Wednesday
July 1, 2015

Posts by henry


Total # Posts: 10,677

Algebra 1
Multiply Eq1 by -2 and add: -10x - 2y = -18 +10x - 7y = 18 Sum: 0 - 9y = 0 Y = 0 In Eq1, replace Y with 0 and solve for X -10x - 2*0 = -18 X = 1.8
February 24, 2015

maths
X pizzas 4X Drinks 12x + 0.5*4x = 112 Solve for X.
February 24, 2015

physics
Thank you Damon! I think I understand what you meant when I read your post My triangle was correct though, yes? I just referred to them wrong?
February 24, 2015

physics
Wait that's not how it's supposed to look. Ok
February 24, 2015

physics
How do I know which trig function to use? I made my second triangle like this _____ \ | \ | \ | \|
February 24, 2015

physics
Why did you swap Betas trig functions?
February 24, 2015

physics
What do you mean, I did indicate on the question that it was west of north?
February 24, 2015

physics
A golfer takes two putts to sink the ball, one is (81.6 ft, 31.7 degrees N of E) and the other is (3.20 ft, 53.4 degrees W of N). What is the displacement of the single putt that would sink the ball on the first try? Well, what I did was make a diagram of the two vectors, I ...
February 24, 2015

Science
M*g = 90 N. M*9.8 = 90 M = 9.18 kg Density = 9.18kg/45mL = 0.204 kg/mL Note: A 90-N. object has a mass of 9.18 kg or 9,180 grams.
February 24, 2015

Finance
V = Vo(1+r)^n r = 5%/365/100% = 0.00013699 = Daily % rate expressed as a decimal. n = 365Comp./yr * 11Yrs = 4015 Compounding periods. V = 10,000(1.00013699)^4015 = $17,332.13
February 24, 2015

Physical science
Fp = Mg*sin35 = 315 Mg = 315/sin35 = 549 N. = Force of gravity. Fn = Mg*Cos35 = 549*Cos35 = 450 N. = Normal force.
February 24, 2015

Physics
d = 42m1[135o] - 34mi[270o] X = 42*Cos135 = -29.7 mi Y = 42*sin135 - 34*sin270 = 63.7 mi. Tan A = Y/X = 63.7/-29.7 = -2.14473 A = -65o = 65o N. of W. = 115o, CCW. d = Y/sin A = 63.7/sin 115 = 70.3 mi. d = V*t = 70.3 V = 70.3/t = 70.3/0.5h = 140.6 mi/h
February 24, 2015

Physics
Vp = -250m/s + i25m/s, Q2. Tan A = Y/X = 25/-250 = -0.10000 A = -5.71o = 5.71o N. of W.= 174.3o,CCW Vp = X/Cos A = -250/Cos(174.3)=251 m/s
February 23, 2015

Physics
V = Vo + a*t = 31m/s[30o] Vo - 4*4 = 31*Cos 30 + i31*sin 30 Vo - 16 = 26.8 + 15.5i Vo = 42.8 + 15.5i Tan A = Y/X = 15.5/42.8 = 0.36215 A = 19.91o Vo = 42.8/Cos 19.91 = 45.5m/s[19.9o] = Initial velocity.
February 23, 2015

physics
d = V*t = 2*0.3 km = 0.6 km 216 * t = 0.6 t = (0.6/216) h. t = (0.6/216)h * 3600s./h = 100 s. Note: The sound travels 600m(0.6km).
February 23, 2015

science
C.
February 23, 2015

Physics
1. M*g = Wt. of roller. Fp = Mg*sin 30 = 2500 Mg = 2500/sin 30 = 5000 N. M = 5000/g = 5000/9.8 = 510.2 kg 2. Fn = Mg*Cos 30 = 5000*Cos 30 = 4330 N = Normal force = Force exerted by the surface.
February 23, 2015

