# Posts by henry

Total # Posts: 14,135

Physics
T1 = 130mi/(65mi/h) = 2 h. T2 = 130mi/(80mi/h) = 1.625 h. Time saved = T1-T2.

algebra
1a. 0.5x + 5 =< 30. b. 0.5x =< 30-5 X =< 50 miles. 2. 12mi/h * 5280ft/mi * 1yd/3ft * 1h/60min = 352 Yds./min. = Speed of the fish. 4.4ft/s * 1yd/3ft * 60s/min = 88 yds./min. = Speed of the boy. 352 - 88 = 264 yds./min faster.

algebra
50steps/min * 20min = 1000 Step head-start for Dori. 90 * T = 50 * T + 1000. 90T = 50T + 1000 T = 25 min. to catch up.

Physics
V = Vo + a*t = 0 + 4*3 =

Physics
V^2 = Vo^2 + 2a^d. V^2 = (3.6)^2 - 2*0.5*5. V = ?.

Physics
Vo = 45km/h = 45000m/3600s = 12.5 m/s. V^2 = Vo^2 + 2a*d. 0 = (12.5)^2 - 2*5.2*d. d = ?.

Physics
Vo = 4m/s[21o]. Yo = 4*sin21 = 1.43 m/s. = Ver. component of initial velocity Y^2 = Yo^2 + 2g*h = 0 @ max htg. (1.43)^2 - 19.6h = 0 h = 0.104 m. d = h/sin21 = 0.104/sin21 = 0.291 m. up incline.

Math
Multiply the numerator and the denominator by the same number: 1/2 = 1*2/2*2 = 2/4 which is equivalent to 1/2.

Math
h = 0.5625 + 7.75 + W = 9. W = 9 - 0.5625 - -7.75 = 0.6875 in. = Width of margins @ bottom of each page.

Algebra
See previous post: Wed, 10-11-17, 6:50PM.

math
I = P*r*t = 800*0.06*2 =

Physics
See previous post: Mon, 10-9-17, 3:36PM.

Science
V^2 = Vo^2 + 2g*h. V^2 = 64^2 - 64*48 = 1024 V = 32 ft./s. 64 - 32 = 32 ft./s = Velocity lost. 32 = k * 64. k = 0.5.

Physics
All angles are measured CCW from +x-axis. Disp. = 52km[259o] + 26[22] + 47[205]. Disp. = (-9.92-51i)+(24.1+9.74i)+(-42.6-19.9i) = -28.42 - 61.16i = 67.44km[65.1o] N. of E.

Physics
Given: M1 = 0.795kg, V1 = 0. M2 = 0.471kg, V2 = 8.17 m/s. M1*V1 + M2*V2 = M1*V3 + M2*V4. 0.795*0 + 0.471*8.17 = 0.795*V3 + 0.471*V4, Eq1: 0.795*V3 + 0.471*V4 = 3.85. Conservation of KE Eq: V3 = (V1(M1-M2) + 2M2*V2)/(M1+M2). V3 = (0(M1-M2) + 2*0.471*8.17)/(0.795+0.471) = 6.08 m...

Physics
a. Range = Vo^2*sin(2A)/g = 5.70 m. Vo^2*sin(76)/9.8 = 5.7 Vo^2*0.099 = 5.7 Vo^2 = 57.57 Vo = 7.59 m/s. b. Vo^2*sin(76)/9.8 = 46.5. Vo = ?.

Another physics please
a. V^2 = Vo^2 + 2g*h. V = 0, Vo = 0.262 m/s, g = -9.8 m/s^2, h = ?. b. V = Vo = 0.262 m/s.

Physics please
V = Vo + g*Tr = 0. 22 - 9.8Tr = 0. Tr = 2.24 s. = Rise time. Tr+Tf = 6.4. 2.24 + Tf = 6.4 Tf = 4.16 s. = Fall time. h = 0.5g*Tf^2 = 4.9*4.16^2^2 = 84.8 m. above gnd. = ht. of tennis ball. h = ho + Vo*Tr + 0.5g*Tr^2 = 84.8 m. ho + 22*2.24 - 4.9*(2.24)^2 = 84.8. ho + 24.69 = 84....

physics 1
See previous post: Sun, 10-8-17, 10:47PM.

physics 1
All angles are measured CCW from +x-axis. Disp. = 24km[330o] + 47[167] + 34[165]. Disp. = (20.78-12i) + (-45.8+10.57i) + (-32.84+8.80i). Disp. = -57.86 + 7.37i = 58.33km [-7.26o] = 58.33km[172.74o].

