Monday

February 8, 2016
Total # Posts: 11,482

**science**

a = (V-Vo)/t = Acceleration in Ft./s^2 V = 20 Ft/s. Vo = 5 Ft/s.
*February 17, 2015*

**physics**

V = sgrt(X^2+Y^2)
*February 17, 2015*

**physics**

V = 5m/s[30o] Vy = 5*sin30 = 2.5 m/s
*February 17, 2015*

**Algebra**

Eq1: x + y = -8 Eq2: x - y = 4 Sum: 2x = -4 X = -2 In Eq1, replace x with -2: -2 + y = -8 Y = -6.
*February 16, 2015*

**physics**

M*g = 27 * 9.8 = 264.6 N. = Wt. of the lawnmower. Fn = 264.6 + Fap*sin36=264.6 + 0.588Fap Fk = u*Fn = 0.66*(264.6+0.588Fap) = 174.64 + 0.388Fap (Fx-Fk) = M*a (Fap*Cos36-(174.64+0.388Fap) = M*a (0.81Fap-174.64-0.388Fap = M*0 0.42Fap - 174.64 = 0 0.42Fap = 174.64 Fap = 416 N. = ...
*February 16, 2015*

**Physics**

W = Mg * d = 2.80*9.8 * (35-10) = 686 J.
*February 16, 2015*

**Physics**

a = (V-Vo)/t =(250-0)/12 =
*February 16, 2015*

**Physics**

a. T^2 = 4pi^2(L/g)=4*3.14^2(0.76/9.8) = 3.06 T = 1.75 s.
*February 15, 2015*

**physical science**

a. h = 0.5g*t^2 = 4.9*4^2 = 78.4 m b. h = 0.5g*t^2 h = 103 m. g = 9.8 m/s^2 Solve for t.
*February 15, 2015*

**Physics**

Incomplete.
*February 15, 2015*

**Business math**

Ordinary interest assumes a business year of 360 days. Exact interest uses 365 days per year. a. I = Po*r*T = 4400*(0.1025/360)*135 = $169.125 b. 4400 + 169.125 = $4569.13
*February 15, 2015*

**math**

d = 120km/h * 2.6667h=Distance traveled. L = d/4 = Liters of fuel used. Cost = $59 * L =
*February 15, 2015*

**science**

V^2 = Vo^2 + 2g*h Vo = 0 g = +9.8 m/s^2 h = 50 m. Solve for V.
*February 15, 2015*

**Physics**

M*g = 150 N. Fp = 150*sin20 = Force parallel. Fn=150*Cos20 = Normal or perpendicular.
*February 15, 2015*

**Physics**

Fx = 280*Cos33o Fy = 280*sin33o
*February 15, 2015*

**Physics**

Xo = 8.57 m/s Yo = -2.61 m/s a. X = Xo + a*t = 8.57 + (-0.105)*6.67 = 7.87 m/s Y = Yo + a*t = -2.61 + 0.101*6.67 = -1.94 m/s b. V^2 = X^2 + Y^2 = 7.87^2 + 1.94^2 = 65.7 V = 8.11 m/s.
*February 13, 2015*

**Physics Honors**

Y^2 = Yo^2 + 2g*h = 0 Yo^2 - 19.6*23.2 = 0 Yo^2 = 454.72 Yo = 21.3 m/s = Ver. component of initial velocity. Yo = Vo*sin A = 21.3 m/s 48*sin A = 21.3 sin A = 0.44,425 A = 26.4o = Angle at which golf was hit. Vo = 48m/s[26.4o] Xo = 48*Cos26.4 = 43.0 m/s. V = Xo + Yi = 43 + 0i...
*February 13, 2015*

**science**

B. 0.29/5 = W/115
*February 12, 2015*

**science**

Wt. = (170/10) * 25 =
*February 12, 2015*

**Physics**

a. Energy = 0.5*C*V^2 V doubled: Energy = 0.5*C*(2V)^2 = 0.5*C*4V^2 So the energy is increased by a factor of 4. b. Yes.
*February 12, 2015*

