Sunday

February 19, 2017
Total # Posts: 13,181

**physics**

The velocity of the truck must be equal to the hor. component of the airplane's velocity: V = 180*Cos47.

*October 28, 2015*

**Calculus**

Let f(x)=x^4. If a=1 and dx=Δx=1/2, what are Δy and dy?

*October 28, 2015*

**Physics**

Wb = M*g = 200 N., M = 200/g = 200/9.8 = 20.4 kg. sin A = 3/10 = 0.30, A = 17.5o. Fp = 200*sin17.5 = 60 N. Fn = 200*Cos17.5 = 191 N. a. Work = F*d = 120 * 10 = 1200 J. b. Mg*h-0 = Mg*h = 200 * 3 = 600 J. c. Conservation Energy : Change in KE = Change in PE = 600 J. d. Fap-Fp-...

*October 27, 2015*

**maths**

P = Po(1+r)^n. r = (6%/2)/100% = 0.03 = Semi-annual % rate expressed as a decimal. n = 2comp./yr. * 1yr. = 2 Compounding periods. P = Po(1+0.03)^2 = Po*1.03^2 = 1.0609Po. I = P-Po = 1.0609Po-Po = 0.0609Po. I/Po * 100% = 0.0609Po/Po = 6.09% = Effective APR.

*October 27, 2015*

**Physic**

V = Vo^2 + 2g*h. Vo = 0, h = 20 m, V = ?

*October 27, 2015*

**physicsn**

Notes: 1. Fp = Force parallel with the hill. 2. Fn = Normal force. 3. Fk = Force of kinetic friction. 4. Ws = Wt. of skier.

*October 27, 2015*

**physicsn**

Ws = M*g = 9.8M. Fp = 9.8M*sin30 = 4.9M. Fn = 9.8M*Cos30 = 8.49M. Fk = u*Fn = u*8.49M. Fp-Fk = M*a. 4.9M-u8.49M = M*(-1.4) Divide by M: 4.9-8.49u = -1.4 -8.49u = -1.4-4.9 = -6.3 u = 0.74.

*October 27, 2015*

**Physics**

a. a=(Vf-Vo)/t = (5-0)/20 = 0.25 m/s^2. d1 = Vo*t + 0.5a*t^2 = 0 + 0.5*0.25*20^2 = 50 m.

*October 27, 2015*

**math**

a scooter is priced between $1000 and $2000. its price is a multiple of 10. All the digits in the price, except for the thousands digit, are even numbers. The value of the hundreds digit is 30 times the value of the tens digit. what is the price of the scooter?

*October 26, 2015*

**science**

Wb = M*g = 10 * 9.8 = 98 N. Fn = 98-40*sin30 = Normal force. Fk = u*Fn = Force of kinetic friction. a = (Fap*Cos30-Fk)/M.

*October 26, 2015*

**Physics**

a = F/m = 5/0.3 = 16.7 m/s^2. V = Vo + a*t. Vo = 20 m/s. t = 0.03 s. V = ?

*October 26, 2015*

**Physics**

Correction: Yf = 36.6 m/s.

*October 26, 2015*

**Physics**

h = 0.5g*t^2 = 68.2 m. 4.9t^2 = 68.2 t^2 = 13.92. t = 3.73 s. Dx = Xo*t = 4.2m/s * 3.73s. = 15.7 m. Yf^2 = Yo^2 + 2g*h. Yf^2 = 0 + 19.6*68.2 = 1336.72. Yf = 36.6 m. Vf = sqrt(Xo^2 + Yf^2) = Final velocity.

*October 26, 2015*

**math 1350**

Bob: X baseball cards. Ted: 2x " " Reggie: 2x-5 " " 2x-5 + x = 82. X = ?. 2x = ?

*October 26, 2015*

**science**

h = 0.5g*t^2.

*October 26, 2015*

**science**

d = 0.5*g*t^2.

*October 26, 2015*

**science/physics**

F = 9C/5 + 32.

