Friday
April 18, 2014

Posts by Henry


Total # Posts: 8,519

Physics
d1 = 61km/h[0o] * (35/60)h = 35.6km[0o]. d2=61km/h[40o] * (10/60)h=10.2km[40o]. d3=61km/h[180o] * (49/60)h=49.8km[180o]. T = (35+10+49)min * 1h/60min = 1.57 h. X=35.6+10.2*cos40+49.8*cos180=-6.39km. Y = 10.2*sin40 + 49.8*sin180 = 6.56 km. tan Ar = Y/X = 6.56/-6.39 = -1.02605 A...

physics
Y = -2.15 km. R = 3.95 km. a. sin A = Y/R = -2.15/3.95 = -0.54430 A = -33o = 57o East of South. R = 3.95km[57o] East of South.

Physics
L = V/F = 489*10^-9 m. 3*10^8/4.89*10^-7 = 6.13*10^14 Hz.

physics
Fr = (Vs-Vc)/(Vs+Va)*Fa Fc = (343-32.3)/(343+60.7)*521 = 401 Hz= Freq. heard by car driver.

MATH
In a school library, there are 3 Chinese Language books for every 5 English Language books. The number of Malay Language book is 5/9 as many as the Chinese Language books. Find the ratio of the number of Malay Language books to the number of English Language books. (Express yo...

physics
You are a Middle Ages cannonball scientist attacking a castle a distance D away. Your job is to get a cannonball of mass m over the walls, which are a height H above the top of the cannonball launcher. At the instant when the cannonball leaves the launcher it will be traveling...

physics
While working on your physics homework in your dorm room you notice a flowerpot fall past your window because someone has carelessly knocked it off the roof. Fortunately, you computer¡¯s video camera captured the whole thing so you can measure the total time the pot...

physical acience
D = 360g/74cm^3 = 4.86 g/cm^3.

Science
See 9:59 AM post.

Physics
Xo = 50 m/s. = Hor. component. Y = 42 m/s = Ver. component. Tot. velocity = sqrt(50^2+42^2)=65.3 m/s

Physics
0.5g*t^2 = 90 m. 4.9t^2 = 90 t^2 = 18.37 t = 4.29 s. Distance = Xo*t = 50m/s * 4.29s=214.3 m. V = Vo+g*t = 0 + 9.8*4.29 = 42 m/s.

physics
Correction: F1 = -100i F5 = -100i-54.5i-88.3 = -88.3-154.5i Tan Ar = -154.5/-88.3 = 1.74972 Ar = 60.3o = Reference angle. A = 60.3 + 180 = 240.3o F5 = X/cos A = -88.3/cos240.3 = 178.2 N. [240.3o]

physics
Resultant = F1 = 100N[270o]. F2 = 250N[320o]. F3 = 100N[60o]. F4 = 200N[140o]. F5 = ? Add to get F1. X=250*cos320+100*cos60+200*cos140=88.3N Y=250*sin320+100*sin60+200*sin140=54.5N tan A = Y/X = 54.5/88.3 = 0.61680 A = 31.7o F2+F3+F4=X/cos A = 88.3/cos 31.7 = 103.8N[31.7o] = 8...

college physics
V = 80km/h = 80000m/3600s = 22.22 m/s. a. V = Vo + a*t = 22.22 m/s. 0 + 1.25t = 22.22. Solve for t. b. V = Vo + a*t = 0 22.22 - 1.75*t = 0. Solve for t. c. V = Vo + a*t = 0 22.22 + a*8.30 = 0. Solve for a; it should be negative.

college physics
a. V = Vo * a*t = 10 + 0.6*7 = 14.2 m/s. b. T = d/r1 - d/r2 = 300/10-300/14.2 = 8.87 s. Saved.

physics
L = Lo + a*(T-To)Lo L = 1.4 + 1.95*10^-5(32-(-15))1.4 = 1.401283 m.

physics
c^2 = a^2 + b^2 = 3.8^2 + 8.1^2 =

science
B.

science
a=(V-Vo)/t = (12.4-0)/3.77 = 3.29 m/s^2 d = 0.5*3.29*3.77^2 = 23.37 m. Work = F*d = (m*g) * d=(1920*9.8)23.37 = 439,805 Joules.

Math Interest Question
AMT = 1.095 * $8,532 =

Physics
m*g = 8.35 N. 1.25 * g = 8.35 g = 6.68 m/s^2.

physics
V^2 = Vo^2 + 2g*d. Solve for V.

