# Posts by henry

Total # Posts: 13,335

**Physics**

See previous post: Mon, 11-23-15, 1:20 PM.

*November 23, 2015*

**Physics**

3a. Momentum conserved. b. Ma*Va + Mb*Vb = Ma*V + Mb*V. 0.50*0.40 + 0.750*0 = 0.50V + 0.75*V. V = ? c. Before: KE = 0.5Ma*Va^2. After: KE = 0.5(Ma+Mb)*V^2. KE will be less after the collision.

*November 23, 2015*

**Algebra**

1a. Fr = 3 - 0.5L/20km * d. Fr = 3 - 0.025d. Fr = Fuel remaining in liters. d = Distance traveled in km. b. Fr = 3 - 0.025*55 = 1.625 Liters. c. No. When d equals 130 km, Fr is negative which means the tank empties before 130 km is reached. The max distance can be calculated ...

*November 23, 2015*

**College physics**

In an inelastic collision, the bodies stick together. Therefore, their velocities are equal. M1*V1 + M2*V2 = M1*V + M2*V. 2500*15[90o] + 1600*16[225o]=2500V + 1600V. 37,500[90o] + 25,600[225o] = 4100V. 37,500i - 18,102 - 18,102i = 4100V. -18,102 + 19,398i = 4100V. 28443[-47o...

*November 22, 2015*

**Science**

Mass = 15Lb * 0.454kg/Lb = 6.81 kg. d = 2Ft * 1m/3.3Ft = 0.606 m. Work=F*d = Mg * d = 6.81*9.8 * 0.606 m = 40.4 J.

*November 22, 2015*

**Physics**

k = 100N./0.150m = 667 N/m.

*November 22, 2015*

**Maths**

Vo = 20m/s[30o]. Xo = 20*Cos30 = 17.3 m/s. Yo = 20*sin30 = 10 m/s. Yf = Yo + g*Tr. Yf = 0. g = -9.8 m/s^2. Tr = Rise time = ?. h = 15 + Yo*Tr + 0.5g*Tr^2 = Meters above sea level. g = -9.8 m/s^2. h = 0.5g*Tf^2. g = 9.8 m/s^2. Tf = Fall time = ?. Tr + Tf = Time in air. Dx = Xo...

*November 22, 2015*

**science**

1750 - 500 = 1250g = Wt. of oil. Density = 1250g/0.5L = 2500g/L.

*November 22, 2015*

**math**

1. C = 7p + 1.50. 2. C = 7*4 + 1.50 = 3. C = 7p + 1.50. C = 43.50. p = ?

*November 22, 2015*

**physics**

P = 0.2/0.8 * 100W. = 25 W.

*November 22, 2015*

**Physics**

1. Vf^2 = Vo^2 + 2g*h. Vf = 0. Vo = 12 m/s. g = -9.8 m/s^2. h = 2. V = 90,000m/3600s = 25 m/s. Vo = 126,000m/3600s = 35 m/s. V = Vo + a*t. a = (V-Vo)/t = (25-35)/t = -10/t. V^2 = Vo^2 + 2a*d. 25^2 = 35^2 + 2(-10/t)*800. 625 = 1225 + (-16,000)/t. -600 = -16000/t. 600t = 16000. ...

*November 21, 2015*

**physics**

Fr = F[0o] + F[126o] = F + F*Cos126 + (F*sin126)i = F - 0.588F + 0.809Fi=0.412F + 0.809i. Tan A = 0.809F/0.412F = 1.96359. A = 63o N. of E. = 63o CCW. Fr = 0.809F/sin63 = 0.908F[63o]

*November 21, 2015*

**Physics AP**

Wc = M*g = 32 * 9.8 = 314. N. Fn = 314*Cos38 = 247 N. = Normal force.

*November 20, 2015*

**Physics**

V^2 = Vo^2 + 2a*d. V = 0. Vo = 7.90 m/s. a = u*g = 0.41 * (-9.8) = -4.02 m/s^2. d = ?

