Sunday

February 19, 2017
Total # Posts: 13,181

**PreCalculus 1**

d. 16*Tf^2 = 27.25-10 = 17.25. Tf = 1.04 s. Dx = Xo*(Tr+Tf) = 130*2.28 = 296.7 Ft. 327-296.7 = 30.3 Ft. from bottom of fence. d^2 = 30.3^2 + 10^2 = 1019.3, d = 31.9 Ft from top of fence.

*July 7, 2016*

**PreCalculus 1**

Vo = 136Ft/s[17]. Xo = 136*cos17 = 130 Ft/s. Yo = 136*sin17 = 39.8 Ft/s. b. Y = Yo + g*Tr = 0, 39.8 - 32Tr = 0, Tr = 1.244 s. = Rise time. h = 2.5 + 39.8*1.244 - 16*1.244^2 = 27.25 Ft a5ove gnd. 16*Tf^2 = 27.25, Tf = 1.305 s. = Fall time. 1.244+1.305 = 2.549 s. to hit ground. ...

*July 7, 2016*

**Math**

(x,0), (-8,9), (0,y). X = 3y, (3y,0), (-8,9),(0,y). m = (9-0)/(-8-3y) = (y-9)/(0+8), 72/(-8-3y) = y-9, -8y-3y^2+72+27y = 72, -3y^2+19y = 0, y(-3y+19) = 0, Y = 0, -3y+19 = 0, 3y = 19, X = 3y = 19, Y = 6 1/3 = 19/3. m = 9/(-8-19) = -1/3. Y = mx + b = 9, (-1/3)(-8) + b = 9, b = 9...

*July 7, 2016*

**Physics**

M*(V2-V1) = 0.1(-20-30) = -5 = The Change in momentum

*July 7, 2016*

**Pre Calculus**

Log4 65,536 = X. 4^x = 65,536, x*Log 4 = Log 65,536, X = Log 65536/Log 4 = 8.

*July 6, 2016*

**Pre Calculus**

Log3 36 = N, 3^N = 36, Take Log of both sides: N*Log 3 = Log 36, N = Log 36/Log 3 = 3.26. Answer: e. None of these.

*July 6, 2016*

**Analytic geometry**

2. (-8,8), (x,y), (2,2). x-(-8) = 2(-2-x), x+8 = -4-2x, X = -4. y-8 = 2(2-y), Y = 4. (-8,8), (-4,4), (-2,2). m = (4-8)/(4-(-8)) = -1. Y = mx+b = 8, -1*(-8)+b = 8, b = 0. Eq: Y = -x.

*July 6, 2016*

**Analytic geometry**

1. (-3,0), (x,y), (3,-5). (3-(-3) = 2(x-(-3), 6 = 2x+6, X = 0. (-5-0) = 2(y-0), -5 = 2y, Y = -2.5. (-3,0), (0,-2.5), (3,-5). m = (-2.5-0)/(0-(-3)) = -5/6. Y = mx + b, -5x/6 + b = 0, -5*(-3)/6 + b = 0, b = -5/2 = -2.5. Eq: Y = (-5/6)x - 5/2.

*July 6, 2016*

**Physics**

Cos15 = 0.966.

*July 4, 2016*

**Physics**

Ws = M*g = 20 * 9.8 = 196 N. Fp = 196*sin20 = 67 N. Fn = 196*Cos20 - F*sin15 = 184-0.26F. Fs = 0.2(184-0.26F) = 36.8-0.052F. = Static friction. F*Cos15-Fp-Fs = M*a. 0.97F-67-(36.8-0.052F) = M*0 = 0. 0.97F-67-36.8+0.052F = 0, 1.022F = 36.8, F = 36 N.

*July 4, 2016*

**Physics**

Wb =M*g = 30 * 9.8 = 294 N. = Fn. Fap-Fs = M*a, 85-Fs = M*0 = 0, Fs = 85 N. u = Fs/Fn = 85/294 = 0.289.