Physics
A. a=(V-Vo)/t = (0-30)/0.005=-6000 m/s^2 B. F = m*a = 0.145 * (-6000) = -870 N.

Physics
See previous post.

Physics
a. h = Vo*t + 0.5g*t^2 = 9 18t - 4.9t^2 = 9 -4.9t^2 + 18t - 9 = 0 t=0.597 s. and 3.08 s(Use quad. formula) Choose t = 0.597 s since the apple reaches its max ht. of 16.5 m, in 1.84 s. V = Vo + g*t = 0 @ max ht. 18 - 9.8*t = 0 9.8t = 18 Tr = 1.84 s. = Rise time. b. If student A...

physics
a. V = Vo + a*t = 0 24.5 - 2*t = 0 2t = 24.5 t = 12.25 s. b. d = Vo*t + 0.5a*t^2 d = 24.5*12.25 -0.5*2*12.25^2 = 150 m. c. d = 41.6 + 150 = 191.6 m. = Required stopping distance. V^2 = Vo^2 + 2a*d a=(V^2-Vo^2)/2d=(0-29.6^2)/383.2 = -2.29 m/s^2. d. V = Vo + a*t = 0 @ stopping d...

Physics
d = Vo*t + (V^2-Vo^2)/2a d = 20*0.8 + (0-20^2)/-14 = 44.6 m.

Physics
a = (V-Vo)/t = 5-0)/4.5 = 1.11 m/s^2. d1 = 0.5a*t^2 = 0.5*1.11*4.5^2=11.25 m. d2 = 5m/s * 4.5s = 22.5 m. D = d1 + d2 = 11.25 + 22.5 = 33.75 m.

Algebra 1
X = Total students. Eq: x/8 = 2 X = 16 Students.

geometry
A(0.0),B(0,2k),C(2h,0),P(h,k). (AP)^2 = (h-0)^2 + (k-0)^2 = h^2 + k^2 Ap = sqrt(h^2+k^2). (BP)^2=(h-0)^2 + (k-2k)^2=h^2 + (-k^2) BP = sqrt(h^2+(-k)^2). (CP)^2=(h-2h)^2 + (k-0)^2=(-h)^2 + k^2 CP = sqrt((-h)^2+k^2).

Math
P1-P2 = 5x+3 (-3x^2+4x+1) - P2 = 5x+3 P2 = (-3x^2+4x+1)-(5x+3) = -3x^2-x-2 = Polynomial # 2.

physics
Distance = 54m/lap * 77laps = 4158 m. Displacement = Df-Do = 0-0 = 0. Do = Starting point. Df = Final distance from starting point. V = D/t = 0/1.5 = 0 r = d/t = 4158/1.5 = 2772 m/h.=1.73 mi/h

Physics
F. V3 = 4 + 3 = 7. To add them directly, both must be on the X-axis.

math
Similar figures have the same shape but the size is usually different.

Math
An Eq is a mathematical statement that says two quantities are equal. The inequality says they are unequal(> or<).

math
Given: AC = 2x-5.3 Ft.

math
Given: AC = 2x-5.3 Ft.

algebra 1
7X-2y=-39 X+5y=5

Algebra
The Present: Son: X yrs old. Father: 7X yrs old. A year ago: Son: (x-1) yrs old. Father: 9(X-1) yrs old. The difference between their ages is the same as last year: 7x-x = 9(x-1)-(x-1) 6x = 9x-9-x+1 -2x = -8 X = 4 yrs = The son's age.

physics
d = 350 100 = 250 m. = Braking distance. a=(V^2-Vo^3)/2d=(0-60^2)/500=-7.2 m/s^2

physics
Vw=(10kg-4kg) * 1m^3/1000kg = 0.006 m^3 = Vol. of water displaced = Vol. of the object submerged. Do = 6kg/0.006m^3 = 1000kg/m^3 = Density of the object. = Density of water(Dw). Do/Dw * Vo = 0.006 m^3 (1000/1000) * Vo = 0.006m^3 Vo = 0.006 m^3 = Vol. of the object. So the obje...

physics
What is the mass of the object?