Physics
V = sqrt(x^2+y^2). X = 1.3 m/s, Y = 2.4 m/s, V = ?.

Phrysics
a. V = Vo + g*Tr = 0 @ max ht. 8 - 9.8Tr = 0 Tr = 0.82 s. = Rise time or time to reach max ht. h = ho + Vo*Tr + 0.5g*Tr^2. h = 2 + 8*0.82- 4.9*0.82^2 = 5.27 m. above gnd. h = 0.5g*Tf^2 = 5.27. 4.9(Tf)^2 = 5.27 Tf = 1.04 s. = Fall time. Tr+Tf = 0.82 + 1.04 = 1.86 s. = Time in ...

Math
x - 0.41x = 13.6 0.59x = 13.6 X = 23.1%.

physics
M*g = 17 * 9.8 = 166.6 N. = Wt. of the total mass. Fn = 166.6*Cos 0 - T*sin20 = 166.6-0.342T = Normal force. Fk = u*Fn = 0.420*(166.6-0.342T) = 70-0.144T Newton. T*Cos20-Fk = M*a. 0.940T-(70-0.144T) = 17*0 0.94T-70+0.144T = 0 1.084T = 70 T = 64.6 N. = Tension in the rope.

Algebra
Parallel lines have equal slopes: m = -4, P1(4,3), P2(x,y). m = (y-3)/(x-4) = -4. y-3 = -4x + 16 Y = -4x + 19.

PHYSICS
M*g = (0.320+0.725) * 9.8 = 10.24 N. Fk = u*Fn = (0.4+0.4)10.24 = 8.19 N. = Force of kinetic friction. Fap-Fk = M*a. Fap-8.19 = ((0.320+0.725)*2.25 Fap = ?.

Physics!
M*g = 800 N. Fp = 800*sin34 = 447.4 N. Fn = 800*Cos34 = 663.2 N. Fap-Fp-Fs = M*a. 240-447.4 + Fs = M*0 = 0 Fs = 207.4 N. = Force of static friction. u = Fs/Fn = 207.4/663.2 = 0.313.

Physics
Fap = 16N[55o], Downward. M*g = 28*9.8 = 274.4 N. = Wt. of box. Fn = Mg + Fap*Sin55 = 274.4 + 16*sin55 = 287.5 N. Fs = u*Fn = 0.41 * 287.5 = 117.9 N. = Force of static friction. F+Fap*Cos55-Fs = M*a. F+16*Cos55-117.9 = 28*0 F + 9.18 - 117.9 = 0 F = 108.7 N.

Mathematics
See previous post: Thu, 10-5-17, 6:32 PM.

Mathematics
(6,2), (6,-6), (-1,2), ((-1,-6)). P = 2(2-(-6)) + 2(6-(-1)) = 16 + 14 = 30 Units. Area = L*W = (2-(-6)) * (6-(-1)) = 8 * 7 = 56 Sq. units.

Physics
Calculate resultant in mi/h and convert to m/s. All angles are CCW from +x-axis. R = 20[90o] + 50[315o] + 10[225]. R = 20i + 35.36-35.36i + -7.07-7.07i R = 28.29 - 22.43i = 36.1 mi/h[-38.4o] = 36.1 mi/h[38.1o] S. of E. R = 36.1mi/h * 1600m/mi * 1h/3600s = 16m/s[38.4o] S. of E.

Physics A level
V1 = a*t = 1.4 * 10 = 14 m/s. d1 = V1*t = 14 * 20 = 280 m. V2^2 = V1^2 + 2a*d2 = 0. 14^2 - 5.6d2 = 0 d2 = 35 m. d = d1+d2 = 280 + 35 = 315 m. = Total distance.

Physics
A. F = M*a = 1.5 * 3.0 = 4.5 N. F = M*a, a = F/M = 4.5/2.5 = 1.8 m/s^2. B. F = 4.5 N.(part A).

