# Posts by henry

Total # Posts: 13,327

**physics**

Ws = M*g = 81.2 * 9.8 = 796 N. = Wt. of sled = Normal force, Fn. Fk = u*Fn = 0.172 * 796 = 137 N. = Force of kinetic friction. Fap-Fk = M*a. Fap-137 = M*0 = 0. Fap = 137 N. = Force applied. Work = Fap*d = 137 * 3.12 = 427 J. = 0.427 kJ.

*December 9, 2015*

**Math**

(2,1), (4,5). Slope = (y2-y1)/(x2-x1) = (5-1)/(4-2) =

*December 9, 2015*

**geometry**

Correction: A = 4.83*5^2.

*December 9, 2015*

**geometry**

A = 4.83*s^2 = 3.83*5^2 = 120.75 m^2.

*December 9, 2015*

**Math**

An ordered pair is a single point and not a line; Therefore, it has no slope.

*December 9, 2015*

**Math**

A. Plug your calculated value of T(2 s.) into the given Eq and solve for S, the ht. B. Tr = 2 s. = Rise time(part A). h = 0.5g*Tf^2 = 264 Ft. g = 32Ft/s^2. Tf = Fall time. Tf = ? Tr + Tf = Time to reach gnd. C. S(o) = ht. when t = 0. In the given Eq, replace t with zero and ...

*December 9, 2015*

**Algebra**

(1 3/4)sugar/(2/3)milk = (7/4)/(2/3) = 7/4 * 3/2 = 21/8 = (2 5/8)/1

*December 8, 2015*

**Math**

r^2 = X^2 + Y^2 (-12)^2 + 5^2 = 169. r = 13. sin A = Y/r = 5/13 = 0.3846.

*December 8, 2015*

**Math**

a. X = Sheldon's distance. x+4 = Leonard's distance. c. x + x+4 = 26. d. 2x = 26-4 = 22. X = 11.

*December 8, 2015*

**math**

Let X = 3: 3x/2 + 7/2 = 2^x. 3*3/2 + 7/2 = 2^3. 9/2 + 7/2 = 8. 16/2 = 8. 8 = 8. So X = 3 satisfies the Eq.

*December 8, 2015*

**Math: Geometry**

New Line = EF/(1/2) = 2EF.

*December 8, 2015*

**contemporary mathematics**

392mi/t = 322/t + 20. 392 = 322 + 20t. 20t = 392 - 322 = 70. t = 3.5 h. r = 392mi/3.5h = 112 mi/h = Speed of the P. train. r = 322mi/3.5h = 92 mi/h = Speed of the F. train.

*December 8, 2015*

**Physics**

X = 5m/s. = Vw. Y = 4 m/s = Vd. a. Tan A = Y/X = 4/5 = 0.8, A = 38.7o. N. of E. = 51.3o E. of N. Vr = X/Cos A=5/Cos38.7=6.4 m/s[38.7o] = Resultant drone velocity. b. d = 120/sin38.7 = 192 m. To cross the field. V*t = 192, 4*t = 192, t = 48 s.

*December 7, 2015*

**physics**

M(g+a)= 478. a = ?

*December 7, 2015*

**physics**

See previous post: Fri, 11-28-14, 9:52 PM.

*December 7, 2015*

**math**

A = b*h = 300yds^2. 15h = 300. h = 20 yds.

*December 7, 2015*

**math**

Scale = 16in/5ft = 3.2 in/ft. Width = 15Ft * 3.2in/ft. = 48 in. Height = 10ft * 3.2in/ft. = 32 in. Area = 48 * 32 = Square inches.

*December 7, 2015*

**AC circuits**

Note: If the voltage across the resistor is incorrect, all voltages will be wrong.

*December 6, 2015*

**AC circuits**

I = VR/R = 10/4 = 2.5A. = Current through all components(R,L, and C). VL = I*XL = 2.5 * 6 = j15.0 Volts. Vc = I*Xc = 2.5 * 8 = -j20.0 Volts. Z = R + j(XL-Xc)) = 4 + j(6-8) = 4 - j2 = 4.47 Ohms[-26.6o]. Es = I*Z = 2.5 * 4.47 = 11.2 Volts. Pf = Cos(-26.6) = 0.894 = Power factor...

*December 6, 2015*

**Physics**

There are errors in your problem that makes it difficult to understand. X = 3 km/h. Y = 10 km/h. Tan A = Y/X = 10/3 = 3.33333. A = 73.3o N. of E. = 16.7o E. of N. d1 = 5/Tan73.3 = 1.50 km downstream. d2 = Sqrt(1.5^2 + 5^2) = 5.22 km to cross. 2. Direction to offset affect of ...