physics
Vo = 85m/s[15o] Xo = 85*cos15 = 82.1 m/s. Yo = 85*sin15 = 22 m/s. Y = Yo + g8*Tr = 0 @ max ht. 22 - 9.8Tr = 0 9.8Tr = 22 Tr = 2.24 s. = Rise time. 0.5g*Tf^2 = h max = 37.7 m. 4.9Tf^2 = 37.7 Tf^2 = 7.69 Tf = 2.77 s. = Fall time. T = Tr + Tf = 2.24 + 2.77 = 5 s. = Flight time. h...

physic
T = 330/100 = 3.30 s. = The Period. T^2 = 4*pi^2(L/g) = 3.3^2 = 10.89 39.5(1.2/g) = 10.89 47.4/g = 10.89 10.89g = 47.4 g = 4.35 m/s^2

physic
Freq. = 1000rev/0.0876s = 11,416rev/s = 11,416 cycles/s = 11,416 Hz.

math
15x^2 - 102x = 3 Divide both sides by 3: 5x^2 - 34x = 1 5x^2 - 34x - 1 = 0 X = 6.83, and -0.03(Used Quad. Formula)

college math HELP!!!!!
P = -x/25 + 190 = -2250/25 + 190 = $100. = Equilibrium price. Check: P = x/75 + 70 = 100 x/75 = 30 X = 2250 Units.

Physics
When an object is placed on a ramp; the friction is ,usually, a fraction of the component of weight perpendicular to the ramp. This fraction is call the coefficient of friction(u). Mathematically, Fk = u*Fn where Fn is the Normal and is perpendicular to the ramp. Fk is the for...

physics
mass = 155/1000 = 0.155 kg. V = 95mi/3600s * 1600m/mi = 42.2 m/s. Momentum=m*V = 0.155 * 42.2=6.54 kg.m/s

Physics
16.9m[225o] 33.8m[0o] 50.7m[50.9o] X=16.9*cos225+33.8+50.7*cos50.9=53.8 m. Y=16.9*sin225+0+50.7*sin50.9 = 27.4 m. tan A = Y/X = 27.4/53.8 = 0.50921 A = 27o D = X/cos A = 53.8/cos27 = 60.38 m.

physics
r = (0.5*150)/1000 = 0.075 m Vc=pi*r^2*h=3.14*0.075^2*1=0.01767 m^3 = Vol. of the cylinder. Vs = 2/3 * 0.01767 = 0.01178 m^3 = Vol. submerged = Vol. of water displaced. 0.01178m^3 * 1000kg/m^3 = 11.78 kg = mass of water displaced. m*g = 11.78kg * 9.8N/kg = 115.4 N = Wt. of wat...

Physics
See previous post: Sun,1-19-14,2:30PM.

Physics
L = V*T = V/F = 340/170 = 2 m.

physics- multiple choice
1a. 2e. 3c.

physics
X = 10 N. Y = 20 N. tan A = Y/X = 20/10 = 2.0 A = 63.43o R=Y/sin A = 20/sin63.43 = 22.4N[63.43o] a

physics
d = r*t = 14 r = 14/t = 14/(0.0056/2) = 5000 m/s.

Science
a. When they are acting in the same direction. F = 5+7 = 12 N. b. When they are acting in opposite directions. F = 7-5 = 2 N.

Maths
Correction: x = -5. Eq: Y = -5UD

Maths
m = UD X = -5 Y = mx + b Y = UD5 + 0 Y = UD5 Y = 8 is a hor. line. b = 8 = Y-intercept m = 0 = The slope of a hor. line. Use the following points for graphing: (-4,8) (-2,8) (0,8) (2,8) (4,8) Note: Y is constant and does not vary; it remains at 8 for all values of X. y =

Physics Please check my answers
Are all the other correct?

Physics Please check my answers
1. Circumference=Pi*D=3.14 * 16=50.27 m. V = 15rev/60s * 50.27m/rev = 12.56 m/s. 2. 0.5*5*t^2 = 20*t 2.5t^2 - 20t = 0 t = 8 s. (Use Quad. Formula). d = 20 * 8 = 160 m. 3. d = Yo*t + 4.9*t^2 d = -10*2.5 + 4.9*2.5^2 = 4. 1. 5. Work = !0*F*d = 10*(mg)*d Work = 10*(1960)*1 = 19,60...

algebra
Y = (1/4)x + 2 Y = (1/4)x m1 = m2 = 1/4 The lines are parallel, because their slopes are equal.