Physics
F = M*g = 60 * 9.8 = 588 N. = Wt. of the person. 0.25hp * 746w/hp = 186.5 Watts. = 186.5 J./s. Work = 186.5J/s * 60s = 11,190 J.

physics
V = a*t.

Math
1a. No, because after Prime Factorization the resulting numbers cannot be factored further. b. Yes, because numbers that are divisible evenly by one only(11,13) cannot be factored.

Physics
Vm = 0.04 *25 = 1.0 volt across meter @ full-scale. Rs = Vm/I = 1.0/(50-0.04) = 0.020 Ohms.

Physics
a. X = 1.30m/s * 0.25s = 0.325 m. Y = yo - 0.5g*t^2. Y = 1.25 - 4.9*(0.25)^2 = 0.944 m. above gnd. b. X = 1.30m/s * 0.500s = Y = 1.25 - 4.9*(0.50)^2 = c. Vy = Vo + g*t. Vy = 0 + 9.8*0.5 = 4.9 m/s. = Ver. component of velocity. Vx = 1.30 m/s and remains constant. V = Sqrt(Vx^2+...

Physics
1. F = M*g = 50 * 9.8 = 490 N. = Wt. of boy. P = F*d/t = 490 * 10.5/45 = 114.3 J/s = 114.3 Watts. = Work rate. 2. KE = PE. 0.5M*V^2 = M*g*h 0.50*0.25*V^2 = 0.25**9.8*10.5 V = ?.

Physics
See previous post: Tue, 10-3-17, 2:44PM.

Physics
Vo = 110mi/h * 1600m/mi * 1h/3600s = 48.89m/s[35o]. = Initial velocity. Xo = 48.89*Cos35 = 40.0 m/s. = Hor. Yo = 48.89*sin35 = 28.0 m/s. = Ver. 4ft * 1m/3.3ft = 1.21 m. 8ft = 2.42 m. 408ft * 1m/3.3ft = 123.6 m. Y = Yo + g+Tr = 0. 28 - 9.8Tr = 0 Tr = 2.86 s. = Rise time or time...

Physics
V^2 = Vo^2 + 2g*h. V^2 = 16^2 - 19.6*8.5 = 89.4 V = 9.46 m/s = The velocity when it reaches the balcony and when it returns to the balcony and grabbed by Karen. V = Vo + g*Tr = 0. 16 - 9.8Tr = 0 Tr = 1.63 s. = Rise time from Jeff's hand to max ht. V = Vo + g*Tf = 9.46. 0...

Physics
V^2 = Vo^2 + 2g*d. V = 0, g = -9.8m/s^2, d = (20-1.5), Vo = ?. To just miss the ceiling, Vo will have to be slightly less than(<) the calculated value.

Physics
h = 0.5g*t^2. h = 25 m., g = 9.8 m/s^2, t = ?.

Physics
V = Vo + g*Tr = 0. 32 - 9.8Tr = 0 Tr = 3.27 s. = Rise time or time to reach max ht. h = Vo*Tr + 0.5g*Tr^2. Vo = 32 m/s, Tr = 3.27 s., g = -9.8 m/s^2, h = ?.

Advanced Algebra
P = Po + Po*r*t. P = 6091 + 6091*0.2379*0.5 =

Physics question
Fn = 31N. = Normal force. Fs = u*Fn = 0.38 * 31 = 11.78 N. = Force of static friction. F-Fs = M*a. F-11.78 = 25*0 F = 11.78 N.

Math
If you add the same number to both sides of an inequality, the inequality is still true. If you subtract the same number from both sides of an inequality, the inequality is still true. Subtract 2 from both sides: x + 2 > 10. X > 8. All real numbers greater than 8 should ...

6th grade math
Eq1,Lily: 5*x + 10*2y = 5*x + 10*y + 200. Replace 2y with 4x and y with 2x: Lily: %*x + 10*4x + %5*x + 10*2x + 200. 5x + 40x = 5x + 20x + 200 X = 10 nickels. In Eq1, replace X with 10 and solve for Y: 50 + 20y = 50 + 10y + 200 Y = 20 dimes. a. 10 + 20 = 30 Coins. b. 5x + 20y...

physics
M*g = 87.9 * 9.8 = 861.4 N. = Wt. of acrobat. All angles are referenced to +x-axis. T1*sin(180-10.1) + T2*sin(10.1) = 861.4. 0.1754T1 + 0.1754T2 = 861.4 T2 = T1 0.1754T1 + 0.1754T1 = 861.4 0.3507T1 = 861.4 T1 = 2456 N. = T2.

math5
Walked X dogs/day last week. Walked x+3 dogs/day this week. 5*(x+3) = 35. 5x + 15 = 35 X = 4 dogs/day last week.

