Thursday

December 8, 2016
Total # Posts: 12,460

**Physics**

Disp. = 21 + 34m[32o]. Disp. = (21+34*Cos32) + (34*sin32)i = 49.8 + 18.0i. Disp. = sqrt(49.8^2+18^2)

*October 15, 2016*

**math**

Tan A = 5m/12m, A = 22.6o. Cos22.6 = 3.4/V, V = 3.68 m/min.

*October 15, 2016*

**science**

R. Density = 750/1000 = 0.75.

*October 15, 2016*

**math**

20-6(2+1) = 2.

*October 14, 2016*

**Physics**

M*g = 100 * 9.8 = 980 N. = Wt. of crate = Normal force(Fn). Fs = us*Fn = 0.4 * 980 = 392 N. = Force of static friction. The crate does not move, because the applied force is less than the fore of static friction(Fs).

*October 14, 2016*

**physics**

M*g = 93 * 9.8 = 911.4 N. = Wt. of firefighter. Mg-Fk = M*a. 911.4 - 710 = 98*a, a = ?. V = Vo^2 + 2a*d. 3.2 = 0 + 2a*d, d = ?.

*October 14, 2016*

**Physics**

See previous post: Fri, 10-14-16, 10:33 AM.

*October 14, 2016*

**Physics**

Given: Vx = 30 m/s., Vy = 53 m/s. 2A. Vx = 30 m/s. Vy = 53 + g*t = 53 - 9.8*4 = 13.8 m/s. 2B. Dx = Vx*t = 30 * 4 = 120 m. Dy = 13.8 * 4 = 55.2 m. 3A. h = 0.5g*t^2 = 4.9*6^2 = 176.4 m.

*October 14, 2016*

**Physics**

Vo = 12m/s[47]. Xo = 12*Cos47 = 8.18 m/s. Yo = 12*sin47 = 8.78 m/s. Xo*T = 40. 8.18*T = 40, T = 4.89 s. = Time in air. Y = Yo + g*Tr_. 0 = 8.78 - 9.8Tr, Tr = 0.896 s. = Rise time. Tr+Tf = 4.89. 0.896 + Tf = 4.89, Tf = 3.99 s. = Fall time. ha = Yo*Tr + 0.5g*Tr^2. ha = 8.78*0....

*October 13, 2016*

**Physics**

a. M*g = 20 * 9.8 = 196 N. = Wt. of crate = Normal(Fn). Fap-Fs = M*a. 75-Fs = 20*0 = 0, Fs = 75 N. = Force of static friction. us = Fs/Fn = 75/196 = 0.383. b. 60-Fk = M*a. 60-Fk = M*0 = 0, Fk = 60 N. uk = 60/196 = 0.306.

*October 13, 2016*

**Physics**

52o S. of E. = 308o CCW. Disp. = 77[21o] + 124[308o]. Disp. = (77*Cos21+124*Cos308) + (77*sin21+124*sin308)I = 148.2 - 70.11i = 164m1[-25.3o] = 25.3o S. of E. = Direction. The crew must fly 164 miles in a direction 25.3o S. of E.

*October 13, 2016*

**Physics**

0.5g*t^2 = 25. 0.83*t^2 = 25, t = 5.49 s. to reach gnd. h = 0.5g*t^2 =4.9*5.49^2 = 148 m.

*October 13, 2016*

**physics**

V^2 = Vo^2 + 2g*h = 23^2 - 19.6*14 =

*October 13, 2016*

**Physics 11**

Vp + 50i = 500[0o]. Vp = 500 - 50i = 503 km/h[-5.71o] = 5.71o S. of E. = Direction.

*October 13, 2016*

**Physics**

D1 = 88 * 2 = 176km, S. D2 = 55 * 1.5 = 82.5km[70o] N. of E. X = 82.5*Cos70 = 28.22 km. Y = -176 + 82.5*sin70 = -98.5 km. D = sqrt(X^2+Y^2) = sqrt(28.22^2+98.5^2) = 102.5 km. Tan A = Y/X = (-98.5)/28.22 = -3.49043, A = -74o = 74o S. of E. = Direction.

*October 13, 2016*

**physics grade 11**

Post the problem.

*October 13, 2016*

**Physics**

V = Vo + a*t = 0 + 2*6 = 12 m/s. V = Vo + a*t. 0 = 12 + a*4, a = -3 m/s^2.

*October 13, 2016*

**Physics**

Ek = 0.5M*V^2 = 500*490 = 245,000 J.

