Thursday

February 23, 2017
Total # Posts: 13,204

**Math**

If a boat was 36' long and i built a model of it 18" long what scale would the model be

*February 23, 2017*

**Maths**

Cost of a cup = $X. Cost of a plate = $Y. Y = 4x.

*February 23, 2017*

**Science**

F = M*a. 5 = 10*a, a = 0.5 m/s^2. a = (V-Vo)/t. 0.5 = 2/t, t = 4 s.

*February 23, 2017*

**Math**

Exponential growth(n^10) is greater.

*February 22, 2017*

**Álgebra**

360o/8sections * 3sections =

*February 22, 2017*

**physics**

V^2 = Vo^2 + 2a*d. 0 = (29.17)^2 - 500*d, d = ?.

*February 22, 2017*

**Algebra**

1 st integer = X. 2nd integer = x+1. 3x + 4(x+1) = 95. x = ?.

*February 22, 2017*

**maths**

P1 = 2L + 2W = 2*15 + 2*10 = 50 M. = P2. W/L = 4/5. W = 0.8L. P2 = 2W + 2L. P2 = 2*0.8L + 2L, 50 = 1.6L + 2L, L = 13.9 M. W = 0.8L = 0.8*13.9 = 11.1 m.

*February 22, 2017*

**Math**

X = The # of min. used. C = Total cost. Plan A: C = 0.1x. Plan B: C = 0.075x + 10.

*February 21, 2017*

**Physics**

30o W. of N. = 120o CCW from + x-axis. The system is in equilibrium: A*Cos120 = - B*Cos (0). A = -B*Cos(0)/Cos120 = 2B. A*sin120 = -(-200), A = 200/sin120 = 231 Lbs. A = 2B, 231 = 2B, B = 115.5 Lbs.

*February 21, 2017*

**physics**

A. X = -23*125 = -2875 m. Y = -12*255 = -3060i. Disp. = sqrt(x^2+y^2). B. Tan A = Y/X. A = ?. = Direction.

*February 20, 2017*

**physics**

Vo = 17m/s[39o]. Xo = 17*Cos39 = 13.2 m/s. Yo = 17*sin39 = 10.70 m/s. A. d = Xo*t. 3.8 = 13.2*t, t = 0.288 s. B. h = Yo*t +0.5g*t^2. h = 10.7*0.288 - 4.9*0.288^2 = 2.67 m.

*February 20, 2017*

**Science**

A. Work = F * d. They did the same amount of work. B. Power is the rate of doing work: P = F * d/t. The one that took the least time used the most power.

*February 20, 2017*

**Vectors**

50o W. of N. = 140o CCW. Vr = Vb + Vc. 20[140] = Vb + (-8i), Vb = 20[140] + 8i, Vb = 20*Cos140+20*sin140 + 8i. Vb = -15.3 + 12.9i + 8i = -15.3 + 20.9i Tan A = Y/X = 20.9/(-15.3) = -1.36601. A = -53.8o = 53.8o N. of W. = 126.2o CCW = 36.2O W of N.

*February 20, 2017*

**Vectors**

B. sin50 = 1.7/d. d = 2.22 km.

*February 20, 2017*

**Vectors**

Your last question doesn't make sense.

*February 20, 2017*

**Vectors**

A. Vr = Vb + Vc. 20[50o] = Vb - 8i, Vb = 20[50]+8i, Vb = 20*Cos50+20*sin50 + 8i, Vb = 12.9 + 15.3i + 8i = 12.9 + 23.3i. Tan A = Y/X =23.3/12.9 = 1.80620, A = 61o.

*February 20, 2017*

**Math**

3n = 5n-14. n = ?.

*February 20, 2017*

**math**

The opposite angles of a parallelogram are equal: A = C = 35 + 25 = 60o. 360-120 = 240o. B = D = 240/2 = 120o.

*February 20, 2017*

**Maths**

$5400 * 1m/$13.50 = 400 m. Cost = 400m * 28.50/m =

*February 20, 2017*

**Algebra**

Po1*r1*t + Po2*r2*t = 2730. Po1*0.06*1 + Po2*0.09*1 = 2730, 0.06Po1 + 0.09Po2 = 2730. Eq1: 6Po1 + 9Po2 = 273,000, Eq2: Po1 + Po2 = 39000. Multiply Eq2 by -6 and Add: +6Po1 + 9Po2 = 273000. -6Po1 - 6Po2 = -234,000. Sum: 3Po2 = 39,000, Po2 = $13,000 Invested in acc. #2. Po1 = 39...

