Friday
September 4, 2015

Posts by Henry


Total # Posts: 10,949

physics
Correction: 1st Ball: d1 = Vo*t + 0.5g*t^2 d1 = 0 + 4.9*2^2 = 19.6 m. in 2 s. V = Vo + g*t = 0 + 9.8*2 = 19.6 m/s. 2nd Ball: d2 = d + 19.6 m. Vo*t + 0.5g*t^2 = V*t + 0.5g*t^2 + 19.6 Vo*t - V*t + 0.5g*t^2-0.5g*t^2 = 19.6 Vo*t - V*t = 19.6 30t- 19.6t = 19.6 10.4t = 19.6 t = 1.88...
August 31, 2014

physics
1st Ball: d1 = Vo*t + 0.5g*t^2 d1 = 0 + 4.9*2^2 = 19.6 m in 2 seconds 2nd Ball: d2 = d1 + 19.6 m Vo*t + 0.5g*t^2 = 4.9t^2 + 19.6 30t + 4.9t^2 - 4.9t^2 = 19.6 30t = 19.6 t = 0.6533 s. To overtake the 1st ball.
August 31, 2014

Physics
C = 8,420.10/2.9 =
August 31, 2014

business
P = Po*(1+r)n Po = $1,000 r = (16%/2)/100% = 0.08 = Semi-annual % rate. n = 10yrs. * 2comp./yr = 20 Compounding periods. P = 1000(1.08)^20 = $4660.96 I = P-Po
August 30, 2014

Physical Science
Wood will float in a liquid if it's density is less than the density of the liquid.
August 30, 2014

physics
1uA = 1*10^-6A = 1*10^-3 mA.
August 29, 2014

Physical Science
Wt. = m*g = 4.82kg * 9.8N/kg = 47.24 N. a = F/m = 10/4.82
August 29, 2014

Physics
a. Tr = -Vo/g = -40/9.8 = 4.08 s. = Rise time. b. h = ho + (V^2-Vo^2)/2g h = 80 + (0-(40^2))/-19.6 = 161.6 m. Above gnd. c. V = Vo + g*t = 40 - 9.8*2 = 20.4 m/s. d. V*2 = Vo^2 + 2g*(h-20) V^2 = 0 + 19.6*(161.6-20) = 2775.36 V = 52.7 m/s. e. h = 4.9t^2 = 161.6 m. 4.9*t^2 = 161....
August 27, 2014

Physics
a. Correct. b. Correct. c. Correct. d. h = ho-(V^2-Vo^2)/2g h = 80-(30^2-4^2)/19.6 = 34.9 m Or V = Vo + gt = 30 m/s. V = 4 + 9.8t = 30 9.8t = 26 t = 2.653 s. h = ho - (Vo*t + 0.5g*t^2) h = 80-4*2.653 + 4.9*2.653^2 = 34.9 m
August 27, 2014

Matt
X = The # of boys. X+250 = The # of girls x/(X+250) = 2/7 7x = 2x + 500 5x = 500 X = 100 Boys. X+250 = 100+250 = 350 Girls.
August 27, 2014

math
(3x-2)^2(3x-2)-(4x+5)^2 = (9x^2-12x+4)(3x-2)-(16x^2+40x+25) = 27x^3-36x^2+12x-18x^2+24x-8-16x^2-40x-25 = 27x^3-70x^2-4x-33.
August 27, 2014

math
The cable is the hyp. of a rt. triangle, and the ht. of the balloon is the ver. side. h = 842*sin65 = 763.1 Ft. = Ht. of the balloon. Tan4 = h/BC BC = h/Tan4 = 763.1/Tan4 = 10,913 Ft = Distance from the target to point C.
August 27, 2014

algebra
Investment @ 7% = Po Investment @ 6% = 32,000-Po Po*r*t + (32000-Po)*r*t = 2,050 Po*0.07*1 + (32000-Po)*0.06*1 = 2050 0.07Po + 1920 - 0.06Po = 2050 0.01Po = 2050-1920 = 130 Po = $13000 @ 7%. 32,000-13000 = $19,000 @ 6%.
August 27, 2014

math
Correct!
August 27, 2014

Physics
See previous post: Tue,8-26-14,10:29 PM.
August 27, 2014

Math
610EUR/800AUD * 1USD/0.753EUR = 1.0126 USD/1AUD Note: EUR in the Equation cancels.
August 27, 2014

