Wednesday

April 23, 2014

April 23, 2014

Total # Posts: 8,529

**PHYSICS**

Wt. of stone = m*g Fp = mg*sin30=Force parallel to incline. Fn = mg*cos30 = Normal force = Force perpendicular to incline. Fs = u*Fn = Force of static friction. Fp-Fs = m*a = m*o = 0 Fp = Fs mg*sin30 = u*mg*cos30 Divide both sides by mg: sin30 = u*cos30 u = sin30/cos30 = 0.577...

**PHYSICS**

Wt. of block=m*g = 126kg * 9.8N/kg=1235N = Fn = Normal force. Fk = u*Fn = 0.7 * 1235 = 864.5 N.= Force of kinetic friction. Fap-Fk = m*a = m*0 = 0 Fap = Fk = 864.5 N = Force applied.

**Physics**

a. Wt.of box=m*g=7.8kg * 9.8N/kg=76.44 N =Fn=Normal force or force perpendicular to the floor. Fs = u*Fn = u*76.44 N.=Force of static friction. Fap-Fs = m*a 48 - u*76.44 = m*0 = 0 u*76.44 = 48 u=0.628 = Coefficient of static friction b. A. No, it is a ratio. u = Fs/Fn c. Fap-F...

**physics**

h = Yo*t + 0.5g*t^2 = 34.3 39.2t - 4.9t^2 = 34.3 -4.9t^2 + 39.2t - 34.3 = 0 t = 1 s. (Used Quad. Formula).

**Physics**

V = Vo + a*t = 27.8 0 + a*3.4 = 27.8 a = 8.18 m/s^2. V = Vo + a*t = 0 + 8.18*5.1 = 41.70 m/s.

**Physics**

Range = Vo^2*sin(2A)/g 200^2*sin(160)/9.8 = 1396 m.

**Physics**

See Related Questions: Wed,2-19-14,9:27 PM.

**physics**

Range = Vo^2*sin(2A)/g = 301.5 m. Vo^2*sin(50)/g = 301.5 .07817Vo = 301.5 Vo^2 = 3857 Vo = 62.10 m/s.

**physics**

To calculate the required force, we'll need to know the force of friction or the coefficient of frictional force.

**physics**

A. F = Fp = 71.5*sin24.1 = 29.20 N. B. Fn = 71.5*cos24.1 = 65.27 N. = Normal force = Force perpendicular to the plane Fs = u*Fn = 0.26 * 65.27 = 16.97 N = Force of static friction. F-Fp-Fs = m*a = m*0 = 0 F-29.20-16.97 = 0 F = 46.17 N. C. Fk = u*Fn = 0.13 * 65.27 = 8.49 N. = F...

**physics**

Fp=mg*sin16.6 = 509.6*sin16.6=145.6 N. = Force parallel to the ramp. Fn = 509.6*cos16.6 = 488.4 N. = Normal force = Force perpendicular to the ramp. d = Vo*t + 0.5a*t^2 = 3.98 m. 0 + 0.5a*4.1^2 = 3.98 8.405a = 3.98 a = 0.474 m/s^2. Fp-Fk = m*a 145.6 - Fk = 52*0.474 -Fk = 24.62...

**Physics**

Vo=20mi/h * 5280Ft/mi*1h/3600s=29.33Ft/s a = (V^2-Vo^2)/2d a = (0-29.33^2)/40 = -21.51 Ft/s^2. V = Vo + a*t = 0 29.33 - 21.51*t = 0 21.51t = 29.33 t = 1.36 s. To stop.

**Physics**

1.Fs = mg*sin A = 583.1*sin1o=10.18 N. 2. Fn = mg*cos1o = 583.1*cos1o=583.0 N.

**Physics**

1. a=(V-Vo)/t = (25.7-0)/0.54=47.6 m/s^2 2. F = m*a = 900.7 * 47.6 = 42,867 N.

**physics**

See previous post: Thu,2-20-14,5:05 PM.

**Physics**

Incomplete.

