Friday

August 22, 2014

August 22, 2014

Total # Posts: 8,924

**physics**

PE = F*h = mg*h = 98*10 = 980 Joules.
*February 3, 2014*

**Physics 1**

d = Vo*t + 0.5g*t^2 = 2 m. 0 + 4.9t^2 = 2 t^2 = 0.408 Tf = 0.639 s. = Fall time. D = 5.0m/s * 0.639s = 3.19 m.
*February 3, 2014*

**Physics**

Correction: 4 Ft = 1.21 m. Not 13.2 m. hmax=1.21+8.22*0.84 - 4.9*0.84^2=4.66 m Above gnd. 0.5g*t^2 = 4.66 m. 4.9t^2 = 4.66 t^2 = 0.95 Tf = 0.97 s. = Fall time. d = 3.36m/s * (0.84+0.97) = 6.1 m.
*February 3, 2014*

**Physics**

V = Vo + g*Tr = 0 at max ht. 8.22 - 9.8Tr = 0 9.8Tr = 8.22 Tr = 0.84 s. = Rise time or time to reach max ht. hmax = ho + Vo*t + 0.5g*t^2 hmax=13.2 + 8.22*0.84 - 4.9*0.84^2=16.7 m. Above gnd. 0.5g*t^2 = 16.7 m. 4.9t^2 = 16.7 t^2 = 3.40 Tf = 1.84 s. = Fall time. d = 3.36m/s * (0...
*February 3, 2014*

**physics**

50N[50o] X = 50*cos50 Y = 50*sin50
*February 3, 2014*

**Physical sciences**

F = 10 + 30 = 40 N.
*February 3, 2014*

**physics**

V^2 = Vo^2 + 2a*d V^2 = Vo^2 - 6*24 = 0 Vo^2 = 144 Vo = 7 m/s = Initial velocity of the block = Speed of the truck.
*February 3, 2014*

**PHYSICS**

Please check your problem for errors.
*February 3, 2014*

**science**

L min. = 10.26 cm W min. = 4.91 cm H min. = 1.52 cm V nom. = 10.27 * 4.92 * 1.53=77.308 cm^3 V min. = 10.26 * 4.91 * 1.52=76.728cm^3 Error = 77.308 - 76.728 = 0.5796 cm^3 NOTE: The fractional error has no units; they cancel. Fractional Error = 0.58cm^3/77.308cm^3 = 0.0075
*February 3, 2014*

**Physics**

V^2 = Vo^2 + 2g*d = 0 + 19.6*10.1 = 198 V = 14.1 m/s.
*February 2, 2014*

**Physics**

X = -7 m/s Y = -8 m/s tan Ar = -8/-7 = 1.14286 Ar = 48.8o = Reference angle. A = 48.8 + 180 = 228.8o, CCW V = -8/sin228.8 = 10.63 m/s[228.8o].
*February 2, 2014*

**physics**

31m/s[44o] X = 31*cos44 = Y = 31*sin44 =
*February 2, 2014*

**Physýcs**

V = Vo + a*t = 17 m/s. 3 + a*5 = 17 5a = 17-3 = 14 a = 2.8 m/s^2.
*February 2, 2014*

**Physýcs**

F = m*a a = acceleration. m=mass of the object being accelerated.
*February 2, 2014*

**physics..**

V^2 = Vo^2 + 2g*h = 0 at max. ht. 40^2 - 19.6*h = 0 19.6h = 1600 h = 81.6 m.
*February 1, 2014*

**physics**

45m[90o] + 60m[180o] + 75m[270o] + 50m[0o]. X = -60 + 50 = -10 m. Y = 45 -75 = -30 m. d^2 = (-10)^2 + (-30)^2 = 1000 d = 31.62 m. Speed=d/t = 31.62m/7.433min.=4.25 m/min
*February 1, 2014*

**physics**

Vo = 37m/s[30.6o] Xo = 37*cos30.6 = 31.8 m/s. Yo = 37*sin30.6 = 18.8 m/s. a. Yo*t + 0.5g*t^2 = 8.9 m. 18.8t - 4.9t^2 = 8.9 -4.9t^2 + 18.8t - 8.9 = 0 t = 3.28 s. and heading downward. (Used Quad. formula). b. Y = Yo - g*Tr = 0 at max ht. 18.8 - 9.8*Tr = 0 9.8Tr = 18.8 Tr = 1.92...
*February 1, 2014*

**physics**

Y^2 = Yo^2 + 2g*h Y^2 = 0 + 19.6*24.93 = 488.6 Y = 22.1 m/s. Xo = 22.1/3 = 7.37 m/s.=Initial velocity
*February 1, 2014*

**physics**

V = 26m/s[-37o] A. Xo = 26*cos(-37) = 20.76 m/s. B. Xo * T = 53 m. 20.76 * T = 53 T = 2.55 s. = Fall time. Y = 26*sin(-37) = -15.65 m/s. Y = Yo + g*T = -15.65 Yo + 9.8*2.55 = -15.65 Yo = -15.65 - 24.99 = -40.64 m/s.=Vert. component of initial velocity. tan A = Yo/Xo = -40.64/...
*January 31, 2014*