**Physics Dynamics**

M*g = 70 * 9.8 = 686 N. = Wt. of sled. Fn = Mg-F*sin20 =
*February 12, 2015*

**Physics Dynamics**

Range = Vo^2*sin(2A)/g = 38 32^2*sin(2A)/9.8 = 38 104.5*sin(2A) = 38 sin(2A) = 0.36364 2A = 21.3o A = 10.7o
*February 12, 2015*

**Physics Dynamics**

Tan A = 35/80 = 0.4375 A = 23.6o a. Tan23.6 = Vc/2 Vc = 2*Tan23.6 = 0.874 m/s = Velocity of the current. b. Direction = 23.6o to the left.
*February 12, 2015*

**Physics**

Vo = 21m/s[40o] Xo = 31*Cos40 = 16.1 m/s. Range=Vo^2*sin(2A)/g = 21^2*sin(80)/9.8 = 44.3 m. Range = Xo*T = 44.3 m. 16.1T = 44.3 T = 2.75 s. = Time in air.
*February 12, 2015*

**Physics**

V^2 = Vo^2 + 2g*h Vo = 2.18 m/s. g = +9.8 m/s^2 h = 70.8 m. Solve for V.
*February 9, 2015*

**College physics**

d = 239mi * 1600m/mi = 382,400 m. = 382.4 km. Work = F*d = 369 * 382.4 = 141,106 kJ.
*February 9, 2015*

**Physics**

Wt. = M*g Work = Mg * h Therefore, the person with the most wt. will do the most work if both covered the same distance up. If they did not cover the same distance, you will have to calculate the work done by each to make a comparison. Power is the rate of doing wt. P = Mg * h...
*February 9, 2015*

**math**

h = -16x^2 + 64x + 80 = 0 Use Quadratic Formula. X = -1, and 6. Select the positive value: X = 6 s. = Time to reach gnd.
*February 9, 2015*

**maths**

a. KE = 0.5*M*V^2 = 130 J. 0.5*11*V^2 = 130 V^2 = 23.64 V = 4.86 m/s. b. V^2 = Vo^2 + 2g*h = 4.86^2 + 19.6*3 = 82.4 V = 9.1 m/s c. V^2 = Vo^2 + 2g*h = 0 + 19.6*15 = 294 V = 17.15 m/s.
*February 9, 2015*

**engineering science n2**

V = Vo + g*t V = 0 Vo = 20 m/s. g = -9.8 m/s^2 Solve for t.
*February 9, 2015*

**physics**

See previous post: Sun, 2-8-15, 8:14 PM.
*February 8, 2015*

**Physics Dynamics**

M*g = 5 * 9.8 = 49 N. = Wt. of box. Fn = 49 - 45*sin40 = 20.1 N. = Normal force. Fk = u*Fn = 0.2 * 20.1 = 4.01 N. = Force of kinetic friction. a = (Fx-Fk)/m = (45*Cos40-4.01)/5 = 6.1 m/s^2
*February 8, 2015*

**physics**

d = V*t d = 18.4 m V = 44.8 m/s Solve for t.
*February 8, 2015*

**Physics**

Series Connection: When one lamp burns out, all of the lamps go out. So you are in the dark until the lamp is replaced.
*February 8, 2015*

**physics**

7grams * 5.66*10^21atoms/gram * 46e/atom = 1.82252*10^24 Electrons. b. 1.82252*10^24e * 1.6*10^-19C/e = 2.916*10^5 C. = Your answer.
*February 8, 2015*

**physics**

1/f = 1/di + 1/do LCD = di*do 1/f = do/di*do + di/di*do 1/f = (do+di)/di*do Invert both sides: f = di*do/(do+di)
*February 8, 2015*

**physics**

KE = KE1 + KE2 = 0.5*M*V^2 + KE2 = 0.5*0.6*3^2 + 2.5 = 5.2 J. KE = 0.5*0.6*V^2 = 5.2 V^2 = 17.33 V = 4.16 m/s.
*February 8, 2015*