Physics
V = 34[20o] + 28[53.1o] X = 34*cos20 + 28*cos53.1 = 48.75 Units. Y = 34*sin20 + 28*sin53.1 = 34.03 Units. V^2=X^2 + Y^2 = 48.75^2 + 34.03^2=3535. V = 59.5 Units.
August 26, 2014

math
20,000,000+484,000+100+60+3.
August 26, 2014

Math
2,5. LCM = 10. 5,10. LCM = 10.
August 26, 2014

math
(2-x)/8 = 3/4 Multiply both sides by 8: 2-x = 6 -x = 6-2 = 4 X = -4. Or 2 - x/8 = 3/4 Multiply both sides by 8: 16-x = 6 -x = 6-16 = -10 X = 10.
August 26, 2014

Math
Kendall: X in. tall. Rachel: 2x in. tall. Rich: (2x+3) in tall. Brian: (2x+3)-1 = 74 in. tall. (2x+3)-1 = 74 2x + 2 = 74 2x = 72 X = 36 in. = Kendall's ht.
August 26, 2014

science
100.0g of 4.0c water is heated until its temperature is 37c. if the specific heat of water is 4.18 j/g c, calculate the amount of heat energy needed to cause this rise in temperature.
August 25, 2014

Physics
Range = 15,000 Meters? Range = Vo^2*sin(2A)/g = 15,000 m. Vo^2*sin(60)/9.8 = 15000 0.08837Vo^2 = 15000 Vo^2 = 169,741 Vo = 412 m/s.
August 25, 2014

physics
Work = Fx*d = 180*cos20 * 5 = 845.7 J. I don't understand what you are saying in the last paragraph.
August 25, 2014

Math
0.06C = 0.30 C = $5.00
August 25, 2014

math
a. 120I = 100 W. I = 0.833A R = V/I = 120/0.833 = 144 Ohms. b. Same procedure as a. c. Same procedure as a. a. Imax = V/(72+0) = 115/(72+0) = 1.60A Imin = 115/(72+88) = 0.719A b. P = V^2/(Rc+R) = 90 W. 115^2/(72+R) = 90 90*(72+R) = 115^2 72+R = 146.94 R = 146.94-72 = 74.94 ...
August 24, 2014

Algebra 2
T1*T2/(T1+T2) = 3*2/(3+2) = 1.2 h/Lawn. T = 1.2h/Lawn * 12Lawns = 14.4 Hours Note: 1.2h = 6/5 h = Time to do 1 Lawn.
August 24, 2014

physics
X = 200 km. Y = -600 km. d^2=X^2 + Y^2=200^2 + (-600)^2=400,000 d = 632 km.
August 24, 2014

math
Undefined.
August 24, 2014

Algebra
(6-3w)(-W^2). We have an algebraic expression that's already factored. So what is the question? Did you mean (6-3W)(-W^2)=0 ? If so, 6-3W = 0 -3W = -6 W = 2 -W^2 = 0 W^2 = 0 W = 0 Solution Set: W = 0, and 2.
August 24, 2014

algebra
Eq1: 5r-9s = -76 Eq2: 9r+5s = 54 Multiply Eq1 by -9 and Eq2 by 5, then add: -45r + 81s = 684 +45r + 25s = 270 Sum: 106s = 954 s = 9 In Eq1, replace s with 9: 5r - 9*9 = -76 5r = 81-76 = 5 r = 1.
August 24, 2014

Math
Incomplete.
August 24, 2014

Geometry
L = 0.5W W = 2L A = L*W = 25 L * 2L = 25 3L = 25 L = 25/3 = 8.333 Sq. units. W = 2L = 2 * 8.333 = 16.666 Sq. units. P = 2W + 2L
August 24, 2014

math
Do you mean 18 is added? If so: 17,26,35. 35 + 18 = 53 So the number is 35.
August 24, 2014

math
1. X = +- Infinity. 2. X < 7.
August 24, 2014

College Algebra 1
4x^2 = 16 x^2 = 4 x^2-4 = 0. The difference of 2 squares: (x+2)(x-2) = 0 x+2 = 0 X = -2. x-2 = 0 X = 2.
August 23, 2014

