Thursday

September 29, 2016
Total # Posts: 12,063

**Physics**

Car A: d = r*t, t = d/r = 500/40 = 12.5 s. Car B: d = 0.5a*t^2, t^2 = d/0.5a = 500/5 = 100, t = 10 s.

*September 27, 2016*

**Physics**

1a. Fk = u*Fn = u * Mg = 0.44 * 5.1*9.8 = 22 N. The force of kinetic friction is greater than the applied force. please check for errors. 3a. (4.1/9.8) * 810 = 339 N.

*September 27, 2016*

**physics**

Y^2 = Yo^2 + 2g*h = 0 + 19.6*6.5 = 127.4, Y = 11.29 m/s. V = sqrt(Xo^2+Y^2) = sqrt(2.2^2 + 11.29^2) = 11.50 m/s

*September 27, 2016*

**physics**

h = 0.5g*t^2. 126 = 4.9t^2, t = 5.07 s. to reach gnd. d = Vx*t = 153 * 5.07 = 775.85 m.

*September 27, 2016*

**Physics**

Disp. = 13m[22.6o] + 17[118.1o]. Disp. = (13*Cos22.6+17*Cos118.1) + (13*sin22.6+17*sin118.1)i, Disp. = 4 + 20i = 20.4m[78.7o N. of E].

*September 25, 2016*

**physics**

M = 160Lbs * 0.454kg/Lb. = 72.64 kg. M*g = 72.64 * 9.8 = 711.9 N., Downward = -711.9 N. T1*Cos(180-39) = -T2*Cos55. T1 = 0.738T2. T1*sin(180-39) + T2*sin55 = 711.9. 0.629T1 + 0.819T2 = 711.9, Replace T1 with 0.738T2: 0.629*0.738T2 + 0.819T2 = 711.9, 1.28T2 = 711.9, T2 = 556 N...

*September 25, 2016*

**Physics**

Correction: d. y^2 = Yo^2 + 2g*h. Y^2 = 0 + 19.6*(53.2-3.05) = 982.94, Y = 31.35 m/s. V = Xo+Yi = 25.9 + 31.35i = 40.7 m/s.[50.4].

*September 25, 2016*

**Physics**

Vo = 41.4m/s[51.2o]. Xo = 41.4*Cos51.2 = 25.9 m/s. Yo = 41.4*sin51.2 = 32.3 m/s. a. Y = Yo + g*Tr. 0 = 32.3 - 9.8Tr, Tr = 3.29 s. = Rise time. h = Yo*Tr + 0.5g*Tr^2. h = 32.3*3.29 - 4.9*3.29^2 = 53.2 m. h = ho - 0.5g*Tf^2. 3.05 = 53.2 - 4.9Tf^2, 4.9Tf^2 = 53.2 - 3.05 = 50.18, ...

*September 25, 2016*

**physic**

Vo = 60 km/h = 60,000m/3600s. = 16.7 m/s. V^2 = Vo^2 + 2a*d. V = 0, Vo = 16.7 m/s, a = -0.80 m/s^2, d = ?.

*September 25, 2016*

**Physics**

Vo = 70.5km/h = 70,500m/3600s = 19.6 m/s. V^2 = Vo^2 + 2a*d. 0 = 19.6^2 - 2*0.32*d, d = ?. 1.24 km = 1240 m. The stopping distance(d) will be less than 1240 m and the driver stops before hitting the deer.

*September 25, 2016*

**Physics**

V = Vo + g*t = 12 + 9.8*2 = 31.6 m/s.

*September 25, 2016*

**Physics**

Disp. = 100*(45/60)[180o] + 100*(30/60)[135o] + 100*(15/60)[90o]. Disp. = 100*0.75[180o] + 100*0.5[135] + 100*0.25[90o], Disp. = -75 + 50[135] + 25[90o], Disp. = (-75-50*Cos135) + (50*sin135+25)i = -110.4 + 60.4i = 126km[-28.7o] = 126km[28.7o N. of W.] = 126km[151.3o CCW). V...

*September 25, 2016*

**physics**

V = Vo + a*t. V = 0, Vo = 20 m/s, t = 2 s., a = ?. "a" will be negative. F = M*a. F will be negative which means that the force is opposing the movement.

