Sunday

December 11, 2016
Total # Posts: 12,465

**Physics**

d1 = 0.5a*t^2 = 0.5*2.4*3^2 = 10.8 m. Head start for Jill. 0.5*4*t^2 = 0.5*2.4*t^2 + 10.8. 2t^2 = 1.2t^2 + 10.8. 0.8t^2 = 10.8 t^2 = 13.5. t = 3.7 s. to catchup.

*September 2, 2015*

**Physics**

A. 9.8/1.67 * 270 = 1584 N. B. M*g = 270 N. M*1.67 = 270. M = 161.7 kg. C. Same as on the moon: 161.7 kg.

*September 2, 2015*

**Algebra**

Equation: 5x + 10y = 245 Cents. Note: They only asked for an Equation. We don't have enough information to solve the problem.

*September 2, 2015*

**Physics**

A. V = d/t = 50m/10s. = 5 m/s. B. = V = 50m/10s = 5 m/s. C. V = 100m/20s = 5 m/s.

*September 2, 2015*

**Physics**

A. h = 10*sin25o. B. d = 10*Cos25.

*August 31, 2015*

**Precalc**

10. Any point on the x-axis has a Y of 0; 12 units to the left of the Y-axis is an X value (-)12: P(-12,0). 12. Q3, or Q4 depending on whether X is positive or negative. 16. X,Y < 0. Q3. 26. (-3,-1), (2,-1). D^2 = X^2 + Y^2 = (2+3)^2 + (-1+1)^2 = 25 + 0 = 25. D = 5. 30. (1,...

*August 31, 2015*

**pre algebra**

Zero is an integer which is a whole number.

*August 31, 2015*

**physic**

M1*V1 + M2*V2 = M1*V3 + M2*V4. 1.2*7.5 + 12*0 = 1.2*(-3.8) + 12*V4. 9 + 0 = -4.56 + 12V4. 12V4 = 13.56. V4 = 1.13 m/s. = Velocity of the wagon.

*August 31, 2015*

**Physics**

V^2 = Vo^2 + 2g*h. V = 30 m/s. g = +9.8 m/s^2. Vo = 0. Solve for h.

*August 31, 2015*

**Physics**

V^2 = Vo^2 + 2g*h. Vo = 0. g = 9.8 m/s^2. h = 1.4 m. Solve for V. Momentum = M*V.

*August 31, 2015*

**physics**

a = (V-Vo)/t. V = 2o m/s. Vo = 0. t = 5 s. F = M*a.

*August 31, 2015*

**Physics**

V = Vo + g*t = 0 + 9.8*6 = 58.8 m/s after the first 6 s. d = Vo*t + 0.5g*t^2 = 58.8*6 + 4.9*6^2 = 529.2 m. in the last 6 s.

*August 31, 2015*

**Physics**

See previous post: Sat, 8-29-15, 3:51 AM.

*August 31, 2015*

**Physics**

a. h = Vo*t + 0.5g*t^2 = 0.644 m. Vo*0.17 - 4.9*0.17^2 = 0.644. 0.17Vo = 0.644 + 0.142 = 0.786. Vo = 4.62 m/s. b. V=Vo + g*t=4.62 - 9.8*0.17 = 2.95 m/s. c. Vo^2 = Vo^2 + 2g*h = 0. h = -Vo^2/2g = -(4.62^2)/-19.6 = 1.09 m. 1.09-0.644 = 0.446 m higher.

*August 30, 2015*

**Trigonometry/ please help!**

Assume that simple harmonic motion of a spring is described by the equation S=4 cos πt/ 2 where s is in centimetres and t is in seconds. When during the time 0<=t<=8 is the spring passing through the origin? I attempted this question but the graph doesn't pass ...

*August 29, 2015*

**Physics**

a. V = a*t = 8.9 m/s. 20*t = 8.9. t = 0.445 s. b. d = 0.5a*t^2. c. d = 0.5a*t^2. d = 4.3 m. a = 20 m/s^2. Solve for t.