Science
d = 0.5g*t^2 = ho-81 4.9*0.25^2 = ho-81 0.306 = ho-81 ho = 0.306 + 81 = 81.31 m. = Initial ht. of the balloon. V^2 = Vo^2 + 2g*ho V^2 = 0 + 19.6*81.31 = 1593.7 V = 39.9 m/s. = Final velocity.
August 22, 2014

Physics
m*g = 20kg * 9.8N/kg = 196 N = Wt. of the wagon. Fap*Cos30 - Fk = m*a Fap*cos30-30 = m*0 = 0 Fap*cos30 = 30 Fap = 30/cos30o = 34.6 N. = Force applied.
August 22, 2014

science
Density = 50g/8cm^3 = 6.25 g/cm^3
August 22, 2014

math
11,13,15,17,19,21,23. Select the number whose digits add up to 4: Answer = 13.
August 21, 2014

physics
Grade = 100%*sin A = 37.7% sin A = 37.7%/100% = 0.377 A = 22.1o To climb a hill, the angle of inclination must be less than 90o.
August 21, 2014

physics
X = 47 km. Y = 69 km. a. d^2 = X^2+Y^2 = 47^2 + 69^2 = 6970 d = 83.49 km. b. Tan A = Y/X = 69/47 = 1.46809 A = 55.74o W of S = 34.26o S of W.
August 21, 2014

physics
Tan30 = (49-14)/(X1+X2) Tan30 = 35/(19+X2) (19+X2)Tan30 = 35 (19+X2) = 35/Tan30 = 60.62 X2=60.62-19 = 41.62 Ft. from the rocks.
August 21, 2014

physics
Density = m/V = 0.70kg/(0.0642m)^3 = 2645 kg/m^3.
August 21, 2014

math
Specific Gravity
August 21, 2014

Math
N = The number. N + 0.2N = 28 1.2N = 28 N = 28/1.2 = 28/(1 1/5) = 28/(6/5) = 28 * 5/6 = 140/6 = 70/3.
August 21, 2014

Algebra
Velocity = 4.5 Ft/s. Downward. Speed = 4.5 Ft/s.
August 21, 2014

physics
distance = 4 + 2 + 4 + 2 = 12 m. Displacement = Df-Do = 0-0 = 0. Df = Final distance. Do = Starting point.
August 21, 2014

physics
Distance = 5 + 3 = 8 km. Displacement = 5-3 = 2 km.
August 21, 2014

physics
Vr = 186m[23o] + 327m[133o] X = 186*cos23 + 327*cos133 = -51.8 m/s. Y = 186*sin23 + 327*sin133 = 311.8 m/s. Tan Ar = Y/X = 311.8/-51.8 = -6.01986 Ar = -80.6o = Reference angle. A = -80.6 + 180 = 99.4o CCW = 9.4o W of N. Vr = Y/sin A = 311.8/sin99.4)=316 m/s [99.4o] = 316 m/s[9...
August 21, 2014

physics
Vs = 3.12 - 1.35 = 1.77 m/s.
August 21, 2014

Physics
Vo = 25m/s[30o] Vx = 25*cos30 = 21.65 m/s. Vy = 25*sin30 = 12.50 m/s. h=(V^2-Vy^2)/2g=(0-(12.5^2)/-19.6=7.97 m Range = Vo^2*sin(2A)/g Range = 25^2*sin(60)/9.8 = 55.23 m. V=Vy + g*t = 12.50 + (-9.8*2) = -7.1m/s 21.65 - 7.1i=22.78m/s[-18.16o]=Velocity 2 seconds after the launch...
August 19, 2014