**Physics**

a. Fe = 710N.[11o] = Exerted force. Xe = 710*cos11 = 697.0 N. = Hor. component of exerted force. a = Xe/m = 697/89.1 = 7.82 m/s^2. b. V = Vo + a*t = 0 + 7.82*0.7=5.48 m/s. NOTE: I used 11o for the given angle, because 110o is not possible.

**physics**

c. a = (95-75-12)/21 = 0.381 m/s^2. d. a = (95-75-20)/21 = 0/21 = 0.

**Math**

6/15 = 30/Y Solve for Y.

**physics**

Wt. of block = 71.5 N. Fp = 71.5*sin24.1 = 29.20 N. = Force parallel to the plane. Fn = 71.5*cos24.1 = 65.27 N. = Normal force = Force perpendicular to the plane. Fs = u*Fn = 0.26 * 65.27 = 16.97 N. = Force of static friction. F-Fp-Fs = m*a = m*0 = 0 F-29.20-16.97 = 0 F = 46.1...

**Finance**

P = Po(1+r)^n = $1,000,000 Po = $420,000 r=Monthly % rate expressed as a decimal. n = 12comp/yr * 23yrs = 276 Compounding periods. P = 420,000(1+r)^276 = 1,000,000 (1+r)^276 = 1,000,000/420,000 = 2.38095 276*Log(1+r) = Log 2.38095 Log(1+r) = Log 2.38095/276 = 0.00136504 1+r = ...

**physics**

Speed = 80km/h = 80000m/3600s = 22.22m/s a = (V-Vo)/t = (22.22-0)/16 = 1.4 m/s^2.

**math**

Hyp. = 200 yds. X = 200*cos43.2 = 145.8 yds. Y = 200*sin43.2 = 136.9 yds. Total = 200 + 145.8 + 136.9 = 482.7 yds.

**Physics**

A. 0.250kW * 10h/day * 365days/yr. = 912.5 kWh./yr Cost = 912.5kWh/yr * $0.15/kWh=$137/yr. B. (0.100/0.250) * 912.5kWh/yr=365kWh/yr Cost = 365kWh/yr * $0.15/kWh = $55/yr Savings = 137 - 55 = $82/yr $100/$82 = 1.22 Years.

**Physics**

Wb = m*g = 21kg * 9.8N/kg = 205.8 N. = Wt. of the block. Fp = 205.8*sin33 = 112.1 N. = Force parallel to the incline. Fe-Fp = m*a = m*0 = 0 Fe - 112.1 = 0 Fe = 112.1 N. = Force exerted.

**Physics**

Y^2 = Yo^2 + 2g*h = o Yo^2 - 19.6*(150-50) = 0 Yo^2 = 1960 Yo = 44.27 m/s. = Ver. component of the initial velocity. Vo = Yo/sin A = 44.27/sin30 = 88.54 m/s. = Initial velocity. Xo = Vo*cos A = 88.54*cos30 = 76.68 m/s. = Hor. component of initial velocity. Y = Yo + g*Tr = 0 @ ...

**Physics**

The procedure is the same as your 8:56 PM. post.

**Physics**

Vo = 150m/s[85o] 1. Xo = 150*cos85 = 13.07 m/s. 2. Yo = 150*sin85 = 149.4 m/s. 3. X = Xo 4. Y = 0 5. a = g = 9.8 m/s^2. 6. h = ho + (Y^2-Yo^2)/2g h = 20 + (0-149.4^2)/-19.6 = 1159 m. Above the plain. 7. Y = Yo + g*t = 0 @ peak. 149.4 -9.8t = 0 9.8t = 149.4 Tr = 15.2 s. = Rise ...

**Physics**

Tf = 5.7/2 = 2.85 s. = Fall time. h = Yo*t + 0.5g*Tf^2 h = 0 + 4.9*2.85^2 = 39.8 m.

**algebra**

Correction: Y = (2/3)x - 1.

**algebra**

2x - 3y = 3 -3y = -2x + 3 Y = (-2/3)x - 1. Slope-intercept form. I don't know which form you want.

**physic**

Incomplete.

