Sunday

October 23, 2016
Total # Posts: 12,190

**physics**

Correct.

*March 19, 2015*

**physics help**

1. D1 = Vx * Tf h = 0.5g*Tf^2 Tf^2 = h/0.5g Tf = sqrt (h/0.5g) = Fall time of fired bullet. h = 0.5g*Tf^2 Tf^2 = h/0.5g Tf = sqrt (h/0.5g) = Fall time of the dropped bullet. Therefore, the fall times are equal. 2. Directly at it.

*March 19, 2015*

**physics**

Vo = 54m/s[42o] Xo = 54*Cos42 = 40.1 m/s. Yo = 54*sin42 = 36.1 m/s. a. Y = Yo + g*Tr = 0 Tr = -Yo/g = -36.1/-9.8 = 3.69 s. = Rise time. Y^2 = Yo^2 + 2g*h = 0 h = -(Yo^2)/2g = (36.1^2)/-19.6=66.5 m. 0.5g*t^2 = 66.5-14 = 52.5 4.9t^2 = 52.5 t^2 = 10.71 t = 3.27 s. = Fall time(Tf...

*March 19, 2015*

**maths**

364

*March 18, 2015*

**maths**

357

*March 18, 2015*

**algebra**

An amusement park charges $8 admission and average of 2000 visitors per day. A survey shows that , for each $1 increase in the admission cost, 100 fewer people would visit the park. Write an equation to express the revenue, R(x) dollars, in terms of a price increase of x ...

*March 18, 2015*

**algebra**

May i ask how you found it?

*March 18, 2015*

**algebra**

A rectangular lot is bordered on one side by a stream and on the other three sides by 600m of fencing. Find the dimensions of the lot if area is a maximum.

*March 18, 2015*

**algebra**

9.6 = 0.128^2/0.11x^3 Multiply both sides by x^3: 9.6x^3 = 0.128^2/0.11 = 0.14895 Divide both sides by 9.6: x^3 = 0.01552 Take cube root of both sides by raising to the 1/3 power: (x^3)^1/3 = 0.01552^(1/3) X = 0.24944

*March 18, 2015*

**physics**

d = V1*T1 + V2*T2 = 118*1.05 + 40*1.15 = 169.9 km. Vavg = d/(T1+T2) = 169.9/2.20 = 77.2 km/h.

*March 18, 2015*

**Physics**

F = M*a = 1100 * 4.6 = 5060 N. d = 0.5a*t^2 = 0.5*4.6*5^2 = 57.5 m. P = F*d/t = 5060 * 57.5/5 = 58,190 J./s = 58,190 W.

*March 18, 2015*

**physics**

d1 + d2 = 18 m. 0.5g*t^2 + Vo*t + 0.5g*t^2 = 18 4.9t^2 + Vo*t - 4.9t^2 = 18 Vo*t = 18 20t = 18 t = 0.9 s. d1 = 0.5g*t^2 = 4.9 * 0.9^2 = 3.97 m.

*March 17, 2015*

**math - slope-intercept**

The slope of the 3 perpendicular lines must be the negative RECIPRECAL of the first line. 1. Y = (2/3)x + 4 2. Y = (-3/2)x + 4 3. Y = (-3/2)x + 5 4. Y = (-3/2)x + 6

*March 17, 2015*

**math**

Ta = 8:00AM + 1 1/2h = 9:30 AM. = Time arrived. d = r*T = 20 km T = 20/r = 20/80 = 1/4 h. = 15 min. Travel time. Ta = 8:30AM + 15 min = 8:45 AM. = Time arrived. 9:30AM - 8:45AM = 8:90 - 8:45 = :45 Min = Difference in arrival time.

*March 17, 2015*

**Maths**

90T = 70(T+1) 90T = 70T + 70 20T = 70 T = 3.5 h.