Physics
sin23.3 = h/0.7 h = 0.7*sin 23.3 = 0.277 m. h = 0.5g*t^2 h = 0.277 m. g = 9.8 m/s^2 Solve for t.
February 23, 2015

physics
Incomplete, and too many errors.
February 23, 2015

Math Vectors
Vr = 400km/h[200o] + 100km/h[225o] X = 400*Cos200 + 100*Cos225 = -447 km/h Y = 400*sin200 + 100*sin225 = -208 km/h Tan Ar = Y/X = -208/-447 = 0.46532 Ar = 25o = Reference angle. A = 25 + 180 = 205o (Q3). V = X/Cos A = -447/Cos205 = 493 km/h. = Resultant velocity.
February 22, 2015

Math
a. Range = Vo^2*sin(2A)/g Range = 1200 Ft. Vo = 500 Ft./s. g = 32 Ft/s^2 Solve for A. b. V^2 = Vo^2 + 2g*h h = -Vo^2/2g Vo = 500 Ft./s. g = -32 Ft./s^2 Solve for h
February 22, 2015

math
Isaiah: X cards. x-x/9 = 560/2 8x/9 = 280 8x = 2520 X = 315 560 - 315 = 245 More than Andy.
February 22, 2015

math
X = 5 km/h Y = -3 km/h i. Speed = Sqrt(X^2+Y^2) = sqrt(5^2+3^2)= 5.83 km/h = 1.62 m/s. b. Tan A = Y/X = -3/5 = -0.60 A = -31o = 31o S. of E. d = 30m/Cos(-31) = 35 m. = Distance to cross. d = V*t = 35 m. t = 35/V = 35/1.62 = 21.6 s.
February 21, 2015

Physics
E = 58.0 Volts 1/Ct = 1/C1 + 1/C2 + 1/C3 1/Ct = 1/3.83 + 1/5.89 + 1/12.9 = 0.5084 Ct = 1.97 uF. Qt = Q1 = Q2 = Q3. Qt = Ct*E = 1.97 * 58 = 114.1 uC Q1 = C1*V1 = 114.1 uC V1 = 114.1/3.83 = 29.8 Volts.
February 20, 2015

physics
Mc = 14 kg = Mass of cart Md = Mass of dog food. d = 0.5a*t^2 = 2.30 m. 0.5a*2.55^2 = 2.3 3.25a = 2.3 a = 0.707 m/s^2. F = M*a M = F/a (Mc+Md) = F/a F = 12 N. a = 0.707 m/s^2 Solve for Md.
February 20, 2015

math
a. A = 4.1m * 2.2m = 9.02 m^2. A max = (4.1+0.01) * (2.2+0.01) = A min. = (4.1-0.01) * (2.2-0.01) = 8.957 m^2.
February 20, 2015

Math
X+X = 2x = Total bought. Red Tulips: x-24 Yellow: 4(x-24) 2x-24 Tulips remaining. x-24 + 4(x-24) = 2x-24 x-24 + 4x-96 = 2x-24 3x = 120-24 = 96 X = 32 2x = 64
February 20, 2015

Algebra 2
W^2 + 5W = 36 W^2 + 5W - 36 = 0
February 20, 2015

physics
Bill, please clarify your problem by adding the missing words.
February 19, 2015

Physics
Circumference = pi*Dia = 3.14 * 32.6cm = 102.4 cm = 1.024 m. Vo = 247rev/60s. * 1.024m/rev=4.22 m/s. V = 378rev/60s * 1.024m/rev = 6.45 m/s. V = Vo + a*t V = 6.45 m/s Vo = 4.22 m/s t = 6.54 s. Solve for a. d = Vo*t + 0.5a*t^2
February 19, 2015

physics
See previous post: Thu, 2-19-15, 6:56 PM.
February 19, 2015

Math
See previous post: Thu, 10-23-14, 6:36 PM.
February 19, 2015

physics
A shorter method: R1 = 100 Ohms R2 = 449 Ohms Ri = Internal resistance. V1 = I1*R1 = 4 * 100 = 400 Volts. V2 = I2*R2 = 1.09 * 449 = 489.41 Volts. Ri = (V2-V1)/(I1-I2) = (489.41-400)/(4-1.09) = 30.73 Ohms. E = I1*R1 + I1*Ri = 400 + 122.9 = 522.9 Volts.
February 19, 2015

