Monday

January 23, 2017
Total # Posts: 13,051

**Math**

Correct.

*November 30, 2015*

**geometry**

a^2 + b^2 = c^2. a^2 + 48^2 = 80^2. a = ?

*November 30, 2015*

**physics**

X = 6 mi/h = Velocity of the current. Y = 13 mi/h = Velocity of the boat. Tan A = Y/X = 13/6 = 2.16666. A = 65.2o N. of E. = 24.8o E. of N. Due to the current. Direction: Head 24.8o W. of N. To offset affect of the current. Tan A =

*November 30, 2015*

**math**

A. h = 30Ft * 1.26cm/Ft = 37.8 cm. = Ht. of the model. 37.8cm * 1toothpick/6.3cm = 6 Toothpicks B. 37.8cm/7.6 =

*November 30, 2015*

**Math**

Db + Dc = 510 mi. Vb*t + Vc*t = 510. Vb*t + (Vb+33.4)t = 510. t = 8.5 hrs. Vb = ? Vc = Vb + 33.4.

*November 29, 2015*

**algebra**

V = y(5y^2+31y+6). A*C = 5*6 = 30 = 1*30. V = y(5y^2+(y+30y)+6) = 0. y(5y^2+y)(30y+6) = 0. y*y(5y+1)6(5y+1) = 0 6y^2(5y+1)(5y+1) = 0. 6y^2 = 0, Y = 0. 5y+1 = 0, Y = -1/5.

*November 29, 2015*

**physics**

Mg*h = 0.5M*V^2. h = 0.5V^2/g = 0.5*8.5^2/9.8 = 3.69 m. V^2 = Vo^2 + 2g*h. Vo = 1.5 m/s. g = 9.8 m/s^2. V = ?

*November 29, 2015*

**Physics**

F2*d2 = F1*d1. F2*6 = 4*3 = 12. F2 = 2 N.

*November 29, 2015*

**math**

X1 = ? X2 = 200. h = X1*Tan45 = (X1+200)*Tan30.

*November 29, 2015*

**algebra**

Width = X Ft. Length = (2x-4) Ft. Square: Each side = x + (2x-4). 2x+2(2x-4) + 4(x + 2x-4) = 264 Ft. 2x+4x-8 + 4x+8x-16 = 264. 18x - 24 = 264. 18x = 288. X = 16 Ft. Rectangle = 2*16 + 2(2*16-4) = 88 Ft. Square = 4(16+32-4) = 176 Ft. So the shorter piece of wire = 88 Ft.

*November 29, 2015*

**Business Math**

a. P = Po*r*t/(1-(1+r)^-t). r = 6%. Po = 0.8 * 193,000 = $154,400 = Amount financed. r = (6%/12)/100% = 0.005 = Monthly % rate expressed as a decimal. t = 30yrs * 12mo/yr. = 360 Months. P = 154,400*0.005*360/(1-1.005^-360) = $333,254.16. Int. = P-Po = 333,254.16-154,400 = $178...

*November 29, 2015*

**math-unit rates**

Jeff hikes 1/4 mile every 2/5 hour. John hikes 1/2 mile every 1/7 hour. A) Who hikes farther in one hour. Show work. B) Who walks faster, Jeff or John. Explain your reasoning

*November 28, 2015*

**math**

M(-4,4), P(x,y), N(6,-2). x - (-4) = 3/4(6 - (-4). x + 4 = 3/4(6+4). X + 4 = 30/4 = 7 1/2. X = 7/2 = 3 1/2 = 3.5 y-4 = 3/4(-2-4). y-4 = -18/4 = -4 1/2. Y = -1/2 = -0.5 P(3.5,-0.5).

*November 28, 2015*

**physics**

h = Vo*t + 0.5g*t^2 = 80 m. -5*t + 4.9*t^2 = 80. 4.9t^2 - 5t - 80 = 0. Use Quadratic Formula: t = 4.58 s.

*November 28, 2015*

**physics**

k = 251N./0.488m = 514 N/m.

*November 28, 2015*

**physics**

a = F/M = 19.6/2.25 = 8.71 m/s^2. V^2 = Vo^2 + 2a*d. Vo = 0. V = ?

*November 28, 2015*

**Algebra**

I don't see the inequality sign.

*November 28, 2015*

**Physics**

h = 15.2*sin22 = 5.69 m. V^2=Vo^2 + 2g*h = 0 + 19.6*5.69 = 111.6 V = 10.6 m/s.

