# Posts by Henry

Total # Posts: 13,939

Math help
n/-3 + 5 > 4. Multiply both sides by(-3) and reverse the inequality sign: n -15 < -12, n < 3. When an inequality is multiplied or divided by a negative number, the inequality sign should be reversed.

Physics
Wavelength = V/F. V = The speed of light. F = Frequency. The wavelength is inversely proportional to the frequency. In other words, if the frequency is doubled; the wavelength is cut in half.

physics
All angles are measured CCW from +x-axis. Disp. = 65km[58o] + 42km[21o]. (65*Cos58+65*sin58) + (42*Cos21+42*sin21 = (34.44+55.12i) + (39.21+15.05i) = 73.65 + 70.17i = 101.7km[43.6o].

math
1. V = Vo(1-r)^t. Vo = Initial value of car. r = 0.08/12mo. = 0.0067/mo. t = Time in months. V = Vo(1-0.0067)^1 = 0.9933Vo. 2. V = Vo(1-r)^t. r = 0.08/52wks. = 0.00154/wk. t = Time in weeks. V = Vo(1-0.00154)^1 = 0.9985Vo. 3. V = Vo(1-r)^t. r = 0.08/365da. = 0.000219/day. V = ...

physics
A. t = 6.50h * 3600s/h = 23,400 s. Po = W/t = 5.50*10^6J/2.34*10^4s = 235 J/s = 235 Watts. B. Work = F*d = Mg*d = 1850*9.8 * 1.2 = 21,756 J. t = 21,756J./(235J/s) = 92.6 s.

financial - simple interest
Pa = 1.0976 * 8000. = Principal after 4 yrs. Pb = 1.1464 * 7000 = Principal after 5 yrs.

financial - simple interest
Investment A: Rate = r. Po = \$8000. T = 4 yrs. Ia = Po*r*T = 8000*r*4 = 32,000r = Int. of Investment A. Investment B: Rate = 1.5r. Po = \$7,000. T = 5 yrs. Ib = Po*1.5r*T = 7000*1.5r*5 = 52,500r = Int. of investment B. Ib = Ia+2000 52,500r = 32,000r + 2000. 20,500r = 2000 r = 0...

Physics
M*g = 35 * 9.8 = 343 N. = Wt. of the desk = Normal force(Fn). A. Fap-Fs = M*a. 275-Fs = 35*0 275-Fs = 0 Fs = 275 N. = Force of static friction. us = Fs/Fn = 275/343 =[ B. Fap-Fk = M*a. 195-Fk = 35*0 Fk = 195 N. = Force of kinetic friction. uk = Fk/Fn = 195/343

math
post it.

math
25x - 16 >= 234. 25x >= 234 + 16 25x >= 250 X >= 10 years.

Math
d = -8200 - (-6500) = -1700 Ft. So the six-gill shark swims 1700 Ft. below the fang-tooth fish.

Math
Slope(m) = 2, P1(3,8), P2(x,y). m = (y-8)/(x-3) 2 = (y-8)/(x-3) Cross multiply: 2(x-3) = (y-8) 2x-6 = y-8 Eq: Y = 2x + 2. Check: Y = 2*3 + 2 = 8.

Physics
A. F = Fap/Cos A = 290/Cos40 = 379 N. = Force parallel with the ramp. Work = F*d = 379 * 20 B. F-Fk = M*a. 379 - 65 = 20*a. a = ?. d = 0.5a*t^2. d = 20m, t = ?.

physics
Correction: Fr = -Ft = -7.47*10^5N.

physics
Yes, the net force is 0, but the book did not ask for the net force; it asked for the force exerted on the tanker by the water. M*g = 1.57*10^8 * 9.8 = 15.4*10^8N. = Wt. of the tanker(Ft) = Normal force(Fn). Fr = u*Fn = 15.4*10^8u. = Resistive force of the water. Ft + Fr = M*a...

physics
F1 * d1 = F2 * d2. 16.4 * 0.590 = F2 * 0.470. F2 = ?

physics
F' = F*Cos A = 65*Cos31 = 55.7N = Hor. component = Component that pulls the wagon. Work = F'*d.

physics
F = M*g = 0.077 * 9.8 = 0.755 N. Work = F*d.

physics
In Scientific notation, the number on the left side of the decimal is always less than 10(a single digit number): F = 139,712. = 1.39712*10^5. If I had placed the decimal between 13 and 9, that would not be in scientific notation; because 13 is not a single digit number. After...

physics
Vo = 89 km/h = 89,000m/3600s = 24.72 m/s. A. V^2 = Vo^2 + 2a*d. 0 = 24.72^2 + 220a. a = -2.78 m/s^2. F = M*a = 1070 * (-2.78) = -2972 N. or 2972 N. of opposing force. B. V^2 = Vo^2 + 2a*d. 0 = 24.72^2 + 4.68a. a = -130.6 m/s^2. F = M*a = 1070 * (-130.6) = -139,712 N. Ratio = ...