**physics**

a = (V-Vo)/t = (9.3-0)/1.39 = 6.69 rad/s^2
*February 8, 2015*

**science**

P = F * d/s = Mg * d/t = 5000 * 25/50 = 2500 J./s = 2500 W.
*February 8, 2015*

**physics**

a. KE = 0.5*M*V^2 = 0.5*66*4.3^2 = 610.2 J. = Energy lost due to friction. b. M*g = 66 * 9.8 = 646.8 N. = Wt. of runner = Normal(Fn). Fk = u*Fn = 0.6 * 646.8 = 388.1 N. = Force of kinetic friction. KE = Fk*d = 610.2 388.1*d = 610.2 d = 1.57 m.
*February 8, 2015*

**physics**

Vo = 111km/h = 111000m/3600s. = 30.8m/s W = KE = 0.5M*Vo^2 =
*February 7, 2015*

**Physics**

2.76km[0o] + 0.85km[270o] X = 2.76*Coso + 0.85*cos270 = 2.76 N. Y = 2.76*sin0 + 0.85*sin270 = Fr = sqrt(X^2+Y^2)
*February 7, 2015*

**Physics**

24N[60o] + 9N[0o] X = 24*Cos60 + 9*Cos0 = 21 N. Y = 24*sin60 + 9*sin0 = 20.8 N. Fr^2 = 21^2 + 20.9^2 = 873.64 Fr = 29.6 N.
*February 7, 2015*

**Physics**

Pellet A: V = Vo + g*Tr Tr = -Vo/g = -27.3/-9.8 = 2.79 s. = Rise time. Tf1 = Tr = 2.79 s. = Time to Fall back to the edge of the cliff. Tf2 = Fall time from edge of cliff to gnd. Ta = Tr + Tf1 + Tf2 = 2.79 + 2.79 + Tf2 = 5.57 + Tf2. = Time in air, pellet A Pellet B: Tb = Tf = ...
*February 7, 2015*

**Physics**

Vo = 17.6m/s[29o] Xo = 17.6*Cos29 = 15.4 m/s Yo = 17.6*sin29 = 8.53 m/s Y = Yo + g*Tr = 0 Tr = -Yo/g = -8.53/-9.8 = 0.870 s. = Rise time. Range = Dx = Vo^2*sin(2A)/g = 17.6^2*sin(58)/9.8 = 26.8 m. h = Yo*Tr + 0.5g*Tr^2 = 8.53*0.870 - 4.9*0.870^2 = 3.71 m. = Max. ht. Xo*(Tr+Tf...
*February 6, 2015*

**Physics**

Vo = 16.0m/s[51o] Yo = 16*sin51 = 12.43 m/s. = Vertical component of initial velocity. Y = Yo + g*Tr = 0 Tr = -Yo/g = -12.43/-9.81 = 1.27 s. = Rise time. h = Yo*Tr + 0.5g*Tr^2 = 12.43*1.27 - 4.9*1.27^2 = 7.89 m. = Max. ht. h = ho - 0.5g*Tf^2 = 2 m 7.89 - 4.9*Tf^2 = 2 4.9Tf^2...
*February 6, 2015*

**physics**

R = E/I = 2.60/0.665 = 3.91 Ohms = Total resistance. Rl = 3.91 - 0.182-0.139 = 3.589 Ohms = Lamp resistance.
*February 6, 2015*

**physics**

See Related Questions: Thu, 9-12-13, 6:35 PM.
*February 6, 2015*

**physic**

See previous post: Sun, 2-8-15, 7:40 PM.
*February 5, 2015*

**Physics**

P = 0.5M*V^2/t = 0.5*65*12^2/3 = 1560 J/s = 1560 Watts
*February 5, 2015*

**PHYSICS**

a. d = Vo*t = 60 m 26 * t = 60 t = 2.31 s. = Fall time. h = 0.5g*t^2 = 4.9*2.31^2 = 26.1 m. b. h = Same as part a.
*February 5, 2015*