*November 20, 2015*

**Physics**

Ws = M*g = 15 * 9.8 = 147 N. = Wt. of suitcase. Fn = Ws-T*sin45 = 147 - T*sin45 = 147-0.707T = Normal force. Fk=u*Fn=0.36*(147-0.707T) = 52.9-0.255T. T*Cos45-Fk = M*a. 0.707T-(52.9-0.255T) = M*0. 0.707T-52.9+0.255T = 0. 0.961T = 52.9 T = 55 N. Fn = 147 - 0.707*55 = 108 N.

*November 20, 2015*

**Physics**

a. See previous post: Thu, 11-19-15, 9:46 PM. b. V^2 = Vo^2 + 2g*h. Vo = 0. g = 9.8 m/s^2.

*November 20, 2015*

**Physics**

Mass = 180Lb * 0.454kg/Lb = 81.72 kg. h = 5mi * 1600m/mi 8000 m. h = 0.5g*t^2 = 8000. g = 9.8 m/s^2 t = ?

*November 19, 2015*

**physics**

E = 0.5*r + 0.5*6 Eq1: E = 0.5r + 3. E = 0.3*r + 0.3*(6+8). Eq2: E = 0.3r + 4.2. E = 0.5r + 3 = 0.3r + 4.2. 0.5r +3 = 0.3r + 4.2. 0.2r = 1.2. r = 6 Ohms = Internal resistance. E=0.5r + 0.5*R = 0.5*6 + 0.5*6 = 6 Volts

*November 19, 2015*

**science**

See Related Questions: Mon,11-5-12, 9:51PM.

*November 19, 2015*

**Math**

1. Work = F*d = 550 * 10*0.5 = Joules. 2. Power = Work/T = Joules/s.

*November 19, 2015*

**Physics**

D = 1200m[90o] + 200[0o] + 500[225o]. X = 1200*Cos90 + 200*Cos0 + 500*Cos225 = Y = 1200*sin90 + 200*sin0 + 500*sin225 = Tan A = Y/X, A = ?. D = X/Cos A, or Y/sin A.

*November 19, 2015*

**physics**

1. M*g = 7159 N. M = 7159/g = 7159/9.8 = 731 kg. Fp = 7159*sin25.6 = 3093 N. = Force parallel to the plank. Fap-Fp = M*a. Fap - 3093 = M*0 = 0. Fap = 3093 N. = Force applied. Work = Fap*d = 3093 * 2.26 = 6991 J. 2. Work = KE2-KE1 = 0.5M*V^2- 0 = 0.5*0.02*354^2 = 1253 J.

*November 18, 2015*

**math**

d = 2.78 - (-2.78) = 2.78 + 2.78 = 5.56.

*November 18, 2015*

**Algebra**

X = Larger number. Y = Smaller number. Eq1: X-Y = 86. x = y+86. 7y = x + 4. Eq2: x - 7y = -4. In Eq2, replace X with y+86: y+86 - 7y = -4. -6y = -90. Y = 15. x-15 = 86. X = 101.

*November 18, 2015*

**Physics**

Magnitude=3.6+3.4i + 5.5+1.9i + 2.5+3.4i = (3.6+5.5+2.5) + (3.4i+1.9i+3.4i) = 11.6 + 8.7i=Sqrt(11.6^2 + 8.7^2) = 14.5

*November 18, 2015*

**Physics**

F = 42N[83o] + 70N[300o]. X = 42*Cos83 + 70*Cos300 = Y = 42*sin83 + 70*sin300 = Tan A = Y/X, A = ? F = X/Cos A, or F = Y/sin A.

*November 18, 2015*

**Math**

1. 2*10^6. 2. 7*10^-7.

*November 18, 2015*

**science**

KE2-KE1 = 0.5M*V2^2 - 0.5M*V1^2 = 0.5*450*30^2 - 0.5*450*26^2 = 202,500 - 152,100 = 50,400 J.