Earth Science
Mass of silver=5cm^3 * 10.5g/cm^3=52.5g. Mass of gold=5cm^3 * 19.3g/cm^3 = 96.5g.

physics
Work = F*d = 335 * 2.07 = 693.5 J.

Physics
Vs = 0.3kg * 1m^3/100kg = 0.003 m^3 = Vol. of Styrofoam = Vol. of water Dis- placed. Mass = 0.003m^3 * 100kg/m^3 = 0.3 kg. T = 0.3kg * 9.8N/kg = 2.94 N. Note: Density of water = 1000kg/m^3.

Finance
Rate = $X per hour. Pay = 28X + 253 = 400 28x = 400 - 253 = 147 X = $5.25 per hour.

QUANTITATIVE REASONING FOR BUSINESS
D = P-T

math
Equivalent fraction = 6/8. (6/8)/(1/8) = 6/8 * 8/1 = 6 Strips.

Physics
h = ho + (V^2-Vo^2)/2g h = 1.75 + (0-19^2)/19.6 = 20.17 m. Xo = 8 m/s = Hor. component of initial velocity. Yo = Ver. component of initial velocity. Vo = 19 m/s = Total initial velocity. cos A = Xo/Vo = 8/19 = 0.42105 A = 65.1o = Angle at which rock is thrown. Yo = Vo*sin A = ...

Geometry - 8th grade
Total Degrees = (N-2)*180 = (5-2)180=540 Missing Angle = 540-(85+110+135+95)=115o

Math
X Heads to start with. (X-24) = Bal. (X-24) - 2/7(X-24) = 5/7(x-24). 5/7(X-24) = X/2 Multiply both sides by 14: 10x-240 = 7x 3x = 240 X = 80 Heads of lettuce.

PHYSICS
Assuming no friction: KE = PE = mg*h = (5*9.8)*10=490 Joules.

Algebra
d1 = (Vb-4)t = 20 Eq1: Vb*t - 4t = 20 d2 = (Vb+4)t = 60 Eq2: Vb*t + 4t = 60 Multiply Eq1 by -1: -Vb*t + 4t = -20 +Vb*t + 4t = 60 Sum:0 + 8t = 40 t = 5 h. In Eq1, replace t with 5: Vb*5 - 4*5 = 20 5Vb = 40 Vb = 8 mi/h = Velocity of the boat.

Physics
d = Xo*T = 68 m. Xo * 2.276 = 68 Xo = 29.9 m/s. = Hor. component of initial velocity. Vo = Xo/cosA = 29.9/cos20.5 = 31.9 m/s = Initial velocity. Impulse = m*Vo = 0.27 * 31.9 = 8.61 kg.m/s.

physics
PE = mg*h = 17*9.8*3.5 = 583.1 Joules. KEo = 583.1 J. , No friction. KE = 0.5m*V^2 = 8.5*4.5^2 = 172.1 J., With friction. KE Lost = KEo-KE = 583.1-172.1 = 411 J. = Work done by friction.

pre cal
a. C = 8.48x + 5.69 b. (X,C),(0,5.69),(50,429.69),Add more points for graphing. c. C = 8.48*200 + 5.69 = $1701.69 d. Same procedure as c. e. Slope = 8.48

math
Tia collected $10 for a walkathon and $ 5 from each friend. What is the total amount of donations she collected from 4 friends? Is my answer below correct? Friend - 1,2,3,4 Donations - $5, $5, $5, $5 = $20 Answer is $20 from 4 friends.

physics
V^2 = Vo^2 + 2a*d a = (V^2-Vo^2)/2d a = (46.5^2-0)/89.6 = 24.13 m/s^2 F = m*a = 57 * 24.13 = 1376 N.

physics
What do you want to know?

Pre-Calc
b. d = 80t - 16t^2 = 96 -16t^2 + 80t - 96 = 0 Divide both sides by 16: -t^2 + 5t - 6 = 0 Use Quadratic Formula and get: t = 2s, and 3 s. Interval: 2< T <3. c. h = (V^2-Vo^2)/2g h = (0-80^2)/64 = 100 Ft. d. V = Vo + g*t = 0 at max ht. t = -Vo/g = -80/-32 = 2.50 s.

math
Tia collected $10 for a walkathon and $ 5 from each friend. What is the total amount of donations she collected from 4 friends? Is my answer below correct? Friend - 1,2,3,4 Donations - $5, $5, $5, $5 = $20 Answer is $20 from 4 friends.