physics
Cannot solve without graphs.
August 19, 2014

Physics
a. X = 30km/h Y = 40km/h Tan A = Y/X = 40/30 = 1.33333 A = 53.13o E. of N. if wind is coming from the West. = 53.13o W. of N. if wind is coming from the East. V = Y/sin A=40/sin53.13=50 km/h[53.13o]
August 19, 2014

math
Thanks! I thought it was 30o from the x axis, because the problem didn't say 30o East of North.
August 18, 2014

math
D = 90km[30o] + 150km[0o] X = 90*Cos30 + 150 = 228 km. Y = 90*sin30 = 45 km. Tan A = Y/X = 45/228 = 0.19742 A = 11.17o D=X/CosA = 228/Cos11.17=232 km[11.17o] Dx = 232*cos11.17 = 227.998 km East of starting point.
August 18, 2014

math
5*15 + 2 = 77 6*15 + 2 = 92
August 18, 2014

math
d = 1in/Xmi. * M mi = M/X inches.
August 18, 2014

math
P = Po + 0.5Po = $81. 1.5Po = 81 Po = $54 = Initial price or Cost.
August 18, 2014

geometry
9<n<14 Values of n: 10, 11, 12, 13. Sum = 10+11+12+13 = 46 cm. 5<n<9 Values of n: 6, 7, 8. Sum = 6+7+8 = 21 cm. n = 5 cm(Isosceles Triangle). n = 9 cm(Isosceles Triangle). Sum Total=5+6+7+8+9+10+11+12+13 = 81 cm.
August 17, 2014

mat
6.5Ft/3in = 2.17Ft/in Depth = 5 + 2.17x X = The # of inches of rain.
August 17, 2014

Physics
Yes, I'm glad it didn't fall on MY head!
August 17, 2014

Physics
Mass = 20kg?(Check for error). a = g = 9.8 m/s^2 F = m * g
August 17, 2014

physics
Vo = 84m/s[45o]. Dx = Vo^2*sin(2A)/g=84^2*sin90/9.8=720 m with zero wind. (720-630)/720 * 100% = 12.5% Decrease.
August 17, 2014

math
d^2 = X^2 + Y^2 = 4^2 + 5^2 = 41 d = 6.4 km. = Shortest distance to his home.
August 17, 2014

Geometry
One side = L units. 2nd side = 3L units. 3rd side = 15 units. 3L < 15 L < 5 L = 4 = Largest possible integer. 3L = 3*4 = 12. P = 4 + 12 + 15 = 31 = Max. possible perimeter.
August 15, 2014

trig
Angular velocity is usually given in rad/s., deg./s, or rev/min. So please check your INFO.
August 15, 2014

Trigonometry
12.4rev/ride * 3rides = 37.2 Revs. A = 37.2rev * 360Deg/rev = 13,392o = 233.6 Radians. Circumference=pi*2r = 3.14*36.6=114.92 m. d = 37.2rev * 114.92m/rev = 4275.2 m. traveled.
August 15, 2014

Physics
Or: d = -(10^2)/-0.6250 = 160 m. 160 - 150 = 10 m. Further.
August 15, 2014

Physics
Vo = 36km/h = 36,000m/3600s = 10 m/s. V = 9km/h = 9000m/3600s = 2.5 m/s. a = (V^2-Vo^2)/2d a = (2.5^2-10^2)/300 = -0.3125 m/s^2. d = (V^2-Vo^2)/2a d = (0-2.5^2)/-0.6250 = 10 m. Further.
August 15, 2014

physics
a=(V^2-Vo^2)/2d=(0-(20^2))/30=-13.3m/s^2
August 14, 2014

phy
M*g = 50 * 9.8 = 490 N. = Wt. of boy. T1*Cos(180-30) + T2*Cos60 = 0. -0.866T1 + 0.5T2 = 0. T2 = 1.732T1. T1*sin(180-30) + T2*sin60 = 490 0.5T1 + 0.866T2 = 490. Replace T2 with 1.732T1: 0.5T1 + 0.866*1.732T1 = 490. 2T1 = 490. T1 = 245 N. T2 = 1.732 * 245 = 424.3 N.
August 13, 2014

