# Posts by Henry

Total # Posts: 13,500

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.

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

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 = ?

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.

Math
N = 4*8 = 32 Students.

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

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

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.

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...

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].

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

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

Physics

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.

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.

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.

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.

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).

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

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.

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.

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 ...

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.

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

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.

Math
Correct.

geometry
a^2 + b^2 = c^2. a^2 + 48^2 = 80^2. a = ?

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 =

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 =

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.

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.

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 = ?

Physics
F2*d2 = F1*d1. F2*6 = 4*3 = 12. F2 = 2 N.

math
X1 = ? X2 = 200. h = X1*Tan45 = (X1+200)*Tan30.

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.

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...

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

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).

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.

physics
k = 251N./0.488m = 514 N/m.

physics
a = F/M = 19.6/2.25 = 8.71 m/s^2. V^2 = Vo^2 + 2a*d. Vo = 0. V = ?

Algebra
I don't see the inequality sign.

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.

algebra

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.

Math
Sale Price = 0.96 * 850 = \$816. Cost = 0.80 * 816 = \$652.80

math
Your number is 32. 32 = 1*32. 32 = 2*2*2*2*2. Sum of its' digits = 3+2 = 5.

geometry
2268Ft^3 * 7.5gal./Ft^3 = 17,010 Gallons T = 17,010gal * 1min/11gal. = 1546 Min. = 27.8 Hours.

physics
KE = PE = M*g*h = 5*9.8*10 =

math
A. Correct. B. Cos15 = 22.5/L1. L1 = 22.5/Cos15 = 23.3. Length = L1 + L2 = 23.3 + 23.3 = 46.6

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.

science
M*V = 10 * 15 = 150.

physics
Incomplete.

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.

electron theory and ohm law
I = E/R.

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) =

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 ...

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 = ?

Physics
Vf^2 = Vo^2 + 2g*h. h = ?

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.

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.

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...

Physics
See previous post: Mon, 11-23-15, 1:20 PM.

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.

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 ...

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...

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.

Physics
k = 100N./0.150m = 667 N/m.

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...

science
1750 - 500 = 1250g = Wt. of oil. Density = 1250g/0.5L = 2500g/L.

math
1. C = 7p + 1.50. 2. C = 7*4 + 1.50 = 3. C = 7p + 1.50. C = 43.50. p = ?

physics
P = 0.2/0.8 * 100W. = 25 W.

Physics
1. Vf^2 = Vo^2 + 2g*h. Vf = 0. Vo = 12 m/s. g = -9.8 m/s^2. h = 2. V = 90,000m/3600s = 25 m/s. Vo = 126,000m/3600s = 35 m/s. V = Vo + a*t. a = (V-Vo)/t = (25-35)/t = -10/t. V^2 = Vo^2 + 2a*d. 25^2 = 35^2 + 2(-10/t)*800. 625 = 1225 + (-16,000)/t. -600 = -16000/t. 600t = 16000. ...

physics
Fr = F[0o] + F[126o] = F + F*Cos126 + (F*sin126)i = F - 0.588F + 0.809Fi=0.412F + 0.809i. Tan A = 0.809F/0.412F = 1.96359. A = 63o N. of E. = 63o CCW. Fr = 0.809F/sin63 = 0.908F[63o]

Physics AP
Wc = M*g = 32 * 9.8 = 314. N. Fn = 314*Cos38 = 247 N. = Normal force.

Physics
V^2 = Vo^2 + 2a*d. V = 0. Vo = 7.90 m/s. a = u*g = 0.41 * (-9.8) = -4.02 m/s^2. d = ?

Physics
Ws = M*g = 15 * 9.8 = 147 N. = Wt. of suitcase. Fn = Ws-T*sin45 = 147 - T*sin45 = 147-0.707T = Normal force. Fk=u*Fn=0.36*(147-0.707T) = 52.9-0.255T. T*Cos45-Fk = M*a. 0.707T-(52.9-0.255T) = M*0. 0.707T-52.9+0.255T = 0. 0.961T = 52.9 T = 55 N. Fn = 147 - 0.707*55 = 108 N.

Physics
a. See previous post: Thu, 11-19-15, 9:46 PM. b. V^2 = Vo^2 + 2g*h. Vo = 0. g = 9.8 m/s^2.