*August 29, 2015*

**Physics**

13.9h - 0.81h = 13.09 h. = Travel time. EB trip = T Hours. WB trip = (T+51/60) Hours. T + (T+0.85) = 13.09 h T + T+0.85 = 13.09. 2T = 12.24. T = 6.12 h. = EB trip. T+0.85 = 6.97 h. = WB trip. a. Vavg=Dt/Tt=(2*4100)/13.9 = 590 km/h. b. Vavg = (2*4100)/13.09 =

*August 29, 2015*

**Physics**

F = M*a. M = 0.4 kg.

*August 29, 2015*

**Physics**

a = (V-Vo)/t = m/s^2. V = 14 m/s. Vo = 0. t = 0.08 s. Solve for a. F = M*a.

*August 29, 2015*

**Physics**

a = (V-Vo)/t = m/s^2. V = 20 m/s. t = 5 s. Vo = 0. Solve for a. F = M*a.

*August 29, 2015*

**Math**

(x^2-y^2)/(x-y)^2 = (x+y)(x-y)/(x-y)(x-y)= (x+y)/(x-y). Recall: a^2-b^2 = (a+b)(a-b).

*August 28, 2015*

**Physics**

1.02V = 3.50 Volts. V = 3.431 Volts.

*August 27, 2015*

**Physics**

a = u*g = 0.0343 * (-9.8) = -0.336 m/s^2. V^2 = Vo^2 + 2a*d = 0. Vo^2 = -2a*d = -2*(-0.336)*12.1 = 8.13. Vo = 2.85 m/s.

*August 27, 2015*

**physics**

V = a*t = 7.5 m/s. 1.5*t = 7.5. t = 5 s. d = 0.5a*t^2 = 0.5*1.5*5^2 = 18.75 m.

*August 27, 2015*

**Physics**

a. Work = = M*g*h = 58 * 9.8 *3.7 = 2103 J. b. Work = M*g*h.

*August 27, 2015*

**physics**

a. = h = 0.5g*t^2 = 35 m. 4.9t^2 = 35. t^2 = 7.14 t = 2.67 s. Time in flight. b. Range = Xo*t = 80 m. Xo*2.67 = 80. Xo = 30.0 m/s. c. Y^2 = Yo^2 + 2g*h = 0 + 19.6*35 = 686. Y = 26.2 m/s. X = Xo = 30.0 m/s.

*August 27, 2015*

**physics**

V^2 = Vo^2 + 2a*d. V = 5.8 m/s. Vo = 9.0 m/s. d = 5.3 m. Solve for a. It will be negative.

*August 26, 2015*

**math**

1. (10+n) + 5 = 15 + n. 2. 8*7 - n 3. n/3 + 1. 4. 6*8 - 10 - n = 38 - n. 5. (n-1) - 2 = n - 3. 6. n*(-n) + 7 = -n^2 + 7.

*August 26, 2015*

**math**

The phase angle is expressed in terms of the apparent power and cosine function: Pa = V*I = Apparent power. P = V*I*Cos A = Real power = Power dissipated in the resistance. Cos A = P/VI.

*August 26, 2015*

**Physics**

9,158,960km^2 = 9,158,960*10^6 m^2 = 9.159*10^12 m^2. m^2 * (kJ/m^2)/h = Total kJ/h.

*August 26, 2015*

**maths**

1. Do the multiplication. 2. Combine like-terms. 4. Factor if possible.

*August 26, 2015*

**maths**

2(x+2)^2 - (2x-1)(x+2). 2(x^2+4x+4) - (2x^2+4x-x-2). 2x^2 + 8x + 8 - 2x^2 - 3x + 2. 5x + 10 = 5(x+2).

*August 26, 2015*

**maths**

2ax - 4bx - ay - 2by. 2x(a-2b) - y(a-2b). (a-2b)(2x-y).

*August 26, 2015*

**maths**

x^2 - 4x - 5. -5 = 1*(-5). -5+1 = -4 = B. x+1 = 0. X = -1. x + (-5) = 0. or x-5 = 0. X = 5. x^2 - 4x - 5 = (x+1)(x-5).

*August 26, 2015*

**maths**

Factor out (a-3).

*August 26, 2015*

**maths**

ax^2 - 2ax - apx. ax(x - 2 - p).

*August 26, 2015*

**Math**

See previous post: Tue, 8-25-15, 2:55 PM.