**physic**

A. M1*V1 + M2*V2 = M1*V3 + M2*V4 0.25*0+0.20*2.20=0.25*V3 + 0.20*1.5[37] 0.44 = 0.25V3 + 0.3[37o] 0.44 = 0.25V3 + 0.3*Cos37 + i0.3*sin37 0.44 = 0.25V3 + 0.240 + 0.181i -0.25V3 = 0.240 - 0.44 + 0.181i = -0.25V3 = -0.20 + 0.181i V3 = 0.8 - 0.734i V3 = sqrt(0.8^2+0.734^2) = 1.18 ...
*February 5, 2015*

**physics**

h = 0.5g*t^2 = 100-25 4.9*t^2 = 75 t^2 = 15.31 t = 3.91 s. = Fall time. Dx = Xo*t = 20 m. Xo*3.91 = 20 Xo = 5.11 m/s. = Hor. velocity.
*February 5, 2015*

**physical**

Fr^2 = F1^2+F2^2
*February 5, 2015*

**physics**

See Related Questions: Sun, 10-21-13, 9:10 PM.
*February 4, 2015*

**physics**

V-Vo = 6.24/m/s[-54.3o]-5.45m/s[38.5o] X = 6.24*Cos(-54.3) - 5.45*Cos38.5 = -0.624 m/s Y = 6.24*sin(-54.3) - 5.45*sin38.5 = -8.46 m/s ax = -0.624/4.0 = -0.156 m/s^2 ay = -8.46/4.0 = -2.115 m/s^2
*February 4, 2015*

**physics**

F = m*a = 7000kg * 9.8N/kg = 68,600 N. W = F*d
*February 4, 2015*

**trig**

067degree
*February 4, 2015*

**Math**

Ax + By + C = 0
*February 4, 2015*

**physics**

R = 650 + 350 + 1000 =
*February 4, 2015*

**math**

a. P = 9/(10+9+6) = 9/25. green P = 6/(10+8+6) = 6/24 = 1/4. blue.
*February 4, 2015*

**physics**

a. V^2 = Vo^2 + 2a*d V = 0 Vo = 16 m/s d = 10 m. Solve for a. b. V = Vo + a*t V = 0 Vo = 16 m/s. a = Value calculated in part a. Solve for t.
*February 3, 2015*

**physics**

X = -3.5 + 0 + 5.5 = 2.0 Y = 4.5 -6.5 -2.5 = -4.5 Tan A = Y/X = -4.5/2 = -2.250 A = -66.0 CW = 294o CCW.
*February 3, 2015*

**algebra**

x = -6 x+6 = 0 x = -4 x+4 = 0 Y = (x+6)(x+4) = 0 Y = x^2 + 4x + 6x + 24 = 0 Y = x^2 + 10x + 24 = 0
*February 3, 2015*

**math**

See previous post: Tue, 2-3-15, 7:55 PM.
*February 3, 2015*

**business calc**

30yrs * 12mo/yr. = 360 Mo. P = 450.23/mo. * 360mo. = 162,082.80 Cost = P-Po = 162,082.80 - 52,000 = 110,082.80
*February 3, 2015*

**Math**

Vo = 5*0^2 - 12*0 + 7 = 7 m/s. t = 0. V = 5*2^2 - 12*2 * 7 = 3 m/s. t = 2 s. a = (V-Vo)/t = (3-7)/2 = -2 m/s^2.
*February 3, 2015*

**math**

Circumference = pi*Dia. = 3.14 * 27 = 84.823 in = 7.07 Ft. 1 Mile = 5,280 Ft. 5,280Ft. * 6.28rad/7.07Ft. = 4,690 Rad.
*February 3, 2015*

**math**

h = ho + ho*0.15*10 = 27 in. ho + 1.5ho = 27 2.5ho = 27 ho = 10.8 In. = Initial ht. h = 10.8 + 10.8*0.15*9 = 25.4 Inches yesterday.
*February 3, 2015*