Physics
I will give you the meaning of the abbreviations, but you will have to write them into the equations. F = Force in newtons. 2. M = Mass in kilograms. 3. g = Acceleration due to gravity in m/s^2. 4. d = Distance in meters. 5. J = Joules. 6. s = Time in seconds. 7. Pin = Power ...

Physics/
I. F = M*g = 850 * 9.8 = 8330 N. = Tension in the cable. II. Po = F*d/t = 8330 * 12/40 = 2499 J./s = 2499 Watts. = Power out. Pin = Po/Eff. = 2499/0.60 = 4165 Watts. = Input power.

Physics
See previous post: yesterday, 9:38PM.

Physics
M*g = 22.5 * 9.8 = 220.5 N. = Wt. of object = Normal force(Fn). Fk = u*Fn = 0.44 * 220.5 = 97 N. = Force of kinetic friction. Fap-Fk = M*a. 0-97 = 22.5a a = -4.3 m/s^2. V = Vo + a*t. 0 = 4.2 - 4.3t t = ?.

Finance
a. RATIO = 911/6045 = 0.151 = 15.1%. The max allowed is 43%. So 15% is very good. b. RATIO = (911+300)/6045 = 0.200 = 20%. The ratio is still good. Therefore, they could easily purchase another vehicle.

Math
b. Y = mx + b. Y = 0.5x + 3.30. The slope-intercept form is a perfect fit for this transaction. c. Slope(m) = Cost per mile. y-intercept(b) = Flat fee. Y = Total cost. x = The number of miles driven.

Physics
M*g = 180,000 * 9.8 = 1,764,000 N. = Wt. of locomotive = Normal force(Fn). Fr = ur*Fn = 0.002 * 1,764,000 = 3528 N. = Force of rolling friction. A. Fap-Fr = M*a. 0-3528 = 180,000*a a = -0.0196 m/s^2. V = Vo+a*t. 0 = 19 - 0.0196t. t = 969.4s. B. V^2 = Vo^2 + 2a*d. 0 = 19^2 - 2*...

Physics
M*g = 4500 * 9.8 = 44,100N. = Wt. of the truck. Fp = 44,100*sin7 = 5374 N. = Force parallel with the slope = Friction force required to prevent the truck from moving.

Chemistry
Hello this is my first experiment I've ever done before and it was fun but I gotta figure out what NaCl produced and what it yielded in percentage. Can someone double check my work. Na2CO3+2HCl=2NaCl+H2O+CO2 Mass of empty crucible & cover: 33.076g Mass of sodium carbonate ...

Algebra 2
1. A = (13pi/30)/(2pi) * 360o. A = 13pi/30 * 1/2p1 * 360 A = 13/30 * 1/2 * 360 = 78o. 2. d^2 = (8-4)^2 + (7-4)^2 = 25. d = 5. 3. Y = (x+8)^2 - 2. Y = x^2 + 16x + 64 - 2 = x^2 + 16x + 62 (-8,-2). 4. Opens Upward. 5. pi radians = 180o. 9. csc B = 5sqrt(3)/5sqrt(2) = sqrt(3)/sqrt...

physics
a. F = M*a. a = F/M = -8000/1000 = -8m/s^2. V^2 = Vo^2 + 2a*d. 0 = 40^2 - 16d d = 100m. to stop. b. V^2 = Vo^2 + 2a*d. V^2 = 40^2 - 16*45 = V = ?.

Math
Mark's age = X years. Jack's age = X+4 years. Dave's age = (X+4)-8 = X-4 years. J*D = (x+4)(x-4) = x^2-16. a. M*P = (x+4)(x-4)+16 = x^2-16+16=X^2 = x*x. Therefore, Mark and Paul are each X years old and twins.

Chemistry
Can someone help me find the grams of what I produced. This is my first experiment I've ever done before and it was fun. Na2CO3 + 2HCl = 2NaCl + H2O + CO2 Empty crucible is: 33.076g I Started with 0.575 Na2CO3 How do I set this up to find how much NaCl that I produced with...