*October 13, 2016*

**Physics**

a. V^2 = Vo^2 + 2g*h = 0 + 19.6*5 = 98, V = 9.90 m/s. Ek = 0.5M*V^2 = 500*98 = 49,000 J. b. V^2 = Vo^2 + 2g*h. 0 = Vo^2 - 19.6*25, Vo = 22.1 m/s. Ek =

*October 13, 2016*

**Java Programming Algorithm Help**

I just realized that my example provided is not clear and wrong. How about "51.283" and "1.982" We know 51 - 1 = 50 and 0.982 - 0.283 = 0.699 BUT, 51.283 - 1.982 = 49.301 Thank you

*October 12, 2016*

**Java Programming Algorithm Help**

Ok so for my assignment, I have to have two String inputs. For example, "1.021" and "2.51" And I need to calculate the difference between these strings (biggest number minus smaller). I can only use the data types: short, char, boolen and String. I cannot ...

*October 12, 2016*

**Physics**

V = Vo + a*t(i) = 4.8 + 3.4i*4.4 = 4.8 + 14.96i = sqrt(4.8^2 + 14.960^2) = 15.71 m/s.

*October 11, 2016*

**physics**

V = Vo + a*t. 21 = 0 + a*7, a = 3 m/s^2. V = 0 + 3*2 = 6 m/s.

*October 11, 2016*

**math**

727.7cm^3 * 19.3g/cm^3 = 14,045 g. Wt. = 14,045g * 1Lb/454g = 30.9 Lbs.

*October 11, 2016*

**Physics**

a. 0.5g*t^2 = 100. 4.9t^2 = 100, t = 4.52 s. b. V = Vo + g*t = 0 + 9.8*4.52 = 44.3 m/s. = Velocity after falling 100 m. Vo*t + 0.5g*t^2 = 100. 44.3*t + 0.5g*t^2 = 100, 4.9t^2 + 44.3t - 100 = 0, Use Quadratic formula: t = (-B+-sqrt(B^2-4AC)/2A. t =(-44.3+-sqrt(44.3^2+1960)/9.8...

*October 11, 2016*

**Science**

X = t^2-4t+7. X = 4^2 - 4*4 + 7 =

*October 11, 2016*

**Physics**

Y^2 = Yo^2 + 2g*h. Yo = sqrt(Y^2-2g*h). So if each object has the same value of Y and h, their initial Y component of velocity would be equal. We have 3 variables: 1. Y = 0 = Vertical component of final velocity. 2. Yo = Vertical component of initial velocity. 3.The max height...

*October 11, 2016*

**physics**

M1*d1 = M2*d2. M1*1.2 = M2*1.5, M1 = 1.25M2. (M1+14)*1.8 = M2*3. (1.25M2+14)1.8 = 3M2, 2.25M2 + 25.2 = 3M2, M2 = 33.6 kg, F2 = M2*g = 33.6*9.8 = 329.3 N. = Wt. of the girl. M1 = 1.25M2 = 1.25*33.6 = 42 kg, F1 = 42*9.8 = 411.6 N. = Wt. of the boy.

*October 11, 2016*

**AP Physics**

M*g = 5*9.8 = 49 N. = Wt. of the box. Fp = 49*sin30 = 24.5 N. = Force parallel t0 the incline. T = Fp = 24.5 N.

*October 10, 2016*

**math**

sin A = a/c = 26/65.2 = 0.39877, A = 23.5o. A + B + C = 180. 23.5 + B + 90 = 180, B = 66.5o.

*October 10, 2016*

**algebra 1**

Incomplete.

*October 10, 2016*

**physics**

V1*t = V2*t + d1. V1*t-V2*t = d1, t(V1-V2) = d1, t = d1/(V1-V2).

*October 10, 2016*

**Geometry**

86o + Xo + Yo = 180o. Yo = 180-86-X = 94-X.

*October 10, 2016*

**pre-calc**

r = 6-4 = 2mi/h.

*October 10, 2016*

**Science**

Vb = 12i + 20 = Sqrt(12^2+20^2) =

*October 10, 2016*

**physics**

M*g = 85 * 9.8 = 833 N. = Wt. of block. Fn = Mg-F*sin38 = 833 - 0.616F = Normal force. F*Cos38-u*Fn = M*a. 0.788F - 0.42(833-0.616F) = M*0 = 0, 0.788F - 349.9+0.259F = 0, 1.047F = 349.9, F = 334.3 N.

*October 9, 2016*

**physics**

1. Vr = Vc + Vb = 4. -3i + Vb = = 4, Vb = 4 + 3i = 5km/h[36.9o]. Direction = 36.9o N. of E. 2. Vr = 4 km/h. = Resultant velocity. 3. 5km/h[36.9o].