*July 4, 2016*

**Physics**

M*g = 25 * 9.8 = 245 N. = Wt. of box. Fp = 245*sin40 = 157.5 N. = Force parallel to the incline. Fn = 245*Cos40 = 187.7 N = Force perpendicular(normal) to the incline. Fap-Fp-Fk = M*a. 500-157.5-Fk = 25*0.75, Fk = ?. k = Fk/Fn

*July 4, 2016*

**Math**

P = Po(1+r)^n P = 0.25 * 29,000 = $7,250 To be saved in 2 years. r = 0.10/2 = 0.05 = Semi-annual % rate. n = 2comp./yr. * 2 yrs. = 4 Compounding periods. Po(1.05)^4 = 7250. Po = 7250/1.05^4 = $5964.59 To be invested now. 0

*July 4, 2016*

**physics**

Vo = 20mi/h * 1600m/mi * 1h/3600s = 8.89s. V = 60mi/h = 26.7 m/s. a = (V-Vo)/t = (26.7-8.89)/10.8 = 1.65 m/s^2. d = Vo*t + 0.5a*t^2

*July 2, 2016*

**physics**

Vr = 5.35 + 15.7i = 16.7 mi/h[71.2o] = Resultant velocity.

*July 2, 2016*

**science physics**

F3 = -16N. = 16N.[180o].

*June 30, 2016*

**science physics**

F3 = -16 N. = 16N.[180o].

*June 30, 2016*

**science physics**

F3 = -16 N. = 16N.[180o].

*June 30, 2016*

**science physics**

F1+F2+F3 = 0, 10 + 6 + F3 = 0, F3 = -16 N.

*June 30, 2016*

**math**

Ganga received $X. Gayatri received (36,000/24,000) * x = $1.5x. x + 1.5x = P, X = 0.4P. x + (1.5x-2500) = 0.5P. Replace X with 0.4P: 0.4P + 0.6P = 0.5P + 2500, P = $5000. = Total profit. g

*June 30, 2016*

**Physics**

V^2 = Vo^2 + 2a*d. V = 10.4 m/s, Vo = 5.20 m/s, a = 4.20 m/s, d = ?.

*June 28, 2016*

**science**

V^2 = Vo^2 + 2a*d. V = 0, Vo = 500 m/s, d = 0.10 m, a = ?. "a" will be negative.

*June 28, 2016*

**Maths**

Eq1: 1.4x + 3y = -1. Eq2: -3x + 2y = -12. Multiply Eq1 by -2, Eq2 by 3, and add: -2.8x - 6y = 2 -9x + 6y = -36 Sum: -11.8x = -34, X = 2.88. In Eq1, replace X with 2.88 and solve for Y.

*June 26, 2016*

**ALGEBRA**

Walking rate = r mi/h. Time = (T-3) hrs. r*(T-3) = 6, r = 6/(T-3). Driving rate = 12r mi/h. Time = T hrs. 12r*T = 180, Replace r with 6/(T-3): (12^6/(T-3))*T = 180, 72T/(T-3) = 180, 72T = 180*(T-3), 72T = 180T-540, T = 5 hrs. r = 180mi/5h = 36 mi/h.

*June 25, 2016*

**pysics**

128km/h = 128,000m/3600s = 35.6 m/s. 128km/h * 1mi/1.6km = 80 mi/h.

*June 25, 2016*

**Math: Personal Finance**

V = 20,000 - 0.25*20,000 = 15,000 = Value after 1 yr. 15,000 - 500 = $14,500. = Amt. paid by Ins.

*June 22, 2016*

**Math: Personal Finance**

P = Po*r*t/(1-(1+r)^-t). r = 0.065/12mo. = 0.00542/mo. = Monthly % rate. P = 750/mo. * 360mo. = $270,000. P = (Po*0.00542*360)/(1-1.00542^-360) = 270,000, (Po*1.950)/0.8571 = 270,000, 2.275Po = 270,000, Po = $118,675.38.

*June 22, 2016*

**Personal Finance**

P = Po(1+r)^n = $3,000. r = 0.06/12mo. = 005/mo. n = 12Comp./yr. * 5yrs. = 60 Compounding periods. Po(1.005)^60 = 3000, Po = ?.

*June 20, 2016*

**math**

c. (840/1192.80)*100% =

*June 20, 2016*

**math**

a. 1192.80 - 10,080/12 = 1192.80 - 840 = $352.80. b. M = 352.80/840 = 0.42 = 42%.