*September 25, 2016*

**Physics**

V = Vo + a*t. V = 26.8 m/s, Vo = 0, t =3.506, a = ?.

*September 25, 2016*

**math**

T = t1*t2/(t1+t2) = 3*5/(3+5) = 1.875 Min. = 1 min, and 52.5 Sec.

*September 25, 2016*

**Physics**

Vo = 28m/s[60o]. Xo = 28*Cos60 = 14 m/s. Yo = 28*sin60 = = 24.2 m/s. b. Y^2 = Yo^2 + 2g*h. 0 = 24.2^2 - 19.6h, h = 29.9 m. c. Y^2 = Yo^2 + 2g*h = 24.2^2 + 19.6(29.9-25.19) = 678, Y = 26.0 m/s = Vertical component. V = Sqrt(Xo^2+Y^2) =

*September 23, 2016*

**maths**

I = Po*r*t = 830*(0.051/365)*212 = $24.59.

*September 23, 2016*

**Trigonometry**

Correction: T2 should 3 hours instead of 4 hours. Disp. = V1*T1 + V2*T2. Disp. = 2.5[75o]*2 + 4[165o]*3, Disp. = 5[75o] + 12[165], Disp. = (5*Cos75+12*Cos165) + (5*sin75+12*sin165)I, Disp. = (1.29-15.5) + (4.83+3.11)i, Disp. = -14.21 + 7.94i = 16.3nM[-29.2o] = 16.3nM[29.2o N. ...

*September 23, 2016*

**Trigonometry**

Disp. = V1*T1 + V2*T2. Disp. = 2.5[75o]*2 + 4[165o]*4, Disp. = 5[75o] + 16[165o], Disp. = (5*Cos75+16*Cos165) + (5*sin75+16*sin165)i, Disp. = (1.29-15.5) + (4.83+4.14)i, Disp. = -14.21 + 8.97i = 16.8nM[-32.3o]. = 16.8nM[32.3o N. of W.].

*September 23, 2016*

**Physics**

Vb = 5m/s[90o+50o] + 4m/s. Vb =(5*Cos140+4) + (5*sin140)i, Vb = 0.170 + 3.21i = 3.214/m/s[87o]. Tan(90-87) = d/45. Tan3 = d/45, d = ?.

*September 23, 2016*

**Math**

Thank you bobpursley

*September 22, 2016*

**Math**

Use the clue bellow to find the mystery number: - The mystery number has 3 digits - The sum of the digits in the mystery number equals 16 - The mystery number is greater than 800 and less than 825 - All digits in the mistery number are even.

*September 22, 2016*

**physics**

d1 = V*(Tr+Tf) = 1.4 * 0.388 = 0.543 m. = Distance covered by skateboard while skater is in air. d2 = Xo*(Tr+Tf) = 3.29 * 0.388 = 1.28 m. = Distance jumped by skater. d2-d1 = 1.28 - 0.543 = 0.734 m. Between skater and skateboard.

*September 22, 2016*

**physics**

Vo =3.80 m/s[30o]. Xo = 3.8*Cos30 = 3.29 m/s. Yo = 3.8*sin30 = 1.9 m/s. Y = Yo + g*Tr. 0 = 1.9 - 9.8Tr, Tr = =.194 s. = Rise time. Tf = Tr = 0.194 s. = Fall time. d = V*(Tr+Tf) = 1.4 * 0.388 = 0.543 m.

*September 22, 2016*

**Physics**

Xo = 18 m/s. = Hor. velocity. h = o.5g*t^2. 123 = 4.9t^2, t = 5.01 s. to reach gnd. d = Xo*t = 18 * 5.01 = 90.2 m.

*September 22, 2016*

**Physics**

d = 4 * 50 = 200 m. Disp. = 0, The distance from starting point.

*September 22, 2016*

**physics**

V = -2.55 + 0.440 + x. -1.33 = -2.11 + x, X = 0.78 m/s Due East. d = V*T, 6440 = (-1.33)*T, T = -4842 s. = 4842 s., West. 0.78m/s * 4842s. = 3777 m., East.

*September 22, 2016*

**Measurement - Distance**

T1 = 10:30 - 8:00 = 2.5 b. d1 = V1*T1 = 75 * 2.5 = 187.5 km. d2 = V*T, (525-187.5) = 80*T, T = 4.22 h. For Chad to reach B. D1 = (525-187.5) - 75*4.22. D1 = 337.5 - 316.5 = 21 = Dist. Michael still need to travel.