*August 25, 2015*

**Algebra**

8/(15x+24y) * (5x+8y)/10 = 8/3(5x+8y) * (5x+8y)/10 = 8/3 * 1/10 = 8/30 = 4/15.

*August 25, 2015*

**math**

My answers: 1. No 2. No 3. Yes. 2/5 * 8/9 = The amount drunk. 4. Yes. 2/5 * 8/9 = 16/45 = The amount drunk.

*August 25, 2015*

**Math**

4X^0.5/(6-X^0.5) = 4X^0.5(6+X^0.5)/(6-X^0.5)(6+X^0.5) = (24x^0.5 + 4x)/(36-X) = (24sqrt(X)+4x)/(36-X). Recall: (a+b)(a-b) = a^2-b^2. sqrt X = X^0.5.

*August 25, 2015*

**Physics**

V1 = a*t = 1.5 * 5 = 7.5 m/s. V2 = V1 + a*t = 7.5 - 2*3 = 1.5 m/s.

*August 25, 2015*

**Physics**

V1 = 15mi/h * 5280Ft/mi * 1h/3600s = 22Ft/s. V2 = 50/15 * 22 = 73.3 Ft/s. a. a = (V2-V1)/t=(73.3-22)/13 = 3.95 Ft/s. b. d = V1*t + 0.5*a*t^2. t = 13 s. Solve for d.

*August 25, 2015*

**Physics**

Vo = 200 cm/s = 2 m/s. V = 10,000 cm/s = 100 m/s. V^2 = Vo^2 + 2g*d = !00^2. 2^2 + 19.6*d = 100^2. Solve for d.

*August 25, 2015*

**physics**

The initial velocity is negative,because the stone was moving upward before it began to free fall. In other words, the balloon containing the stone was moving upward as the stone began to move downward. If the stone had been THROWN downward from a stationary object, the ...

*August 25, 2015*

**physics**

See previous post: Sat, 8-22-15, 11:06 AM

*August 25, 2015*

**Physics**

A. V^2 = Vo^2 + 2g*h = 9.5^2 - 19.6*3.6 = 19.69. V = 4.44 m/s. B. V = Vo + g*t = 4.44. 9.5 - 9.8t = 4.44. -9.8t = -5.06. t = 0.533 s.

*August 24, 2015*

**Physics**

M*g = 1.5 * 9.8 = 14.7 N.=Wt. of blk A. a. PE = M*g*h = 14.7*0.5 = 7.35 J. b. V^2 = Vo^2 + 2g*h = 0 + 19.6*0.5 = 9.8. 3.13 m/s. KE = 0.5M*V^2 = 0.5*1.5*3.13^2 = 7.35 J. c. M1*V1 + M2*V2 = M1*V + M2*V. 1.5*3.13 + 1.5*0 = 1.5V + 1.5V. 4.7 + 0 = 3V. V = 1.57 m/s. d. KEa = KEb = ...

*August 24, 2015*

**Physics**

Vo = 20mi/h * 5280Ft/mi * 1h/3600s. = 29.3 m/s. V = 30/20 * 29.3 = 44 m/s. a = (V-Vo)/t = (30-20)/t = 10/t. d = 0.5*a*t^2 = 500 Ft. 0.5*(10/t)*t^2 = 500. 5t = 500. t = 100 s. a = 10/t = 10/100 = 0.10 Ft/s^2

*August 24, 2015*

**Physics**

d1 = d2. V1*t1 = 0.5a*t^2. V1*12 = 0.5*4.4*12^2. Solve for V1(m/s).

*August 23, 2015*

**physics**

See Related Questions: Thu, 9-15-11, 4:06 PM.

*August 23, 2015*

**physics**

d1 = V1*t1 t1 = d1/V1 = 20/30 = 0.667 h. V2=40Ft/s * 1m1/5280Ft * 3600s/h = 27.3 mi/h. t2 = d2/V2 = 20/27.3 = 0.733 h. V3 = 90km/h * 1m1/1.6km = 56.3 mi/h. t3 = d3/V3 = 20/56.3 = 0.355 h. d = d1+d2+d3 = 20 + 20 + 20 = 60 mi. T = t1+t2+t3 = 0.667 + 0.733 + 0.355 = 1.76 h. V = d...