*June 20, 2016*

**math**

200 * 1.60 = $320 = Total cost. Selling price = $P. (0.4*200)cookies * 1.50/cookie = $120 Received for broken cookies. (0.6*200)P + 120 = 1.35*320, 120P + 120 = 432, P = $2.60 each.

*June 20, 2016*

**Physics**

V^2 = Vo^2 + 2a*d = 0. 30^2 + 2a*0.1 = 0, 0.2a = -900, a = -4500 m/s^2. F = M*a = 0.1 * (-4500)= -450 N.

*June 18, 2016*

**Physics**

a. V^2 = Vo^2 + 2g*h = 24^2 - 19.6 *(13-2) = b. V = Vo + g*t. V = (part a), Vo = 24 m/s, g = -9.8m/s^2, t = ?.

*June 18, 2016*

**math**

P1: X min. P2: 2x min. 2x*x/(2x+x) = 18, 2x^2/3x = 18, 2x/3 = 18, 2x = 54 min, X = 27 min.

*June 16, 2016*

**Trigonometry**

Tan11.3 = h/50, h = ?.

*June 16, 2016*

**Trigonometry**

Tan15 = 1000/d, d = ?

*June 16, 2016*

**Trigonometry**

1. We draw 2 rt triangles with a common vertical side: 1. Draw hor. line OB. 2. Locate point "A" to the left of "B" to form AB. 3. Draw a ver. line at O and label it 70 m. 4. Draw the hyp. of each triangle with one going to A and B. Tan60 = 70/OA, OA = 70/...

*June 16, 2016*

**Math**

Please check for Typos.

*June 16, 2016*

**physics of science**

d = 2.54cm/in * 0.01in 0.0254 cm = 2.54*10^-4 m. V^2 = Vo^2 + 2a*d. a = (V^2-Vo^2)/2d =(0-400)/5.08*10^-4 = -7.87*10*5 m/s^2.

*June 16, 2016*

**physics of science**

V^2 = Vo^2 + 2a*d. a = (V^2-Vo^2)/2d =

*June 16, 2016*

**science**

sin25.4 = h/53, h = 53*sin25.4 = 22.7 m. PE = M*g*h = 60*9.8*22.7 = 13,367 J. KE = PE, 0.5M*V^2 = 13,367, 30*V^2 = 13367, V = 21.1 m/s. = Velocity at bottom of slope.

*June 15, 2016*

**Physics**

h = Vo*t + 0.5g*t^2 = 12 m. Vo*0.536 - 4.9*0.536^2 = 12, Vo = 25.0 m/s. V = Vo + g*t = 25 - 9.8*0.536 = 19.8 m/s When caught.

*June 15, 2016*

**Pre-Cal**

sin63 = h/13, h = ?

*June 15, 2016*

**physics**

All angles are measured CCW from due East. Vr = 3 + 5[300o]. Vr = 3 + 5*cos300+5*sin300 = 3 + 2.5 - 4.33i = 5.5 - 4.33i = 7m/s[322o] = Velocity of the rain. 322o CCW = 38o S. of E.

*June 15, 2016*

**science**

D = Zero.

*June 15, 2016*

**physical science**

Vo = 60mi/h * 5280Ft/mi * 1h/3600s = 88 Ft/s. V = 50/60 * 88Ft/s = 73.3 Ft/s. V = Vo-a*t = 88-2*3 = 82 Ft/s. Yes, because The driver is still above the speed limit after decelerating for 3 seconds.

*June 14, 2016*

**maths**

Let adjacent angle = X degrees. There are 4 angles; the opposite angles are equal. x + (x-20) + x + (x-20) = 360o. X = 100o, (x-20) = 80o.

*June 14, 2016*

**Physics**

Vo = 120m/s[35o]. Xo = 120*Cos35 = 98.3 m/s. Yo = 120*sin35 = 68.8 m/s. a. Y = Yo + g*Tr = 0. 68.8 - 9.8Tr = 0, Tr = 7.02 s. = Rise time. h = ho + Yo*Tr + 0.5g*Tr^2 = 20 + 68.8*7.0 - 4.9*7.0^2 = 261.5 m. above gnd. 0.5g*Tf^2 = 261.5. 4.9*Tf^2 = 261.5, Tf = 7.31 s. = Fall time...