**Math**

Multiply Eq1 by 3 and add: 12x-6y = 21 3x+6y = 9 Sum:15x = 30 X = 2 In Eq2, replace x with 2: 3*2 + 6y = 9 6 + 6y = 9 6y = 9 - 6 = 3 Y = 1/2.
*February 3, 2015*

**Math**

P = X + 1.3X P = 2.3X
*February 3, 2015*

**algebra**

Correct!
*February 3, 2015*

**Math**

The slopes of perpendicular lines are negative reciprocal of each other. a. m1 = (1-4)/(-1-1) = -3/-2 = 3/2 b. m2 = (-1-3)/(-1-3) = -4/-2 = 2 The 2 lines are not perpendicular. Note: If the slope of the 2nd line was -(2/3), the lines would be perpendicular.
*February 3, 2015*

**physics**

T1*sin(90+45) + T2*sin45 = 40. 0.707T1 + 0.707T2 = 40. T1 = T2. Replace T2 with T1: 0.707T1 + 0.707T1 = 40. T1 = 28.3 N. = T2.
*February 3, 2015*

**math**

What are the critical values on the graph of y = x^3 - 6x^2 + 9x + 3?
*February 3, 2015*

**physics**

0.200 kg block: d = 0.5a*t^2 = 0.44 m. 0.5a*2^2 = 0.44 2a = 0.44 a = 0.22 m/s^2. 0.400 kg block: d = 0.5a*t^2 = 0.5 * 0.22*2^2 = 0.44 m
*February 2, 2015*

**Physics**

Jack: V = d/t = 9*25m/160.1s. = Ans. in m/s. Jill: V = d/t = 10*25m/160.1s = Ans. in m/s.
*February 2, 2015*

**physics**

W = F*d = 34.5*10^6 * 393*10^3 = Answer in Joules.
*February 2, 2015*

**Physics**

V = Vo + g*Tr = 0 7.65 - 9.81*Tr = 0 9.81Tr = 7.65 Tr = 0.780 s. = Rise time. h = ho + Vo*Tr + 0.5g*Tr^2 h = 12.7 + 7.65*0.78 - 4.9*0.78^2 = 15.69 m. Above gnd. a. V^2 = Vo^2 + 2g*h = 0 + 19.6*15.69 = 307.4 V = 17.53 m/s b. h = 0.5g*t^2 = 15.69 4.9t^2 = 15.69 t^2 = 3.20 t = 1....
*February 2, 2015*

**Physics**

Vo = 8.50m/s[-23o] Xo = 8.50*Cos(-23) = 7.82 m/s. Yo = 8.50*sin(-23) = -3.32 m/s. = Ver. component of initial velocity.
*February 2, 2015*

**Physics**

P = Es*Is = 150,000 Watts 120*Is = 150,000 Is = 1250 Amps. = Current flowing through secondary coils. Ip = 140/25000 * 1250 = 7 Amps = current through primary coils and transmission lines.
*February 2, 2015*

**Physics**

M1*V1 + M2*V2 = M1*V3 + M2*V4 0.045*134 + 1.5*0 = 0.045*78 + 1.5*V4 Solve for V4.
*February 2, 2015*

**Physics**

Conservation of momentum: Total momentum before the collision = Total momentum after the collision. M1*V1+M2*V2 = M1*V+M2*V = (M1+M2)*V 46*529 + 1000*0 = 1046*V Solve for V.
*February 2, 2015*

**Physics**

a = (V-Vo)/t V = 16.7 m/s Vo = 10.3 m/s. M = F/a
*February 2, 2015*

**physics**

1. Fx = 20*cos30 = 17.32 N. 2. Work = Fx*d = 0 * 10 = 0 3. a. 4. W = Fx*d = 255*Cos60 * 15 = 5.
*February 2, 2015*

**Physical Science**

Scale1 = x Newton. Scale2 = 2x Newton x + 2x = 1200 N. Solve for x.
*February 2, 2015*