*September 22, 2016*

**Physics**

1. V = Vo + a*t. 15 = 0 + a*5 a = 3 m/s^2. 2. V = Vo + a*t. 0 = 15 - 5*t, t = 3 s. 3. d1 = Vo*t + 0.5a*t^2. Vo = 0, t = 5, a = 3 m/s^2, d1 = ?. d2 = Vo*t. Vo = 15 m/s, t = 15 s, d2 = ?. V^2 = Vo^2 + 2a*d3. V = 0, Vo = 15 m/s, a = -5 m/s^2, d3 = ?. d1+d2+d3 = Total dist.

*September 21, 2016*

**physics**

Vo = 120Ft/s[37o]. Xo = 120*Cos37 = 95.85 Ft/s. Yo = 120*sin37 = 72.22 Ft/s. a. Y = Yo + g*Tr. 0 = 72.22 - 32Tr, Tr = 2.26 s. = Rise time. Tf = Tr = 2.26 = Fall time. Tr+Tf = 2.26 + 2.26 = 4.52 s. = Time in air. b. h = Yo*Tr + 0.5g*Tr^2. h = 72.22 - 16*2.26^2 = 81.5 Ft. c. d...

*September 21, 2016*

**Physics**

V^2 = Vo^2 + 2a*d. Vo = 0, a = 3.6 m/s^2, d = 61 m., V = ?.

*September 20, 2016*

**math**

Tan17 = 30/d, d = ?

*September 20, 2016*

**Math**

a. V = -1.5 + 10 = 8.5 m/s, East. b. V = 2.1 + 15 = 17.1 m/s, East.

*September 20, 2016*

**geometry**

Correction: apothem = s/2*Tan(180/n). 5 = S/2*Tan(180/3), S = 17.32 cm. P = 17.32 + 17.32 + 17.32 = 52 cm.

*September 20, 2016*

**geometry**

All of the angles are equal: A = B = C = 180/3 = 60o. All of the sides are equal: a = b = c. h = 5 cm, sin60 = h/a = 5/a, a = 5/sin60 = 5.77 cm. P = a + b + c = 5.77 + 5.77 + 5.77 = 17 cm.

*September 20, 2016*

**Physics**

h = 0.5g*t^2. 0.8 = 4.9t^2, t = 0.404 s. To reach gnd. d = 5m/s * 0.404s. = 2.02 m. From base of table.

*September 20, 2016*

**Physics**

Vo = a*t = 3 * 60 = 180 m/s. V^2 = Vo^2 + 2g*h. 0 = 180^2 - 19.6h, h = 1653 m. Above gnd. h = 0.5g*t^2. 1653 = 4.9t^2, t = 18.4 s. To reach gnd. V = Vo + g*t = 0 + 9.8*18.4 = 180 m/s.

*September 19, 2016*

**physics**

See previous post: Sun, 9-18-16, 6:50 PM.

*September 18, 2016*

**Physics**

M*g = 20 * 9.8 = 196 Newtons.

*September 18, 2016*

**Physics**

V^2 = Vo^2 + 2a*d. 5^2 = 20^2 + 2a*25. 2a*25 = -375, a = -7.5 m/s^2. V = Vo + a*t. 5 = 20 - 7.5t, t = 2 s.

*September 18, 2016*

**physics**

Energy = 1.25kW * (6.5/60)h = 0.135 kWh.

*September 18, 2016*

**physics**

F = 1.8C + 32.

*September 18, 2016*

**Physics**

See previous post.

*September 17, 2016*

**Physics**

5.1m = 1/2 of h max. hmax = 10.2 m.

*September 17, 2016*

**Physics**

V^2 = Vo^2 + 2g*h. 10^2 = 0 + 19.6h, 19.6h = 100, h = 5.1 m.

*September 17, 2016*

**physics**

See previous post: Thu, 9-15-16, 10:47 PM.

*September 17, 2016*

**Physics**

X = 3.17 - 1.49 = 1.68 m. Y = -4.49 - (-2.83) = -1.66 m. d = Sqrt(X^2+Y^2) = Sqrt(1.68^2+1.6^2) = 2.36 m. V = d/t = 2.36m/325s = 0.00727m/s.