Math
Eq1: x + y = 21. Eq2: 5x + 2y = 66. Multiply Eq1 by (-)5 and add the Eqs: -5x - 5y = -105 +5x + 2y = +66. Sum: -3y = -39 Y = 13. In Eq1, replace Y with 13 and solve for X: x + 13 = 21. X = 8.

Math
F + 0.81F = 3.98 million. F = 2.199 million in 2007. Change = 3.98 - 2.199 = 1.78 Million. Year 2007 = Reference year.

Physics
Period is the time for 1 cycle. Example: Freq. = 10 Hz = 10 cycles/s. Period = 1/F = 1/10cycles/s = 0.1 s/cycle. So the period is the time for 1 cycles.

Physics
a. h = 0.5g*t^2. h = 2 m, g = 9.8 m/s^2, t = ?. b. d = Xo*t. Xo = 30 m/s., t = Value from part a, d = ?. c. i. The horizontal component of velocity is initially 30 m/s and remains constant. ii. The vertical component is initially 0 and increases as the arrow moves toward ...

physics
1. Vo = 10m/s[70o]. Xo = 10*Cos70 = 3.42 m/s. Yo = 10*sin70 = 9.40 m/s. a. Y = Yo + g*Tr = 0 @ max ht. 9.40 + (-9.8)Tr = 0 Tr = 0.959 s. = Rise time. Tf = Tr = 0.959 s. = Fall time. T = Tr+Tf = 0.959 + 0.959 = 1.92 s. = Time in flight. Range = Xo*T = 3.42 * 1.92 = 6.56 m. b. ...

Physics
Vo = 20m/s[53o]. Xo = 20*Cos53 = 12.04 m/s. Yo = 20*sin53 = 15.97 m/s. a. Y = Yo + g*Tr = 0 @ max. ht. 15.97 - 9.8Tr = 0 Tr = 1.63 s. = Rise time. Tf = Tr = 1.63 s. = Fall time. Tr+Tf = 1.63 + 1.63 = 3.26 s. = Time to reach point X. b. d = Xo*(Tr+Tf) = 12.04 * 3.26 = 39.25 m. ...

PHYSIC!!
P = F*d/t = Mg*d/t = 980 * 30/20 = 1470 J/s = 1470 Watts. 1470w./(746w/hp) = 1.97 hp.

Physics
Vo = 22.5m/s[38o]. Xo = 22.5*Cos38 = 17.7 m/s. Yo = 22.5*sin38 = 13.9 m/s. Y = Yo + g*Tr = 0 @ max ht. 14 + (-9.8)*Tr = 0 Tr = 1.43 s. = Rise time. Tf = Tr = 1.43 s. = Fall time. Tr+Tf = 1.43 + 1.43 = 2.86 s. or about 3 s.

Physics
Vo = Initial velocity. Xo = Horizontal component of initial velocity. Yo = Vertical component of initial velocity. Tr = Rise time or time to reach max. height. Tf = Fall time.

Physics
a. Tr+Tf = 10 s. = Time in air. Tr = Tf, Tr+Tr = 10, Tr = 5 s. = Rise time. Y = Yo + g*Tr = 0 @ max ht. Yo + (-9.8)*5 = 0 Yo = 49 m/s or about 50 m/s. b. Yo = Vo*sin50 = 49. Vo = 49/sin50 = 64.0 m/s. c. Xo = Vo*Cos50 = 64*Cos50 = 41.1 m/s. Range = Xo*(Tr+Tf) = 41.1 * 10 = 411 ...

physics
V = 60mi/h * 1600m/mi * 1h/3600s = 26.7 m/s. V = Vo + a*t = 26.7. 0 + a*4 = 26.7 a = 6.67 m/s^2. d = 120Ft/(3.3ft/m) = 36.4 m. V^2 = Vo^2 + 2a*d = 0. (26.7)^2 + 2a*36.4 = 0 a = -9.79 m/s^2. deceleration = 9.79 m/s^2. Ratio = 6.67/9.79 = 0.681.