*November 18, 2015*

**Match**

1. 27 3/5 + 15.9 = 27.6 + 15.9 = 43.5. 0.37 * 43.5 = 16.095 2. 27 3/5 + 15.9 = 27 3/5 + 15 9/10 = 27+6/10 + 15+9/10 = 42 + 15/10 = 42+1.5 = 43.5. 0.37 * 43.5 = 16.095 The first method is shorter and easier; I didn't have to deal with fractions.

*November 18, 2015*

**Math**

2000 mL = 2Liters. 2Liters * 3.5g/Liter = 7.0 Grams.

*November 18, 2015*

**algebra**

-1.7-(-13.4) = -1.7 + 13.4 = 11.7o

*November 18, 2015*

**Physics**

D=20[30o] + 30[90o] + 40[180o]+20[315o] X=20*Cos30+30*Cos90+40*Cos180+20*Cos315 = Y=20*sin30+30*sin90+40*sin180+20*sin315 = Tan A = Y/X. A = ?. D = X/Cos A, or Y/sin A.

*November 18, 2015*

**Math**

1. 18balloon * 2.5Ft/balloon. = 45 Ft. 45Ft. * 1yd/3Ft = 15 Yds.

*November 17, 2015*

**Math**

1. Add X striped balls. Add 10x/6 = 5x/3 white balls. x + 5x/3 = 112. 3x + 5x = 336. X = ? 5x/3 = ? 2. 4/6 = 14/16. 4*16 = 64. 6*14 = 84. The cross products are not equal; therefore, the ratios are not equivalent.

*November 17, 2015*

**Math**

C = 4.5*4 - 7 = $11.

*November 17, 2015*

**Math**

T=30,000phones * 4h/1300phones=92.3 h. 1. A = X Degrees, B = (X-34) Degrees. Supplementary angles are angles whose sum is 180o: x + (x-34) = 180. X = ?. X-34 = ? 2. A = X Degrees, B = (2x+9) Degrees. x + (2x+9) = 90o. X = ? 2x+9 = ?

*November 17, 2015*

**Physics**

V^2 = Vo^2 + 2g*h = 0 + 19.6*1.54 = 30.2 V = 5.49 m/s.

*November 17, 2015*

**Algebra 2**

d = (120+V)T = 490 mi. Eq1: 120T + VT = 490. Eq2: 120T - VT = 350. Sum: 240T = 840. T = 3.5 h. In Eq1, replace T with 3.5 and solve for V.

*November 17, 2015*

**none**

a = 16. b = 16. c = ? c^2 = a^2 + b^2.

*November 17, 2015*

**Physics**

a. -T2*Cos44 + T1*Cos42 = 0. T1*Cos42 = T2*Cos44. T2 = 1.033T1. T2*sin44 + T1*sin42 = -(-608) = 608 N. 1.033T1*sin44 + T1*sin42 = 608. 0.718T1 + 0.669T1 = 608. 1.39T1 = 608. T1 = 438.3 N. b. T2 = 1.033 * 438.3 = 452.8 N.

*November 17, 2015*

**physic**

a. V^2 = Vo^2 + 2g*h Vo = 0. g = 9.8 m/s^2. V = ? b. PE-KE = M*g*h - 0.5M*V^2 = Energy lost. V = 1 m/s.

*November 17, 2015*

**Science**

V = Vo + g*t. Vo = 0. g = 9.8 m/s^2. V = ?

*November 17, 2015*

**Science**

Vf^2 = Vo^2 + 2a*L. Vf = 71 m/s. Vo = 0. a = 1.6 m/s^2. L = ?

*November 17, 2015*

**Physics**

h = 0.5g*t^2 = 1.5 m. 4.9t^2 = 1.5. t^2 = 0.31. t= 0.553 s. = Fall time. Dx = Xo*t = 1.2 m. Xo*0.533 = 1.2 Xo = 2.17 m/s.