5th grade math
C = 6P + 2 C = 6*5 + 2 = $32.

Physics
F1 = 10N[0o]. F2 = 10N[45o]. F3 = 10N[90o]. F4 = 10N[270o]. F5 = 10N[315o]. X = 10*cos0+10cos45+10cos90+10cos270+10 cos315=10 + 7.07 + 0 + 0 + 7.07=24.14 N. Y = 10sin0+10sin45+10sin90+10sin270+10 sin270+10sin315 = 0 + 7.07 + 10 - 10 - 7.07 = 0 N. F = X + Yi = 24.14 + 0 = 24.14...

math 7
Correction: Ricky's age 10 yrs from now =(2x-3)+10 = 2x+7.

math 7
Nila's age = X yrs old, now. Nila's age = (X-3) yrs old, 3 yrs ago. Ricky's age = 2(X-3) yrs old, 3 yrs ago. Ricky-Nila = 2(X-3)-(X-3) = (X-3) yrs older than Nila. Ricky's age, now = X + (X-3) = (2x-3) yrs old. Ricky's age 10 yrs from now = 10(2x-3) = (20x-...

Physics
Vo = 68km/h = 68,000m/3600s = 18.89 m/s. V=Vo + a*t = 18.89 + 1.35*4.7 = 25.2m/s = Final velocity. D = Vo*t + 0.5*a*t^2 D = 18.89*4.7 + 0.5*1.35*4.7^2=103.7 m.

physics
d^2 = (2n)^2 + n^2 = 112^2 4n^2 + n^2 = 12,544 5n^2 = 12544 n^2 = 2508.8 n = 50 m. = North leg. 2n = 100 m. = West leg. tan A = 2n/n = 2.0 A = 63.43o West of North = Direction.

Physics
a=(V-Vo)/t = (15-75)/12.55 = -4.78 m/s^2 d = Vo*t + 0.5*a*t^2 d = 75*12.55 + 0.5*(-4.78)*12.55^2 = 564.8 m.

Physics
D = -20 + 13 - 30i - 27 = -34 - 30i tan Ar = -30/-34 = 0.88235 Ar = 41.42o = Reference angle. A = 41.42 + 180 = 221.4o D = -34/cos221.4 = 45.3km[221.4o].

physics
V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*7.34 = 143.864 V = 12 m/s.

business math
P = Po*(1+r)^n r = 11%/100% = 0.11 = APR expressed as a decimal. n = 1Comp/yr * 19yrs = 19 Compounding periods. Plug the above values into the given Eq

business math
1. P = Po*(1+r)^n r = (8%/4)/100% = 0.02 = Quarterly % rate expressed as a decimal. n = 4Comp /yr * 1yr = 4 Compounding periods. P = 1,000,000(1.02)^4 = 1,082,432.16 Int. = P-Po 2. APY = (I/Po)*100% =

trig
Both answers are correct.

MATH
1. I = P*r*t = 1200*0.04*3 = $144.00 2. $160/$100 = 1.60 = 160% % Mark-up = 160% - 100% = 60 %. 3. 70/50 = 1.40 = 140 %. %Increase = 140%-100% = 40 %. 4. 60/75 = 0.80 = 80 % %Decrease = 80% - 100 = -20%.

Science
a = F/m = 320/58.2 = 5.5 m/s^2.

Math
Reiny, we meet again!! LOL! Oh well, we got the same answer!

Math
Eq1: 3x - 9y = 3 Eq2: 6x - 3y = -24 In Eq1, solve for X: 3x = 9y + 3 X = 3y+1 In Eq2, replace X with 3y+1: 6(3y+1) - 3y = -24 18y+6 - 3y = -24 15y = -30 Y = -2. In Eq1, replace Y with-2: 3x-9*(-2) = 3 3x + 18 = 3 3x = -15 X = -5. Solution set: (-5,-2). Eq1: Y - X/2 = 6 Eq2: 2x...

Inequalities help?
1. m-7 < 6 m < 6+7 m < 13 2. p + 12 > 9 p > 9-12 p > -3 3. x - 5 => 9

physical science
V = 36m/s * 1mi/1600m * 3600s/h = 81mi/h

Physics
m1*V1-m2*V2 = 4.82*5.03-2.72*3.52=14.7 m*V = 14.7 V = 14.7/m = 14.7/(4.82+2.72) = 1.95 m/s

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