# Posts by henry

Total # Posts: 13,363

**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*

**physics**

2. Continued. d = V*t, V = 3*10^5 km/s, t = ?.

*January 28, 2017*

**physics**

1. 10^56/10^35 = 2. d = 3.3AU * 1.499*10^8km/AU =

*January 28, 2017*

**Pre Cal**

A ) B + C = 180. A + 62 + 48 = 180, A = 70o. sinB/b = sinA/a. b = ?.

*January 27, 2017*

**biology**

1)Can you suggest reasons why a phylogeny based on molecular evidence and a phylogeny based on morphology and other evidence might not be exactly the same? 2) Zoologist worldwide are sequencing a mitochondrial gene CO1 (cyctochrome c oxidase subunit), which is found in all ...

*January 27, 2017*

**Physics**

M*g = 300 * 9.8 = 2940 N. = Wt. of furniture. Fk = Force of kinetic friction. F1 = 45 N. F2 = 80*Cos25 = 72.5 N. F1+F2 - Fk = M*a. Fk = ?.

*January 27, 2017*

**Physics**

a. V = Vo + a*t. V = 0, Vo = 15 m/s, t = 0.3 s., a = ?. a will be negative. b. F = M*a. F will be negative.

*January 27, 2017*

**physics**

F = 2N/0.2cm * 2cm = 20 H. Work = F*d.

*January 26, 2017*

**math**

X tickets sold. x/6 children's tickets. 40 seniors tickets. X/2 adult tickets. x/6 + 40 + x/2 = X. x/6 + 40 + 3x/6 = x, 4x/6 - x = -40, -2x/6 = -40, X = 120. x/6 = 120/6 = 20. x/2 = 120/2 = 60 2*20 + 3*40 + 6*60 = $520 Collected.

*January 26, 2017*

**math**

Correction: Ignore the "10".

*January 26, 2017*

**math**

10 100ft^2/2 = 50 ft^2/sq. s^2 = 50, s = 7.071 ft. 7.071ft/side * 8sides = 56.57 ft = total required. But we have only 56 ft.

*January 26, 2017*

**math**

At = Ag + Arg. At = 6 + Arg, We need to know the dimensions of the area surrounding the rose garden. Then we could calculate At, the total area which leaves only one unknown(Arg), the area of the rose garden.

*January 26, 2017*

**Science**

d = V*t.

*January 26, 2017*

**Math**

Flour/Milk = Y/X = 5/4. a. Yes. b. Y/X = 5/4, Y/14 = 5/4, Y = ?.

*January 25, 2017*

**Math**

See previous post: Wed, 1-25-17, 8:22 P.M.

*January 25, 2017*

**physics**

Disp. = -34i + 117 + 64.5i + 28.5 = 145.5 + 30.5i. Magnitude = sqrt(145.5^2+30.5^2) =

*January 25, 2017*

**Math**

Wed.: d = r*t1 = 50mi/h * (43/60)h = 35.83 mi. Thu.: t2 = d/r = 35.83/68 = 0.527 h. = 31.6 min. t1-t2 = 43-31.6 = 11.4 min = Time saved.

*January 25, 2017*

**Physics**

40m/1min = 40m/60s = 0.667 m/s.

*January 25, 2017*

**Math**

5/20 = 1/4. A. = 1/4. D. 25/10 = 1/4.

*January 24, 2017*

**physics**

The positive and negative plates of a parallel-plate capacitor have an area of 1.05 cm by 1.05 cm. Their surface charge densities are +1.00×10-6 C/m2 and -1.00×10-6 C/m2, respectively. A proton moving parallel to the plates enters the middle of the space between ...

*January 24, 2017*

**science**

The system is in equilibrium: 30o W. of N. = 120o CCW. T1*Cos120 = -T2*Cos60. T1 = T2. T1*sin120 + T2*sin60 = -(-10) = 10. T2*sin120 + T2*sin60 = 10, 0.866T2 + 0.866T2 = 10, T2 = 5.77 N. T1 = T2 = 5.77 B.

*January 24, 2017*

**applied mechanics**

Vo = 72000m/3600s = 20 m/s. V = Vo + a*t = 0. 20 + a*5 = 0, a = -4 m/s^2. V^2 = Vo + 2a*d. V = 0, Vo = 20 m/s, a = -4 m/s^2, d = ?.

*January 24, 2017*

**Algebra**

K = (M2-M1)/(d2-d1) = (30-12)/(18-15) = 6 kg/cm . d = (12kg/6kg) * 1cm = 2 cm. L + 2 = 15, L = 13 cm.