*March 17, 2015*

**Calculus**

Compute dy/dx using the chain rule. y = (u/4) + (4/u) u = (x - x^7) dy/dx =

*March 17, 2015*

**physics**

KE = 0.5*M*Vo^2 = 1400 J. Vo^2 = 1400/0.5M = 1400/2 = 700 Vo = 26.5 m/s. = Initial velocity. KE = 0.5*M*Xo^2 = 120 J. Xo^2 = 120/0.5M = 120/2 = 60 Xo = 7.75 m/s=Hor. component of initial velocity. Xo = Vo*Cos A = 7.75 m/s. 26.5*Cos A = 7.75 Cos A = 0.29230 A = 73o Yo = Vo*sin ...

*March 17, 2015*

**physics**

a. V = 5.23m/1.52s. = 3.44 m/s. b. L = V*T = 3.44m/s * 0.84s = 2.89 m.

*March 17, 2015*

**Physics**

Vo = 40m/s[30o] Xo = 40*cos30 = 34.64 m/s. Yo = 40*sin30 = 20 m/s. Y = Yo + g*Tr = 0 Tr = -20/-9.8 = 2.04 s. = Rise time. Y^2 = Yo^2 + 2g*h = 0 h = -(Yo^2)/2g = -(20^2)/-19.6=20.4 m. h = 0.5g*t^2 = 20.4 4.9t^2 = 20.4 t^2 = 4.16 t = 2.04 s. = Fall time(Tf). Range = Xo * (Tr+Tf...

*March 17, 2015*

**physics**

Xo = 20 m/s Yo = 30 m/s Vo = sqrt(20^2+30^2) = 36.1 m/s Y = Yo + g*t = 30 + (-9.8)*2 = 10.4 m/s. = Ver. component of velocity 2 s later. X = Xo = 20 m/s and remains constant. V^2 = X^2 + Y^2 = 20^2 + 10.4^2 = 508.16 V = 22.5 m/s. = Total velocity.

*March 16, 2015*

**physics**

V = Vo + a*t V = 0 Vo = 29.3 m/s t = 4.9 s. Solve for a. It will be negative. F = M*a Solve for F. It will be negative.

*March 16, 2015*

**sciences**

Incomplete.

*March 16, 2015*

**Physics**

V = 100m/9.83s. = 10.17 m/s. KE = 0.5*M*V^2 = 0.5*65*10.17^2=3361 J.

*March 16, 2015*

**Science**

Fap = 24 N. = Force applied. a = 2.28 m/s^2? Fk = 14 N. (Fap-Fk) = M*a M = (Fap-Fk)/a = (24-14)/2.28 = 4.39 kg. = Mass of the box.

*March 16, 2015*

**Science**

The vertical component of velocity is zero.

*March 16, 2015*

**Physics**

V^2 = Vo^2 + 2a*d V = 0 Vo = 12 m/s a = -3 m/s^2 Solve for d.

*March 16, 2015*

**physics**

M*g = 17kg * 9.8N./kg = 166.6 N. = Wt. of box. Fn = 166.6 - 88.9*sin56 = 92.9 N. = Normal force. Fk = u*Fn = 0.24 * 92.9 = 22.3 N. = Force of kinetic friction. a = (F*Cos A-Fk)/M = F = 88.9 N. A = 56o M = 17 kg Solve for a.

*March 15, 2015*

**physics**

M1*V1 + M2*V2 = M1*V + M2*V 450*30i + 560*(-35) = 450V + 560V 13,500i - 19,600 = 1,010V b. V = -19.41 + 13.37i V = sqrt = (19.41^2+13.37^2) = 23.6 m/s. a. Momentum = M1*V + M2*V = 450*23.6 + 560*23.6 = 23,836 kg-m/s. c. Tan A = Y/X = 13.71/-19.41=-0.70634 A = -35.2o = 35.2o CW...

*March 15, 2015*

**science**

For a given power level, transmitting at a high voltage reduces the current transmitted which reduces the I^2R loss in the transmission lines. Step-down transformers are used to reduce the voltage to the required level for home use.