*October 26, 2015*

**Physics**

Wc = M*g = 1300 * 9.8 = 12,740 N. = Normal force, Fn. Fp = Mg*sin A = Mg*sin 0 = 0. = Force parallel to the plane. Fk = u*Fn = 0.8 * 12,740 = 10,192 N. a = (Fp-Fk)/m = (0-10,192)/1300 = -7.84 m/s^2. d = (Vf^2-Vo^2)/2a = (0-(28^2))/-15.68 = 50 m.

*October 25, 2015*

**Physics - Check Answers ASAP**

1. M = 70 kg. Slope = 35o? L = 60 m. h = 60*sin35 = 34.4 m. Work = F*h = Mg*h = 70*9.8 * 34.4 = 23,608 J. 3. 19kW = 19kJ/s. = 19,000 J/s 6.8*10^7J * 1s./ 1.9*10^4J = 3580 s. = 0.994 h. or 1 h. 4. d = 0.5g*t^2 5. 24h/day * 365days/yr. * 3600s./h = 6. 200km[60o] N. of E. Dx = ...

*October 25, 2015*

**Urgent physics help**

A. D = 230mi/h * 2.5h = 575 mi. B. Dx = 575*Cos60 = C. Dy = 575*sin60 = D. Vr = 575mi[60o]/2.5h = Resultant velocity. Vx = Vr*Cos60 =

*October 25, 2015*

**Quick Physics check**

How did you arrive at your answer? See previous post: Wed, 10-21-15, 5:38 PM.

*October 25, 2015*

**physics**

Effective Intensity = 0.12 * 250W/m^2 = 30W/m^2. Area=(1200W * 1m^2/30W) = 40 m^2.

*October 25, 2015*

**physics**

Ws = M*g = 18 * 9.8 = 176.4 N. Fn = 176.4 - 45*sin30 = Normal force. Fk = u*Fn = Force of kinetic friction. F(net) = 45*Cos30-Fk

*October 24, 2015*

**physics**

See previous post: Fri, 10-23-15, 10:39 PM.

*October 24, 2015*

**physics**

Ws = M*g = 18 * 9.8 = 176.4 N. a. Fn = 176.4 - 45*sin30 = 153.9 N. = Normal force = Force perpendicular to the plane.

*October 23, 2015*

**Physics**

a = Fap/M = -250/50,000 = -0.005 m/s^2. Vf = Vo + a*t = 0. t = -Vo/a = 0.30/-0.005 = 60 s.

*October 23, 2015*

**Physics**

a. Wo = M*g = 4 * 9.8 = 39.2 N. d = 39.2N. * 1m/150N. = 0.261 m.

*October 23, 2015*

**MAth**

2^4 = 16. 2^-4 = 1/2^4 = 1/2^2*2^2 = 1/4*4 = 1/16.

*October 23, 2015*

**Physics**

h = 9.4*sin8.0 = 1.31 m. h = 0.5g*t^2 = 1.31 m. g = 9.8 m/s^2. t = ?

*October 22, 2015*

**Physics**

Vf = Vo + a*t = 20 + 2*4 = 28 m/s. Dc = 20*4 + 0.5*2*4^2 = 96 m. in 4 sec. Dc = 28m/s * 6s = 168 m. in 6 sec. Dc = 96 + 168 = 264 m. in 10 sec. Dt = 18m/s * 10s. = 180 m. in 10 sec. (264-8) - 180 = Distance in front of the truck.

*October 22, 2015*

**physics**

d = 2.06*sin28.8 = 0.992km, Due North.

*October 22, 2015*

**Science**

Vf = 100,000m/3600s. = 27.8 m/s. a = (Vf-Vo)/t = (27.8-0)/10 = 2.78 m/s^2

*October 22, 2015*

**Algebra**

Sun: X tickets were sold. Sat: 3x " " " Fri: 2x " " " $2(x + 3x + 2x) = $2160. X = ?

*October 22, 2015*

**math**

Assume 5 cm is measured on the drawing. d = 5cm * 3m/1cm = 15 m. = Actual distance.

*October 22, 2015*

**math**

(2/3)/6 = 2/3 * 1/6 = 2/18 = 1/9 cup.