Maths
100% - 20% + 8% = 88% = 0.88. Cost = 0.88 * 4000 = \$3,520.

Math
John's sale = \$X. Steve's sale = \$3X. Paul's sale = \$12X. Charlie's sale = \$8X. x + 3x + 12x + 8x = 4*\$200. X = ?. 3X = ?. 12X = ?. 8X = ?.

Math
Multiply both sides by 8/7: 8/7*3/10in = 8/7*7/8mile. 24/70in = 1 mile 12/35in = 1 mile. 0.343in = 1 mile.

Estimating the product of decimal and a whole numb
0.5 * 50 = 25.

Math
50cm = 0.50m. Yes. 3m/0.50m = 6 Pieces.

Trigonometry
Circumference = pi*D = 3.14 * 10 = 31.4 ft. Va = 1rev/31.4ft. * 6.28rad/rev * 45ft./s = 9 rad/s. Va = 9rad/s * 1rev/6.28rad =

Trigonometry
Circumference = pi*D = 3.14D ft. Vp = Vb, Vp is velocity of the pulley, and Vb is velocity of the belt. 3.14D ft/rev * 360rev/60s = 40. D = 2.12 Ft. = Diameter of the pulley.

Physics
h = 0.5g*t^2. 2.80 = 16t^2 t = 0.424s = Fall time. a. d = Xo*t. 12.75 = Xo*0.424. Xo = 30.1 ft/s = Initial hor. velocity of the ball. Xo = 30.1ft/s * 1mi/5280ft * 3600s/h = 20.52 mi/h. b. Y^2 = Yo^2 + 2g*h. Y^2 = 0 + 64*2.80 = 179.2 Y = 13.40 ft./s. = Ver. component of final ...

Pre Algebra
1. -36x^2y^3z. 2. -4yz. 3. 4x^2-10x. 4. -4x^2+10x.

physics
All angles are measured CCW from the +x-axis. Fr = 30N[145o] + 40[205o] + 50[220o]. Fr = (-24.57+17.21i) + (-36.25-16.90i) + (-38.30-32.14i) -99.12 - -31.83i = 104.11N[17.8o] S. of W. = 104.11N[197.8o]CCW. = resultant force. To keep the body in equilibrium, F4 must be equal in...

physics
What is the direction of the 3rd force?

Physics
400-Fk = M*a. 400-Fk = M*0 = 0 Fk = 400 N.

PHYSICS
(44.9cm/210cm) * 135N. =

Science
Vo = 800m/s[-30o]. Xo = 800*Cos330 = 693 m/s. Yo = 800*sin(-30) = -400 m/s. Y^2 = Yo^2 + 2g*h. Y^2 = (-400)^2 + 19.6*150 = 162,940 Y = 404 m/s. = Final velocity of ver. component. Y = Yo + g*Tf. 404 = -400 + 9.8Tf Tf(Fall time) = ?

As physics
Yes!!!

As physics
It means the two objects stick together and move with the same velocity.

physics
If you want to convert 70km/h to m/s: 70km/h = 70,000m/3600s = 1 hour = 3600s.

Math
37<2.5n<52. 14.8<n<20.8. So the compound inequality states that the number of monthly payments(n) is greater than 14.8 but less than 20.8. a = 14.8(15). b = 20.8(21).

Math
Correction: a<2.5n<b. 37<2.5n<52 Divide by 2.5: 14.8M<n<20.8M.

Math
Compound inequality: a<2.5n<2.5<52. 37<2.5n<52 Divide by 2.5: 14.8M<n<20.8M.

Math
A. 1/2.

Math
Cost = 59 + 13*44 =

Geometry
c^2 = 9^2 + 12^2. C = 15 Ft. (Rt. triangle). Possible values: 9, 12, 15Ft. The 9 and 12 Feet lengths form Isosceles triangles.

Math
37 + 1.5x = 50. X = ?.

Finance
D/E = 0.604 D/36,231 = 0.604 D = 0.604 * 36,231

physics

Math
Correction: r = 0.02/12 = 0.001667/mo.

Math
P = Po(1+r)^n. Po = 0.9 * 13,700 = r = 0.0212mo., = 0.001667/mo. n = 12Comp./yr. * 3yrs. = 36 Compounding periods. P/36 = Monthly payments.

Math
All of your prob. are similar.