*October 9, 2016*

**physics**

V^2 = Vo^2 + 2a*d. 0 = 22.5^2 + 2a*41, a = ?. "a" will be negative which means that the acceleration opposes the motion. F = M*a = 1240*a.

*October 9, 2016*

**physics**

M*g = 350 N. Fn = Mg-Fap*sin42 = Normal force. Fn = 350-250*sin42 = Fap*Cos42-Fk = M*a. 250*Cos42-Fk = M*0 = 0, Fk = ?. u = Fk/Fn.

*October 9, 2016*

**physics**

M*g = 80 * 9.8 = 784 N. = Wt. of cabinet = Normal force(Fn). Fk = u*Fn. 300 = u*784, u = ?.

*October 9, 2016*

**math**

T = t1*t2/(t1+t2).

*October 9, 2016*

**physical**

Work = F*d =

*October 8, 2016*

**physics**

M = 300Lbs * 0.454kg/Lb = 136.2 kg. Fk = u*Fn = u*Mg = 0.04 * (136.2*9.8) = 53.4 N. = Force of kinetic friction. Fap-Fk = M*a. Fap-53.4 = M*0 = 0, Fap = 53.4 N. = Force applied.

*October 8, 2016*

**physisc**

h = 145 m ?.

*October 8, 2016*

**Physics**

12*I = 60, I = 5A. A*h = 80, 5*h = 80, h = 16.

*October 8, 2016*

**Physics**

20*Log(Ns/Np) = 13. Log(Ns/Np) = 13/20 = 0.65, Ns/Np = 10^0.65 = 4.47. Ns = 4.47Np.

*October 7, 2016*

**physics**

k = 3kg/12cm = 0.25 kg/cm. d = 4kg * 1cm/0.25kg = 16 cm. Or d = (4kg/3kg) * 12cm = 16 cm.

*October 7, 2016*

**Physics**

Hydrogen.

*October 7, 2016*

**physics**

T = M*g + M*a = M(g+a) = 8000*11.2 =

*October 7, 2016*

**Physics**

1. -T1*Cos60 = -T2*Cos45. T1 = -T2*Cos45/-Cos60 = 1.41T2. T1*sin60 + T2*sin45 = -(-150). 0.866T1 + 0.707T2 = 150, 0.866*(1.41T2) + 0.707T2 = 150, 1.225T2 + 0.707T2 = 150, 1.93T2 = 150, T2 = 77.7 N. T1 = 1.41 * 77.7 = 109.9 N.

*October 7, 2016*

**math**

X birds. Y dogs. Eq1: x + y = 30. Eq2: 2x + 4y = 86. Multiply Eq1 by -4: -4x - 4y = -120 +2x + 4y = 86. Sum: -2x = -34, X = 17 birds.

*October 6, 2016*

**physics**

V = Vo + a*t. 3 = 7 + a*3, a = - 1.333 m/s^2. F = M*a = 5 * (-1.33) = -6.67 N. The negative sign means that the force opposes the movement of the object.

*October 6, 2016*

**Trig**

Tan A = 5(Q3), A = 78.7o. S. of W. = 180+78.7 = 258.7o CCW. Sin B = 2/3(Q2), B = 41.8o N. of W. = 180-41.8 = 138.2o CCW. A-B = 258.7 - 138.2 = 120.5o, Q2.

*October 6, 2016*

**physics**

V = Vo + a*t. 12.4 = 39.3 - 2.8t, t = ?. Since the velocity is decreasing, the acceleration is negative.

*October 6, 2016*

**physics**

M1*d1 = M2*d2. d1 = M2*d2/M1 = 600*d2/500 = 1.2d2. d1 + d2 = 22. 1.2d2 + d2 = 22, d2 = 10 m. From its' end. d1 = 1.2d2 = 1.2*10 = 12 m. From its' end.

*October 6, 2016*

**physics**

L = Sqrt(X^2+Y^2) = Sqrt(2^2 + 13^2) =

*October 6, 2016*

**physics**

d = Vo*t + 0.5*t^2. 12 = 10*t + 2t^2, 2t^2 + 10t - 12 = 0. t^2 + 5t - 6 = 0. (t-1)(t+6) = 0, t-1 = 0, t = 1 s. t+6 = 0, t = -6. Solution: t = 1 s.

*October 6, 2016*

**Physics**

Work = F*d = Mg * d = 0.065*9.8 * 2.3 =

*October 5, 2016*

**Physics**

h = Vo*t + 0.5g*t^2. h = 120*4 - 4.9*4^2 =

*October 5, 2016*

**Physics**

d = 0.5a*t^2.