High School Physics
X = 10 m/s Y = 20 m/s V^2 = X^2 + Y^2 V^2 = 10^2 + 20^2 = 500 V = 22.4 m/s = Resultant velocity. a = (V-Vo)/t = (22.4-0)/t = 22.4/t m/s^2 d = 0.5*a*t^2 = 150 0.5*(22.4/t)*t^2 = 150 m (11.2/t)*t^2 = 150 11.2t = 150 t = 13.4 s.
August 12, 2014

Math
C = 75 + 5f. C is the dependent variable. It depends on the value of f.
August 12, 2014

pHYSICS`
m*g = 50kg * 9.8N/kg = 490 N. = Wt. of cart. Fk = u*mg = 0.2 * 490 = 98 N. = Force of kinetic friction. a=(V-Vo)/t = (0.90-0)/2.8 = 0.321 m/s^2/ F-Fk = m*a F - 98 = 50*0.321 = 16.07 F = 16.07+98 = 114.1 N.
August 11, 2014

physics
T = 50min * 1h/60min = 5/6 h. T = t1 + t2 = 5/6 h. d/(Vb-Vs) + d/(Vb+Vs) = T 8/(Vb-2.8) + 8/(Vb+2.8) = 5/6 LCD = (Vb-2.8)(Vb+2.8). (8(Vb+2.8)+8(Vb-2.8))/(Vb-2.8)(Vb+2.8)= 5/6. (8Vb+22.4+8Vb-22.4)/(Vb-2.8)(Vb+2.8)=5/6 16Vb/(Vb-2.8)(Vb+2.8) = 5/6 Cross multiply: 96Vb = 5(Vb-2.8...
August 10, 2014

Math
Eq1: 2r - 7s = -6 Eq2: 7r - 2s = 32 Multiply Eq1 by (-7) and Eq2 by 2; then add: -14r + 49s = 42 +14r - 4s = 64 Sum: 45s = 106 S = 2 16/45 = 106/45. In Eq1, replace s with 106/45: 2r - 7*(106/45) = -6 2r - 742/45 = -6 Multiply by 45: 90r - 742 = -270 90r = -270 + 742 = 472 r...
August 10, 2014

Algebra
15x(x+2) + 1(x+2) Factor out x+2: (x+2)(15x+1) = Final answer.
August 10, 2014

physics
a = (V-Vo)/t = (-4.4-6)/0.04=-260 m/s^2.
August 10, 2014

physics
I=(V1-V2)/(R1+R2) = (12-8)/(15+1)=
August 10, 2014

PHYSICS
d = 0.5a*t^2 = 10 m. 0.5a*(5.5)^2 = 10 15.125a = 10 a = 0.661 m/s^2. V = a*t = 0.661 * 5.5 = 3.636 m/s. d = Vo*t - o.5a*t^2 d=3.636*5.10 - 0.5*0.661*5.10^2=9.95 m.
August 10, 2014

physics
h = (V^2-Vo^2)/2g h = (0-(10^2)/-20 = 5.0 m.
August 10, 2014

Alegbra
a. (42,900-5100)/60 = b. Po = 42900 - 5100 = $37,800. P = Po*r*t/(1-(1+r)^-t) r = (2.5%/12)/100* = 0.00208 = Monthly % rate expressed as a decimal. t = 60 Months. P = (37,800*0.00208*60)/(1-1.00208^-60) = $40,251.02 Monthly Payments = P/t
August 10, 2014

physics
Vo = a*t = 17m/s^2 * 20s = 340 m/s. h1 = 0.5a*t^2 = 0.5*17*20^2 = 3400 m. = Ht. at which the engine shuts off. hmax = h1 + (V^2-Vo^2)/2g. hnax = 3400 + (0-(340^2)/-19.6 =9298 m. = 9.298 km above gnd. The rocket did not reach the required 12 km.
August 9, 2014

physics
T = 7days/week * 24h/day = 168 h. 0.2kW * 168h = 33.6 kWh Used. Cost = $0.14/kWh * 33.6kWh = $4.70
August 9, 2014

physics
D = Vo*t + 0.5a*t^2 D = 2*10 + 0.5*0.2*10^2 = 30 m.
August 9, 2014

math
B = # of boys in camp. 0.3B = # of boys from N.Y.S. 0.2 * 0.3B = 0.06B=# of boys from N.Y.C. (0.06B/B)*100% = 6% = Percentage of boys in camp from N.Y.C.
August 8, 2014

math
A = C pi*r^2 = pi*D pi*r^2 = pi*2r Divide both sides by pi*r r = 2 Inches. D = 2r = 2 * 2 = 4 Inches.
August 8, 2014