**Physics**

See Related Questions: Fri, 1-31-14, 10:23 PM.
*February 2, 2015*

**Physics**

Vo = 31.1m/s[37o] Xo = 31.1*Cos37 = 24.84 m/s. Yo = 31.1*sin37 = 18.72 m/s. Y = Yo + g*Tr = 0 18.72 - 9.8*Tr = 0 9.8Tr = 18.72 Tr = 1.91 s. = Rise time. Y^2 = Yo^2 + 2g*h = 0 h=-Yo^2/2g = -(18.72)^2/-19.6 = 17.88 m = Max. ht. 0.5g*t^2 = 17.88 - 5.50 4.9t^2 = 12.38 t^2 = 2.53 t...
*February 2, 2015*

**Science**

Fs = u*Fn = 0.4 * 20 = 8 N.
*February 2, 2015*

**Physics**

M*g = 150 N. g = 1.63 m/s^2 Solve for M(kg).
*February 2, 2015*

**science**

h = o.5g*t^2 h = 10 m. g = +9.8 m/s^2 Solve for t.
*February 2, 2015*

**physics**

Please disregard my 5:24 PM post.
*February 2, 2015*

**physics**

Tr = 1.5 + 1 = 2.5 s. = Rise time or time to reach max ht. V = Vo + g*Tr = 0 Vo -9.8*2.5 = 0 Vo = 24.5 m/s. = Initial velocity. h = Vo*t + 0.5g*t^2 = 24.5*1.5 - 4.9*1.5^2 = 25.7 m. = Ht. of the tower.
*February 2, 2015*

**physics**

Tr = 1.5 + 1 = 2.5 s. = Rise time or time to reach max ht. V = Vo + g*Tr = 0 Vo -9.8*2.5 = 0 Vo = 24.5 m/s. = Initial velocity. h max = Vo*t + 0.5g*t^2 = Vo*2.5 - 4.9*2.5^2 = 2.5Vo -
*February 2, 2015*

**physics**

d = 3.70 m. h = 1.67 m. V^2 = Vo^2 + 2g*h = 0 + 19.6*1.67 = 32.73 V = 5.72 m/s. = Velocity at bottom of incline. d = 0.5g*t^2 = 1.67 m. 4.9t^2 = 1.67 t^2 = 0.341 t = 0.584 s. = Time to reach bottom. V = Vo + a*t a = (V-Vo)/t V = 5.72 m/s Vo = 0 Solve for a.
*February 1, 2015*

**Physics**

Not enough INFO.
*February 1, 2015*

**Physics**

See Related Questions: Fri, 1-31-14, 10:23 PM.
*February 1, 2015*

**physics**

Vo = 1520m/s[35.5o] Yo = 1520*sin35.5 = 883 m/s. KE = 0.5M*Yo^2 = 0.5*25*883^2 KE = 0.5M*Yo^2 = 0.5*25*883^2=9,746,113 J. PE = KE = Mg*h = 9,746,113 25+9.8*h = 9,746,113 245h = 9,746,113 h = 39,780 m.
*February 1, 2015*

**PYHSICS**

With Arrow A = 9i B = -4 a. A+B = 9i + (-4) Q2. A+B = sqrt(9^2+(-4^2) = 9.85 Units. Tan Theta = 9/-4 = -2.25 Theta = -66.0 + 180 = 114o, CCW(Q2). b. A-B = 9i - (-4) = 9i + 4 A-B = sqrt(9^2+4^2) = 9.85 Units. Tan Theta = 9/4 = 2.25 Theta = 66o c. B-A = -4 - 9i X = -4 Y = -9
*February 1, 2015*

**physics**

Fg = 440 Hz = Freq. of the generator. Vg = 40 m/s = Velocity of the generator. Vs = 343 m/s = Velocity of sound. Vr = 0 = Velocity of the receiver(person listening to the sound). Fr = ((Vs+Vr)/(Vs-Vg))*Fg Fr = ((343+0)/(343-40))*440 = (343/303)*440 = 498.1 Hz. = Freq. heard by...
*February 1, 2015*