**physic**

d = 40km[315o]+2.8km[30o]+5.2km[112o] X = 28.28 + 2.425 - 1.948 = 28.76 km. Y = -28.28 + 1.4 + 4.821 = -22.06 km. d = sqrt(28.76^2+(-22.06)^2) = 36.2 km. NOTE: To find X, multiply by the cosine; to find Y, multiply by the sine.

**physic**

Speed=1450mi/h = 1450mi/3600s=0.403mi/s.

**math**

First Day: X-pencils sold. 2X-notebooks sold. Second Day: 2X-pencils sold. 3X-notebooks sold. First Day: X + 2X = 18 Pencils X = 6 Pencils. 2x + 3x = 30 Notebooks X = 6 Notebooks First Day: X = 6 Pencils sold. 2x = 2*6 = 12 Notebooks sold. Second Day: 2x = 2*6 = 12 Pencils sol...

**Math**

4. P = Po*r*t/(1-(1+r)^-t)) Po = $700 r = (15%/12)/100% = 0.0125 = Monthly % rate expressed as a decimal. t = 12 Months. Plug the above values into the given Eq and get: P = 758.17 Monthly payment = P/12 5. Po = 0.80 * 128,000 = t = 30yrs * 12mo/yr = 360 mo. Answer: P = $283,4...

**Math**

4. P = Po*r*t/(1-(1+r)^-t)) Po = $700 r = (15%/12)/100% = 0.0125 = Monthly % rate expressed as a decimal. t = 12 Months. Plug the above values into the given Eq and get: P = 758.17 Monthly payment = P/12 5. Po = 0.80 * 128,000 = t = 30yrs * 12mo/yr = 360 mo. Answer: P = $283,4...

**Physics**

F = F1 + F2 = -9.5 + 19.5[10o] F = -9.5 + 19.5*cos10 + (19.5*sin10) F = -9.5 + 19.20 + 3.39i F = 9.7 + 3.39i a = X/m = 9.7/21 = 0.462 m/s^2.

**Physics**

a. Tan A = Y/X = -100/38 = -2.63158 A = -69.2o = 69.2o S of E=20.8o E of S. The bird must head 20.8o W of S. b. d = V*t = 600 km 100t = 600 t = 6 h.

**Physics**

A. F = F1 + F2 = 81N[80o] + 90N[22o] F=(81*cos80+90*cos22)+(81*sin80+90*sin 22)i = 97.51 + 113.5i F = sqrt(97.51^+113.5^2) = 149.6 N. B. Tan A = Y/X = 113.5/97.51 = 1.16398 A = 49.3o = Direction.

**physics**

V^2 = Vo^2 + 2a*d a = (V*2-Vo^2)/2d a = (0.59^2-0)/0.86 = 0.405 m/s^2. Fn = m*a = 72 * 0.405 = 29.1 N.

**physics**

Y^2 = Yo^2 + 2g*h = 0 Yo^2 - 19.6*0.291 = 0 Yo^2 = 5.70 Yo = 2.39 m/s = Ver. component of initial velocity. Vo = Yo/sin A = 2.39/sin3.42 = 40.0 m/s. [3.42o]

**Physics**

Dx = Xo * Tf = 0.315 m. 0.582 * Tf = 0.315 Tf = 0.541 s. = Fall time or time in air Y = Yo + g*t = 0 + 9.8*0.541 = 5.30 m/s. = Ver. component of final velocity.

**Physics**

d = Vo*t + 0.5g*t^2 = 5.15 m. 0 + 4.9t^2 = 5.15 t^2 = 1.05 Tf = 1.025 s. = Fall time. Dx = Xo * Tf = 11.9 m. Xo * 1.025 = 11.9 Xo = 11.6 m/s = Required speed.

**physics**

Vo = 35.2 Ft/s * 1m/3.3Ft = 10.7 m/s.

**physics**

Y^2 = Yo^2 + 2g*h = 0 Yo^2 - 64*11.7 = 0 Yo^2 = 748.8 Yo = 27.4 Ft/s = Ver. component of the initial velocity. Vo = Yo/sinA = 27.4/sin51 = 35.2 Ft/s = Initial velocity = Speed at which the animal must leave gnd.

