Sunday

January 22, 2017
Total # Posts: 13,047

**Physics**

h = Vo*t + 0.5g*t^2 = 20-5. Vo*3 - 4.9*3^2 = 15. 3Vo = 15 + 44.1 = 59.1. Vo = 19.7 m/s. = Initial velocity. V = Vo + g*t. Vo = 19.7 m/s. g = -9.8 m/s. t = 3 s. V = ? Note: V will be negative which means that the bullet has passed it's peak and moving downward.

*September 8, 2015*

**physics**

Xo = Vo*Cos A = 120*Cos33 =

*September 8, 2015*

**Physics**

See Related Questions: Wed, 9-2 09, 11:44 PM.

*September 8, 2015*

**science**

a. h = ho - (Vo*t + 0.5g*t^2) h = 40 - (-5*0.25 + 4.9*0.25^3) = 40.9 m V = Vo + g*t = -5 + 9.8*0.25=-2.55 m/s. b. h = 40 - (-5*1 + 4.9*1^2) = 40.1 m. V = -5 + 9.8*1 = 4.8 m/s.

*September 8, 2015*

**physics**

Vb = 4mi/h * 1609m/mi * 1h/3600s = 1.79 m/s. Vw = a*t = 0.30 * 2.7 = 0.81 m/s. Vr. = sqrt(Vb^2+Vw^2) = 1.96 m/s. = Resultant velocity. D = Vr*t = 1.96*2.7 = 5.29 m. Tan A = Y/X = Vw/Vb = 0.81/1.79=0.45251 A = 24.3o = Direction.

*September 8, 2015*

**math**

17 + 15/3 - 2^4 = 17 + 5 - 16 = 6.

*September 7, 2015*

**algebra**

100% - 60% = 40% Did not shop for clothes. 0.40P = 2500. P = 6,250 People at the mall. 6250-2500 = 3,750 People shopped for clothes. Yes!!

*September 7, 2015*

**physics 201**

d = 0.5a*t^2 = 10 m. 0.5a*3.9^2 = 10. 0.5a = 0.657. a = 1.31 m/s^2. L = 0.5*a*t^2. a = 1.31 m/s^2. t = 3.9 + 1 = 4.9 s. L = ?

*September 7, 2015*

**physics**

Range = Vo^2*sin(2A)/g = 4 m. Vo^2*sin(90)/9.8 = 4. 0.102Vo^2 = 4. Vo^2 = 39.2. Vo = 6.3 m/s. * 1mi/1600m * 3600s/h = 14.1 mi/h.

*September 6, 2015*

**Physics**

Incomplete.

*September 6, 2015*

**physcial science**

V = Vo + g*t. Vo = 0. g = 9.8 m/s^2. t = 3.4 s. V = ?

*September 6, 2015*

**science**

Incomplete.

*September 6, 2015*

**Physics**

X = 55.9 m/s. Y = 26.6 m/s. a. Speed = sqrt(X^2+Y^2). b. Tan A = Y/X = 26.6/55.9 = 0.47585. A = 25.4o S. of E. = 64.6o With vertical

*September 6, 2015*

**Physics**

D = 736.4[130o] + 134[199o] + 157[195o]. X=736.4*Cos130 + 134*Cos199 + 157*Cos195 = -473.3 - 126.7 - 151.7 = -751.7 Paces. Y=736.4*sin130 + 134*sin199 + 157*sin195 =564.1 - 43.63 - 40.63=479.8 Paces. Q2. a. Magnitude=sqrt(X^2+Y^2) = 892 Paces. b. Tan A = Y/X = 479.8/-751.7=-0....

*September 6, 2015*

**physics**

Vo = 95000m/3600s = 26.4 m/s. V = 85000m/3600s = 23.6 m/s. Vo*t + 0.5a*t^2 = V*t + 55. 26.4*18 + 0.5a*18^2 = 23.6*18 + 55 a = ?

*September 5, 2015*

**Physics**

Vp = 85,000m/3600s = 23.61 m/s. Vs = 130,000/3600 = 36.11 m/s. Ds = 36.11m/s * 3s = 108.3 m. Head start Vo*t + 0.5a*t^2 = Vs*t + 108.3 23.61t + 0.5*2.30*t^2 = 36.11t + 108.3. -12.5t + 1.15t^2 = 108.3. 1.15t^2 - 12.5t - 108.3 = 0. Use Quadratic Formula. t = 16.6 s.

*September 5, 2015*

**Physics**

20t + 20t = 18 m. t = 18/40 = 0.45h = 1620 s.

*September 5, 2015*

**PHYSICS**

h = 0.5g*t^2 h = 6 Ft. g = 32Ft/s^2. t = ?.

*September 5, 2015*

**physics**

Note: Since the current is 10 times the previous current, the resistance is 1/10 of the previous resistance: 990/10.

*September 5, 2015*

**physics**

990*R/(990+R) = 990/10. 990*R/(990+R) = 99. 990*R = (990+R)99. 10R = 990+R. 9R = 990. R = 110 Ohms.