physics
E = Battery terminal voltage(e.m.f.). Ri = Internal resistance. R1 = 100 Ohms. R2 = 449 Ohms. I*R1 + I*Ri = E 4*100 + 4*Ri = E Eq1: -E + 4Ri = -400 I*R2 + I*Ri = E 1.09*449 + 1.09*Ri = E Eq2: -E + 1.09Ri = -489.41 Subtract Eq2 from Eq1: Eq1: -E + 4Ri = -400 Eq2: -E + 1.09Ri...
February 19, 2015

physics
V = 4.93revs/1.47s * 6.28rad/rev = 21.1 rad/s = Angular velocity. V = Vo + a*t V = 21.1 rad/s. Vo = 0 t = 1.47 s. a = rad/s^2 Solve for a.
February 19, 2015

Math 222
g^2 - 6g - 55 = 0 -55 = 5*(-11) g+5= 0 g+(-11) = 0 g-11 = 0 (g+5)(g-11)= 0
February 19, 2015

physics
Vo = 20m/s[40o] Xo = 20*Cos40 = 15.32 m/s. Yo = 20*sin40 = 12.86 m/s. a. Y^2 = Yo^2 + 2g*h Y = 0 Yo = 12.86 m/s. g = -9.8 m/s^2 Solve for h. b. Y = Yo + g*Tr Y = 0 Yo = 12.86 m/s. g = -9.8 m/s^2. Solve for Tr.(Rise time or time to reach max. ht.) c. V = Xo + Yi = Xo + 0 = Xo d...
February 19, 2015

physics
a. V = Vo + a*t V = 25.1 m/s Vo = 0 t = 0.48 s. Solve for a. b. F = M*a M = 910 kg a = Value calculated in part a.
February 19, 2015

Chemistry
Human bodies maintain their balance (homeostasis) through a series of equilibria. An important equilibrium involves calcium ion because Ca2+ is important for muscle contractions in the heart as well as for strong bones. Bone is a complex tissue consisting of living cells and ...
February 19, 2015

Chemistry
A 500.0 mL sample of saturated nickel(II) phosphate solution was analyzed spectrophotometrically and found to contain 1.88 × 10-5 g of nickel. (a) Determine the molarity of the nickel(II) phosphate solution. (b) Calculate the solubility product constant, Ksp for nickel(...
February 19, 2015

Chemistry
The solubility of insoluble substances changes depending on the nature of the solution. Below are two solutions in which Cu(OH)2 is dissolved; in each case, the solubility of Cu(OH)2 in those solutions is not the same as it is in pure water. (a) For each Cu(OH)2 solution below...
February 19, 2015

Physics
See previous post: 9-16-13, 8:40 PM.
February 18, 2015

physics
T^2 = 4pi^2*(L/g) L/g = T^2/4pi^2 = 4.17^2/39.5 = 0.440 0.75/g = 0.44 g = 0.75/0.44 = 1.70 m/s^2. It is on the moon!
February 18, 2015

physics
a. T = 2min/60cycles = 120s/60cycles = 2s/cycles b. F = 1/T = 1cycle/2s. = 0.50 cycles/s. = 0.50 Hz.
February 18, 2015

science
B.
February 18, 2015

physical science
T = 50km * 1h/5km * 60min/h = 600 min.
February 18, 2015

physics
Incomplete.
February 18, 2015

Physical Science
a. h = 0.5g*t^2 h = 20 m g = +9,8 m/s^2 Solve for t. b. V^2 = Vo^2 + 2g*h Vo = 0 g = +9.8 m/s^2 h = 20 m. Solve for V.
February 17, 2015

Physics
Please clarify your problem: Does V mean Voltage or velocity? Did you give all of the INFO? If: V = Supply voltage. V1 = Voltage across R1. V2 = Voltage across R2. R1 and R2 connected in series. Then, V = V1 + V2
February 17, 2015