*June 12, 2016*

**Algebra**

If 1/2 = 2/4, Then 2/1 = 4/2.

*June 11, 2016*

**physics**

Correction: Speeder: Vo = 117,000m/3600s = 32.5 m/s. Ds = 32.5*t = Distance traveled by speeder. Patrol car: a = (7600m/3600s)/s = 2.11 m/s^2. a. 32.5t = 0.5*2.11*t^2, 1.05t = 32.5, t = 31 s. b. Ds = Dp = 32.5*t = 32.5*31 = 1006 m.

*June 10, 2016*

**physics**

Speeder: Vo = 117,000m/3600s = 32.5 m/s. Ds = Vo*t = 32.5*t. = Distance traveled by speeder. Patrol car: a = (7600m/3600s)/s = 2.11 m/s^2. V = 175,000m/3600s = 48.6 m/s. Vo = 0. V^2 = Vo^2 + 2a*D, Dp = V^2/2a = (48.6)^2/4.22 = 560 m = Distance traveled by patrol car. a. Ds = ...

*June 10, 2016*

**Pre-Calculus**

X type A printers. Y type B printers. Eq1: x + y => 100. Eq2: 45x + 35y => 3850. Multiply Eq1 by -35 and add the Eqs: -35x - 35y => -3500. +45x + 35y => +3850. 10x => 350, X => 35 Type A printers. In Eq1, replace x with 35: 35 + y => 100, Y => 65 Type B...

*June 8, 2016*

**maths,science, physics**

M1*V1 + M2*V2 = M1*V + M2*V. 4000*3.5 + M2*0 = 4000*2 + M2*2 14,000-8000 = 2M2 M2 = 3,000 kg.

*June 5, 2016*

**Physics**

V = Vo + g*Tr = 0. Tr = -Vo/g = -20/-9.8 = 2.04 s. = Rise time. h = ho + Vo*Tr + 0.5g*Tr^2. h = 29 + 20*2.04 - 4.9*2.04^2 = 49.4 m Above gnd. 0.5g*Tf^2 = 49.4, 4.9Tf^2 = 49.4, Tf^2 = 10.08, Tf = 3.18 s. = Fall time. T = Tr + Tf = 2.04 + 3.18 = 5.22 s. To strike the water.

*June 4, 2016*

**physics**

F = 8beats/8s. = 1beat/s = 1cycle/s = 1 Hz.

*June 4, 2016*

**Physics**

All angles are measured CCW from due east. D = 29km[60o] + 20km[270o] + 10km[150o] =

*June 3, 2016*

**Physics**

Correction: D = 23i + 19.9+11.5i = 19.9 + 34.5i = 39.8m[60.0o]. Direction = 60.0o N . of E.

*June 3, 2016*

**Physics**

D = 23[90o] + 23[30o]. D = 23i + 19.9+11.5i = 19.9 + 42.9i = 47.3m[65.1o]. Direction = 65.1o N. of E.

*June 3, 2016*

**Physics**

V = 36km/h = 36000m/3600s = 10 m/s. V = Vo + a*t = 10 m/s. 0 + a*10 = 10, a = 1 m/s^2. V = Vo + a*t = 0. 10 + a*20 = 0, 20a = -10, a = -0.5 m/s^2.

*May 31, 2016*

**physics**

Vb = Di/Dw * Vi = Vi/9. Di/1000 * Vi = Vi/9, Divide both sides by Vi: Di/1000 = 1/9, Di = 1000/9 = 111.11 kg/m^3 = Density of the ice cube.

*May 31, 2016*

**Physics**

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

*May 28, 2016*

**finance**

a. Net Income = 591,000 - 255,000 - 0.36*591,000 = b. $591,000. c. 0.36 * 591000 =

*May 22, 2016*

**General Chemistry**

Thank you bobpursley..how can I determine the max concentration for Fe(OH)3 that will dissolve though?

