 2015*

**Physics**

Vo = 120m/s[25o]. Xo = 120*Cos25 = 108.8 m/s. Yo = 120*sin25 = 50.71 m/s. Yf = Yo + g*Tr = 0 at max h. Tr = -Yo/g = 50.71/-9.8 = 5.17 s. = Rise time. Tf = Tr = 5.17 s. = Fall time. a. T = Tr + Tf = Time of Flight. b. Range = Xo*T. c. h max = Yo*Tr + 0.5g*Tr^2. g = -9.8 m/s^2.

*October 15, 2015*

**physics**

Wb = M*g = 330 * 9.8 = 3234 N. Fp = 3234*sin A = Force parallel to the incline. Fn = 3234*Cos A = Force perpendicular to the incline. Fs=u*Fn = 0.25 * 3234*Cos A = 809*Cos A = Force of static friction. Fp-Fs = M*a. 3234*sin A-8o9*Cos A = M*0 = 0. 3234*sin A = 809*Cos A. Divide...

*October 15, 2015*

**Physis**

h = 0.5g*t^2.

*October 15, 2015*

**Algebra 2**

If you mean: (x-3)/x = 3/5. Multiply Eq by 5x: 5x-15 = 3x. 5x - 3x = 15. 2x = 15. X = 7.5.

*October 13, 2015*

**Algebra 2**

x - 3/x = 3/5. Multiply Eq by 5x: 5x^2 - 15 = 3x. 5x^2 - 3x -15 = 0. Use Quad. Formula. X = -1.46, and 2.06.

*October 13, 2015*

**Algebra 2**

In Eq2, replace Y with 5: x - 5 = 2. X = 7. (x, y) = (7, 5).

*October 13, 2015*

**college algebra**

V = Vo + g*Tr = 0 at max h. Tr = -Vo/g = -108/-32 = 3.375 s. = Rise time. Tf = Tr = 3.375 s. = Fall time. A. T = Tr+Tf B. h = Vo*t + 0.5g*t^2 = 180 Ft. 108t - 16t^2 - 180 = 0. -16t^2 + 108t - 180 = 0. Use Quad. Formula. t = 3.0 s.

*October 13, 2015*

**algebra**

V = 460mi/1h = 460 mi/h. Or V = 920mi/2h = 460 mi/h. Or V = 1380mi/3h = 460 mi/h. Or V = 1840mi/4h = 460 mi/h. Get it? d = V*T = 5060 miles. 460*T = 5060. T = 11 h.

*October 13, 2015*

**Science**

A. M*V

*October 13, 2015*

**Science**

A. m*V.

*October 13, 2015*

**Revolution and frequency i need help physics**

P = 15min/60rev = 0.25 min./rev. F = 1/P = 1/0.25 = 4 rev./min. Or F = 60rev/15min. = 4 rev/min.

*October 13, 2015*

**math**

2. Cr = 2pi. C = 2pi/r. Not equivalent.

*October 13, 2015*

**science**

d = 600 + 420 = 1020 km.

*October 13, 2015*

**Algebra**

2.28*10^-8 = 0.0000000228. 7^-2 = 1/7^2 = 1/49. I'm not sure what they want here.

*October 13, 2015*

**Math**

3.56*10^-5 = 0.0000356

*October 13, 2015*

**physics**

M*g = 16.5 * 9.8 = 161.7 N. = Wt. 0f cart. a. F*Cos27.9-Fk = M*a. 0.884F - 48.1 = M*0 = 0. 0.884F = 48.1. F = 54.4 N. = Force exerted. b. Work = F*d = 54.4 * 36.6 = 1992 J. c. Work = Fk*d = 48.1 * 36.6 = 1760 J. d. Work=Mg * d = 161.7 * 36.6 = 5918 J.

*October 13, 2015*

**algebra**

2.7*10^-5 / 9*10^-6 = 0.3*10^1 = 3. When dividing, subtract the exponent in the denominator from that in the numerator.