*February 19, 2017*

**Physics**

post it.

*February 19, 2017*

**Physics**

V = 80m/s[-20O]. Vx = 80*Cos(-20) = 75.2 m/s. Vy = 80*sin(-20) = -27.4 m/s. A. Range = V^2*sin(2A)/g. Range = 80^2*sin(2*20)/9.8 = 420 m. B. Tan20 = h/420, h = 153 m. h = Vy*t + 0.5g*t^2. 153 = -27.4*t + 4.9t^2, 4.9t^2 - 27.4t - 153 = 0, Using the Quadratic Formula: t = 9.04 s...

*February 18, 2017*

**Math**

L = 23.5 ft. W = 11 ft. h = 2/3 ft. 1 yd^3. = 27 ft^3. V = L*W*h. Yards = V/27.

*February 18, 2017*

**physics**

Incomplete.

*February 18, 2017*

**electronic**

Incomplete.

*February 18, 2017*

**physical science**

R = pL/A. p = 110*10^-8 Ohm.m = 110*10^-6 ohm.cm. L = 220 cm. r = 0.056 cm. A = pi*r^2 = 3.14*0.056^2 = 9.85*10^-3 cm^2. R = (110*10^-6*220)/(9.85*10^-3) = 2.46 Ohms.

*February 17, 2017*

**pyhsical science**

R = pL/A A = pi*r^2 = pi*(2r)^2 = pi*4r^2. R2 = 2pL/(pi*4r^2) = pL/Pi*2r^2.

*February 17, 2017*

**Maths**

Wt. of box = 20 N. Fp1 = 4*Cos20 = 3.76 N. = Force acting Parallel to ramp(upward). Fp2 = 20*sin A = Force acting parallel to ramp(downward). Fp2-Fs-Fp1 = 0. 20*sin A-5-3.76 = 0. Equilibrium. A = ?. 9 20*sin A-5-3.76 = 0. 20*sin A = 8.76, A = 10.8o. = Angle of elevation.

*February 17, 2017*

**algebra**

1. a^2 + b^2 = c^2. 15^2 + b^2 = 20^2, 225 + b^2 = 400. b^2 = 400-225 = 175, b = sqrt(25*7) = 5*sqrt7. 2. 9^2 + 12^2 = c^2. c^2 = 81 + 144 = 225, c = sqrt(225) = 15.

*February 16, 2017*

**Algebra**

Eq1: A = x * y = 48ft^2. Eq2: P = 2x + 2y = 28 Ft.

*February 16, 2017*

**Scienc**

2. Acceleration. 3. A. 6. D. Friction opposes motion. 7. A. Velocity includes magnitude and direction. 8. A. 10. C. 11. F = M*a = 3 * 7 = 21 N.

*February 16, 2017*

**Math**

A. V(t) = Vo - 899t. Vo = Initial value. B. V(t) = Vo + 899t.

*February 15, 2017*

**Science**

M*g = 50 * 9.8 = 490 N. = Wt. of box. Fp = 490*sin30 = 245 N. = Force parallel with incline. Fn = 490*Cos30 = 424 N. = Normal force. Fs = u*Fn = = 424u. = Force of static friction. Fp-424u = M*a. 245-424u = M*0 = 0, U = ?.

*February 15, 2017*

**Physics**

1 gal. = 8 Lbs. = 3.63 kg. M = 10,000gal * 3.63kg/gal. = 36,320 kg. PE = M*g*h = 36,320*9.8*61.5 Joules.

*February 14, 2017*

**physics**

V*a*(T2-T1) = 136. 1.53*a*(15.1-92.2) = 136, a = ?.

*February 14, 2017*

**physics**

a = 13*10^-6/oC = Temp. coeff. h*a*(T2-T1) = 0.197. h*13*10^-6(40-(-9)) = 0.197, h*0.000637 = 0.197, h = 309.3 m.

*February 14, 2017*

**physics**

a = 13*10^-6/deg.C = Temp. coeff. 358*a*(T2-T1) = 358*13*10^-6*(22-1.99) = 0.093 m. = 9.3 cm.

*February 14, 2017*

**Math 115**

C = 0.79P, P>100.

*February 14, 2017*

**physics**

d = 0.5a*t^2. 8 = 0.5a*4^2, a = 1 m/s^2. V = Vo + a*t.= 0 + 1*4 = 4 m/s.

*February 13, 2017*

**physics**

(14*10^-6/19*10^-6) * 3600cm = 2653 cm.