**Physics**

1a. 2.5m[30o] X = 2.5*cos30 = 2.17 m. Y = 2.5*sin30 = 1.25 m. P1(2.17,1.25). 3.8m[120o] X = 3.8*cos120 = -1.9 m. Y = 3.8*sin120 = 3.29 m. P2(-1.9,3.29). 1b. (2.17,1.25), (-1.9,3.29) d^2=(-1.9-2.17)^2 + (3.29-1.25)^2= 20.73 d = 4.55 m. 2. A + B = -14 29i + B = -14 B = -14 -29i ...

**physics**

Fr = ((Vs+Vr)/(Vs-Vc))*Fc = 392 Hz. ((770+0)/(770-Vc))*349 = 392 ((770)/(770-Vc))*349 = 392 268,730/(770-Vc) = 392 301,840 - 392Vc = 268,730 -392Vc = -33,110 Vc = 84.5 mi/h = Velocity of the car. Vs = Speed of sound in air. Vr = Velocity of the receiver(hearer) of the sound.

**Physics**

L = V/F = 2*0.70 = 1.40 m. V/470 = 1.40 V = 1.40 * 470 = 658 m/s.

**Math**

The solution should satisfy both Eqs.

**Math**

Y = 15*sin(90-62) = 7.04 mi. X = 7 + 15*cos(90-62) = 20.2 mi. d = sqrt(20.2^2+7.04^2) = 21.4 mi.

**Math**

Tan13.25 = h/(X+156.25) h = (X+156.25)*Tan13.25 h = 0.23547x + 36.79 Tan18.17 = h/X h = 0.32820x h = 0.23547x + 36.79 = 0.32820x 0.23547x - 0.32820x = -36.79 -0.09273x = -36.79 X = 396.7 Ft. Tan18.17 = h/396.7 h = 396.7*Tan18.17 = 130.2 Ft = Ht. 0f tower.

**physics**

1. V = Vo + g*t = 0 @ max ht. 10 - 10t = 0 Tr = 1 s. = Rise time or time to reach max. Ht. Tf = Tr = 1 s. = Time to fall back to top of bldg. d = Vo*t + 0.5g*t^2 d = 10*(3-2) + 5*(3-2)^2 = 15 m. Below top of blgd. 2. Tr + Tf = 4 s. Tr = Tf = 2 s. V = Vo + g*Tr = 0 @ max ht. Vo...

**physical science**

Wt. = 80kg * 1.625N/kg = 130.7 N. g on moon = 1.625 m/s^2.

**Math**

X = 6y + 4 In Eq2, replace x with 6y+4 3(6y+4)-18y = 4 18y + 12 - 18y = 4 12 = 4. NO solution!

**Math**

The point of intersection or solution should satisfy both Eqs.

**Math**

15Coupons * 5Candy bars/coupon=75 candy bars. Average = Sum/8 16/4 = 20/x. Solve for X.

**science**

In the above procedure, m*a means mass* acceleration. MA = 20/1.2 = 16.67=Mechanical advantage MA = Fo/Fin = 16.67 Fo/300 = 16.67 Fo = 16.67 * 300 = 5,000 N. = Output. m*g = 5000 m * 9.8 = 5000 m = 510.2 kg. = Combined mass.

**science**

sin A = 1.2m/20m = 0.06 A = 3.44o Fap-Fp = m*a = m*0 = 0 300 - Fp = 0 Fp = 300 N = Force parallel to the ramp. Fp = mg*sin A = 300 N. m * 9.8*sin3.44 = 300 0.588m = 300 m = 510.2 kg. = Combined mass.

**Physics**

calculate the work required to launch a satellite from the surface of the earth (radius6380km) to orbit 6000 km above the surface

**Foundations Math 12**

P = Po(1+r)n r = (5.2%/4)/100% = 0.013 = Quarterly % rate expressed as a decimal. n = 4comp/yr * 4yrs = 16 Compounding periods. P = 30,000(1.013)^16 = $36,886.92 ((36886.92-30000)/30000) * 100% = 23% Return rate.

**Foundations Math 12**

Glad I could help!