Math
Correction: P = 150 * 48 = \$7200.

Math
P = Po(1+r)^n. P = 4 * 150 = \$600. r = 0.15/12mo. = 0.0125/mo. n = 12Comp./yr. * 4yrs. = 48 Compounding periods. Po = ?.

Math
P -= Po(1+r)^n. Po = \$9000. r = 0.08/12 = 0.00667/mo. n = 12Comp./yr. * 5yrs. = 60 Compounding periods.

physics
V = 6.2 + 7.8i = 9.96km/h[51.5o].

d = d1+d2 = 12 + 16 = 28km = Total distance ran. If the time was 3h, r = 28km/3h = 9.33 km/h = Avg. speed. Disp. = 16 + 12i = 20km[36.9o]. V = 20km[36.9o]/3h = 6.67km/h[36.9o].

College Algebra
b^2 + 12b + 36-48 = 0. b^2 + 12b - 12 = 0 Use Quadratic formula: b = (-B +- sqrt(B^2-4AC))/2A. b = (-12 +- sqrt(12^2+48))/2 = ?. You should get 0.928, and -12.928. Note: 48 is positive, because we are subtracting a -48.

physics
M*g = 15 * 9.8 = 147N. = Wt. of crate. sin A = h/d = 2.5m/5.7m = 0.43860 A = 26o. a. F = Fp = 147*sin A = Force parallel with the incline. b. Work = F*d = d = 5.7m. Work in Joules.

physics
V1 = V2. d1 = d2 = 6.4km/2 = 3.2 km before collision. M*g = 1.2*10^6, M = 1.2*10^6/9.8 = 1.22*10^5 kg. V^2 = Vo^2 + 2a*d. V^2 = 0 + 0.52*3200 V = 40.8 m/s. = Velocity before collision. KE = 2(M*V^2/2) = M*V^2.

Algebra
Eq3: 2x + 2z = 4. Z = 2-x. In Eq1 replace z with 2-x. -x -y - (2-x) = -8 -x - y -2 + x = -8 Y = 6. In Eq2, replace y with 6 and solve for z: -4 + 4*6 + 5z = 7. Z = -13/5. Z = 2-x. -13/5 = 2-x X = 2 + 13/5 = 23/5. (x,y,z) = (23/5, 6, -13/5).

Physics
59.72*10^23/6.39*10^23 = 9.35 Times Mass of mars.

V^2 = Vo^2 + 2g*h. 0 = 27.5^2 - 19.8h h = 38.6m. above launching point. ho + h = 2 + 38.6 = 40.6m above gnd. V = Vo + g*Tr. 0 = 27.5 - 9.8Tr Tr = 2.81s. = Rise time. 0.5g*Tf^2 = 40.6. Tf(fall time) = ?. Tr+Tf = Time to reach gnd.

Physics Help!!!
Circumference = pi*2r = 3.14 *2*0.355 = 2.23m. Disp. = 12.7m * 1rev/2.23m * 6.28rad/rev = 35.8rad.

Physics Due Tonight Help!!!!!

Geometry
1. Draw 2 rectangles. 2. Starting from the lower left hand corner, go CCW and label the 1st one CDEF. 3. Repeat step 2 for the 2nd rectangle, labeling it KLMN. a. KL = CD. b. KN = CF. c. MN = EF. d. LM = DE.

math
Tan A = y/x = 300/1000 = 0.300. A = 16.7o.

Physics
Conservation of momentum: Mc*V1 + Mt*V2 = Mc*V3 + Mt*V4. 0.01*2 + 0.36*0 = 0.01V3 + 0.36V4. Eq1: 0.01V3 + 0.36V4 =0.02. V3 = 2-36V4 Conservation of KE: 0.5Mc*V1^2 = 0.5Mc*V3^2 + 0.5Mt*V4^2. 0.5*0.01*2^2 = 0.005V3^2 + 0.18V4^2. Eq2: 0.005V3^2 + 0.18V4^2 = 0.02. Eq1 = 0.02; Eq2...

physics
a. k = F/d = M*g/d = (0.536*9.8)/0.18m = 29.2N/m.

Science
KE = 0,5M*V^2.