*November 28, 2015*

**algebra**

Your problem doesn't make sense; please check the wording.

*November 28, 2015*

**Physics**

X = 1.5 m/s = Velocity of water. Y = 2.2 m/s = Velocity of the swimmer. Tan A = Y/X = 2.2/1.5 = 1.46667. A = 55.7o N. of E. Direction = 55.7o N. of W. = 34.3o W. of N.

*November 28, 2015*

**Math**

Sale Price = 0.96 * 850 = $816. Cost = 0.80 * 816 = $652.80

*November 28, 2015*

**math**

Your number is 32. 32 = 1*32. 32 = 2*2*2*2*2. Sum of its' digits = 3+2 = 5.

*November 27, 2015*

**geometry**

2268Ft^3 * 7.5gal./Ft^3 = 17,010 Gallons T = 17,010gal * 1min/11gal. = 1546 Min. = 27.8 Hours.

*November 27, 2015*

**physics**

KE = PE = M*g*h = 5*9.8*10 =

*November 27, 2015*

**math**

A. Correct. B. Cos15 = 22.5/L1. L1 = 22.5/Cos15 = 23.3. Length = L1 + L2 = 23.3 + 23.3 = 46.6

*November 27, 2015*

**science**

I did a physics experiment and now i need help with the matlab fit. can someone tell me how to do this fit in matlab? a1*[sin(a2(x-a3))/(a2(x-a3)]^2*[cos(a4(x-a3))]^2 i have a program that fits a graph to a function i just ask how to write this function.

*November 27, 2015*

**science**

M*V = 10 * 15 = 150.

*November 27, 2015*

**physics**

Incomplete.

*November 26, 2015*

**1Physics**

a. k=F/(L2-L1)=2*9.8/(15-10) = 3.92N/cm = 392N/m. b. F = 3.92N/cm * (20-10)cm = 39.2 N. a = F/M = 39.2/2 = 19.6 m/s^2. c. V^2 = Vo^2 + 2a*d = 0 + 2*19.6*0.10 = 3.92. V = 1.98 m/s. d.

*November 25, 2015*

**electron theory and ohm law**

I = E/R.

*November 25, 2015*

**PHYSICS**

F = M*a, M1 = F/a = 72/5 = 14.4 kg. M2 = 5/20 * M1 = 5/20 * 14.4 kg = 3.6 kg a = F/(M1+M2) = 72/(14.4+3.6) =

*November 25, 2015*

**physics**

Change in V. = 110km/h[S25oE] - 110km/h[S25oW]. X = 110*Cos25 - (-110*Cos25) = 199.4 m/s. Y = -110*sin25 - (-110*sin25) = 0. Change in V. = X = 199.4 m/s. The above angles are referenced to the y-axis. If the angles were referenced to the x-axis: X = 93 m/s, Y = 0. The angles ...

*November 24, 2015*

**physics**

0.4Vo = Vo + g*t. 0.4Vo = Vo + (-9.8*3). 0.6Vo = 29.4. Vo = 49 m/s. Vf^2 = Vo^2 + 2g*h. Vf = 0. g = -9.8 m/s^2. h = ?

*November 24, 2015*

**Physics**

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

*November 24, 2015*

**Math**

X adult tickets: $3.50 ea. Y child tickets: $1.25 ea. Eq1: x + y = 37. Eq2: 3.5x + 1.25y = $73.25. Multiply Eq1 by -3.5 and add the Eqs.

*November 24, 2015*

**Physics**

d = Vo*t + 0.5*a*t^2 = 1000 m. Vo*34.3 + 0.5*0.0377*34.3^2 = 1000 m. 34.3Vo + 22.2 = 1000 34.3Vo = 978. Vo = 28.5 m/s.

*November 23, 2015*

**physics**

Tan A = Y/X = 0.165/(31/2) = 0.01065. A = 0.61 Degrees = B = Angle the wire makes with the hor. -T2*Cos 0.61 + T1*Cos 0.61 = 0. T1*Cos 0.61 = T2*Cos 0.61. T1 = T2. T2*sin 0.61 + T1*sin 0.61 = M*g. Replace T2 with T1: T1*sin 0.61 + T1*sin 0.61 = 1.54*9.8 2*T1*sin 0.61 = 15.1 N...

*November 23, 2015*

**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*