*February 13, 2017*

**physics**

M*g = 532 * 9.6 = 5214 N. = Wt. of piano. Work = F*d = 372 * 14 = 5208 J. PE = Mg*h = 5208. 5214h = 5208, h = 1.0 m.

*February 12, 2017*

**Physics**

M = 28.44 kg. F1 = 3964N[63.74o]. F2 = 130N[180o]. Fx = 3964*Cos63.74 - 130*Cos180 = 1624 N. Fx = M*a. a = Fx/M = 1624/28.44 = 57 m/s^2.

*February 12, 2017*

**Physics**

Fr = 5.9[28o] + 5[90o]. X = 5.9*Cos28 = 5.2Units. Y = 5*sin28 + 5*sin90 = 7.35 Units. Fr = sqrt(x^2+y^2) = Tan A = Y/X = 7.35/5.2 = 1.41346, A = 54.7o = The direction.

*February 12, 2017*

**Math**

1. x + y = 9. 2xy = 40, xy = 20, X = 20/y. x + y = 9. 20/y + y = 9, Multiply by Y: 20 + y^2 = 9y, y^2 - 9y + 20 = 0, (x-4)(x-5) = 0, Y = 4, and 5. x + y = 9. Solution set: (x,y)=(4,5),(5,4). So the numbers are 4, and 5. 2. 1st number = X. 2nd number = x+4. x^2 + (x+4)^2 = 208...

*February 12, 2017*

**Physics**

Vo = 5m/s[60o]. Xo = 5*cos60 = 2.5 m/s. Yo = 5*sin60 = 4.33 m/s. 1. Y = Yo + g*t. 0 = 4.33 - 9.8t, t = ?. 2. Y^2 = Yo^2 + 2g*h. 0 = 4.33^2 - 19.6h, h = ?. 3. Range = Vo^2*sin(2A)/g. Range = 5^2*sin(120)/9.8 =

*February 12, 2017*

**science**

The Elasticity of the balloon. The balloon can be stretched beyond its' normal size and can return to normal if the elastic limit is not exceeded.

*February 11, 2017*

**physics**

a. (185+182+183+182+182+184+183)/7 =

*February 11, 2017*

**Physics**

I drew out image of the situation but still need help. Can someone help with this problem about swinging on wrecking ball when at 1st: wrecking ball is in line with birdbath when at a peak in its trajectory, and in line with front door at the lowest point in the trajectory. ...

*February 11, 2017*

**math**

M*g = 35 * 9.8 = 343 N. = wt. of carton. Fp = 343*sin40 = 220.5 N. = Force parallel to the incline. Fn = 343*cos40 = 262.8 N. = Normal force. Fp-Fs = M*a. 220.5 - Fs = 35*0, Fs = 220.5 N. = Force of static friction.

*February 11, 2017*

**math**

Correction: 326 = 0.816T2, T2 = 400 N.

*February 11, 2017*

**math**

60o W. of N. = 150o CCW from +x-axis. 45o E. of N. = 45o CCW from +x-axis. The system is in equilibrium: 326*cos150 = -T2*cos45. 326 = 0.742T2, T2 = 400 N. Fb = -(T1*sin150+T2*sin45). Fb = -(326*sin150+400*sin45) = -446 N. = 446 N. Downward. M*g = 446. M = 446/g = 446/9.8 = 46...

*February 11, 2017*

**Physics**

While swinging on the wrecking ball, a student notices that, at first, the wrecking ball is in line with her birdbath when it is at a peak in its trajectory, and in line with her front door at the lowest point in the trajectory. However, since drag is acting against the ...

*February 10, 2017*

**Physics**

I was able to figure out mass of ball = to 720kg and velocity of ball and her is 1.90m/s

*February 10, 2017*

**Physics**

While swinging on the wrecking ball, a student notices that, at first, the wrecking ball is in line with her birdbath when it is at a peak in its trajectory, and in line with her front door at the lowest point in the trajectory. However, since drag is acting against the ...

*February 10, 2017*

**Slopes**

m = (7-4)/(-5-0) = -0.6 Y = mx + b. 4 = -0.6*(6) + b, b = 7.6. Eq: Y = -0.6x + 7.6

*February 9, 2017*

**Math**

r = 226mi/2h = 113 mi/h. d = r*t =

*February 9, 2017*

**Math**

csc A = 4/3. sin A = 3/4, x^2 + 9 = 16, X = sqrt7 = 7^(1/2). Cot A = sqrt7/3. sin A + sin A * cot^2 A = 3/4 + 3/4*(7^(1/2))^2 = 3/4+3/4*7 = 24/4 = 6.