*August 23, 2015*

**Physics**

See previous post: Sat, 8-22-15, 10:49 AM

*August 23, 2015*

**calc**

V = t^2 - 2t = 3^2 - 2*3 = 3 Ft/min. d = V*t = 3Ft./min. * 3min. = 9 Ft.

*August 22, 2015*

**Physics**

h = Vo*t + 0.5g*t^2 = -8*6 + 4.9*6^2 = 128.4 m.

*August 22, 2015*

**Physics**

M*g = 1500 * 9.8 = 14,700 N. = Wt. of block. = Normal(Fn). Fap-Fs = M*a. 200-Fs = M*0 = 0. Fs = 200 N. Fs = u*Fn. u = Fs/Fn = 200/14,700 = 0.0136.

*August 22, 2015*

**physics**

W1*d1 = W2*d2. 10 * 2.5 = 15*d2. d2 = 25/15 = 1.67 m. from the center. d2 = 2.5-1.67 = 0.83 m. from the end.

*August 22, 2015*

**Maths proportions**

1. 9/4.5 = 5/L. Solve for L. 2. 36/20.52 = 120/C. 3. Same procedure as #1and #2. 4. 20 Grams = 0.02 kg. C = 0.020kg * 60/kg = 5. ht. = 623Ft. * 1m/3.281Ft

*August 22, 2015*

**Physics.**

d = V*t.

*August 21, 2015*

**math**

B is my answer also.

*August 21, 2015*

**Algebra**

2x(x-5)^-3(1-2x(x-5)^-1) = 2x/(x-5)^3 * (1-2x/(x-5)) = 2x/(x-5)^3 * ((x-5)/(x-5)-2x/(x-5) = 2x/(x-5)^3 * (-x-5)/(x-5) = 2x(-x-5))/(x-5)^4).

*August 21, 2015*

**Trigonometry and Analysis**

To avoid the decimals: $1.00 = 100 Cents. $0.84 = 84 Cents. 0.01 = 1 Cent.

*August 21, 2015*

**Trigonometry and Analysis**

X Dimes. 2x Pennies. 10*x + 1*2x = 84 Cents. 12x = 84. X = 7 Dimes. 2x = 2*7 = 14 Pennies.

*August 21, 2015*

**Physics**

Vsw = Vs + Vw = 3 + 2i, Q1. Tan A = 2/3 = 0.66667. A = 33.7o E. of N. Body angle = 33.7o W. of N.

*August 21, 2015*

**ALGEBRA**

1b. 3. Divide each price by the wt of the cereal and choose the lowest price: 4.29/28oz = $0.15/oz.

*August 21, 2015*

**Physics**

Range = Vo^2*sin(2A)/g=200^2*sin(60)/9.8 = 3535 m.

*August 21, 2015*

**physics**

V = Vo + a*t = 6 + 1.5*4 = 12 m/s. d1 = Vo*t + 0.5*a*t^2=6*4 + 0.5*1.5*4^2 = 24 + 12 = 36 m. d2 = (V^2-Vo^2)/2a = (0-144)/-2.4=60 m. d = d1+d2 = 36 + 60 96 m.

*August 21, 2015*

**Physics**

See previous post: Thu, 8-20-15, 4:47 PM.

*August 20, 2015*

**Physics**

V=34mi/h * 1609m/mi * 1h/3600s.=15.2 m/s. d = V*t = 80 m. 15.2t = 80. t = 5.3 s.

*August 20, 2015*

**Physics-PLEASE HELP**

d1 = V1*t1 = 1 km. t1 = 1/V1 = 1/5 = 0.20 h. t2 = 1/V2 = 1/7 = 0.143 s. V=d/(t1+t2)=2km/(0.20+0.143)h=5.8 km/h.

*August 20, 2015*

**Pre-Calculus**

1. D(0.5,1), V(h,1), F(1.5,1). F - D = 1/2a. 1.5-0.5 = 1/2a. 1/2a = 1. 2a = 1. a = 0.5. h-0.5 = 1/4a = 1/2 = 0.5. h = 1.0. X = a(y-k)^2 + h. X = 0.5(y-1)^2 + 1. Vertex form. X = 0.5(y^2-2y+1). X = 0.5y^2 -y + 1.5. Standard form.