*September 17, 2016*

**Physics**

Vo = 45,000m/3600s = 12.5 m/s. If she tries to stop: V^2 = Vo^2 + 2a*d. 0 = 12.5^2 - 2*5.8*d. 11.6d = 156.25, d = 13.5 m. To stop. Therefore, she should stop the car.

*September 17, 2016*

**Physics**

1. Range = Vo^2 * sin(2A)/g. 7.73 = Vo^2 * sin(54.2)/9.8. 7.73 = Vo^2 * 0.0828, Vo^2 = 93.4, Vo = 9.66 m/s. Range = (9.66*1.03)^2 * sin(54.2)/9.8 =

*September 16, 2016*

**MATH**

32,800 - 0.2*32,800 = 26,240/mo. Remaining. Bank = 0.25 * 26,240 = 6,560/mo. Other Expenses = 0.75 * 26,240 = 19,680/mo.

*September 15, 2016*

**physics**

V^2 = Vo^2 + 2g*h = 15.3^2 + 19.6*4.40 = 320.33, V = 17.9 m/s.

*September 15, 2016*

**Physics**

Range = Vo^2*sin(2A)/g. 4.22 = Vo^2*sin(24.8)/9.8. 4.22 = Vo^2*0.0428, Vo^2 = 98.6, Vo = 9.93 m/s.

*September 15, 2016*

**physics**

Fr = 415[-20o] + 470[50o]. Fr = (415*Cos(-20)+470*Cos50) + (415*sin(-20)+470*sin50). Fr = (390+302) + (-142+360)i. Fr = 692 + 218i = 726N[17.5o]. Fr = M*a; a = Fr/M = 726[17.5]/290 = 2.50m/s^2[17.5o].

*September 14, 2016*

**Algebra II**

d = 44g.

*September 14, 2016*

**algerbra help plzzz**

I found NONE.

*September 14, 2016*

**physics**

1. V^2 == Vo + 2g*h = 0; Vo = -2g*h = 19.6*10 = 196 m/s. = Initial velocity. V = Vo + g*Tr = 0; Tr = -Vo/g = -196/-9.8 = 20 s. = Rise time. Tf = Tr = 20 s. Tr+Tf = 20 + 20 = 40 s. = Time in air. 2. Vo = 196 m/s(Part 1).

*September 13, 2016*

**pre algebra 8th grade(0, 0.3), (1, 0.5), (2, 0.7),**

Please ignore the 3 points preceding my name.

*September 13, 2016*

**pre algebra 8th grade(0, 0.3), (1, 0.5), (2, 0.7),**

Y = mx + b, Y = 0.2x + 0.3. When y = 0, x = -1.5. X-int. When x = 0, y = 0.3. Y-int. When x = 5, y = 1.3. P1(-1.5,0), P2(0,0.3), P3(5,1.3). Use the above points for graphing.

*September 13, 2016*

**Physics**

V = 68km/h = 68000m/3600s = 18.9 m/s. d = v*t + 0.5a*t^2. d = 18.9*0.75 - 0.5*5.5*0.75^2 = 12.6 m.

*September 13, 2016*

**science**

F = M*a.

*September 13, 2016*

**Math**

S = 44; Not 4. h = -16t^2 + 64t + 44 = 64. Divide both sides by 4: -4t^2 + 16t + 11 = 16, -4t^2 + 16t -5t = 0, Use Quadratic Formula: t = {-16 +- Sqrt(256-80))/-8, t = (-16 +- 13.3)/-8 = 0.342, and 3.66 Seconds. t = 3.66 seconds.

*September 13, 2016*

**Physics**

a. D = 1.13km[0o] + 1.01km[270o] + 3.95km[130.2o] = (1.13+3.95*Cos130.2) + (1.01*sin270+3.95*sin130.2)i = -1.42 - 1.009i = 1.74km[35.4o W. of S.]. b. D/t = 1.74km[35.4o W. of S.]/1.966h = 0.885km/h[35.4o W. of S.].

*September 12, 2016*

**science**

What is the previous question?

*September 10, 2016*

**Physical science**

V = Vo + a*t = 40, Vo - 6*1.5 = 40, Vo = 49 m/s.