*January 24, 2017*

**Science**

F = m*g in Newtons(N). Work = F*d in Joules.

*January 24, 2017*

**Math**

Assuming simple interest: P = Po + I = Po + Po*r*t. P = 6500 + 6500*0.09*4 = 6500 + 2340 = $8840 = Total amt. paid. I = P=Po =

*January 24, 2017*

**Math**

a. d = r*t. b. t = d/t. Eq1: t1 + t2 = 4 1/3 h. = 13/3 h. Eq2: 60t1 + 90t2 = 350 km. Solve the 2 Eqs simultaneously: -60t1 - 60t2 = -260 +60t1 + 90t2 = 350 sum: 30t2 = 90, t2 = 3 h. t1 + 3 = 13/3, t1 = 4/3 = 1 1/3 h. d1 = 60 * 4/3 = d2 = 90 * 3 =-

*January 24, 2017*

**Geometry**

As = 2pir^2 + pi*2r*h. As = (6.28*8^2) + (3.14*16*24) = 1608 m^2.

*January 23, 2017*

**Math**

a. 3:05, and 3:10. b. 5:00, and 6:05. c. 10:00, and 11:00.

*January 23, 2017*

**Maths**

c = X cm. a = x+20 cm. b = x+20 + 50 cm. a + b + c = 270. x+20 + x+20+50 + x = 270. X = ?. b = x+20+50.

*January 23, 2017*

**physics**

T = 2pi*sqrt(L/g). pi = 3.14., L = 1.25 m., g = 9.8 m/s^2.

*January 23, 2017*

**math**

a = b. x+2y = -2x+6y+1. Eq1: 3x-4y = 1. a + b + c = 28. x+2y -2x+6y+1 + 4y = 28. Eq2: -x+12y = 27. Add Eq1 and Eq2, solve for X, and Y: +3x - 4y = 1 -3x + 36y = 81(3*Eq2). sum: +32y = 82, Y = 41/16. In Eq1, replace Y with 41/16, and solve for X: 3x - 4*41/16 = 1, X = 15/4. X...

*January 22, 2017*

**Mathematics**

1. P1 = Po + Po*r*t. P1 = 12,500 + 12,500*0.12*3 = 2. P2 = Po(1+r)^n. Po = 12,500, r = 0.10. n = 1comp./yr. * 3yrs. = 3 compounding periods. P1-P2 =

*January 22, 2017*

**math**

Eq1: 4x + 2y = -2. m1 = -A/B = -4/2 = -2. m2 = m1 = -2. P2 = (-5,-7). Y = mx + b = -7, -2x + b = -7, b = -7+2x = -7 + 2(-5) = -17. Eq2:Y = -2x - 17.

*January 20, 2017*

**physical science**

Fr = -300 + 150 = -150 N. = 150 N. to the left.

*January 20, 2017*

**math**

C = pi*D = 3.14 * 25 = 78.5 in. 5,280ft/mi * 12in/ft. * 360o/78.5in * 295mi =

*January 19, 2017*

**Math**

The altitude(ht.) bisects the vertical angle and the base: 118/2 = 59o. Tan(90-59) = h/5. h = ?.

*January 19, 2017*

**Math**

Concentration = 6*120mg/60mls =

*January 18, 2017*

**Physical Science.**

Displacement is the straight-line distance from the end point to the starting point. The path traveled might not be a straight line. Displacement =< Distance traveled.

*January 18, 2017*

**Algebra**

T = T1*T2/(T1+T2) = 16*15/(16+15) =

*January 18, 2017*

**math**

0nes place = 9. tens place = X. hundreds place = X+1. x + x+1 = 11. X = 5. 659 blocks.

*January 18, 2017*

**Algebra 2**

2 People: 60boxes/10min . = 6 boxes/min. 6 People: (6/2) * 6 = 18 boxes/min. T = 120boxes * 1min/18boxes = 6.67 min.

*January 18, 2017*

**dynamics**

V1 = 400m/20s = 20 m/s. V2 = 400m/30s = 13.33 m/s. a = (V2-V1)/(T2-T1) = (13.33-20)/(30-20) = -0.667 m/s^2. V2 = V1 + 2a*d. 13.33 = 20 - 2*0.667*d. d = ?.

*January 18, 2017*

**physics**

a. M1*V1 + M2*V2 = 2.9*5.4 - 1.5*1.4 = 13.6

*January 17, 2017*