*November 16, 2015*

**Math**

Your problem isn't clear; there appears to be errors. Based on my interpretation: 1/T = 1/t1 + 1/t2 + 1/t3. T = ?

*November 16, 2015*

**algebra**

X football cards. 5x baseball cards. x + 5x = 120. X = ?

*November 16, 2015*

**Algebra 1**

W = 30 cm. L/4 + 12 = 30. L/4 = 18 L = 72 cm. h = 20 cm. V = L*W*h.

*November 15, 2015*

**Physics HELP**

D = 4300[49o] + 6500[21o]. X = 4300*Cos49 + 6500*Cos21 = Y = 4300*sin49 + 6500*sin21 = Tan A = Y/X. A = Direction. Magnitude = X/Cos A. or Y/sin A.

*November 15, 2015*

**Physics**

V = 820*sin25 =

*November 15, 2015*

**physics**

D = 15i + 5 -10i - 5 = 5i = 5 km Northwards.

*November 15, 2015*

**physics**

db = 10*Log(Io/Iin.) = 10*Log(28.7/55.1)

*November 15, 2015*

**physics**

R*C < 1*10^-4 s. 1000*C < 1*10^-4. C < 1*10^-7 Farads < 0.10 Microfarads.

*November 15, 2015*

**maths**

P=Po(1+r)^n = 5Po Po = Initial investment. r = (4%/4)/100% = 0.01=Quarterly % rate. n = The number Compounding periods. Po(1.01)^n = 5Po. Divide by Po: 1.01^n = 5. n*Log 1.01 = Log 5. n = Log5/Log1.01 = 162 Compounding periods. 162Comp. * 1yr./4Comp. = 40.5 yrs.

*November 15, 2015*

**PHYSICS**

a. h = ho + (Vf^2-Vo^2)/2g. ho = 60 m. Vf = 0. Vo = 30 m/s. g = -9.8 m/s^2. h = ? b. Vf = Vo + g*Tr. Vf = 0. Vo = 30 m/s. g = -9.8 m/s^2. Tr = Rise time. Tr = ? b. 0.5g*Tf^2 = h(Part a). g = 9.8 m/s^2. Tf = Fall time. Tf = ? Tr + Tf = Time to reach gnd.

*November 15, 2015*

**Physics**

Vf^2 = Vo^2 + 2a*d. Vf = 0. Vo = 50000m/3600s = 13.9 m/s. a = -5m/s^2. d = ?

*November 14, 2015*

**Physics**

Wb = M*g = 3.1 * 9.8 = 30.4 N. Fp = 30.4*sin28 = 14.3 N. = Force parallel to the incline. Fn = 30.4*Cos28 = 26.8 N. = Normal force Fp-Fk = M*a. Fp-Fk = M*0 = 0. Fk = Fp = 14.3 N. = Force of kinetic friction. u = Fk/Fn = 14.3/26.8 = 0.533.

*November 14, 2015*

**Math**

P = Po(1+r)^n = 2Po Po(1.06)^n = 2Po. Divide by Po: (1.06)^n = 2. n*Log 1.06 = Log 2. n = Log 2/Log 1.06 = 11.9 Compounding periods = 11.9 yrs.

*November 14, 2015*

**maths**

See previous post: Sat, 11-14-15r, 3:48 AM.

*November 14, 2015*

**math**

Angle A = X Degrees. Angle B = 2X Degrees. x + 2x = 180o X = 60o = A. 2X = 120o = B. C = A = 60o. The opposite angles are =. D = B = 120o. A+B+C+D = 60 + 120 + 60 + 120 = 360o.

*November 14, 2015*

**physics**

Girl's distance: d2 = 6m/2=3 m from pivot point(center). M1*d1 = M2*d2. 75*d1 = 50*3 = 150. d1 = 2 m. = Boy's distance.

*November 14, 2015*

**physics**

Do you know the angle?