*August 19, 2015*

**math**

Y = x^4 - x^3 - 12x^2 = 0. Roots are: -3, 0, and 4.

*August 19, 2015*

**math**

Y = x^3 - 13x - 12 = 0. X = -1, x+1 = 0. (x^3 - 13x - 12)/(x+1) = x*2 - x - 12. x^3-13x-12 = (x+1)(x^2-x-12). Factor the Quadratic: (x+1)(x+3)(x-4) = 0. x+3 = 0, X = -3. x-4 = 0, X = 4. The roots are: X = -1, -3, and 4.

*August 19, 2015*

**math**

Y = x^3 -2x^2 - 7x - 4 = 0. By trial and error, I found that (-1) satisfies the Eq, and it is our 1st root. x = -1, x + 1 = 0. Using synthetic(Long-hand) division, divide the cubic Eq by x+1: (X^3 - 2x^2 - 7x - 4)/(x+1)=x^2 - 3x - 4 x^3 - 2x^2 -7x - 4 = (x+1)(x^2-3x-4). Factor...

*August 19, 2015*

**physics**

post it.

*August 19, 2015*

**physics**

D = 10.3[90o] + 6.1[45] + 5[180]. X = 10.3*Cos90 + 6.1*Cos45 + 5*Cos180 = 0 + 4.31 - 5 = -0.69 Blocks. Y = 10.3*sin90 + 6.1*sin45 + 5*sin180 = 10.3 + 4.31 + 0 = 14.61 Blocks. D = sqrt(X^2+Y^2) = sqrt((-0.69)^2 + 14.61^2) = 14.6 Blocks. Tan A = Y/X = 14.61/-0.69 = -87.3o = 87....

*August 18, 2015*

**usiness math**

P = Po + Po*r*t = 30,000 + 30,000*(0.04/360)*45 - 10,000 = 30,000 + 150 -10,000 = $20,150.

*August 18, 2015*

**physics**

Xo = 15 m/s = Hor. component of initial velocity. Tr = 1.2 + 1.2 = 2.4 s. = Rise time. Y = Yo + g*Tr = 0. Yo = -g*Tr = -(-9.8)*2.4 = 23.5 m/s. = Ver. component 0f initial velocity. Y = Yo + g*t = 23.5-9.8*1.2 = 11.74 m/s. a. V = sqrt(Xo^2+Y^2)=sqrt(15^2+11.74^2) = 19 m/s. b. Y...

*August 18, 2015*

**Physics PLEASE HELP!**

KE = 0.5M*V^2. M = 1.*10^-3 kg. V = 1.*10^3 m/s. Solve for KE.

*August 17, 2015*

**physics**

d = V*t = 8.69*10^-2. 4.61*10^-6m/s * t = 8.69*10^-2. t = 8.69*10^-2/4.61*10^-6 = 1.89*10^4 = 18900 s. = 5.25 h.

*August 17, 2015*

**physics**

Xo = 25 m/s. Remains constant. Yo = 45 m/s. Decreases to zero at max ht. Therefore, V = 25 m/s at max ht.

*August 17, 2015*

**physical science**

V = a*t = 3.125 * 4 = 12.5 m/s.

*August 17, 2015*

**physics**

Vo = 20m/s.[50o]. Xo = 20*Cos50 = 12.9 m/s. Yo = 20*sin50 = 15.3 m/s. Y = 0 m/s at max ht. KE = 0.5M*Xo^2 = 0.5*0.8*12.9^2 = 66.6 J.

*August 17, 2015*

**Physics**

Impulse = F*t.

*August 16, 2015*

**Physics**

D = 1200m[90o] + 2000[0] + 500[225]. X = 1200*Cos90 + 2000*Cos0 + 500*Cos225 = 0 + 2000 - 354 = 1646 m. Y = 1200*sin90 + 2000*sin0 + 500*sin225 = 1200 + 0 - 354 = 846 m. Tan A = Y/X = 846/1646 = 0.51397. A = D = X/Cos A.