*October 5, 2016*

**Business Finance**

See previous post: Wed, 10-5-16, 7:27 PM.

*October 5, 2016*

**Business Finance**

P = Po(1+r)^n. Po = $3500. r = 0.05/2 = 0.025. n = 2Comp./yr. * 5yrs. = 10 Compounding periods. P = ?.

*October 5, 2016*

**Physics**

F1 = 100*Cos60 = 50 N.

*October 5, 2016*

**Science homework**

Incomplete.

*October 5, 2016*

**Science**

Incomplete.

*October 5, 2016*

**College Physics**

Incomplete.

*October 5, 2016*

**alegebra**

(1.08*10^-3) * (9.3*10^-3) = 10.044*10^-6 = 1.0044*10^-5.

*October 4, 2016*

**Maths**

A. 58 * t + 32 * t = 900 km. 90t = 900, t = 10 Hours. B. V1 = 58km/h = 58,000m/3600s = 16.11 m/s. V2 = 32km/h = 32,000/3600s = 8.89 m/s. V1*t + V2*t = 900 m. 16.11t + 8.89t = 900, t = 36 s.

*October 4, 2016*

*****

V = pi*r^2*h. 37000 = 3.14*25^2*h, h = ?.

*October 4, 2016*

**Maths**

d1 = r*t = 8 * (5*60) = 2400 m. d2 = 6 * (5*60) = 1800 m. d1-d2 = 2400 - 1800 = 600 m. Apart.

*October 4, 2016*

**Physics**

d = r*t = 340 * (0.1/2) = 17 m.

*October 4, 2016*

**Physics**

Vo = 52m/s[28o]. Xo = 52*Cos28 = 45.91 m/s. Yo = 52*sin28 = 24.41 m/s. a. Y^2 = Yo^2 + 2g*h. 0 = (24.41)^2 - 19.6h, h = ?. b. Range = Vo^2*sin(2A)/g. A = 28o, Range = ?.

*October 4, 2016*

**Physics**

Vo = 130km/h = 130,000m/3600s = 36.11m/sw. a. h = 0.5g*t^2. 1004 = 4.9t^2, t = ?. b. d = Vo*t = 36.11 * t,

*October 4, 2016*

**Physics(check my answer please!!)**

Vo = 8m/s[20o]. Xo = 8*Cos20 = 7.52 m/s. Yo = 8*sin20 = 2.74 m/s. a. Y = 0 m/s at max ht. V = sqrt(Xo^2+Y^2) = sqrt(7.52^2 + 0^2) = 7.52 m/s. b. Y = Yo + g*Tr. 0 = 2.74 - 9.8Tr, Tr = 0.279 s. = Rise time. b. h = ho + Yo*Tr + 0.5g*Tr^2. h = 5 + 2.74*0.279 - 4.9*0.279^2 = 5.38 m...

*October 3, 2016*

**math**

What is the int. rate? I don't know what you mean by 5-3 7.

*October 3, 2016*

**physics**

h = 0.5g*t^2. 65 = 4.9t^2, t = ?. d = Vo*t = 50 * t =

*October 3, 2016*

**Math Algrebra**

1. N = (35-1) + (40-1) + 1 = 2. N = (35-1) + (300-125) = 209. 3. N = (35-1) + (300-125) = 209. 4. (1000-100)/3 = 300.

*October 1, 2016*

**science**

Incomplete.

*September 30, 2016*

**math**

1. Y = Co + C*x. 22.45 = Co + C*200, Co = 22.45 - 200C. 29.65 = Co + C*350. Co = 29.65 - 350C. = 22.45 - 200C 150C = 7.20, C = 0.048/min. Co = 22.45 - 200*0.048 = $12.85/mo. = Initial cost. Y = 0.048x + 12.85. 2. Y = 0.048*110 + 12.85 = $18.13. 3. 34.10 = 0.048x + 12.85, X = ?.

*September 30, 2016*

**maths**

(3N-2)/(2N+5) = 13/15. 13(2N+5) = 15(3N-2), 26N + 65 = 45N - 30, N = 5.

*September 30, 2016*

**Algebra**

Y = 20 + 52stamps/4yrs. Y = 20 + 13stamps/yr. Y = 20 + 13x. Y = The number of stamps. X = The number of years.

*September 29, 2016*

**algebra 1**

what are the minimum and maximum distances a car can travel if it has a 15 gallon tank and can travel 26 miles per gallon with an absolute deviation of 4miles per gallon?

*September 29, 2016*

**Grade 11 Physics**

The first stone: 45 = 4.9t^2, t = 3.03 s. = Fall time. The 2nd stone: h = Vo*t + 0.5g*t^2. 45 = Vo*(3.03-1) + 4.9(3.03-1)^2, 45 = Vo*2.03 + 4.9*2.03^2. Vo = ?.