Algebra
V = 3 3/4 * 3 * 3 1/4 = 15/4 * 3 * 13/4 = 585/16 = 36.5625 Cubic Ft. 36.5625/(1/64) = 2,340 Cubes.

Algebra 2 A
X Lbs. of jelly beans. 2x Lbs. of gummy candy. 9-(x+2x) = (9-3x) Lbs. of hard candy. 3*x + 2*2x + 3*(9-3x) = 23.00. 3x + 4x + 27-9x = 23 X = 2.0 Lbs. of jelly beans. 2x = 2 * 2 = 4 Lbs. of gummy candy. 9-3x = 9-3*2 = 3 Lbs. of hard candy.

physics
V = 20*Cos30.

Physics
V^2 = Vo^2 + 2a*d. 7^2 = 15^2 + 2a*88 -176a = 15^2-7^2 a = -1.0 m/s^2. 0 = 15^2 + 2*(-1)d. d = 112.5 m. 112.5 - 88 = 24.5 m. further.

physics
M*g = 21.5 * 9.8 = 210.7 N. = Wt. of food. Fpd = 210.7*sin55.5 = 173.6 N. = Force parallel to the incline and downward. sin55.5 = 210.7/Fpu. Fpu = 256 N. = Force parallel to the incline and upward. Since the force acting up the incline is greater than that acting down the ...

Physics
V = 200[40o] + 50[0o]. V = 200*Cos40+200*sin40 + 50 V = 153.2+128.6i + 50 = 203.2 + 128.6i = 240.5mi/h[32.3o] N. of E.

CIRCUITS
P = E^2/(R1+R2) = 240^2/(25+5) = 1920 Watts = Current power. Rt = (25+5)/3 = 10 Ohms = Total resistance required to triple the power. Rt = R1*R3/(R1+R3) + R2 = 10. (25*R3)/(25+R3) + 5 = 10 25R3/(25+R3) = 5 25R3 = 125 + 5R3 R3 = 6.25 Ohms.

Science
KE = 0.5M*V^2 = 0.5*0.03*(1500)^2 = 33,750 J.

physics
1. Vi = 5.4km/s * 1mi/1.6km * 3600s/h = 12,150 mi/h. 2. h = Vi*t + 0.5g*t^2. g = 3/8 * 9.8 = 3.675 m/s^2 t = 6min * 60s/min = 360 s. h = 5400*360 + 0.5*3.675*360^2 = 2.18*10^6 m., max.

Algebra
The freight travels r mi/h. The passenger train travels r+14 mi/h. Df = Dp. 5r = 3(r+14) 5r = 3r + 42 r = 21 mi/h. r+14 = 21 + 14 = 35 mi/h. Laura, Your Eq is correct, but you made an error when solving it.

Math
d1 + d2 = 200. 20mi/h * 2h + r*2 = 200 40 + 2r = 200 r = 80 mi/h.

Mathematics
1.*10^3. The positive "3" means move the decimal 3 places to the right to convert to standard form. (-3) means move the decimal 3 places to the left. 1.*10^3 = 1,000. 1.*10^-3 = 0.001.

Physics
Terry: d = Vo*t + 0.5g*t^2 = 29. 9t + 4.9t^2 = 29 4.9t^2 + 9t -29 = 0. Use Quadratic Formula: t = -9 +- Sqrt(9^2+4*4.9*29)/9.8 = 1.68 s. = Time to reach bottom of well. Sam: V = Vo + g*Tr = 0. 9 - 9.8Tr = 0 Tr = 0.918s = Rise time. Tf1 = Tr = 0.918s = Fall time to launching ...

Math
Smallest = X. Middle = x+1. Largest = x+2. 2x = (x+2) + 11. X = 13. x+1 = 13+1 = 14. x+2 = 13+2 = 15.