*May 20, 2016*

**General Chemistry**

Ferric Hydroxide, Fe(OH)3, is an insoluble salt with a solubility of 10^-39. 1) What is the maximum concentration of ferric hydroxide that can dissolve? 2) Using Le Chatalier's Principle, explain why iron (III) solutions are more soluble in acidic solution.

*May 20, 2016*

**math**

Smaller box = 2*2*3. Larger box = 3*4*5. 2 small boxes stacked = L*W*2h = 2*2*6. Too tall to fit in large box. 2 small boxes side-by-side = L*2W*h = 2*4*3. So 2 smaller boxes will fit in the larger box.

*May 20, 2016*

**Physics**

K = 0.5N/0.0.6cm = 0.833 N/cm. Length = 35 + 2N*1cm/0.833N = 37.40 cm. Increasing the force above 2N do not increase length further.

*May 14, 2016*

**Science**

GPS or Geographic Positioning System

*May 10, 2016*

**math**

The first and the last terms of an Arithmetic Progression are 6 and 171 in that order. If there are 14 terms, find the 16th term of the Arithmetic Progression.

*May 8, 2016*

**Physics**

See previous post.

*May 7, 2016*

**Physics**

3.10km[25o]. 3.1*sin25 = 1.31 km due north, 3.1*Cos25 = 2.81 km due east. I assumed you meant 25o N. of E, because northeast = 45o.

*May 7, 2016*

**physics**

Convert to unit Vector: (51.2,30.8). Tan A = Y/X = 30.8/51.2 = 0.60062, A = 31o. R = = X/Cos A = 51.2/Cos31 = 59.7km[31o]. (x/59.7,y/59.7) = (51.2/59.7,30.8/59.7) = (0.86,0.52).

*May 7, 2016*

**physics**

a. 30km[315o,CCW] = 21.21 - 21.21i. b. 60km[60o,CCW] = 30 + 52i. R = 21.21-21.21i + 30+52i = 51.2 + 30.8i.

*May 7, 2016*

**physics**

Vo*t + 0.5a*t^2 = 62.4 m. Vo*4.2 - 0.5*5.6*4.2^2 = 62.4, 4.2Vo - 49.39 = 62.4, 4.2Vo = 111.79, Vo = 26.6 m/s. V^2 = Vo^2 + 2a*d. Vo = 26.6 m/s, a = -5.6 m/s^2, d = 62.4 m, V = ?.

*May 7, 2016*

**physics**

V = Vo + a*t. V = 0, a = -2.5 m/s^2, t = 10 s, Vo = ?.

*May 7, 2016*

**Math?**

The Lateral area is the area of the 4 vertical sides: A = 2(5*7) + 2(16*5) = 230 m^2.

*May 6, 2016*

**Maths**

2. V = Vo(1-r)^n. a. V = 1500(1-0.21)^6 = $364.63 b. V = 1500(1-0.21)^n = 60. 1500(0.79)^n = 60, 0.79^n = 60/1500 = 0.04, n*Log0.79 = Log0.04, n = Log0.04/Log0.79 = 13.7 Years.

*May 6, 2016*

**math**

Ar = Ab - Ad. Ar = 15000 - 15000*(0.075/360)*120 = $14,625 = Amt. received(proceeds). Ar = Amount received. Ab = Amount borrowed. Ad = Amount discounted.

*May 6, 2016*

**math 5th grade**

L = 5/6 yds. = 2 1/2 Ft. W = 3*2 1/2 = 15/2 = 7 1/2 Ft. Area = L*W = 2 1/2 * 7 1/2 = 5/2 * 15/2 = 75/4 = 18 3/4 square Ft. Or Area = L*W = 5/6 * 2 1/2 =[ 5/6 * 5/2 = 25/12 = 2 1/12 sq. yds. 1yd = 3ft, 1sq yd. = 3^2 = 9 sq. Ft. A = 2 1/12sq yds * 9sq ft/sq yd = 25/12 * 9 = 225/...