*September 10, 2016*

**Physics (Help Plz)**

1. d = r*t1 = 2.5, 3.5 * t1 = 2.5, t1 = 0.714 Hours. r*t2 = 2.5, 8 * t2 = 2.5, t2 = 0.3125 Hours. Average Speed = 5/(t1+t2). 2. 3.5 * 0.5t + 8 * 0.5t = 5, 5.75t = 5, t = 0.870 Hours. 3. Average Speed = 5/t.

*September 9, 2016*

**ENGLISH**

RIDDLE:My weakness and fame equals

*September 9, 2016*

**physic**

A. Ha = Hb, ho-0.5g*t^2 = ho-(Vo*t + 0.5g*t^2). 17 - 4.9t^2 = 23.5 - (7.36*t + 4.9t^2. 17 - 4.9t^2 = 23.5 - 7.36t - 4.9t^2. -4.9t^2 + 4.9t^2 + 7.36t = 23.5-17. 7.36t = 6.5, t = 0.883 s. h = 17 - 4.9*(0.883)^2 = 13.2 m. Above gnd. B. Va = Vo + g*t = 0 + 9.8*0.883 = 8.65 m/s. Vb...

*September 8, 2016*

**Physics**

d = 8.5m/s * 240s =

*September 8, 2016*

**physics**

Correction: V = Xo + Yi = 250 - 207i = 325Ft/s[-39.6o].

*September 8, 2016*

**physics**

Vo = 500Ft/s[60o]. Xo = 500*Cos60 = 250 Ft/s. Yo = 500*sin60 = 433 Ft/s. Y = Yo + g*Tr = 0, 433 - 32Tr = 0, Tr = 13.53 s. Rise time. h = Yo*t + 0.5g*t^2. h = 433*20 - 16*20^2 = 2260 Ft. and falling. Y = Yo + g*t = 433 - 32*20 = -207 Ft/s = 207 Ft/s, Downward. V = Xo + Yi = 250...

*September 8, 2016*

**Physics**

d = 25m/s * 50s =

*September 8, 2016*

**Physics**

A. See previous post: Thu, 9-8-16, 8:11PM.

*September 8, 2016*

**Physics**

Speed = 80m/5s = 16 m/s. A. See previous post.

*September 8, 2016*

**physics**

105mi/h * 5,280Ft/mi * 1h/3600s = 154 Ft/s. d = r*t = 43, 154*t = 43, t = ?.

*September 8, 2016*

**physics**

D = 5 + 7[-45o] = (5+7Cos(-45)) + (7*sin(-45))I = 9.95 - 4.95i = 11.11mi[-26.4o] = 11.11mi[26.4 S. of E.].

*September 8, 2016*

**PHYSICS**

Fr = (5[30o] + 5[0o] = (5*Cos30+5) + (5*sin30)I = 9.33 + 2.5i = 9.66[15o].

*September 8, 2016*

**Physics**

V = 1[90o] + 4[225o]. V = (1*Cos90+4*Cos225)+(1*sin90+4*sin225)I = (0+2.83) + (1-2.83)I = 2.83 - 1.83i = 3.37n[-32.9o] = 3.37n[32.9o S. of E].

*September 8, 2016*

**profit and loss**

P/150 = 0.20, P = $30.

*September 8, 2016*

**math**

a. 1. i345 = 345i. 2. 32/-5i = 32*5i/(5i*5i) = 160i/25i^2 = 160i/-25. 3. 6/(7-8i) = 6*(7+8i)/(7-8i)(7+8i) = 42+48i/(49+56i-56i-64i^2) = 42+48i/(49+64) = 42+48i/113. 4. 9/(-8+7i). Use same procedure as part 3 and remember that i^2 = -1.

*September 8, 2016*

**math**

a. F = 44N[54o] + 77[90] + 60[146] + 88[245]. X = 44*Cos54+77*Cos90+60*Cos146+88*Cos245 = Sum of hor. components. Y = 44*sin54+77*sin90+60*sin146+88*sin245 = Sum of ver. components. Tan A = Y/X, A = ? Resultant = X/Cos A or Sqrt(X^2+Y^2).