**physics**

Fn = -4100 + 8000 + 1200 = 5100 N., Due East. = Net force. a = Fn/m = 5100/6800 = 0.75 m/s^2, Due East.
*January 31, 2014*

**Math**

Correct.
*January 31, 2014*

**Physics**

V = Vo + a*t = 0 43 + a*0.28 = 0 0.28a = -43 a = -153.6 m/s^2
*January 31, 2014*

**science**

a. F = m * a. Newtons .
*January 31, 2014*

**physics**

Vo*t + 0.5g*t^2 = 100-50 = 50 0 + 4.9t^2 = 50 t^2 = 10.20 t = 3.19 s. V = Vo + g*t = 0 + 9.8*3.19 = 31.3 m/s = The velocity after the 1st 50 m drop = The initial velocity (Vo) for the 2nd 50 m drop. 31.3*t + 4.9t^2 = 50 4.9t^2 + 31.3t - 50 = 0 t = 1.32 s.(Use Quad. Formula).
*January 31, 2014*

**physics**

a=(V^2-Vo^2)/2d = (640^2-0)/2.4=170,667 m/s^2. V = Vo + a*t t=(V-Vo)/a = (640-0)/170,667=0.00375 s. = 3.75 ms.
*January 31, 2014*

**physics**

Dc = Dt 0.5a*t^2 = 9.5*t 1.1t^2 = 9.5t 1.1t^2 - 9.5t = 0 t = 8.64 s. (Use Quad. formula). D = 9.5 * 8.64 = 82.1 m. V = Vo + a*t = 0 + 2.2*8.64 = 19.0 m/s.
*January 31, 2014*

**science**

Ws = 0.08m^3 * 7840kg/m^3 * 9.8=6147 N. = Wt. of the steel in air. Ww=0.08m^3 * 1000kg/m^3 * 9.8 = 784 N. = Wt. of the water displaced. Ws in water = 6147 - 784 = 5363 N.
*January 30, 2014*

**Math**

See previous post.
*January 30, 2014*

**Math**

P(1,8), m = -8. Y = mx + b = 8 -8*1 + b = 8 b = 16. Eq: Y = -8x + 16.
*January 30, 2014*

**Physics**

See previous post: Thu.,1-30-14,10:32PM.
*January 30, 2014*

**Physics**

V=25mi/h * 1609m/mi * 1h/3600s=11.17 m/s Momentum = m*V = 0.01 * 11.17 = 0.1117 m-m/s.
*January 30, 2014*

**science**

Work = F*d = mg*d = 210 * 7 = 1470 J.
*January 30, 2014*

**physics**

Vo = 8.15m/s[-19o] Xo = 8.15*cos(-19) = 7.71 m/s. Yo = 8.15*sin(-19) = -2.65 m/s. A.Dx=Xo * Tf = 7.71m/s * 2.50s=19.26 m/s B. h = Yo*T + 0.5g*T^2 h = -2.65*2.5 + 4.9*2.5^2 = 24 m. C. -2.65*T + 4.9T^2 = 24-12 = 12 4.9T^2 - 2.65T - 12 = 0 T = 1.86 s.
*January 30, 2014*

**physical science**

V = Vo + g*t = 0 @ max ht. Vo - 9.8*4.24 = 0 Vo = 41.55 m/s. = Initial velocity, up. = Final velocity, down.
*January 30, 2014*

**science**

L = Lo + a/oC(T-To)*Lo L = 0.125 + 1.9*10^-6(100-200)0.125 = 0.124976
*January 30, 2014*

**Engineering science N4**

Distance = Vo^2*sin(2A)/g = 12000 m 700^2*sin(2A)/9.8 = 12000 50000*sin(2A) = 12000 sin(2A) = 12000/50000 = 0.240 2A = 13.9o A = 6.94o
*January 30, 2014*

**physics**

V = 60km/h = 60000m/3600s = 16.7 m/s. a = (V-Vo)/t = 4.5 m/s^2 (16.7-0)/t = 4.5 t = 16.7/4.5 = 3.70 s. d1 = 0.5a*t^2 = 2.25*3.7^2 = 31 m. d2 = V*t = 16.7m/s * 180s = 3,000 m. d3 = 60 m. d1+d2+d3 = 30.8 + 3000 + 60 = 3091 m. = Total distance traveled. V^2 = Vo^2 + 2a*d a = (V^2...
*January 30, 2014*

**physic**

Avg. speed = d/t = 6.8/2.4 = 2.83 m/s.
*January 29, 2014*

**physics**

h = Vo*t + 0.5g*t^2 h = 0 + 4.9*0.75^2 = 2.76 m.
*January 29, 2014*

**geometry**

Changing a number to scientific notation gives you a number less than 10 multiplied by a power of 10: 3500 = 3.5*10^3 3.5 is less than 10; the exponent(3) means that moving the decimal 3 places to the right restores the number to standard form. 0.0035 = 3.5*10^-3. The negative...
*January 29, 2014*