*August 16, 2015*

**physics**

a. F = 160N/m * 0.15m = 22.5 N. b. a = F/m = 22.5/0.40 = 56.25 m/s^2.

*August 16, 2015*

**physics**

Vo = 180000,/3600s. = 50 m/s. a. V = Vo + a*t = 0. t =-Vo/a = -50/-0.4 = 125 s. b. D = Vo*t + 0.5a*t^2. D = 50*125 - 0.2*2500 = 3125 m.

*August 16, 2015*

**science**

M1*V1 + M2*V2 = M1*V + M2*V. 6.4*9.9 + 2.1*0 = 6.4V + 2.1V. Solve for V.

*August 16, 2015*

**science**

p1 = M*V = 3.4 * 9.9 = 33.7. = Momentum. p2 = 3.4 * (-4.5) = -15.3. p2-p1 = -15.3 - 33.7 = -49. Magnitude = 49. The negative sign means the momentum decreased.

*August 16, 2015*

**math**

A. d = 6t + 5t = 11 km. 11t = 11. t = 1 hr. = Time they meet. d1 = 6km/h * 1h = 6km. = Distance Rodney traveled when they met. d2 = 5km/h * 1h = 5km = Distance Ca0uls traveled. B. 6(t-1/12) + 5t = 11 km. 6t-0.5 + 5t = 11. 11t = 11.5. t = 1.045 h.

*August 15, 2015*

**AP Physics**

a. Dp + Df = 345 m. 27*(T-0.36) + 5.9T = 345. 27T-9.72 + 5.9T = 345. 32.9T = 354.72. T = 10.78 s. = Time they meet. V = Vo + a*T = 0. a = -Vo/T = -27/10.78 = -2.50 m/s^2. = Min. rate.

*August 15, 2015*

**physics**

a. V1 = Vo + a*t=12.5 + 0.450*7=15.7m/s. d1 = 12.5*7 + 0.225*7^2 = 98.5 m. b. d2 = V1*T2 = 300-98.5 = 201.5 15.7*T2 = 201.5 T2 = 12.8 s. T1+T2 = 7 + 12.8 = 19.8 s. To travel 300 m with acceleration. d = Vo*T3 = 300 m. 12.5*T3 = 300. T3 = 24 s. To travel 300 m without ...

*August 15, 2015*

**Physics**

M*g = 96.3 * 9.8=943.7 N.=Wt. of player. = Normal force(Fn). a. Fk = u*Fn = 0.619 * 943.7 = 584.2 N. b. a = u*g = 0.619 * (-9.8)=-6.07 m/s^2. V = Vo + a*t = 0. Vo = -a*t = -(-6.07)*1.0 = 6.07 m/s.

*August 15, 2015*

**Algebra 1**

The ans. is B.

*August 14, 2015*

**Algebra 1**

Y = (x+3)(x-2) = 0. x+3 = 0. x = -3. x-2 = 0. x = 2. So the ans. is a.

*August 14, 2015*

**Algebra 1**

Y = a(x-h)^2 + k = -1. a(0-4)^2 - 5 = -1 16a - 5 = -1. 16a = 4. a = 0.25. Y = 0.25(x-4)^2 - 5.

*August 14, 2015*

**physics**

R = 4m[90o] + 15m[0o] + 18m[-37o]. X = 4*Cos90 + 15*Cos0 + 18*Cos(-37o) = 0 + 15 + 14.4 = 29.4 m. Y = 4*sin90 + 15*sin0 + 18*sin(-37) = 4 + 0 -10.8 = -6.8 m. a. sqrt(X^2+Y^2)=sqrt(29.4^2+(-6.8)^2) = 30.2 m. = Magnitude. b. Tan A = Y/X = -6.8/29.4 = -0.23129. A = -13.3o = 13.3o...

*August 14, 2015*

**physics**

M*g = 14.4 * 9.8 = 141.1 N.=Wt. of sled. Fn = 141.1 - 66.9*sin32 = 105.7 N. = Normal force. Fap*Cos A-Fk = M*a. 66.9*Cos32-Fk = M*0 = 0. Fk = 56.7 N. = Force of kinetic friction. u = Fk/Fn.

*August 14, 2015*