*September 8, 2016*

**Math**

d = 20mi/h * xh = 20x miles. d = (20-4)mi/h * xh + 6 = 20x 16x + 6 = 20x, X = 1.5 Hours. d = 20 * 1.5 = 30 Miles from nest. Dt = 2 * 30 = 60 Miles. = Total distance traveled. d = V*t = 30, 20*t1 = 30, t1 = 1.5 Hours. 16*t2 = 30, t2 = 1.875 Hours. t1+t2 = 1.50 + 1.875 = 3.375 ...

*September 8, 2016*

**math**

$X invested in 1st acc. (10,000-x) invested in 2nd acc. I = I1 + I2 = X*r1*t + (10,000-x)*r2*t = 575. X*.05*1 + (10,000-x)*.06*1 = 575. X = ?.

*September 7, 2016*

**math**

One bro. owned $X. The other bro. owned $3x/7. X + 3x/7 = 1,260,000. Multiply both sides by 7 and solve for X.

*September 7, 2016*

**Physics**

I need to know the direction(angle) of each vector.

*September 7, 2016*

**math**

See your previous post.

*September 7, 2016*

**math**

See previous post.

*September 7, 2016*

**math**

See previous post: Wed., 9-7-16, 3:18 AM.

*September 7, 2016*

**math**

a. Tan35 = h/(d+30), h = (d+30)Tan35). Tan55 = h/d, h = d*Tan55. (d+30)Tan35 = d*Tan55. (d+30)0.7 = 1.43d, d = ? b. h = d*Tan55.

*September 7, 2016*

**Physics (College)**

d = 2 * 12.8 = 25.6 km. t = (21+13)/60 = 0.567h. Speed = d/t = 25.6km/0.567h = 45.2 km/h.

*September 7, 2016*

**Physics**

d 26mi * 1.6km/mi = 41.6 km. t = 2h + (6/60)h + (32/3600)h. t = 2 + 0.1 + 0.00889 = 2.109h. Speed = d/t = 41.6km/2.109h = 19.73 km/h.

*September 6, 2016*

**Physics**

D1/D2 = (1/2)/(2/3) = 1/2 * 3/2 = 3/4.

*September 6, 2016*

**Physical Science**

h = 0.5g*t^2 = 4.9*0.8^2 =

*September 5, 2016*

**math**

X girls in the class. (53-x) boys in the class. 5x/7 + 3/5(53-x) = 35. 25x + 21(53-x) = 1225. 25x + 1113-21x = 1225. 4x = 112, X = 28. 53-28 = 25 Boys in the class.

*September 4, 2016*

**math**

35 fish in smaller tank. X fish in larger tank. 5/7(x-15) = 35+15 = 50. 5(x-15) = 350, 5x - 75 = 350, X = 85.

*September 4, 2016*

**math**

See previous post: Sat 9-3-16, 1:43 PM.

*September 4, 2016*

**math**

P = Po(1+r)^n. Po = $25,000. r = 0.06/12mo. = 0.005/mo. n = 1Comp./mo. * 12mo. = 12 Compounding periods. t = 12 mo. P/t = Monthly payment.

*September 4, 2016*

**Math**

X Boys in the class. Y Girls in the class. 3x/4 + 2y/3 = 30, Multiply by 12: Eq1: 9x + 8y = 360. x/4 + y/3 = 42-30 = 12, Multiply by 12: Eq2: 3x + 4y = 144. Multiply Eq2 by -3 and add: 9x + 8y = 360 -9x - 12y = -432 Sum: -4y = -72, Y = 18. 3x + 4*18 = 144, X = 24.

*September 3, 2016*

**Math**

Remainder = 13/13 - 7/13 = 6/13. Next-to oldest share = 2/3 * 6/13 = 12/39. Youngest bro. share = 13/13-7/13-12/39 = 39/39-21/39-12/39 = 6/39 = 2/13. 2/13 * x = 6.00, X = $39. = Sum of money shared.

*September 3, 2016*

**profit and loss**

Profit = 0.1 * 100 = $10. 0.1x = 20, X = $200 = New selling price.

*September 2, 2016*

**PHYSICS CLASS 9**

V^2 = Vo^2 + 2a*d. Vo = 40km/h = 40,000m/3600s = 11.11 m/s. V = 0, a = -0.6m/s^2, d = ?.

*August 31, 2016*