**physics**

Fn = m*g*cos27.5
*January 29, 2014*

**Physics**

See previous post.
*January 28, 2014*

**Physics**

V^2 = Vo^2 + 2g*h V^2 = 0 + 19.6*50. Solve for V.
*January 28, 2014*

**physics**

Fn = 2*450*cos 15 = 869.3 N.
*January 28, 2014*

**Physics**

Vo^2*sin(2A)/g = 14 m. Vo^2*sin(92)/9.8 = 14 0.10198*Vo^2 = 14 Vo^2 = 137.3 Vo = 11.72 m/s. v
*January 28, 2014*

**math**

8/6 = 1 1/3 Slice per person. So you give each person 1 slice. Then, cut each of the remaining 2 slices into 3 pieces. Then give each person 1 piece.
*January 28, 2014*

**Physics**

V^2 = Vo^2 + 2g*d = 0 + 19.6*(10-5)=98 V = 9.90 m/s. V^2 = 0 + 19.6*10 = 196 V = 14 m/s.
*January 28, 2014*

**physics**

V = 5 * 8 * 10 = 400 m^3. Mass = 400m^3 * 1.3kg/m^3 = 520 kg.
*January 28, 2014*

**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 ...
*January 27, 2014*

**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.
*January 27, 2014*

**Physics**

L = V/F = 489*10^-9 m. 3*10^8/4.89*10^-7 = 6.13*10^14 Hz.
*January 26, 2014*

**physics**

Fr = (Vs-Vc)/(Vs+Va)*Fa Fc = (343-32.3)/(343+60.7)*521 = 401 Hz= Freq. heard by car driver.
*January 26, 2014*

**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 ...
*January 26, 2014*

**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...
*January 26, 2014*

**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...
*January 26, 2014*

**physical acience**

D = 360g/74cm^3 = 4.86 g/cm^3.
*January 26, 2014*

**Science**

See 9:59 AM post.
*January 26, 2014*

**Physics**

Xo = 50 m/s. = Hor. component. Y = 42 m/s = Ver. component. Tot. velocity = sqrt(50^2+42^2)=65.3 m/s
*January 26, 2014*

**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.
*January 26, 2014*

**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]
*January 26, 2014*

**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] = ...
*January 26, 2014*

**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.
*January 25, 2014*

**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.
*January 25, 2014*

**physics**

L = Lo + a*(T-To)Lo L = 1.4 + 1.95*10^-5(32-(-15))1.4 = 1.401283 m.
*January 24, 2014*

**physics**

c^2 = a^2 + b^2 = 3.8^2 + 8.1^2 =
*January 24, 2014*

**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.
*January 24, 2014*

**Math Interest Question**

AMT = 1.095 * $8,532 =
*January 24, 2014*

**Physics**

m*g = 8.35 N. 1.25 * g = 8.35 g = 6.68 m/s^2.
*January 23, 2014*

**physics**

V^2 = Vo^2 + 2g*d. Solve for V.
*January 23, 2014*

**Physics**

A. a=(V-Vo)/t = (0-30)/0.005=-6000 m/s^2 B. F = m*a = 0.145 * (-6000) = -870 N.
*January 23, 2014*

**Physics**

See previous post.
*January 23, 2014*

**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...
*January 23, 2014*

**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 ...
*January 23, 2014*

**Physics**

d = Vo*t + (V^2-Vo^2)/2a d = 20*0.8 + (0-20^2)/-14 = 44.6 m.
*January 22, 2014*

**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.
*January 22, 2014*

**Algebra 1**

X = Total students. Eq: x/8 = 2 X = 16 Students.
*January 22, 2014*

**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).
*January 22, 2014*

**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.
*January 22, 2014*

**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
*January 21, 2014*

**Physics**

F. V3 = 4 + 3 = 7. To add them directly, both must be on the X-axis.
*January 21, 2014*

**math**

Similar figures have the same shape but the size is usually different.
*January 21, 2014*

**Math**

An Eq is a mathematical statement that says two quantities are equal. The inequality says they are unequal(> or<).
*January 21, 2014*

**math**

Given: AC = 2x-5.3 Ft.
*January 21, 2014*

**math**

Given: AC = 2x-5.3 Ft.
*January 21, 2014*

**algebra 1**

7X-2y=-39 X+5y=5
*January 21, 2014*

**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.
*January 21, 2014*

**physics**

d = 350 100 = 250 m. = Braking distance. a=(V^2-Vo^3)/2d=(0-60^2)/500=-7.2 m/s^2
*January 21, 2014*

**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 ...
*January 21, 2014*

**physics**

What is the mass of the object?
*January 21, 2014*

**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...
*January 20, 2014*

**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
*January 20, 2014*

**physic**

Freq. = 1000rev/0.0876s = 11,416rev/s = 11,416 cycles/s = 11,416 Hz.
*January 20, 2014*

**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)
*January 20, 2014*

**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.
*January 20, 2014*

**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 ...
*January 19, 2014*

**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
*January 19, 2014*

**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.
*January 19, 2014*

**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 ...
*January 19, 2014*

**Physics**

See previous post: Sun,1-19-14,2:30PM.
*January 19, 2014*

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