*November 14, 2015*

**physics**

See previous post: Sat, 11-14-15,

*November 14, 2015*

**physics**

a. AM band: L1 = V/F = 3*10^8/5.5*10^5 = L2 = 3*10^8/1.585*10^6 b. FM band: L1 = V/F = 3*10^8/8.8*10^7 = L2 = 3*10^8/1.08*10^8 =

*November 14, 2015*

**Physics**

V = Vo + a*t. Vo = 60,000m/3600s = 16.7 m/s. V = 90,000/3600s. = 25 m/s. t = ?.

*November 14, 2015*

**physics**

d = 5.5rev * 6.28rad/rev = 34.6 radians. V = 34.6rad./3s. = 11.5 rad/s.

*November 14, 2015*

**Physics**

d1 = r*t = 160 km. 80*t = 160. t1 = 2 hrs. d2 = r*t = 160 km. 100*t = 160. t2 = 1.6 hrs. r(avg.) = (d1+d2)/(t1+t2) = 320/3.6 = 88.9 km/hr.

*November 14, 2015*

**maths**

4/4 - (1/4+1/4) = 4/4 - 2/4 = 2/4 = 1/2 Left. 1/2 - 1/3 = 3/6 - 2/6 = 1/6 Left for wife. (1/6)/(2/6) * 100,000 = 1/2 * 100,000 = 50,000 = Wife's amount.

*November 14, 2015*

**Math**

A = X Degrees. B = (4x+20) Degrees. x + (4x+20) = 90o. X = ?

*November 14, 2015*

**Math**

Correction: Math-99Henry. should be Math Henry.

*November 13, 2015*

**High school /physic**

Vf = Vo + g*t. Vf^2 = Vo^2 + 2g*h.

*November 13, 2015*

**Math**

See previous post: Thu, 11-12-15, 11:06 PM.

*November 13, 2015*

**Math**

P = Income-Expense=20x-((20x/2)+18)=200. 20x - (10x+18) = 200. 20x - 10x - 18 = 200. 10x = 218. X = 21.8 or 22 Copies.

*November 13, 2015*

**University of North Dakota**

Correction: Change 49.5 to 495.

*November 13, 2015*

**University of North Dakota**

Acc. #1: Po1 = $X @ 9.5%. Acc. #2: Po2 = $(33,000-X) @ 1.5%. Po1*r1*t = Po2*r2*t. X*0.095*1 = (33,000-X)*0.015*1. 0.095x = 49.5 - 0.015x. 0.11x = 495. X = $4500. 33000-X = 33000-4500 == $28,500.

*November 13, 2015*

**Math**

d = 16t^2 = 1551 Ft. t^2 = 96.9375. t = 9.8 s. V = 64h?? 62

*November 12, 2015*

**math**

V = 0.3125 * 18 * 15 = in^3. Wt. = V*D = V * 0.698 = The surface area(As) is the area of the 6 sides: As = 2*W*h + 2*L*h + 2*L*W. L = 18 1n. W = 15 in. h = 0.3125 in.

*November 12, 2015*

**Math homework**

6/6-1/6 = 5/6 = Remainder. 5/6-2/5 = 25/30-12/30 = 13/30 Left.

*November 12, 2015*

**algebra**

Y = x^2+5x-36 = 0 -36 = -4*9, -4+9 = 5 = B. (x-4)(x+9) = 0.

*November 12, 2015*

**PHYSICS**

D = 350rev/60s * 0.64s * 6.28rad/rev =

*November 12, 2015*

**PHYSICS**

Do you think we might need to know the angles?

*November 12, 2015*

**Physics**

V^2 = Vo^2 + 2a*d = 0. a = -(Vo^2)/2d. It will be negative.

*November 11, 2015*

**Physics**

C = pi*2r = 3.14 * 2*0.98 = 6.15 m. 0.44rev/s. * 6.15m/rev = 2.71 m/s. = Tangential speed.

*November 11, 2015*

**physics**

Wo = M*g = 2 * 9.8 = 19.6 N. Fn = 19.6-20*sin20 = Normal force. Fk = u*Fn = Force of kinetic friction. Net force = 20*Cos20 - Fk.