Physics
I = 7.0 mA V = 14.7 Volts. v1 = 3.5 Volts. V2 = 1.4 Volts. a. V3 = V-V1-V2 b. R3 = V3/I I = 0.007 Amps
February 17, 2015

Physics
See previous post.
February 17, 2015

physical
Vo = 18.7m/s[51o] Xo = 18.7*Cos51 = 11.8 m/s. Yo = 18.7*sin51 = 14.5 m/s. Y^2 = Yo^2 + 2g*h = 0 h = -Yo^2/2g = -14.5^2/-19.6 = 10.8 m. Y^2 = Yo^2 + 2g*d = 0 + 19.6*(10.8-2.5)= 162.68 Y = 12.8 m/s = Ver. component. V^2 = Xo^2 + Y^2 = 11.8^2 + 12.8^2 = 303.08 V = 17.4 m/s. = ...
February 17, 2015

science
a = (V-Vo)/t = Acceleration in Ft./s^2 V = 20 Ft/s. Vo = 5 Ft/s.
February 17, 2015

physics
V = sgrt(X^2+Y^2)
February 17, 2015

physics
V = 5m/s[30o] Vy = 5*sin30 = 2.5 m/s
February 17, 2015

Algebra
Eq1: x + y = -8 Eq2: x - y = 4 Sum: 2x = -4 X = -2 In Eq1, replace x with -2: -2 + y = -8 Y = -6.
February 16, 2015

physics
M*g = 27 * 9.8 = 264.6 N. = Wt. of the lawnmower. Fn = 264.6 + Fap*sin36=264.6 + 0.588Fap Fk = u*Fn = 0.66*(264.6+0.588Fap) = 174.64 + 0.388Fap (Fx-Fk) = M*a (Fap*Cos36-(174.64+0.388Fap) = M*a (0.81Fap-174.64-0.388Fap = M*0 0.42Fap - 174.64 = 0 0.42Fap = 174.64 Fap = 416 N. = ...
February 16, 2015

Physics
W = Mg * d = 2.80*9.8 * (35-10) = 686 J.
February 16, 2015

Physics
a = (V-Vo)/t =(250-0)/12 =
February 16, 2015

Physics
a. T^2 = 4pi^2(L/g)=4*3.14^2(0.76/9.8) = 3.06 T = 1.75 s.
February 15, 2015

physical science
a. h = 0.5g*t^2 = 4.9*4^2 = 78.4 m b. h = 0.5g*t^2 h = 103 m. g = 9.8 m/s^2 Solve for t.
February 15, 2015

Physics
Incomplete.
February 15, 2015

Business math
Ordinary interest assumes a business year of 360 days. Exact interest uses 365 days per year. a. I = Po*r*T = 4400*(0.1025/360)*135 = $169.125 b. 4400 + 169.125 = $4569.13
February 15, 2015

math
d = 120km/h * 2.6667h=Distance traveled. L = d/4 = Liters of fuel used. Cost = $59 * L =
February 15, 2015

science
V^2 = Vo^2 + 2g*h Vo = 0 g = +9.8 m/s^2 h = 50 m. Solve for V.
February 15, 2015

Physics
M*g = 150 N. Fp = 150*sin20 = Force parallel. Fn=150*Cos20 = Normal or perpendicular.
February 15, 2015

Physics
Fx = 280*Cos33o Fy = 280*sin33o
February 15, 2015

Physics
Xo = 8.57 m/s Yo = -2.61 m/s a. X = Xo + a*t = 8.57 + (-0.105)*6.67 = 7.87 m/s Y = Yo + a*t = -2.61 + 0.101*6.67 = -1.94 m/s b. V^2 = X^2 + Y^2 = 7.87^2 + 1.94^2 = 65.7 V = 8.11 m/s.
February 13, 2015