*December 6, 2015*

**Physics**

L = 40 + 12*10^-6/Co(T-20) = 40.01. 40 + 12*10^-6T - 240*10^-6 = 40.01. 40 - 0.00024 + 12*10^-6T = 40.01. 39.99976 + 12*10^-6 = 40.01. 12*10^-6T = 40.01 - 39.99976 = 0.01024. T = 853.333 Degrees C.

*December 6, 2015*

**math**

post it.

*December 6, 2015*

**Physics**

Ws = M*g = 150*9.8 = 1470 N. Fp = 1470*sin40 = 945 N.=Force parallel to the ramp. Fn = 1470*Cos40 = 1126 N. = Normal force Fk = u*Fn = 0.54 * 1126 = 608 N. = Force of kinetic friction. Fp-Fc-Fk = M*a. 945-Fc-608 = M*0 = 0. 337-Fc = 0. Fc = 337 N. = Force of the curator. a. ...

*December 5, 2015*

**Math**

3x - 5x = 18. 2x = 18. X = 9. 3x = 3*9 = 27 = 1st number. 5x = 5*9 = 45 = 2nd number.

*December 5, 2015*

**MATH**

7.48*10^5.

*December 5, 2015*

**math**

I = 280/40 * 4 = 28 Amps. or E = I*R = 4*280 = 1120 v. I = E/R = 1120/40 = 28 Amps.

*December 3, 2015*

**PreCalculas**

2. D(3/4,-3), V(h,-3), F(5/4,-3). 1/2a = 5/4-3/4 = 2/4 = 1/2. 2a = 2, a = 1. 1/4a = 1/(4*1) = 1/4. h = 3/4 + 1/4a = 3/4 + 1/4 = 4/4 = 1. X = a(y-k)^2 + h. X = (y+3)^2 + 1, Vertex form. X = y^2 + 6y + 10, Standard form.

*December 3, 2015*

**PreCalculas**

1. V(2,5), F(2,-3). 1/4a = -3-5 = -8. 4a = -1/8. a = -1/32. Y = a(x-h)^2 + k. Y = (-1/32)(x-2)^2 + 5, Vertex Form

*December 3, 2015*

**physics**

See previous post: Tue, 12-1-15, 12:30 PM.

*December 3, 2015*

**physics**

a football thrown at 45o has max range: Range = Vo^2*sin(2A)/g=36^2*sin(90)/9.8 = 132.2 m.

*December 3, 2015*

**math**

6*Cos x + 2.46*Cos x - 1.72*sin x = 7*Cos x. 8.46*Cos x - 1.72*sin x = 7*Cos x. 8.46*Cos x - 7*Cos x = 1.72*sin x. 1.46*Cos x = 1.72*sin x. Divide by Cos x: 1.72*sin x/Cos x = 1.46. Replace sin x/Cos x with Tan x: 1.72*Tan x = 1.46. Tan x = 1.46/1.72 = 0.84848. X = 40.3 Degrees.

*December 3, 2015*

**physics**

V^2 = Vo^2 + 2g*h. Vo = 0. g = 9.8 m/s^2. h = 3 m. V = ?

*December 3, 2015*

**pysics**

Vo = 200m/s[35o]. Yo = 200*sin35 = 114.7 m/s. Y^2 = Yo^2 + 2g*h. Y = 0. g = -9.8 m/s^2. h = ?

*December 3, 2015*

**Physics Check My Work Please**

g is used when the motion is vertical. The block is moving horizontally. Therefore, the acceleration must be calculated: Fk = Ma, a = Fk/M = -12/8 = -1.5 m/s^2. V^2 = Vo^2 + 2a*d. a = -1.5 m/s^2. Fk is negative, because it opposed the motion.

*December 3, 2015*

**Math**

N = 4*8 = 32 Students.

*December 2, 2015*

**Physics**

PE = KE Mg*h = 0.5M*V^2. M*g = 45*9.8. h = ?

*December 2, 2015*

**Physics**

See previous post: Tue, 12-1-15, 12:33 PM.

*December 2, 2015*

**algebra**

-7y^2-4y+6 = 7y^2-4y-4-2y^2+2y+6. -12y^2-2y+4 = 0. Divide by -2: 6y^2 + y - 2 = 0. A*C = -12 = 4*(-3) 6y^2 + (4y-3y) - 2 = 0. (6y^2+4y) - (3y+2) = 0. 2y(3y+2) - (3y+2) = 0. (3y+2)(2y-1) = 0. 3y+2 = 0, Y = -2/3. 2y-1 = 0, Y = 1/2.

*December 2, 2015*

**Science**

Unless otherwise indicated, all angles are measured CCW from +x-axis. Vr = 725m/s[131.2o] + 106.7m/2[68.2o]. X = 725*Cos131.2 + 106.7*Cos68.2= -438 m/s. Y = 725*sin131.2 + 106.7*sin68.2 = 645 m/s. Tan A = Y/X = 645/-438 = -1.47162. A = 55.8o N. of W. Vr = Y/sin A = 645/sin55.8...