*October 22, 2015*

**physics**

M*g = 1000 * 9.8 = 9800 N. Fp = 9800*sin33 = 5337 N. = Force parallel to the incline. a = Fp/M = 5337/1000 = 5.34 m/s^2.

*October 22, 2015*

**sri krishna**

3-4-5 triangle with each side multiplied by 4: hyp. = 20 = 5*4. 3*4 = 12. 4*4 = 16. So X = 4. so

*October 22, 2015*

**Math**

3/4 * M = 48. M = 4/3 * 48 = $64.

*October 22, 2015*

**Physics**

a. Vf = Vo + g*Tr = 0. Tr = -Vo/g = -15/-9.8 = 1.53 s. = Rise time. b. h1 = Vo*Tr + 0.5g*Tr^2 = Ht. above the roof. g = -9.8 m/s^2. h = h1 + 20. c. h = 0.5g*Tf^2. h = h1 + 20. g = 9.8 m/s^2. Tf = Fall time. Tf = ? Tr + Tf = Total flight time. d. Vf^2 = Vo^2 + 2g*h. Vo = 0. g...

*October 22, 2015*

**Physics**

Need more INFO.

*October 22, 2015*

**math**

d = 5days * 2(13/2)mi/day = 65 Miles. 65mi/4gal. = 16.25 mi/gal.

*October 21, 2015*

**math**

144/32 = 4 R16 = 4 Thirty-two inch pieces with 16 inches left.

*October 21, 2015*

**math**

(3 2/3)/2/3 = (11/3)/2/3 = 11/3 * 3/2 = 33/6 = 5 3/6 = 5 1/2 or 5 pieces.

*October 21, 2015*

**physics**

Yf^2 = Yo + 2g*h = 0. Yo = -2g*h = -2*(-9.8)*0.449 = 8.8 m/s. Yo = Vo*sin3.40 = 8.8 m/s. Vo = 8.8/sin3.4 = 148 m/s.

*October 21, 2015*

**math**

Sole X necklaces. Sold 3x watches. 4*x + 7*3x = $300. X = ?.

*October 21, 2015*

**Physics- PLEASE HELP!!**

Hannah and Tammy please show how you arrive at your answer.

*October 21, 2015*

**maths**

1 - (2/5 + 1/3) = 15/15 -(6/15 + 5/15)= 15/15 - 11/15 = 4/15 Left.

*October 21, 2015*

**physics**

D = 26km[90o] + 62km[60o]. X = 62*Cos60 = 31km. Y = 26 + 62*sin60 = 79.7 km. Q1. Tan A = Y/X = 79.7/31 = 2.57076. A = 68.7o = Direction. D = Y/sin A = 79.7/sin68.7 = 85.5 km[68.7o].

*October 21, 2015*

**Quick physics check**

Fr = 60[135o]CCW + 5[330o]CCW. X = 60*Cos135 + 5*Cos330 = -38.1 N. Y = 60*sin135 + 5*sin330 = 39.9 N. Q2. Tan A = Y/X = 39.9/-38.1 = -1.04794. A = -46.3o = 46.3o N. of W. = Direction. Fr=Sqrt(X^2 + Y^2)=Sqrt(38.1^2 + 39.9^2) = 55.2 N. = Resultant force.

*October 21, 2015*

**Physics**

M*g = 9990 N., M = 9990/9.8 = 1019 kg. V = 64.87 mi/h * 1600m/mi * 1h/3600s. = 28.83 m/s. KE = 0.5M*V^2 = 0.5*1019*(28.83)^2 = 423,481 J. PE = Mg*h = KE. 9990*h = 423,481. h = ?

*October 21, 2015*

**physics 11**

X = -2.7 m/s. Y = 1.3 m/s. Q2. a. Tan A = Y/X = 1.3/-2.7 = -0.48148. A = -25.7 m/s = 25.7o N. of W. = 64.3o W. of N. = Direction. Vr = Sqrt(X^2 + Y^2) = Sqrt(2.7^2+1.3^2)= 3.0 m/s = Resultant velocity. Dr = Sqrt(20^2 + 41.5^2) = 46.1 m. = Resultant distance. Dr = Vr*T = 46.1 m...