*September 5, 2015*

**Physics**

See previous post: Sat, 9-5-15, 12:29 AM

*September 5, 2015*

**Physics**

D=65m[90o] + 200[0o] + 110[30o] + 150[270]. X = 200 + 110*Cos30 = 295.3 m. Y = 65 + 110*sin30 - 150 = -30 m., Q4. Tan A = Y/X = -30/295.3 = -0.10159. A = -5.80o = 5.8o S. of E. = Direction. D = X/Cos A = 295.3/Cos5.8 = 297 m.

*September 5, 2015*

**physics**

3600s/h * 24h/d * 365d/y = 31,536000 s/yr Accuracy = (8/31,536,000) * 100% = 2.54*10^-5.

*September 4, 2015*

**Physics**

a. V^2=Vo^2 + 2a*h=(46.4)^2 - 4.36*138 = 1551.28. V = 39.4 m/s. at shut-off. h max = 138m + -(Vo^2)/2g = 138 + (39.4^2)/19.6 = 217 m. Above gnd. b. V = Vo + a*T1 = 39.4 m/s. 46.4 - 2.18T1 = 39.4. -2.18T1 = - 7. T1 = 3.21 s. h = Vo*T2 + 0.5g*T2^2 = 217-138. 39.4T2 - 4.9T2^2 = ...

*September 4, 2015*

**Physics**

a. Range = Vo^2*sin(2A)/g = 400 Ft. Vo^2*sin(60)/32 = 400. 0.02706Vo^2 = 400. Vo^2 = 14,782. Vo = 122 Ft./s. b. Yo = Vo*sin A = 122*sin30 = 61 Ft/s. = Ver. component of initial velocity. Y^2 = Yo^2 + 2g*h = 0. h = -(Yo^2)/2g = -(61^2)/-64 = 58.1 Ft. c. Xo = Vo*Cos A=122*Cos30...

*September 4, 2015*

**Physics**

See Related Questions: Mon, 9-29-14, 12:56 AM.

*September 4, 2015*

**Phsyics**

See previous post: Thu, 9-3-15, 7:22 PM.

*September 4, 2015*

**science (physics)**

Fap-Fs = 50-2 = 48 N. = Net force.

*September 4, 2015*

**Physics**

V^2 = Vo^2 + 2g*h = 0. h = -Vo^2/2g = -(14.5^2)/-19.6 = 10.73 m. Above the roof. V = Vo + g*Tr = 0. Tr = -Vo/g = -14.5/-9.8 = 1.48 s. = Rise time. 0.5g*Tf^2 = 62+10.73. 4.9*Tf^2 = 72.73. Tf^2 = 14.8. Tf = 3.85 s. = Fall time. Tr+Tf = 1.48 + 3.85 = 5.33 s. = Time in flight.

*September 4, 2015*

**math**

X = 500km. Y = 200km. Tan A = Y/X = 200/500 = 0.400. A = 21.8o N. of W.= 68.2o W. of N. = The Bearing. D = 500/Cos21.8 = 539 km.

*September 4, 2015*

**calculus**

Vo = 20mi/h * 5280Ft/mi * 1h/3600s. = 29.3 Ft/s. = Initial velocity. V = (50/20) * 29.3 = 73.3 Ft/s. V^2 = Vo^2 + 2a*d. Solve for a, Ft/s^2.

*September 4, 2015*

**Physics**

See previous post: Thu, 9-3-15, 9:53 PM.

*September 3, 2015*

**Physics**

V = Vo + a*t. V = 15.9 m/s. a = 3.21 m/s^2. t = 2.41 s. Solve for Vo.

*September 3, 2015*

**physics**

The heading of wind from southwest is northeast which is 45o N. of E. Vaw = Va + Vw = -734i. Va + 110[45o] = -734i. Va + 110*Cos45 + i110*sin45 = -734i. Va + 77.8 + 77.8i = -734i. Va = -77.8 - 811.8i, Q3. Tan A = -811.8/-77.8. = 10.43445. A = 84.5o S. of W. = 5.5o W. of S. = ...

*September 3, 2015*

**Physics**

10.5 km = 10,500 m. V1*t + V2*t = 10,500. 9.5t + 10.4t = 10,500. 19.9t = 10,500. t = 528 s.

*September 3, 2015*

**physics**

Dc = 100km + Dt. Vc*t = 100 + Vt*t. 120*t = 100 + 80*t. 40t = 100. t = 2.5 h. To catchup. Dc = V*t = 120 * 2.5 = 300 km To catchup.

*September 3, 2015*

**physics**

KE = 0.5*M*V^2 = 12,000 J. 0.5*60*V^2 = 12000. V = 20 m/s. Speed = 0.020km/s * 3600s/h = 72 km/h.

*September 3, 2015*

**physics**

540/600 * 110 = 99 Hz. Fb = 110 - 99 = 11 Hz. = Beat Freq.

*September 3, 2015*

**physics**

B = 10*Log(1) = 10 * 0 = 0.

*September 3, 2015*

**physics**

5 = 10*Log(y/100) Log(y/100) = 0.5 y/100 = 10^0.5 = 3.16. Multiply both sides by 100: Y = 316.

*September 2, 2015*

**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*