Physics
A. k = F/d = M*g/d = 1.9*9.8/0.029 = 642N/m. B. 0.0906m * 642N/m = 58.2N. Mass = 58.2/9.8 = 5.94kg.

physics
d = Vo^2*sin(2A)/g = 73.4 m. A = 45o @ max hor. distance. Vo^2*sin(90)/9.8 = 73.4. Vo^2/9.8 = 73.4 Vo = 26.8m/s[45o]. Yo = 26.8*sin45 = 19m/s. = Ver. component. Y^2 = Yo^2 + 2g*h. 0 = 19^2 - 19.6h. h = ?.

Physics
M*g = 50 * 9.8 = 490 N. = Wt. of the crate. Fn = 490*Cos 0 + 315*sin21 = 602.9 N. = Normal force. Fk = u*Fn = 0.21 * 602.9 = 126.6 N. = Force of kinetic friction. Fap-Fk = M*a. 315*Cos21-126.6 = 50a, a = ?. d = 0.5a*t^2, t = 15s.

Force, Gravity, Resultant Force, Vectors
a. ii. Tan A = Y/X = 5*10^7/12*10^7 = 0.41667, A = 22.6o = The direction. 12*10^7/Cos22.6 = 13*10^7 = 1.3*10^8N. = Magnitude.

Force, Gravity, Resultant Force, Vectors
a. i. The problem does NOT ask for the resultant force, it only asks for the x- and y-components of the resultant force: x1+x2 = 12*10^7. y1+y2 = 5*10^7 (x,y) = (12*10^7, 5*10^7).

Math help
(3^1/3 * 5^-1/2)^6. Multiply both exponents by 6: 3^6/3 * 5^-6/2 Replace the improper fractions by whole numbers: 3^2 * 5^-3 = 9 * 1/5^3 = 9 * 1/125 = 9/125. I hope this helps.

Algebra I
D = Do + (h/1000)*6ft D = 220 + (2500/1000)6ft = 235 ft.

Physics
Disp. = 3 + (-6) = -3km = 3km West.

Math
A. d = 2 * 1004 = 2008 miles. 2008mi/(25mi/gal) = 80.32 gal, max required. B. 80.32gal * 3.69/gal = \$296.38 = Budget for gas. They fill-up each time they use 3/4 of a tank of gas(12.75 gal). 12.75gal * 25mi/gal = 318.75 miles/fill-up. 2008mi/(318.75mi/fill-up) = 6.3 or 7 fill...

Physics
V^2 = Vo^2 + 2g*h. V^2 = 0 + 19.6*0.7 = 13.72 V = 3.7 m/s = Velocity at the bottom of the ramp. M1*V1 + M2*V2 = M1*0 + M2*V. 0.05*3.7 + M2*0 = 0 + 0.2V 0.185 = 0.2V V = 0.925m/s = Final velocity of the truck.

Maths
0.85(Pw+38) = 53.55. Pw + 38 = 63 Pw = 25. = Price of the watch.

PHYS
M*g = 22 * 9.8 = 215.6 N. = Wt. of the Mass. k = 215.6N/0.15m = 1437.33N/m.

science
Increasing the length of a pendulum increases the period and decreases the frequency.

Math
4*3.141*(7*10^5)^2 = 12.564*49*10^10 = 615.636*10^10 = 6.15636*10^12. 8

physics
See previous post: 10-24-17, 6:05 PM.

physics
M1*V1 + M2*V2 = M1*V3 + M2*V4. 0.230*56.1 + M2*0 = 0.230*41.4 + 0.0446*V4. V4 = ?.

Physics
a. X1 = 4*0^2 + 2 = 2m. @ t = 0s. X2 = 4*3^2 + 2 = 38m. @ 3s. Disp. = X2-X1 = 38 - 2 = 36m. b. V = 36m/3s. = 12m/s. c. V(0s) = 0 m/s. d. a = (12-0)/(3-0) = 4m/s^2. e. a(0s) = 0m/s^2. a(3s) = 4m/.s^2.

math
r = 0.08/4 = 0.02 = Quarterly % rate expressed as a decimal. I1 = P1*r*t = 2000*0.02*1 = \$40.00 I2 = P2*r*t = 2040*0.02*1 = \$40.80 I3 = P3*r*t = 2080.80*0.02*1 = \$41.62 I4 = P4*r*t = 2122.42*0.02*1 = \$42.45 Bal. = 2000 + 164.87 = 2164.87.

Math
Right now: My son is X yrs. old. My age = 3x years old. Five yrs. ago: My son's age: x-5. My age: 3x-5. 3x-5 = 4(x-5). 3x-5 = 4x-20 X = 15 = My son's age now. my son

Physics
V^2/R = 10. V^2/250 = 10.

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