*March 15, 2015*

**science**

M = 30m^3 * 1.3kg/m^3 = 39 kg.

*March 15, 2015*

**college algebra**

P = Po(1+r)^n = 6,000 r = (3.5/4)/100% = 0.00875 = Quarterly % rate expressed as a decimal. n = (17yrs.*12mo/yr. + 3mo.)/3 = 69 Compounding periods. Po(1.00875)^69 = 6000 1.824Po = 6000 Po = $3289.17

*March 14, 2015*

**Physics**

1. Mass = 0.50g/1000 = 0.0005 kg KE = M*V^2/2 = 0.0005*5^2/2 = 4. MA = 450/150 = 3.0

*March 14, 2015*

**business maths**

a. P = Po(1+r)^12 = 2Po Divide both sides by Po: (1+r)^12 = 2 Take Log of both sides: 12*Log(1+r) = Log 2 Divide both sides by 12: Log(1+r) = Log 2/12 = 0.02509 1+r = 10^(0.02509) = 1.0595 r = 0.0595 = 5.95% b. 12Comp./yr. * 12yrs. = 144 Compounding periods. P = Po(1+r)^144 = ...

*March 14, 2015*

**physics**

Li = (Dc/Dm) * Lo = (8930/13,600) * 20 = 13.1 cm = Length immersed.

*March 14, 2015*

**physics**

M*g = 14 * 9.8 = 137.2 N. = Wt. of chair. Fn = Mg + F*sin43 = 137.2 + 40*sin43 = 164.5 N. = Normal force.

*March 14, 2015*

**trig**

h = 5*sin65 = 4.53 m.

*March 13, 2015*

**Science Help Please**

C. Amplitude and wavelength.

*March 13, 2015*

**Swakop High**

$X @ 5% $(6000-x) @ 8% 0.05x + 0.08(6000-x) = 0.06*6000 Multiply both sides by 100: 5x + 8(6000-x) = 6*6000 Solve for x.

*March 13, 2015*

**math**

(3/4)Ft/3Ft = 3/4 * 1/3 = 3/12 = 1/4 Yd. 7 1/4 - 1/4 = 7 Yds. remaining. Length = 7/3 = 2 1/3 Yds. each.

*March 13, 2015*

**math**

1/6 = x/18 Solve for x.

*March 12, 2015*

**physics**

a. V^2 = Vo^2 + 2g*h V = 0 Vo = 24.8 m/s g = -9.8 m/s^2 Solve for h.

*March 12, 2015*

**Physics**

Fp = Mg*sin30 = 0.5Mg = Force parallel to the plane. 0.5Mg = 18.5 Mg = 37 N = Wt. of the toy. M = 37/g = 37/9.8 = 3.8 kg = Mass of toy

*March 12, 2015*

**Math**

4+1 = 5 Miles.

*March 12, 2015*

**math**

Length = L ft. Width = 3L/4 A = L * 3L/4 = 432 Ft^2 Solve for L.

*March 12, 2015*

**Math**

V = L*W*h = 300 in^3 Solve for h.

*March 12, 2015*

**physics**

a. Q = C*V Solve for V. Energy = C*V^2/2 b. Calculated V in part a. c. To double the stored energy, multiply V by the square root of 2: The new voltage = sqrt(2) * V.

*March 12, 2015*

**Physical Science (H)**

V = 3640g * 1mL/1.02g = 3569 mL

*March 12, 2015*

**physics**

M1*V1 = M2*V2 + M3*V3 2.4*V1 = 1.2*3.78[90o] + 1.2*5.28[32.8o] 2.4V1 = 4.54i + 4.44 + 5.33 + 3.43i 2.4V1 = 9.77 + 7.97i V1 = 4.07 + 3.32i V1 = sqrt(4.07^2+3.32^2) = 5.25 m/s

*March 11, 2015*

**Physics**

Vp + Vw = 100i Vp + 40 = 100i Vp = -40 + 100i = Velocity of the plane Tan A = 100/-40 = -2.50 A = 111.8o CCW = 21.8o W of N d = V*t = 500 km t = 500/V = 500/100 = 5 h.