*September 29, 2016*

**Math**

Your parenthesis is incomplete.

*September 29, 2016*

**Physics**

M*g = 9 * 9.8 = 88.2 N. = Wt. of block. A. Fp = 88.2*sn20= 30.2 N. = Force parallel to the in.cline. Fn = 88.2*Cos20 = 82.9 N. = Normal or force perpendicular to the incline. Fs = u*Fn = u*82.9. Fp-Fs = M*a. 30.2-82.9u = M*0 = 0, 82.9u = 30.2, u = 0.364 = Static coefficient of...

*September 28, 2016*

**Physics**

d = Vo*t + 0.5a*t^2. d = 85*3.5 + 0.5*4*3.5^2 = 322 m.

*September 28, 2016*

**Physics**

Work is measured in Joules.

*September 28, 2016*

**science**

a = (V-Vo)/t = (5-2)/10 = 0.30 m/s^2. F = M*a.

*September 27, 2016*

**Physics**

See Related Questions: Thu, 9-22-16, 1:49 PM.

*September 27, 2016*

**Physics**

Vo = 25.6m/s[56o]. Yo = 25.6*sin56 = 21.22 m/s. Y^2 = Yo^2 + 2g*h. (15.3)^2 = (21.22)^2 - 19.6h, h = ?.

*September 27, 2016*

**physics**

Tan15 = 1.90/d. d = ?.

*September 27, 2016*

**Physics**

a. V^2 = Vo^2 + 2g*h1. 0 = 6.05^2 - 19.6h1, h1 = 1.87 m. V^2 = Vo^2 + 2g*(h1+h2) = 0 + 19.6*(1.87+12.7) = 285.6, V = 16.9 m/s. b. V = Vo + g*Tr. 0 = 6.05 - 9.8Tr, Tr = 0.617 s. = Rise time. h = 0.5g*Tf^2. 1.87+12.7 = 4.9Tf^2, Tf = 1.72 s. = Fall time. Tr+Tf = 0.617 + 1.72 = 2....

*September 27, 2016*

**physics**

V = Vo + g*Tr. V = 0 = Final velocity. Vo = Initial velocity. g = -9.8 m/s^2. Tr = Rise time, or time to reach max ht. h = o.5g*Tf^2. h = Ht. g = 9.8m/s^2. Tf = Fall time. I hope this helps.

*September 27, 2016*

**Physics**

Car A: d = r*t, t = d/r = 500/40 = 12.5 s. Car B: d = 0.5a*t^2, t^2 = d/0.5a = 500/5 = 100, t = 10 s.

*September 27, 2016*

**Physics**

1a. Fk = u*Fn = u * Mg = 0.44 * 5.1*9.8 = 22 N. The force of kinetic friction is greater than the applied force. please check for errors. 3a. (4.1/9.8) * 810 = 339 N.

*September 27, 2016*

**physics**

Y^2 = Yo^2 + 2g*h = 0 + 19.6*6.5 = 127.4, Y = 11.29 m/s. V = sqrt(Xo^2+Y^2) = sqrt(2.2^2 + 11.29^2) = 11.50 m/s

*September 27, 2016*

**physics**

h = 0.5g*t^2. 126 = 4.9t^2, t = 5.07 s. to reach gnd. d = Vx*t = 153 * 5.07 = 775.85 m.

*September 27, 2016*

**Physics**

Disp. = 13m[22.6o] + 17[118.1o]. Disp. = (13*Cos22.6+17*Cos118.1) + (13*sin22.6+17*sin118.1)i, Disp. = 4 + 20i = 20.4m[78.7o N. of E].

*September 25, 2016*

**physics**

M = 160Lbs * 0.454kg/Lb. = 72.64 kg. M*g = 72.64 * 9.8 = 711.9 N., Downward = -711.9 N. T1*Cos(180-39) = -T2*Cos55. T1 = 0.738T2. T1*sin(180-39) + T2*sin55 = 711.9. 0.629T1 + 0.819T2 = 711.9, Replace T1 with 0.738T2: 0.629*0.738T2 + 0.819T2 = 711.9, 1.28T2 = 711.9, T2 = 556 N...

*September 25, 2016*

**Physics**

Correction: d. y^2 = Yo^2 + 2g*h. Y^2 = 0 + 19.6*(53.2-3.05) = 982.94, Y = 31.35 m/s. V = Xo+Yi = 25.9 + 31.35i = 40.7 m/s.[50.4].

*September 25, 2016*