Physics Honors
Y^2 = Yo^2 + 2g*h = 0 Yo^2 - 19.6*23.2 = 0 Yo^2 = 454.72 Yo = 21.3 m/s = Ver. component of initial velocity. Yo = Vo*sin A = 21.3 m/s 48*sin A = 21.3 sin A = 0.44,425 A = 26.4o = Angle at which golf was hit. Vo = 48m/s[26.4o] Xo = 48*Cos26.4 = 43.0 m/s. V = Xo + Yi = 43 + 0i...
February 13, 2015

science
B. 0.29/5 = W/115
February 12, 2015

science
Wt. = (170/10) * 25 =
February 12, 2015

Physics
a. Energy = 0.5*C*V^2 V doubled: Energy = 0.5*C*(2V)^2 = 0.5*C*4V^2 So the energy is increased by a factor of 4. b. Yes.
February 12, 2015

Physics Dynamics
M*g = 70 * 9.8 = 686 N. = Wt. of sled. Fn = Mg-F*sin20 =
February 12, 2015

Physics Dynamics
Range = Vo^2*sin(2A)/g = 38 32^2*sin(2A)/9.8 = 38 104.5*sin(2A) = 38 sin(2A) = 0.36364 2A = 21.3o A = 10.7o
February 12, 2015

Physics Dynamics
Tan A = 35/80 = 0.4375 A = 23.6o a. Tan23.6 = Vc/2 Vc = 2*Tan23.6 = 0.874 m/s = Velocity of the current. b. Direction = 23.6o to the left.
February 12, 2015

Physics
Vo = 21m/s[40o] Xo = 31*Cos40 = 16.1 m/s. Range=Vo^2*sin(2A)/g = 21^2*sin(80)/9.8 = 44.3 m. Range = Xo*T = 44.3 m. 16.1T = 44.3 T = 2.75 s. = Time in air.
February 12, 2015

Physics
V^2 = Vo^2 + 2g*h Vo = 2.18 m/s. g = +9.8 m/s^2 h = 70.8 m. Solve for V.
February 9, 2015

College physics
d = 239mi * 1600m/mi = 382,400 m. = 382.4 km. Work = F*d = 369 * 382.4 = 141,106 kJ.
February 9, 2015

Physics
Wt. = M*g Work = Mg * h Therefore, the person with the most wt. will do the most work if both covered the same distance up. If they did not cover the same distance, you will have to calculate the work done by each to make a comparison. Power is the rate of doing wt. P = Mg * h...
February 9, 2015

math
h = -16x^2 + 64x + 80 = 0 Use Quadratic Formula. X = -1, and 6. Select the positive value: X = 6 s. = Time to reach gnd.
February 9, 2015

maths
a. KE = 0.5*M*V^2 = 130 J. 0.5*11*V^2 = 130 V^2 = 23.64 V = 4.86 m/s. b. V^2 = Vo^2 + 2g*h = 4.86^2 + 19.6*3 = 82.4 V = 9.1 m/s c. V^2 = Vo^2 + 2g*h = 0 + 19.6*15 = 294 V = 17.15 m/s.
February 9, 2015

engineering science n2
V = Vo + g*t V = 0 Vo = 20 m/s. g = -9.8 m/s^2 Solve for t.
February 9, 2015

physics
See previous post: Sun, 2-8-15, 8:14 PM.
February 8, 2015

Physics Dynamics
M*g = 5 * 9.8 = 49 N. = Wt. of box. Fn = 49 - 45*sin40 = 20.1 N. = Normal force. Fk = u*Fn = 0.2 * 20.1 = 4.01 N. = Force of kinetic friction. a = (Fx-Fk)/m = (45*Cos40-4.01)/5 = 6.1 m/s^2
February 8, 2015

physics
d = V*t d = 18.4 m V = 44.8 m/s Solve for t.
February 8, 2015

Physics
Series Connection: When one lamp burns out, all of the lamps go out. So you are in the dark until the lamp is replaced.
February 8, 2015