*October 13, 2015*

**physics**

h = 0.5g*t^2.

*October 13, 2015*

**science**

g on the moon = 1/6 g on earth: 1/6 * 60N = 10 N. = Wt. on the moon. Or M*g = 60 N. M*9.8 = 60. M = 6.122 kg. g = 9.8/6 = 1.633 m/s^2. on moon. M*g = 6.122 * 1.633 = 10 N.

*October 13, 2015*

**phyisics**

D = 28m[325o]CCW + 45m[270o]CCW. X = 28*Cos325 + 45*Cos270 = 22.9 + 0 = 22.9 m. Y = 28*sin325 - 45*sin270 = -16.1 - 45 = -61.1 m. Q4. Tan A = Y/X = -61.1/22.9 = -2.66812. A = -69.5o = [E69.5oS] = 290.5 CCW. D = Y/sin A = -61.5/sin290.5 = 65.2 m. V = D/T = 65.2m/6.9s = 9.5 m/s...

*October 12, 2015*

**Math**

a. h = -4.9*1^2 + 24.5*1 + 1. b. Y = Yo + g*Tr = 0 at max h. Tr = -Yo/g = -24.5/-9.8 = 2.5 s. = Rise time or time to reach max h. c. h max = -4.9Tr^2 + 24.5Tr + 1 d. h max = 0.5g*Tf^2 Tf = ?. T = Tr + Tf.

*October 12, 2015*

**physics**

Wb = M*g = 12 * 9.8 = 117.6 N. = Normal force, Fn. Fx-Fk = M*a. Fx-Fk = M*0 = 0. Fk = Fx = 30 N. Fk = u*Fn. u = Fk/Fn = 30/117.6 = 0.255. Note: Since the velocity is constant, the acceleration is zero.

*October 12, 2015*

**Physics**

Xo = 96.8 mi/h * 5280Ft/mi * 1h/3600s = 142 Ft/s. Dx = Xo*Tf = 60 Ft. 142Ft/s * Tf = 60. Tf = 0.423 s. = Fall time. d = 0.5g*Tf^2 = 16*0.423^2 = 2.86 Ft., Vertically.

*October 12, 2015*

**Physics**

See related Questions: Tue, 9-2-14, 11:13 AM.

*October 12, 2015*

**Physics**

1. Dx = Xo*Tf = 8.2 m. h = 0.5g*Tf^2 = 3.3 m. 4.9*Tf^2 = 3.3. Tf^2 = 0.673. Tf = 0.821 s. = Fall time. Xo*0.821 = 8.2 m. Xo = 10.0 m/s. 2. Dx = Xo*Tf. h = 0.5g*Tf^2 = 1.6 m. 4.9*Tf^2 = 1.6. Tf^2 = 0.327. Tf = 0.571 s. Dx = 10m/s * 0.571s. = 5.71 m.

*October 12, 2015*

**Math**

60mi/h=60mi/3600s. * 1600m/mi = 26.7 m/s 10mi/h = 10/60 * 26.7 = 4.44 m/s. 500Ft. * 1m/3.3Ft = 152 m. a = (Vf-Vo)/t = (26.7-0)/7.6 = 3.51 m/s. Vf^2 = Vo^2 + 2a*d. Vo^2 = Vf^2-2a*d = 4.44 - (-8.88)*152 = 1354.2 Vo = 36.8 m/s. = Max. initial velocity for the given stopping ...

*October 12, 2015*

**Physics**

Wc = M*g = 60 * 9.8 = 588 N. = Normal force, Fn. Fk = u*Fn = 0.3 * 588 = 176.4 N. Work = Fk*d = 176.4 * 12 = 2117 J. Fap-Fk = M*a. 200-176.4 = 60*a. 60a = 23.6. a = 0.393 m/s^2. Work = M*a * d = 60*0.393 * 12 = 283 J.