*November 11, 2015*

**Pre-Alegebra**

3. Irrational. 4. D^2 = 15^2 + 8^2, D = 17. 5. You can test each choice by taking the cube root or raising it to the 1/3 power: 100^(1/3) = 4.64 125^(1/3) = 5 = A perfect cube. 6. Whole number/Integer. 7. 9/10. 8. Sqrt(35) = 5.92 In. Cut the 6-in. piece. 10. Riley: Sqrt(36) = ...

*November 11, 2015*

**Physics**

V^2 = Vo^2 + 2g*h. Vo = 0. g = 9.8 m/s^2. h = 2.1 m. V = ?

*November 11, 2015*

**physics**

Vf^2 = Vo^2 + 2g*h = 0. h = -Vo^2/2g + 1.5 = Meters above gnd. Vo = 20 m/s. g = -9.8 m/s^2.

*November 11, 2015*

**nwfsc**

V = I * R = 20 * 7 = 140 Volts. R = V/I = 140/14 = 10 Ohms.

*November 10, 2015*

**Math**

Libby: $60. Jess: 3/4 * 60 = $45. Stephanie: 1/3 * 45 = $15. Total:

*November 10, 2015*

**Math**

P(1, 2). Slope = 3. (1, 2), (x, y). m = (y-2)/(x-1) = 3. (y-2) = 3(x-1).

*November 9, 2015*

**math**

I've solved several of your problems. Where is the end?

*November 9, 2015*

**math**

Same procedure as your previous post.

*November 9, 2015*

**math**

I = Po*r*t = $1200. r = (18%/12)/100% = 0.015 = Monthly % rate expressed as a decimal. t = 1 Mo. Po*0.015*1 = 1200. Po = $80,000.

*November 9, 2015*

**math**

P = Po + Po*r*t = 2Po. Po + Po*0.1*t = 2Po Divide by Po: 1 + 0.1t = 2. 0.1t = 1. t = 10 Years.

*November 9, 2015*

**math**

I = Po*r*t. I = $3600. Po = $20,000. r = 0.12. t = ?.

*November 9, 2015*

**math**

P = Po + Po*r*t.

*November 9, 2015*

**Physics**

a. Vo = 60000m/3600s. = 16.7 m/s. Vf = 40000m./3600s. = 11.1 m/s. b. a = (Vf-Vo)/t = (11.1-16.7)/8 = -0.699 m/s^2.

*November 9, 2015*

**AP Physics**

Wb = M*g = 55 * 9.8 = 539 N. Fp = 539*sin40 = 347 N. = Force parallel to the ramp. Fn = 539*Cos40 = 413 N. = Normal force. Fp-Fk = M*a. 347-Fk = M*0 = 0. Fk = 347 N. = Force of kinetic friction. u = Fk/Fn.

*November 8, 2015*

**physics**

180N[W60oN] + [140N[90o] + 180N[E60oN]+ Ws = 0. Ws=-(-180*Cos60+180*sin60+140i+180*Cos60 +180*sin60) = -(155.9i+140i+155.9i) = -452i = -452 = 452 N. Downward. = Wt. of the sign. The horizontal components cancelled: 180*Cos60 - 180*Cos60 = 0.

*November 8, 2015*

**physics**

a = M1/M2 * a1 = 2.9/6.2 * 2.7 = 1.26 m/s^2.

*November 8, 2015*

**Science**

Mass = 200Lbs * 0.454kg/Lb = 90.8 kg. Wb = M*g = 90.8 * 9.8 = 889.84 N. = Normal force(Fn). a = 10Ft/s^2 * 1m/3.3Ft = 3.03 m/s^2. Fk = u*Fn = 0.25 * 889.84 = 222.5 N. = Force of kinetic friction. Fap-Fk = M*a. Fap = Applied or required force. Fap = ?.

*November 8, 2015*