*October 20, 2015*

**Physics**

1. Vf^2 = Vo^2 + 2a*d Vo = 0. Vf = ?. 2. d = 0.5a*t^2.

*October 20, 2015*

**College Physics**

Wc = M*g = 1670 * 9.8 = 16,366 N. N/m = 16,366N./6.5m.

*October 20, 2015*

**physcial science**

D.

*October 20, 2015*

**Physics**

See previous post: Tue, 10-20-15, 11:26 AM.

*October 20, 2015*

**Physics**

See previous post: Tue,10-20-15, 11.26 AM.

*October 20, 2015*

**Physics. Appreciate the help I can get.**

a = (F-Fk)/M = (720-320)/400 = 1.0 m/s^2 A. d = Vo*t + 0.5a*t^2. Vo = 5 m/s. t = 6 s. d = ?. B. Work = F*d. C. Power = Work/t in J/s = Watts.

*October 20, 2015*

**NFCS**

Change = a*t = 0.219m/s^2 * 11.2s. =

*October 20, 2015*

**Physics 101**

Increase = (39-10)C*9.8*10^-6/C * 250 m. = 0.071 m.

*October 20, 2015*

**math**

Kim has X decals. 2x/3 on 5 cars. Remaining = x - 2x/3 = 1x/3. 2/5 * 1x/3 = 2x/15 decals on 2 bikes. Remaining = 6. 2x/3 + 2x/15 + 6 = X. 10x + 2x + 90 = 15x. 15x-12x = 90. 3x = 90. X = 30 = Total decals. 2x/3 = 60/3 = 20 Decals on 5 cars. 20decals/5cars = 4 decals/car.

*October 20, 2015*

**AP physics**

Vf^2 = Vo^2 + 2a*d = 0. a = -(Vo^2)/2d = -(10^2)/50 = -2.0 m/s^2 F = M*a = 60 * (-2.0)=-120 N. Retarding force.

*October 20, 2015*

**Physics 101 help (dumb it down please)**

M1*V1 + M2*V2 = M1*V + M2*V. M1 = 12,000 kg, V1 = 22 m/s. M2 = 1200 kg, V2 = 16 m/s. V = ?.

*October 20, 2015*

**PHYSICS**

Vf = 50.4km/h = 50400m/3600s = 14 m/s. a = (Vf-Vo)/t = (. Vo = 0. d = 0.5a*t^2.

*October 19, 2015*

**Physics**

M*g = 1600 * 9.8 = 15,680 N. Fp = 15,680*sin20 = 5363 N. Fn = 15,680*Cos20 = 14,734 N. Fk = u*Fn = 0.09 * 14,734 = 1326 N. Fw-Fp-Fk = M*a = M*0 = 0. Fw = Fp+Fk = 5363 + 1326 = 6689 N. = Force of the winch. Power = Fw * V = 6689 * 1.21 = 8094 J/s. = 8094 Watts.

*October 19, 2015*

**algebra**

-5(3-Q) + 4 = 5Q - 11. -15+5Q + 4 = 5Q - 11. 5Q - 5Q = -11 + 15 - 4. 0 = 0. Infinite solutions.

*October 19, 2015*

**Physics**

h = 0.5g*t^2 = 1.70 m. g = 9.8 m/s^2. t = ?.

*October 19, 2015*

**phPhysical Science**

Disp. = -16 + 20 = 4 km. V = 4km/(5+6)hrs. = 0.364 km/hr., East.

*October 19, 2015*

**AP physics**

h = 30*sin12 = 6.24 m. Vf^2 = Vo^2 + 2g*h = 0 + 19.6*6.24 = 122.3. Vf = 11.1 m/s.

*October 18, 2015*

**physics**

Yf = Yo + g*t = 12 - 10*2.4 = -12 m/s. Vf = sqrt(9^2 + 12^2) = 15 m/s.

*October 18, 2015*

**Physics**

Distance = 10 + 15 = 25 m. X = -10 m. Y = -15 m. Q3. Tan A = Y/X = -15/-10 = 1.50. A = 56.3o S. of W. = 236.3o CCW. Displacement = -15/sin236.3 = 18 m[236.3o] CCW.