*March 11, 2015*

**Physics**

Mass = 60Lbs * 0.454kg/Lb = 27.24 kg M*g = 27.24 * 9.8 = 267 N. = Wt. of box Fn = 267 + Fap*sin45 = Normal force. Fk = u*Fn = 0.2*(267+Fap*sin45) = 53.4 + 0.141Fap Fap*Cos45-Fk = M*a 0.707Fap-53.4 - 0.141Fap = M*0 = 0 0.566Fap = 53.4 Fap = 94.3 N. = Force applied. d = 30/3.3...

*March 11, 2015*

**physics**

a = (V-Vo)t = (5-0)/10 = 0.5 m/s^2 d = 0.5*a*t^2 = 0.5*0.5*10^2 = 25 m. P = F*d/t = 10 * 25/10 = 25 J/s = 25 W.

*March 11, 2015*

**Physics**

What is t1/2?

*March 10, 2015*

**Physics help please!**

What is t1/2?

*March 10, 2015*

**Algebra**

See Related Questions: Mon, 1-26-15, 3:08 PM.

*March 10, 2015*

**Science**

P = Mg*h/t = Mg * 30/24 = 15,000 Mg = 12,000 N. = Total Wt.

*March 10, 2015*

**science past year**

5. E1 = 60 V. E2 = 30 V. R1 = 0.5 Ohms. R2 = 10-Ohm Load. R3 = 0.6 Ohms. R2*I2 + R1*I1 = 60 V. I1 = I2 + I3 R2*I2 + R1*(I2+I3) = 60 10I2 + 0.5I2 + 0.5I3 = 60 Eq1: 10.5I2 + 0.5I3 = 60 R2I2 - R3I3 = 30 V. Eq2: 10I2 - 0.6I3 = 30 Multiply Eq1 by 0.6 and Eq2 by 0.5. Then add the ...

*March 10, 2015*

**science past year**

1. E = 10 Volts. R1 = 1.5 Ohms. R2 = 3 Ohms. R = ? 1.1.1 R1//R2 = R1*R2/(R1+R2) = (1.5*3)/(1.5+3) = 1 Ohm. Rt = E/I = 10/2 = 5 Ohms = Total resistance. R = 5-1 = 4 Ohms. 1.1.2 Pd = E*I = 10 * 2 = 20 Watts. 1.2 0.004/C*(35-10)C * 100 = 10 Ohm Increase. 6. Rt = (R1*R2/(R1+R2) + ...

*March 10, 2015*

**Physics**

Fp = ((Vs+Vp)/(Vs-Vh))*Fh Fp = ((343+0)/(343-23)*378 = 405.2 Hz. Fp = Freq. heard by the person. Vp = Velocity of the person. Vs = Velocity of sound in air. Vh = Velocity of the horn. Fh = Freq. of the horn.

*March 10, 2015*

**physics**

Range = Vo^2*sin(2A)/g = 18 A = 60o g = 9.8 m/s^2 Vo = Initial velocity in m/s. Solve for Vo.

*March 10, 2015*

**physics**

a. V^2 = Vo^2 + 2g*h Vo = 0 g = 9.8 m/s^2 h = 50 m. Solve for V.

*March 10, 2015*

**physics**

a. V = Vo + a*t Vo = 30 m/s V = 10 m/s t = 5s. Solve for a. It will be negative. b. d = Vo*t + 0.5a*t^2

*March 10, 2015*

**physics**

M*g = 92 * 9.8 = 901.6 N. = Wt. of crate = Normal force, Fn. Fk = u*Fn = 0.357 * 901.6 = 321.9 N. = Force of kinetic friction. a. Fex-Fk = 289 - 321.9 = -32.9 N. The Force of friction is greater than the exerted force.