*February 9, 2017*

**Finance**

My answer is unsecured debt.

*February 8, 2017*

**math**

Income/wk. = $12/wash * XWASHES = $12X. Cost/wk. = ($12/h*40h)2 + $450/wk. = $1410. Profit/wk. = 12x - 1410 = $3.25/wash * xwashes. = $3.25x. Profit/wk. = 12x - 1410 = 3.25x, X = 161.14 or 162 Washes.

*February 8, 2017*

**algebra**

Vp*t = 1600. Vp*5 = 1600, Vp = 320 mi/h. in still air. (Vp-Vw)*5.5 = 1600. 5.5Vp - 5.5Vw = 1600. 5.5*320 - 5.5Vw = 1600, Vw = ?.

*February 7, 2017*

**Physics**

8 - 5 = 3 N. M*g = 3, M = 3/9.8 = 0.306 kg = Mass of water displaced. V*D = 306 grams. V*1 = 306, V = 306 cm^3. volume of water displaced = volume of candle holder. M*g = 8 N. M = 8/g = 8/9.8 = 0.816 kg = Mass of candle holder. D = 816g/306cm^3 = 2.67 g/cm^3.

*February 7, 2017*

**Science**

F = M*G = 500 * 10 = 5000 N. P = F*d/(t*0.4) = 5000*80/(10*0.4) = 100,000 Watts.

*February 7, 2017*

**Science**

F = M*a. a = F/M. = 15,000/500.

*February 7, 2017*

**Physics**

2. F4 =-(F1*sin90+F2*sin170+F3*sin34.8)F4 = -(70 + 8.68 + 34.2) = -113 N. = 113 N. Downward.

*February 6, 2017*

**Physics**

F1 = 70N[90o]. F2 = 50N[170o], CCW from +x-axis. F3 = 60N[Xo]. 1. The hor. component of F2 and F3 must be equal and opposite: F3*Cos X = -F2*Cos170. 60*Cos X = -50*Cos170, Cos X = 0.82067, X = 34.8o. 2.

*February 6, 2017*

**Physics**

F1 = 70N[90o]. F2 = 50N[170o], CCW from +x-axis. F3 = 60N[Xo]. F3*Cos X = -F2*Cos170. 60*Cos X = -50*Cos170, Cos X = 0.82067, X = 34.8o.

*February 6, 2017*

**Physics**

V = 1000mi/2wks * 1wk./7days * 1day/24h = 2.98 mi/h.

*February 6, 2017*

**Physics**

a. V = Vo + a*t. -45 = 36 + a*0.002, a = ? F = M*a. b. V = Vo + a*t. 45[30o] = 36 + a*0.002, 39 + 22.5i = 36 + a*0.002, 3 + 22.5i = a*0.002, a = 1500 + 11,250i = 11,350 m/s^2[82.4o]. F = M*a = 0.15 * 11,350[82.4o] = 1,702N[82.4o]. Magnitude = 1,702 N.

*February 6, 2017*

**math**

I don't see the scale.

*February 6, 2017*

**Physics**

Range = Vo^2*sin(2A)/g. Range = 65^2*sin(2*37)/9.8 = 414.4 m.

*February 5, 2017*

**Physics**

V = Vo + a*t. 55 = 70 + a*25, a = ?.

*February 5, 2017*

**Physics**

V = 68mi/72min * 60min/h =

*February 5, 2017*

**Physics**

V^2 = Vo^2 + 2g*h. 0 = 69^2 - 19.6h, h = ?. V = Vo + g*t. 0 = 69 - 9.8t, t = ?.

*February 5, 2017*

**physics**

V^2 = vo^2 + 2g*h. V^2 = 0 + 19.6*27, V = 23 m/s.

*February 5, 2017*

**Math**

(x-2)/x > 1/2. 2x-4 > x, X > 4. Let x = 5. (5-2)/5 = 3/5.

*February 5, 2017*

**math**

A diagram of the problem: 1. Draw a rectangle with the longest sides hor. 2. Draw a hor. line through the ver. sides to form two rectangles. 3. Label the ver. sides of the lower rectangle h1(15m) and the ver. sides of the top rectangle h2. 4. Draw a diagonal from the upper ...

*February 4, 2017*

**math**

Tan 17 = h1/d. Tan 17 = 15/d, d = 49.1 m. = Distance between the buildings. Tan32 = h2/d. Tan32 = h2/49.1, h2 = 30.7 m. = ht. from window of 1st bldg. to top of 2nd bldg. h = h1+h2 = 15 + 30.7 = 45.7 m. = ht. of 2nd bldg.