physics
7grams * 5.66*10^21atoms/gram * 46e/atom = 1.82252*10^24 Electrons. b. 1.82252*10^24e * 1.6*10^-19C/e = 2.916*10^5 C. = Your answer.
February 8, 2015

physics
1/f = 1/di + 1/do LCD = di*do 1/f = do/di*do + di/di*do 1/f = (do+di)/di*do Invert both sides: f = di*do/(do+di)
February 8, 2015

physics
KE = KE1 + KE2 = 0.5*M*V^2 + KE2 = 0.5*0.6*3^2 + 2.5 = 5.2 J. KE = 0.5*0.6*V^2 = 5.2 V^2 = 17.33 V = 4.16 m/s.
February 8, 2015

physics
a = (V-Vo)/t = (9.3-0)/1.39 = 6.69 rad/s^2
February 8, 2015

science
P = F * d/s = Mg * d/t = 5000 * 25/50 = 2500 J./s = 2500 W.
February 8, 2015

physics
a. KE = 0.5*M*V^2 = 0.5*66*4.3^2 = 610.2 J. = Energy lost due to friction. b. M*g = 66 * 9.8 = 646.8 N. = Wt. of runner = Normal(Fn). Fk = u*Fn = 0.6 * 646.8 = 388.1 N. = Force of kinetic friction. KE = Fk*d = 610.2 388.1*d = 610.2 d = 1.57 m.
February 8, 2015

physics
Vo = 111km/h = 111000m/3600s. = 30.8m/s W = KE = 0.5M*Vo^2 =
February 7, 2015

Physics
2.76km[0o] + 0.85km[270o] X = 2.76*Coso + 0.85*cos270 = 2.76 N. Y = 2.76*sin0 + 0.85*sin270 = Fr = sqrt(X^2+Y^2)
February 7, 2015

Physics
24N[60o] + 9N[0o] X = 24*Cos60 + 9*Cos0 = 21 N. Y = 24*sin60 + 9*sin0 = 20.8 N. Fr^2 = 21^2 + 20.9^2 = 873.64 Fr = 29.6 N.
February 7, 2015

Physics
Pellet A: V = Vo + g*Tr Tr = -Vo/g = -27.3/-9.8 = 2.79 s. = Rise time. Tf1 = Tr = 2.79 s. = Time to Fall back to the edge of the cliff. Tf2 = Fall time from edge of cliff to gnd. Ta = Tr + Tf1 + Tf2 = 2.79 + 2.79 + Tf2 = 5.57 + Tf2. = Time in air, pellet A Pellet B: Tb = Tf = ...
February 7, 2015

Physics
Vo = 17.6m/s[29o] Xo = 17.6*Cos29 = 15.4 m/s Yo = 17.6*sin29 = 8.53 m/s Y = Yo + g*Tr = 0 Tr = -Yo/g = -8.53/-9.8 = 0.870 s. = Rise time. Range = Dx = Vo^2*sin(2A)/g = 17.6^2*sin(58)/9.8 = 26.8 m. h = Yo*Tr + 0.5g*Tr^2 = 8.53*0.870 - 4.9*0.870^2 = 3.71 m. = Max. ht. Xo*(Tr+Tf...
February 6, 2015

Physics
Vo = 16.0m/s[51o] Yo = 16*sin51 = 12.43 m/s. = Vertical component of initial velocity. Y = Yo + g*Tr = 0 Tr = -Yo/g = -12.43/-9.81 = 1.27 s. = Rise time. h = Yo*Tr + 0.5g*Tr^2 = 12.43*1.27 - 4.9*1.27^2 = 7.89 m. = Max. ht. h = ho - 0.5g*Tf^2 = 2 m 7.89 - 4.9*Tf^2 = 2 4.9Tf^2...
February 6, 2015

physics
R = E/I = 2.60/0.665 = 3.91 Ohms = Total resistance. Rl = 3.91 - 0.182-0.139 = 3.589 Ohms = Lamp resistance.
February 6, 2015

physics
See Related Questions: Thu, 9-12-13, 6:35 PM.
February 6, 2015

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