Physics
Mass = 180Lb * 0.454kg/Lb = 81.72 kg. h = 5mi * 1600m/mi 8000 m. h = 0.5g*t^2 = 8000. g = 9.8 m/s^2 t = ?

physics
E = 0.5*r + 0.5*6 Eq1: E = 0.5r + 3. E = 0.3*r + 0.3*(6+8). Eq2: E = 0.3r + 4.2. E = 0.5r + 3 = 0.3r + 4.2. 0.5r +3 = 0.3r + 4.2. 0.2r = 1.2. r = 6 Ohms = Internal resistance. E=0.5r + 0.5*R = 0.5*6 + 0.5*6 = 6 Volts

science
See Related Questions: Mon,11-5-12, 9:51PM.

Math
1. Work = F*d = 550 * 10*0.5 = Joules. 2. Power = Work/T = Joules/s.

Physics
D = 1200m[90o] + 200[0o] + 500[225o]. X = 1200*Cos90 + 200*Cos0 + 500*Cos225 = Y = 1200*sin90 + 200*sin0 + 500*sin225 = Tan A = Y/X, A = ?. D = X/Cos A, or Y/sin A.

physics
1. M*g = 7159 N. M = 7159/g = 7159/9.8 = 731 kg. Fp = 7159*sin25.6 = 3093 N. = Force parallel to the plank. Fap-Fp = M*a. Fap - 3093 = M*0 = 0. Fap = 3093 N. = Force applied. Work = Fap*d = 3093 * 2.26 = 6991 J. 2. Work = KE2-KE1 = 0.5M*V^2- 0 = 0.5*0.02*354^2 = 1253 J.

math
d = 2.78 - (-2.78) = 2.78 + 2.78 = 5.56.

Algebra
X = Larger number. Y = Smaller number. Eq1: X-Y = 86. x = y+86. 7y = x + 4. Eq2: x - 7y = -4. In Eq2, replace X with y+86: y+86 - 7y = -4. -6y = -90. Y = 15. x-15 = 86. X = 101.

Physics
Magnitude=3.6+3.4i + 5.5+1.9i + 2.5+3.4i = (3.6+5.5+2.5) + (3.4i+1.9i+3.4i) = 11.6 + 8.7i=Sqrt(11.6^2 + 8.7^2) = 14.5

Physics
F = 42N[83o] + 70N[300o]. X = 42*Cos83 + 70*Cos300 = Y = 42*sin83 + 70*sin300 = Tan A = Y/X, A = ? F = X/Cos A, or F = Y/sin A.

Math
1. 2*10^6. 2. 7*10^-7.

science
KE2-KE1 = 0.5M*V2^2 - 0.5M*V1^2 = 0.5*450*30^2 - 0.5*450*26^2 = 202,500 - 152,100 = 50,400 J.

Match
1. 27 3/5 + 15.9 = 27.6 + 15.9 = 43.5. 0.37 * 43.5 = 16.095 2. 27 3/5 + 15.9 = 27 3/5 + 15 9/10 = 27+6/10 + 15+9/10 = 42 + 15/10 = 42+1.5 = 43.5. 0.37 * 43.5 = 16.095 The first method is shorter and easier; I didn't have to deal with fractions.

Math
2000 mL = 2Liters. 2Liters * 3.5g/Liter = 7.0 Grams.

algebra
-1.7-(-13.4) = -1.7 + 13.4 = 11.7o

Physics
D=20[30o] + 30[90o] + 40[180o]+20[315o] X=20*Cos30+30*Cos90+40*Cos180+20*Cos315 = Y=20*sin30+30*sin90+40*sin180+20*sin315 = Tan A = Y/X. A = ?. D = X/Cos A, or Y/sin A.

Math
1. 18balloon * 2.5Ft/balloon. = 45 Ft. 45Ft. * 1yd/3Ft = 15 Yds.

Math
1. Add X striped balls. Add 10x/6 = 5x/3 white balls. x + 5x/3 = 112. 3x + 5x = 336. X = ? 5x/3 = ? 2. 4/6 = 14/16. 4*16 = 64. 6*14 = 84. The cross products are not equal; therefore, the ratios are not equivalent.

Math
C = 4.5*4 - 7 = \$11.

Math
T=30,000phones * 4h/1300phones=92.3 h. 1. A = X Degrees, B = (X-34) Degrees. Supplementary angles are angles whose sum is 180o: x + (x-34) = 180. X = ?. X-34 = ? 2. A = X Degrees, B = (2x+9) Degrees. x + (2x+9) = 90o. X = ? 2x+9 = ?

Physics
V^2 = Vo^2 + 2g*h = 0 + 19.6*1.54 = 30.2 V = 5.49 m/s.

Algebra 2
d = (120+V)T = 490 mi. Eq1: 120T + VT = 490. Eq2: 120T - VT = 350. Sum: 240T = 840. T = 3.5 h. In Eq1, replace T with 3.5 and solve for V.

Post a New Question