**Foundations Math 12**

P = Po*(1+r)^n r = (5.3%/12)/100% = 0.004417 = Monthly % rate expressed as a decimal. n = 12Comp/yr * T yrs = 12t Compounding periods. P = 150,000(1.004417)^12t = 200.000 (1.004417)^12t = 200,000/150,000=1.33333 12t*Log(1.004417) = Log1.33333 12t*1.914*10^-3 = 124.9377*10^-3 1...

**Foundations Math 12**

P = Po(1+r)^n Use same procedure as your 2-16-14, 4:08 AM post. Po = $46,000 P = $100,000

**Physics**

h = Vo*t + 0.5g*t^2 h = 0 + 4.9 * 2.4^2 = 28.22 m. = Ht. or elevation of gun above gnd.

**physics**

Y^2 = Yo^2 + 2g*h = 0 Yo^2 = -2g*h = 19.6*3.5 = 68.6 Yo = 8.28 m/s=Ver. component of initial velocity. Vo = Yo/sin A = 8.28/sin27 = 18.24 m/s. = Initial velocity.

**physic 1**

Wc = m*g = 1700kg * 9.8N/kg = 16,660 N. = Wt. of car. a. Fn=16,660*cos15 = 16.1 N.=Normal force. b. Fp = 16660*sin15 = 4312 N. = Force parallel to the road. Fp-Fs = 0 4312-Fs = 0 Fs = 4312 N. = Force of static friction.

**physics**

Vo = 5 + i7.35 = 8.89m/s[55.8o] Dx = Vo^2*sin(2A)/g Dx = 8.89^2*sin(111.6)/9.8 = 7.5 m.

**physics**

P = 1/7 s. F = 1/P = 7 cycles/s = 7 Hz.

**Physics**

65 * T1 = 126 T1 = 1.9385 h. 70.6 * T2 = 126 T2 = 126/70.6 = 1.7847 h. T1-T2=1.9385-1.7847 = 0.1538h=9.23 min.

**Math**

P = 35,000 + 0.03*17*35,000 = $52,850

**Physics**

False. Any wire carrying current has an electric field around it.

**Algebra**

See related Questions: Tue,2-11-14,6:23 PM.

**algebra**

Dana's speed = r mi/h Chuck's speed = (r+5) mi/h r*t = 132 mi. t = 132/r = Dana's time. (r+%)*t = 152 t = 152/(r+5) = Chuck's time. Dana's time = Chuck's time: 132/r = 152/(r+5). Solve for r.

**physics**

1c. Not true. 4. 90km/h = 90000m/3600s = 25 m/s. 5. 100N[170o] + 100N[50o] X = 100*cos170 + 100*cos50 = -34.2 N. Y = 100*sin170 + 100*sin50 = 93.97 N. Tan Ar = Y/X = 93.97/-34.2 = -2.74764 Ar = -70o = Reference angle. A = -70 + 180 = 110o Fr = Y/sin110 = 93.97/sin110 = 100[110...

**Physics**

Wm = m*g = 30kg * 9.8N/kg = 294 N. = Wt. of the mass. Fp = 294*sin35 = 168.6 N. = Force parallel to the incline. Fn = 294*cos35 = 240.8 N. = Normal force or force perpendicular to the incline. Fs = u*Fn = 0.22 * 240.8 = 52.98 N. = Force of static friction. Fap-Fp-Fs = 0 Fap = ...

**Algebra**

Job A: X hours/wk. Job B: Y hours/wk. 10x + 7.5y => $300 job B:

**Algebra**

a. C = 8x + 75. b. C = 8x + 75 = 18,955 8x = 18,955 - 75 = 18,880 X = 2360. c.

**physics**

d = (Vs-Vw)t = 6000 m. (10-Vw)1080s = 6000 10800-1080Vw = 6000 1080Vw = 10,800-6000 = 4800 Vw = 4.444 m/s.

**physic**

Fn = 3580 - 660 - 1470 = 1450 N. = Net force. a = Fn/m = 1450 / 4110 = 0.362 m/s^2.

**Physics**

a = sqrt(750^2+850^2) = 1134 m/s^2. F = m*a = 0.39 * 1134 = 442.1 N.

**physic**

Incomplete.

**physics**

See previous post.