*October 12, 2015*

**applied mechanics**

Incomplete.

*October 12, 2015*

**Physics**

A = 0o: Fn = Wb = 120 N. = Normal force Fn = 120-F*sin A = 0.5*120. 120-100*sin A = 60. -100*sin A = -60. sin A = 0.60. A = 36.9o.

*October 11, 2015*

**Physics**

W1*d1 = W2*d2. 45*0.6 = 60*d2. d2 = 0.45 m.

*October 11, 2015*

**Science**

F = 0.060m * 950N/m = 57 N. Work = F*d = 57 * 0.06 = 3.42 J.

*October 11, 2015*

**science**

There are too many errors in your problem. Please retype.

*October 10, 2015*

**PHYSICS**

M*g = 25 N. M*9.8 = 25. M1 = 2.55 kg. h = L*sin30 = 1 * sin30 = 0.5 m. PE = Mg*h = 25 * 0.5 = 12.5 J. at top of incline. KE = 0.5M*V1^2 = 12.5 J. at bottom of incline. 0.5*2.55*V1^2 = 12.5. 1.28V1^2 = 12.5. V1^2 = 9.8. V1 = 3.13 m/s. at bottom of incline. M2 = 40/g = 40/9.8 = ...

*October 10, 2015*

**Physics**

F1 + F2 = 19[58o] + -25+16.5i = 19*Cos58+i19*sin58 -25 + 16.5i = 10.1 + 16.1i - 25 + 16.5i=-14.9+32.6i,Q2 = 35.8N.[65.4o] N. of W. = 35.8N[144.2o] CCW.

*October 10, 2015*

**Calculus**

Also isn't there an infinite number of solutions to this equation? How are you supposed to solve it then?

*October 10, 2015*

**Calculus**

Can you show some more steps in between I can't get how to solve for y and x with only 1 equation.

*October 10, 2015*

**Calculus**

(x^2+y^2)^2=16y Find all values of x where the tangent line is vertical I found the derivative and looked for where it was undefined but it didn't work

*October 10, 2015*

**Physics**

T1*sin148 + T2*sin74 = 725 N. Eq1: 0.53T1 + 0.96T2 = 725. T1*Cos148 + T2*Cos74 = 0. Eq2: -0.85T1 + 0.28T2 = 0. -0.85T1 = -0.28T2. T1 = 0.324T2. In Eq1, Replace T1 with 0.324T2: 0.53*0.324T2 + 0.96T2 = 725. 0.172T2 + 0.96T2 = 725. 1.13T2 = 725. T2 = 640.5 N. T1 = 0.324*640.5 = ...

*October 10, 2015*

**Calculus**

what is the limit as h approaches 0 of ((x+h)^pi-x^pi)/h? Multiple choice answers: A: lnx B: lnx (x^pi) C: Pi lnx D: (pi^2) ln (x^2) E: (pi^x) lnx I know this is d/dx x^pi, or Pi x^(Pi-1)

*October 10, 2015*

**Physics**

Yf^2 = \Yo^2 + 2g*h = 0. Yo^2 = -2g*h = -2*(-9.8)*25 = 490. Yo = 22.1 m/s. a. Yf = Yo + g*Tr = 0. 22.1 - 9.8Tr = 0. Tr = 2.26 s. = Rise time. Tf = Tr = 2.26 s. = Fall time. Xo = Yo = 22.1 m/s. = Hor. velocity. Dx = Xo*(Tr+Tf) = 22.1 * 4.52 = 100 m. b. Range = Vo^2*sin(2A)/g. ...

*October 10, 2015*

**Science**

V = 1.23m/4.66*10^-8s. = 2.639*10^7 m/s.

*October 9, 2015*

**Conversions?**

1. 4106/1000 = 4.106 kilomockingbirds. 2. 10^-3 * 10^6=10^3 = 1,000 Microphones

*October 9, 2015*

**math**

Glad I could help.

*October 9, 2015*