*March 9, 2015*

**Math**

2h[135o] + 3h[55o] X = 2*Cos135 + 3*Cos55 = 0.307 h. Y = 2*sin135 + 3*sin55 = 3.87 h. Tan A = Y/X = 3.87/0.307 = 12.61 A = 85.5o = The direction. T = Y/sin85.5 = 3.88 h.

*March 9, 2015*

**physics**

d = Vo^2*sin(2A)/g = 300^2*sin(60)/9.8 =

*March 9, 2015*

**physics for physical science**

See Related Questions: Sun, 2-3-13, 1:05 PM.

*March 9, 2015*

**Math**

r = 14 Ft. X = 10.7 Ft. CosA = X/r

*March 8, 2015*

**Math**

X = 13 Ft. Y = Ht. = 10 Ft. TanA = Y/X

*March 8, 2015*

**math**

See your previous post.

*March 8, 2015*

**physics**

M*g = 20 * 9.8 = 196 N. = Wt. of block. Fp = 196*sin30 = 98 N. = Force parallel t0 the incline. Fn = 196*Cos30 = 169.7 N. = Normal force Fk = u*Fn = 0.2 * 169.7 = 33.95 N. = Force of kinetic friction. a. Fap-Fp-Fk = M*a a = 0 Fap = Force applied. Solve for Fap. Work = Fap * d ...

*March 8, 2015*

**math**

See your previous post.

*March 8, 2015*

**Math**

b. T = Tr + Tf = 1.94 + 1.94 = 3.88 s. Tr = Rise time. Tf = Fall time.

*March 8, 2015*

**Math**

t = -B/2A = -62/-32 = 1.94 h = -16*1.94^2 + 62*1.94 + 2 = 62.1 Ft.

*March 8, 2015*

**Chemistry**

What is the method used to separate water from bleached wood pulp?

*March 8, 2015*

**Math**

X1=Mike's distance from bottom of tower. X1+21.2 = Lani's distance from bottom of tower. Tan40 = h/X1 h = X1*Tan40 Tan38.5 = h/(X1+21.2) h = (X1+21.2)*Tan38.5 h = X1*Tan40 = (X1+21.2)*Tan38.5 0.839X1 = 0.795X1 + 16.86 0.044X1 = 16.86 X1 = 383 m. h = 383 * Tan40 = 322 m.

*March 8, 2015*

**math**

V = Vo - Vo*r*t = 5000 - 5000*0.05*5 = 5000 - 1250 = $3750 = Value after 5 yrs.

*March 7, 2015*

**physics**

See Related Questions: Wed, 5-28-14, 8:01 PM.

*March 7, 2015*

**Physics**

M1*V1 + M2*V2 = M1*V3 + M2*V4 0.02*0.25 - 0.04*0.15 = 0.02*(-0.16) + 0.04*V4 0.005-0.006 = - 0.0032 + 0.04*V4 -0.001 + 0.0032 = 0.04*V4 0.04*V4 = 0.0022 V4 = 0.055 m/s.

*March 7, 2015*

**Physics**

Impulse = M*V

*March 7, 2015*

**Physics**

Range = Vo^2*sin(2A)/g = 7^2*sin(80)/9.8 = 4.92 m.

*March 7, 2015*

**Physics**

Vo = 5m/s[35o] Yo = 5*sin35 = 2.87 m/s. Y^2 = Yo^2 + 2g*h = 0 h = -Yo^2/2g = -(2.87)^2/-19.6 = 0.42 m

*March 7, 2015*

**Physics**

See previous post: Fri, 3-6-15, 4:28 AM.

*March 7, 2015*

**Geometry**

Horizon: C = 0.30x + 28 X = Minutes used. Sprint: C = 0.029x + 30

*March 7, 2015*

**math word problem**

r = 66Ft./6s = 11 Ft/s

*March 7, 2015*

**Dynamics of machinery**

See Related Questions: Wed, 12-31-14, 5:48 AM.