*October 18, 2015*

**math**

b. 36cookies/2hr. = 18 Cookies/hr. T = 120Cookies * 1hr/18Cookies = 6.67 hrs.

*October 18, 2015*

**Physics**

Wb = M*g = 10 * 9.8 = 98 N. = Normal force, Fn. Fs = Force of static friction. Fap-Fs = M*a. 8 - Fs = M*a = M*0 = 0. Fs = 8 N. Fs = u*Fn = 8 N. u = 8/Fn = 8/98 = 0.082.

*October 18, 2015*

**physics**

Wc = M*g = 1.3 * 9.8 = 12.74 N. Fp = 12.74*sin25 = 5.38 N. = Force parallel to the incline. a. Fap-Fp = M*a. Fap-5.38 = M*0 = 0. Fap = 5.38 N. = Force applied.

*October 18, 2015*

**Physics**

M*g = 2.9 * 9.8 = 28.4 N. = Wt. of the brick = Normal force, Fn. Fk = u*Fn = 0.33 * 28.4 = 9.38 n. = Force of kinetic friction. Fap-Fk = M*a. Fap-9.38 = M*0 = 0. Fap = 9.38 N.

*October 17, 2015*

**maths**

5 yrs. ago: Amreen was X yrs. old. Juhi was 3x yrs. old. 10 years later: Amreen is x+10 yrs. old. Juhi is 3x+10 yrs. old. (3x+10) = 2(x+10). 3x + 10 = 2x + 20. X = 10. Amreen = x+10 = 10 + 10 = 20 yrs. old. Juhi = 3x+10 = 3*10 + 10 = 40 yrs. 0ld.

*October 17, 2015*

**Science**

1. False. The forces are balanced. 2. Air resistance. 7. Size of an object.

*October 17, 2015*

**physics**

M*g = 82 * 9.8 = 803.6 N. = Wt. of crate. = Normal force, Fn. Fk = u*Fn = 0.3 * 803.6 = 241 N. = Force of kinetic friction. F-Fk = M*a. 314-241 = 82*a. 82a = 73. a = 0.890 m/s^2. Vf^2 = Vo^2 + 2a*d. Vo = 0. Vf = ?.

*October 16, 2015*

**PHYSICS**

See previous post: Fri, 10-16-15, 12:41 AM.

*October 16, 2015*

**physics**

a. h = 0.5g*Tf^2. h = 414.1 m. g = 9.8 m/s^2. Tf = ? = Fall Time. Dx = Xo*Tf. Dx = 95.3 m. Xo = ? = Initial hor. speed. b. Y = Yo + g*Tf. Yo = 0. Y = ? = Ver. component of total velocity. Speed = Sqrt(Xo^2 + Y^2).

*October 16, 2015*

**physics**

Fo = (340+Vo)/(340-Vs1)*Fs1. Fo = (340+0)/(340-20) * 500 = 531.25 Hz. = The freq. heard by the observer. Fo = (340+0)/(340-23) * 500 = 536.28 Hz. Fb = 536.28 - 531.25 = 5.028 Hz = Beat freq. Note: The Freq. of S1 and S2 are equal, but their velocities are different. Therefore...

*October 16, 2015*

**Physics**

Dx = Vo^2*sin(2A)/g. Vo = 11 m/s. A = 30o g = 9.8 m/s^2. Dx = ?

*October 16, 2015*

**Physics**

a. h = 0.5g*t^2. g = 9.8 m/s^2. h = 1.05 m. t = ? b. Dx = Xo*t. Xo = 1.90 m/s. t = Value calculated in part a.

*October 15, 2015*

**physics**

Dx = Vo^2*sin(2A)/g = 44. m. Vo^2*sin(68)/9.8 = 44. Vo^2*0.0946 = 44. Vo^2 = 465.1. Vo = 21.6 m/s. at 34o below the hor. Xo = Vo*Cos A = 21.6*Cos34 = 17.9 m/s. Dx = 17.9*T = 44. T = 2.46 s. = Time in air.