*February 4, 2017*

**Math**

Yes! -9(x-63) = x + (-49) = x-49.

*February 4, 2017*

**PHYSICS**

A window washer pulls herself upward using the bucket-pulley apparatus.. Part A) How hard must she pull downward to raise herself slowly at constant speed? The mass of the person plus the bucket is 80 kg . Part B) If she increases this force by 16 %, what will her acceleration...

*February 4, 2017*

**physics**

The cable supporting a 2150-kg elevator has a maximum strength of 2.2×104 N . What maximum upward acceleration can it give the elevator without breaking?

*February 4, 2017*

**Physics**

1. V^2 = Vo^2 + 2a*d. (3*10^6)^2 = 0 + 2a*0.15, a = ?. 2. F = M*a, a = F/M = 4.9/0.5 =

*February 3, 2017*

**maths**

(75+82+90+X)/4 = 85. X = ?.

*February 3, 2017*

**physics**

See previous post.

*February 3, 2017*

**physics**

V = pi*r^2*(h2-h1). V = 3.14*6^2*(135-120) = 1696 cm^3.

*February 3, 2017*

**Algebra**

1. (3,2), (1,-4) m = (y2-y1)/(x2-x1) = (-4-2)/(1-3) = -6/-2 = 3. 2. (-2,4), (-4,6). m = (6-4)/(-4-(-2)) = 2/-2 = -1. 3. (7,4), (-5,-2). m = (-2-4)/(-5-7) = -6/-12 = 1/2. Y = mx + b 4 = (1/2)7 + b, b = 1/2. Y = (1/2)x + 1/2. 4. (1,4), (2,-8). m = (-8-4)/(2-1) = -12, Y = mx + b...

*February 1, 2017*

**Math**

3pizzas/4bro. = 3/4 Pizza/bro.

*January 31, 2017*

**Physics**

V1 = a1*t1 = 1.76 * 20 = 35.2 m/s. d1 = 0.5a1*t1^2 = 0.88*20^2 = V2 = V1 + a*t = 35.2 - 5.93*5 = 5.55 m/s. The 5-second deceleration is not enough to bring the car to a full stop. d2 = V1*t + 0.5a*t^2. d2 = 35.2*5 - 0.5*5.93*5^2 = d = d1+d2 =

*January 31, 2017*

**algebra**

14x -3 y to the negative 4 / 2x5 y to the negative 2 how do you do this

*January 31, 2017*

**math**

1. I = Po*r*t = 1200*(0.105/12)*3. 2. P = Po + Po*r*t. P = 1200 + 1200*0.0775*2 = 3. 100%-20% = 80% financed. Po = 0.80 * 69,500 =

*January 31, 2017*

**Math**

4. 30/80 = 6/16. Not 6/18.

*January 30, 2017*

**Math**

1. 4/20 = 1/5. Not 1/6.

*January 30, 2017*

**math**

a. 1957 total CDs. X pop CDs. x-256 hip-hop CDs. (x-256)/3 country CDs. x + (x-256) + (x-256)/3 = 1957. Multiply both sides by 3 and solve for x. c. Country CDs/3.

*January 30, 2017*

**Physics**

V2 = V1 + a*t. 60 = 0 + a*4, a = 15 m/s^2. d = V1*t + 0.5a*t^2. V1 = 0, t = 4 s., a = 15 m/s^2, d = ?.

*January 30, 2017*

**physics**

Mb*V1 + Ma*V2 = Mb*V3 + Ma*V4. 5*3 - 10*3 = 5*V3 + 10*2, -15 = 5V3 + 20, V3 = -7 m/s = 7 m/s to the left.

*January 30, 2017*

**Science**

Incomplete.

*January 29, 2017*

**Science**

A. d = Vo*t + 0.5a*t^2. d = 0 + 1*30^2 = B. V = a*t.

*January 29, 2017*

**physics**

Tan A = (-3.50)/116.5 = -0.030043, A = -1.72o = 1.72o S. of E. Tan1.72 = d/153, d = 4.59 m.

*January 29, 2017*

**Physics**

Range = Vo^2*sin(2A)/g. 2.4 = 7^2*sin(2A)/9.8. A = 14.7o. = Minimum launching angle. Max. range occurs at 45o: Range = 7^2*sin(2*45)/9.8 = 5 m., max. Range of launch angles = 14.7 t0 45o.

*January 28, 2017*

**algebra**

t = 4/8 * 32h =

*January 28, 2017*