*May 5, 2016*

**physics**

Vo = 2 m/s[30o]. Xo = 2*Cos30 = 1.73 m/s. Yo = 2*sin30 = 1.0 m/s. Y = Yo + g*Tr. Y = 1 -9.8*Tr = 0, -9.8Tr = -1, Tr = 0.102 s. = Rise time or time to reach max ht. Tf = Tr = 0.102 s. = Fall time. Tr+Tf = 0.102 + 0.102 = 0.204 s. = Time in air. Y = 1 - 9.8*0.2 = -0.96 m/s. Y = ...

*May 5, 2016*

**physics**

Cos30 = V/10. V = ?.

*May 5, 2016*

**physics**

Correction: B. Impulse = F*t.

*May 5, 2016*

**physics**

a = (V-Vo)/t. V = 50 m/s, Vo = 0, a = ?. A. F = M*a. B. Impulse = M*t. C. Momentum ch. = M*V-M*Vo. C.

*May 5, 2016*

**Science (PhYsics)**

C = pi*2r = 3.14 * 1 = 3.14 m. Vo = 200rev/min * 3.14m/rev. * 1min/60s = 10.5 m/s. Since the velocity is constant, the acceleration is zero: a = (V-Vo)/t = (10.5-10.5)/t = 0/t = 0.

*May 5, 2016*

**Mathematics**

P1/P2 = 2/5, A1/A2 = (2/5)^2 = 4/25.

*May 5, 2016*

**physics**

b. Fk = u*Mg = 0.25 * 1.5*9.8 = 3.675 N. PE = KE - Fk*d = 19-3.675*d = 1.5*9.8*d, 19-3.675d = 14.7d, -18.375d = -19, d = 1.03 m.

*May 4, 2016*

**physics**

V = 75000m/h * 1h/3600s = 20.83 m/s. a. KE = 0.5M*V^2. b. PE = Mg*h = KE(Part "a"). g = 9.8 m/s^2, h = ?.

*May 4, 2016*

**Physics**

d = r*t =

*May 4, 2016*

**math**

Vb = 40km/2h = 20 km/h. Downstream. Vb = 40km/4h = 10 km/h. Upstream. Vb = (20+10)/2 = 15 km/h. In still water. Vs = 20 - 15 = 5 km/h. = Velocity of the stream.

*May 4, 2016*

**physics**

A. Work = F*d = 75 * 2 = 150 J. B. Work also = Change in kinetic energy = 0.5M*V^2 = 150, M = 65 kg, V = ?.

*May 4, 2016*

**physics**

A. k = 15N/0.450m = 33.3 N/m. B. F = 0.75m * 33.3N/m = 25 N.

*May 4, 2016*

**Physics**

D = 2.5 + 5i = 5.24 km[63.43o].

*May 4, 2016*

**HELP MATH ASAP**

Your problems are written in a very unconventional manner which makes them difficult to read and understand. Normal format: (x,y) = (3,4), (6,7).

*May 4, 2016*

**phy**

V = 45rev/min * 6.28rad/rev * 1min/60s = 4.71 rad/s. V = Vo + a*t = 4.71. 0 + a*4.5 = 4.71, a = 1.05 rad/s^2. D = Vo*t + 0.5a*t^2. D = 0 + 0.5*1.05*3^2 = 4.73 rad. V = Vo + a*t = 0 + 1.05*3 = 3.15 rad/s.

*May 4, 2016*

**Science**

E = 40 Volts, r = 5 Ohms, R = 15 Ohms. I = E//(r+R) = 40/20 = 2A. Vt = I*R = 2 * 15 = 30 Volts.

*May 2, 2016*

**science**

Q1. Matter. Q3. Density = 9g/45mL = 0.2 g/mL.

*May 2, 2016*

**science**

The answer is A.

*May 2, 2016*

**physics**

Cos30 = d/1780, d = ?.

*May 2, 2016*

**Math**

8W = 3F, 1W = 3/8F, 4W = 12/8F = 3/2F, 1D = 3/2F, 8D = 12F.

*May 1, 2016*

**Solid Mensuration**

There are 6 identical circles; the radius of each circle is 2 in.

*April 30, 2016*

**Solid Mensuration**

Diameter = 2/6 = 1/3 Ft. = 4 in. Radius = 1/2 * 4 = 2 In.

*April 30, 2016*