*October 15, 2015*

**physics**

Vo = 15 m/s. Yf^2 = Yo^2 + 2g*h. Yf = 0. g = -9.8 m/s^2. h = 2 m. Yo = ?. sin A = Yo/Vo. A = ?

*October 15, 2015*

**Physics**

Vo = 120m/s[25o]. Xo = 120*Cos25 = 108.8 m/s. Yo = 120*sin25 = 50.71 m/s. Yf = Yo + g*Tr = 0 at max h. Tr = -Yo/g = 50.71/-9.8 = 5.17 s. = Rise time. Tf = Tr = 5.17 s. = Fall time. a. T = Tr + Tf = Time of Flight. b. Range = Xo*T. c. h max = Yo*Tr + 0.5g*Tr^2. g = -9.8 m/s^2.

*October 15, 2015*

**physics**

Wb = M*g = 330 * 9.8 = 3234 N. Fp = 3234*sin A = Force parallel to the incline. Fn = 3234*Cos A = Force perpendicular to the incline. Fs=u*Fn = 0.25 * 3234*Cos A = 809*Cos A = Force of static friction. Fp-Fs = M*a. 3234*sin A-8o9*Cos A = M*0 = 0. 3234*sin A = 809*Cos A. Divide...

*October 15, 2015*

**Physis**

h = 0.5g*t^2.

*October 15, 2015*

**Algebra 2**

If you mean: (x-3)/x = 3/5. Multiply Eq by 5x: 5x-15 = 3x. 5x - 3x = 15. 2x = 15. X = 7.5.

*October 13, 2015*

**Algebra 2**

x - 3/x = 3/5. Multiply Eq by 5x: 5x^2 - 15 = 3x. 5x^2 - 3x -15 = 0. Use Quad. Formula. X = -1.46, and 2.06.

*October 13, 2015*

**Algebra 2**

In Eq2, replace Y with 5: x - 5 = 2. X = 7. (x, y) = (7, 5).

*October 13, 2015*

**college algebra**

V = Vo + g*Tr = 0 at max h. Tr = -Vo/g = -108/-32 = 3.375 s. = Rise time. Tf = Tr = 3.375 s. = Fall time. A. T = Tr+Tf B. h = Vo*t + 0.5g*t^2 = 180 Ft. 108t - 16t^2 - 180 = 0. -16t^2 + 108t - 180 = 0. Use Quad. Formula. t = 3.0 s.

*October 13, 2015*

**algebra**

V = 460mi/1h = 460 mi/h. Or V = 920mi/2h = 460 mi/h. Or V = 1380mi/3h = 460 mi/h. Or V = 1840mi/4h = 460 mi/h. Get it? d = V*T = 5060 miles. 460*T = 5060. T = 11 h.

*October 13, 2015*

**Science**

A. M*V

*October 13, 2015*

**Science**

A. m*V.

*October 13, 2015*

**Revolution and frequency i need help physics**

P = 15min/60rev = 0.25 min./rev. F = 1/P = 1/0.25 = 4 rev./min. Or F = 60rev/15min. = 4 rev/min.

*October 13, 2015*

**math**

2. Cr = 2pi. C = 2pi/r. Not equivalent.

*October 13, 2015*

**science**

d = 600 + 420 = 1020 km.

*October 13, 2015*

**Algebra**

2.28*10^-8 = 0.0000000228. 7^-2 = 1/7^2 = 1/49. I'm not sure what they want here.

*October 13, 2015*

**Math**

3.56*10^-5 = 0.0000356

*October 13, 2015*

**physics**

M*g = 16.5 * 9.8 = 161.7 N. = Wt. 0f cart. a. F*Cos27.9-Fk = M*a. 0.884F - 48.1 = M*0 = 0. 0.884F = 48.1. F = 54.4 N. = Force exerted. b. Work = F*d = 54.4 * 36.6 = 1992 J. c. Work = Fk*d = 48.1 * 36.6 = 1760 J. d. Work=Mg * d = 161.7 * 36.6 = 5918 J.

*October 13, 2015*