Math
V = Vo(1+r)^n. Vo = \$420. r = 0.03/12 = 0.0025/mo. n = 1Comp/mo. * 2mo. = 2 compounding periods. V = ?.

physcis
V = Vo + a*t = 7. 2 + a*10 = 7, a = 0.5 rev/s^2. or a = 0.5rev/s^2 * 6.28rad/rev = 3.14 rad/s^2.

algebra
Yes, that is true. But when you divide both sides by (-2) to solve for x; you will have to reverse inequality sign. -2x - 20 >= 75. -2x >= 95 X <= -47.5. Therefore, all values of x that are less than or equal to (-47.5) will satisfy the given inequality.

math
Correction: Multiples of 40: 40, 80, 120, 160.

math
Multiples of 32: 32*1 = 32, 32*2 = 64. Therefore 32 and 64 are multiples of 32. Multiples of 32: 32, 64, 96, 128, 160. Multiples of 40: 40: 40, 80, 120, 160. LCM = 160.

Algebra
Frank is X years old. Gabriel is x-3 years old. When their ages are doubled: Frank is 2x years old. Gabriel is 2x-6 years old. x + (x-3) = 17. 2x-3 = 17 X = 10 years = Frank's age. x-3 = 10-3 = 7 years = Gabriel's age.

Physics
F = 1.8C + 32 = 107. C = 41.67o. Error = 42 - 41.67 =

Math
3.16*10^3 = 3160.

Physics
I'm assuming the cheetah is running at 0.029 km/s (29m/s). V = Vo + a*t = 29. 0 + 4.14*t = 29. t = ?.

science
a. Cos A = 0.3/0.5 = 0.6. A = 53.13o = B. T1*sin53.13 + T2*sin(180-53.13) = +15. T2 = T1: T1*sin53.13 + T1*sin126.9 = 15 0.8T1 + 0.8T1 = 15 T1 = 9.375 N. = Tens1on in the string. b. Cos A = 0.3/0.33 = 0.90909, A = 24.62o. T1*sin24.62 + T2*sin(180-24.62) = +15. T2 = T1 T1 = ?. ...

physics HELP
1. V^2 = Vo^2 + 2a*d. a. V^2 = 0 + 0.36*494, V = ?. b. d = 0.5a*t^2. 494 = 0.5*0.18*t^2. t = ?. 2. V = Vo + a*t = 0 + 1.4*4.1 = 5.74 m/s. V^2 = Vo^2 + 2a*d. 0 = (5.74)^2 - 3.6d. d = ?.

Math
(3/4)/(3/5) = x/1. 3/4*5/3 = x/1, X = 5/4 h.

physics
k = 20N/(10.01-0.10) = 2.02 N/m = Force constant or spring constant.

my success
a, b, and d.

Geometry
A. 1/3 * 36 = 12 Boys. B. 36 - 11 = 25 Girls. C. p = 25/36 =

Math
No. 4 + 10 = 10 + 4 is commutative.

Math
sin60 = AD/CD = 2.54/CD. CD = ?.

Math
280 + 0.06(s-136-5000) = \$328.54. 280 + 0.06s-308.16 = 328.54, 0.06s - 28.16 = 328.54, S = \$5945. = Gross sales.

Physics
V = Vo + g*Tr = 0. 30 - 9.8Tr = 0, Tr = 3.06 s. = Rise time. Tf = Tr = 3.06 s. Tr+Tf = 3.06 + 3.06 = 6.12 s. = Time in air.

math
See previous post: Sun, 9-17-17, 12:42 PM.

physic
C = pi * Diameter = Circumference. We need to know the radius or diameter of the tire. Rev. = d/C. d = 50,000 Miles. d and C must be in the same unit(meters or miles).

physic
36o W. of N. = 90+36 = 126o CCW from E. (a+b) = 5.2 + 3.70[126o]. (a+b) = 5.2 + 3.70*Cos126+3.70*sin126, (a+b) = 5.2 - 2.17+2.99i, (a+b) = 3.03 + 2.99i = 4.26m[44.62o] A. Magnitude = 4.26 m. B. Direction = 44.62o. (b-a) = 3.70[126o] - 5.2. (b-a) = -2.17+2.99i - 5.2, (b-a) = -7...

Math
Wt. = 900Liters * 1oz/0.03Liters = 30,000 Ozs. = 1875 Lbs./min. Mass = 1875Lbs * 0.454kg/Lb. = 851.25 kg./min. P = M*g*d/t = 851.25/60s * 9.8 * 50 = 6952 J/s = 6952 Watts. h.p. = 6952/746 = 9.32.

trigonometry
See previous post: Sun, 9-17-17, 12:34 AM.