*March 7, 2015*

**physics**

M1*V1 + M2*V2 + M3*V3 = M1*V + M2*2[60o] + M3*3[30o] M1 = M2 = M3? M1*V1 + M1*V2 + M1*V3 = M1*V + M1*2[60o] + M1*3[30o] M1*4 + M1*0 + M1*0 = M1*V + M1*2[60] + M1*3[30] Divide both sides by M1: 4 = V + 2[60] + 3[30] 4 = V + 2*Cos60 + 2*sin60 + 3*Cos30 + 3*sin30 4 = V + 1 + 1....

*March 7, 2015*

**physics**

V^2 = Vo^2 + 2a*d = 0 + 2*2*9 = 36 V = 6 m/s

*March 7, 2015*

**Physics**

h = 19.5 - 1.6 = 17.9 m. Dx = 58 m. 1. h = 0.5g*T^2 = 17.9 4.9T^2 = 17.9 T^2 = 3.65 T = 1.91 s. = Fall time. Dx = Vo*T = 58 Vo * 1.91 = 58 Vo = 58/1.91 = 30.3 m/s 2. V^2 = Vo^2 + 2g.h = 0 + 19.6*17.9 = 350.84 V = 18.7 m/s

*March 7, 2015*

**physics**

Xc = 1/(2pi*F*C) Ohms. F = 2490 Hz C = 30*10^-6 Farads. 2pi = 6.28 Xc = ?

*March 6, 2015*

**math**

What is the area of the largest rectangle with lower base on the x-axis and upper vertices on the curve y equals 27 minus x^2?

*March 6, 2015*

**Science**

Total momentum before the collision = Total momentum after the collision. C. 100kg m/s.

*March 6, 2015*

**Physics**

Fo = ((Vs+Vo)/(Vs-Vg))*Fg = 1185 Hz ((343+Vo)/(343-0))*1099 = 1185 ((343+Vo)/343)*1099 = 1185 Multiply both sides by 343/1099: 343 + Vo = 1185 * 343/1099 = 369.8 Vo = 369.8 - 343 = 26.84 m/s = Velocity of the observer.

*March 6, 2015*

**Physics**

M*V1 + M*V2 = 30,000 V1 = 20 m/s V2 = 5 m/s Solve for M.

*March 6, 2015*

**Physics**

d = Xo*t = 15 m. 12t = 15 t = 1.25 s. = Fall time.

*March 6, 2015*

**Physics**

d = Vx*Tf = 3 m. 0.5m/s * Tf = 3 Tf = 6 s. = Fall time. h = 0.5g*Tf^2 = 4.9 * 6^2 = 176.4 m.

*March 6, 2015*

**Physics**

h = 0.5g*t^2 = 7.5 4.9t^2 = 7.5 t^2 = 1.53 t = 1.24 s. = Fall time. d = Vx*t = 15m/s * 1.24s = 18.6 m.

*March 6, 2015*

**physics**

T = M*g + M*a

*March 6, 2015*

**physics**

Vo=1.65 rev/s * 6.28rad/rev=10.362 rad/s V=0.485rev/s * 6.28rad/rev = 3.05 rad/s a. a = (V-Vo)/t

*March 6, 2015*

**Physics**

d = V*t = 4800 m t = 4800/343 = 14 s.

*March 5, 2015*

**Calculus, HELP!!**

1) A rectangular page is to contain 24 square inches of print. The page has to have a 6-inch margin on top and at the bottom and a 1-inch margin on each side. Find the dimensions of the page that minimize the amount of paper used. 2) A cable runs along a wall from C to P at a ...

*March 5, 2015*

**physics**

d1 = V*t = 42m/s * 0.8s = 33.6 m. Head start for the speeder. d2 = d1 + 33.6 m. 20*t + 0.5*a*t^2 = 42*t + 33.6 20t+ 0.5*5*t^2 = 42t + 33.6 2.5t^2 -22t = 33.6 2.5t^2 - 22t - 33.6 = 0 Use Quadratic Formula. t = 10.13 s.

*March 5, 2015*