Physics
a. h = 12*s1n30 = 6 m. V^2 = Vo + 2g*h = 0 + 19.6*6 = 117.6 V = 10.84 m/s. b. m*g=83kg * 9.8N/kg = 813.4 N.=Wt. of the child. Fn = mg*cos30 = 813.4*cos30 = 704.4 N. = Normal = Force perpendicular to the slide. Fk = u*Fn = 0.30 * 704.4 = 211.3 N. = Force of kinetic friction. ...
August 8, 2014

Physics
d2 = d1+29 Vo2*t + 0.5a*t^2 = Vo1*t + 29 m 42t + 1.5t^2 = 28t + 29 1.5t^2 + 42t - 28t = 29 1,5t^2 + 14t = 29 1.5t^2 + 14t - 29 = 0 Use Quadratic Formula and get: t = 1.745 s. To pass the train. V = Vo + a*t = 42 + 3*1.745 = 47.24 m/s.
August 8, 2014

Math 221
See previous post: Thu, 8-7-14, 11:29PM.
August 8, 2014

Math 221
AC Method: 1. 2a^2 * 3a + 1 A*C = 2*1 = 2. 2+1 = 3 = B 2a^2 + (2a+a) + 1 Form 2 Binomials and factor: (2a^2+2a) + (a+1) 2a(a+1) + (a+1) (a+1)(2a+1). 2. 15x^2 + 31x + 2 A*C = 15*2 = 30 = 30*1. Sum = (30+1)=B. 15x^2 + (30x+x) + 2 (15x^2+30x) + (x+2) 15x(x+2) + (x+2) (x+2)(15x+1...
August 7, 2014

algebra
b = p-a-c
August 7, 2014

math
Shortest side = X. Other side = 2X. x + 2x > 11 3x > 11 X > 11/3 X > 3 2/3 X = 4 = Shortest possible length. 2X > 22/3 2X > 7 1/3 2X = 8.
August 7, 2014

math
Y yards * (3/8)jumps/yard = 3Y/8 Jumps.
August 7, 2014

Physics
Average Speed = (40+60)/2 = 50 km/h
August 7, 2014

trigonometry
X = 4 Ft/s Y = -2km/h = -2000m/3600s * 3.3Ft/m = -1.833 Ft/s Tan A = Y/X = -1.833/4 = -0.45825 A = -24.62o = 24.62o South of East. = 65.38o East of South = Direction. Magnitude = X/Cos A = 4/Cos(-24.62) = 4.4 Ft/s.
August 7, 2014

trigonometry
m*g = 200,000N. Fp = mg*sin A = 200,000*sin28 = 98,894 N = Force parallel with the incline = The pull on the rope.
August 7, 2014

Physics
Circumference=pi * 2r = 3.14 * 3=9.42 m. d = 0.5a*t^2 = 9.42 0.5*2.3*t^2 = 9.42 1.15t^2 = 9.42 t^2 = 8.19 t = 2.86 s.
August 6, 2014

math
3. Discount=((10.80-9.18)/10.80)*100%=15%. 4. Tax = (3.20/100)*Va = $1952 Solve for Va(assessed value). 7. Loan Amount = 7250-3000 = $4250 Cost = 7250 + 4250*(0.125/12)*9 = 8. Same procedure as #3. 9. Rate = ((4250-3910)/4250)*100% =
August 6, 2014

  1. Pages:
  2. <<Prev
  3. 12
  4. 13
  5. 14
  6. 15
  7. 16
  8. 17
  9. 18
  10. 19
  11. 20
  12. 21
  13. 22
  14. 23
  15. 24
  16. 25
  17. 26
  18. Next>>

Members