*December 2, 2015*

**Science**

Vp = 725m/s[W.48.8oN] + 106.7[E68.2N] = -725*Cos48.8+725*sin48.8 + 106.7*Cos68.2 +106.7*sin68.2 = -478+546i + 39.6+99.1i = -438.4 + 645.1i = 780m/s[W55.8oN] = 780m/s[N34.2oW].

*December 2, 2015*

**Algebra plz help**

1. Correct. 2. Correct. 3. Incorrect. See previous post: Mon, 11-30-15, 9:08 PM.

*December 2, 2015*

**math**

Proportion: S/m = 2/11. 16/m = 2/11, m = 88 min. 19/m = 2/11, m = 104 min.

*December 2, 2015*

**Physics**

Need more INFO.

*December 2, 2015*

**Physics**

V = 60,000/3600s = 16.7 m/s. C = pi*D = 3.14 * 0.75m = 2.36 m. Va = 16.7m/s * 6.28Rad/2.36m=44.3 Rad/s.

*December 2, 2015*

**physics**

Vo = 172.5m/s[30o]. Xo = 172.5*Cos30 = 149.4 m/s. Yo = 172.5*sin30 = 86.25 m/s. a. Yf^2 = Yo^2 + 2g*h. h = -(Yo)^2/2g = -(86.25)^2/19.6 = 379.5 m. b. Y = Yo + g*Tr = 0. Tr = -Yo/g = -86.25/-9.8 = 8.80 s. = Rise time. NOTE: In your Eq, use (-)9.8 for g.

*December 1, 2015*

**Physics**

Vo = 5.2m/s[56o]. Xo = 5.2*Cos56 = 2.91 m/s. Yo = 5.2*sin56 = 4.31 m/s. h=-Yo^2/2g + 1.1=-(4.31)^2/-20 + 1.1 = 2.03 m. Above gnd. Y^2 = Yo^2 + 2g*h = 0 + 20*2.03 = 40.6 Y = 6.37 m/s. X = Xo = 2.91 m/s.

*December 1, 2015*

**Physics**

Eq1: Xo = Vo*Cos A = Speed at max h. Vo = 6.8Xo. In Eq1, replace Vo with 6.8Xo: Xo = 6.8Xo*Cos A. Divide by 6.8Xo: Cos A = 1/6.8 = 0.14706 A = 81.5 Degrees.

*December 1, 2015*

**Physics**

Vo = 29.6m/s[46.9o]. Xo = 29.6*Cos46.9. = m/s. Yo = 29.6*sin46.9 = m/s. Y = Yo + g*Tr. Y = 0. g = -9.8 m/s^2. Tr = Rise time. Tr = ? Y^2 = Yo^2 + 2g*h. Y = 0. h = ? 0.5g*Tf^2 = h + 32. g = 9.8 m/s^2. Tf = Fall time. Tf = ? D = Xo*(Tr+Tf).

*December 1, 2015*

**waves andoscillation**

F = 0.13m * 130N/m = 16.9 N. a = F/M = 16.9/0.60 = 28.2 m/s^2.

*November 30, 2015*

**PHYSICS**

Displacement = 1000i +1000i + 200[225o] = 1000i + 200*Cos225 + 200*sin225 = 1000i - 141.4 - 141.4i = -141.4 + 858.6i = 870m[99.4o]CCW = 80.6o N. of W. V = D/t = 870m[99.4o]/960s = 0.91 m/s.

*November 30, 2015*

**Algebra**

(3/2,-2), (-3,7/3). Slope = (y2-y1)/(x2-x1). Slope = (7/3-(-2))/(-3-3/2) = (7/3+2)/(-6/2-3/2) = (7/3+6/3)/(-9/2) = (13/3)/(-9/2) = 13/3 * (-2/9) = -26/27.

*November 30, 2015*

**science**

The signal rides on a higher frequency called the carrier frequency. The carrier is modulated in the transmitter and demodulated in the radio. To demodulate means to separate the voice or music from the carrier. The carrier may be Frequency Modulated (FM) or Amplitude ...

*November 30, 2015*

**Math**

d1 = V1*T1 = 40 * 3 = 120 mi. d2 = V2*T2 = 55 * T2 = 55T2. Vavg. = (d1+d2)/(T1+T2) = 50 mi/h. (120+55T2)/(3+T2) = 50. 120 + 55T2 = 150 + 50T2. 5T2 = 30. T2 = 6 Hours.

*November 30, 2015*

**PHYSICS**

V = d/t = (300 + 100)/(60+20) = 5 m/s.

*November 30, 2015*

**Math**

A function crosses a vertical line only once. Your relation crosses a vertical line twice:(-8,-6), and (-8,1). The x-coordinate shows twice; that is the clue. Therefore, it is not a function.

*November 30, 2015*

**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*