**physics**

1. V^2 = Vo^2 + 2g*h h = (V^2-Vo)/2g = (0-6^2)/-19.6=1.84 m. 2. Zero. 3. Calculated in #1.

**physics**

V = 25km/h = 25000m/3600s = 6.94 m/s. KE = 0.5m*V^2 = 10^4 J. 0.5m*6.94^2 = 10000 24.08m = 10000 m = 415.3 kg.

**Math**

P = Po(1+r)^n. r = (5.6%/4) / 100% = 0.014 = Quarterly % rate expressed as a decimal. n = 4comp/yr. * 4yrs = 16 Compounding periods. Plug the above values into the given Eq and solve for P.

**physics**

h = Vo*t + 0.5g*t^2 = 1.75 m 0 + 4.9*t^2 = 1.75 Solve for t.

**Physics**

To get help, You will have to explain how the resistors are connected and identify Vx.

**Physics**

a. Fp = 518*sin25 = 218.9 N. = Force parallel to the incline. m*g = 518 N. m = 518/g = 518/9.8 = 52.86 kg. a = F/m = 218.9/52.86 = 4.14 m/s^2. b. V = Vo + a*t = 0 + 4.14*6=24.85 m/s.

**physics**

Correction: a = (0.75^2-0)/3.2 = 0.1758 m/s^2. b. Fp-Fk = m*a 10.77-Fk = 2.6*0.1758 = 0.4570 Fk = 10.77 - 0.4570 = 10.31 N u = Fk/Fn = 10.31/23.09 = 0.4466

**physics**

a. Wb = M*g = 2.6kg * 9.8N/kg=25.48 N. = Weight of block. Fp = 25.48*sin25 = 10.77 N. = Force parallel to the inclined plane. Fn = 25.48*cos25 = 23.09 N. = Normal Force = Force perpendicular to the incline. a=V^2-Vo^2)/2d a = (0.75^2-0)/2.6 = 0.2163 m/s^2. b. Fp-Fk = m*a 10.77...

**Physics**

F = mg*sin30 = 180 * sin30 = 90 N.

**Physics**

Use same procedure as previous problem.

**physics**

F1+F2+F3+F4+F5+F6 = 0 i57+40-i77-40+50*cos60+i50*sin60+F6=0 The student can finish this problem by using the same procedure as the previous problem.

**Physics**

F1 + F2 + F3 = 0 33N[215o] + 45N[315] + F3 = 0 33*cos215+i33*sin215+45*cos315+i45*sin315+F3 = 0 23.33 - i18.93 + 31.82 - i31.82 + F3=0 55.15 - i50.75 + F3 = 0 F3=-55.15 + i50.75=sqr(-55.15^2+50.75^2)= 74.95 N. = The equilibrant. Tan Ar = Y/X = 50.75/-55.15=-0.92022 Ar = -42.62...

**math**

(8,-5), (-6,2) m = (2-(-5))/(-6-8) = 7/-14 = -1/2. Y = mx + b = -5 (-1/2)*8 + b = -5 b = -5 + 4 = -1 Y = (-1/2)x -1 Y = -x/2 - 1 Multiply both sides by 2: 2y = -x - 2 X + 2Y = -2

**Physics**

1. V=62mi/h*1600m/mi*1h/3600s=27.56m/s a = (V-0)/t = (27.56-0)/2.5 = 11.02m/s^2 2. V=90mi/h * 1600m/mi * 1h/3600s=40m/s a = (V-0)/t = 11.02 m/s^2. Solve for t. 3. V = (180/90) * 40m/s = 80 m/s. a = (V-0)/t = 11,02 m/s^2. Solve for t. 4. Yes, with constant acceleration.

**algebra**

I = (240/540) * 12

**physical science**

a. Fap-Ff = m*a = m*0 Fap - Ff = 0 The velocity is constant. Therefore, the acceleration is zero. Fap = Force applied. Ff = Force of friction. b. Fap - Ff = 0 100 - Ff = 0 Ff = 100 N.

**Algebra**

Pitch = (Y/X) * 100% = (13/13.8) * 100%

Pages: <<Prev | 1 | 2 | 3 | **4** | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>