Posts by Damon
Total # Posts: 32,928

Math
400.00  57.38  33.50 + 20.00 = ??? 
physics
speed = 3 * 10^8 m/s / 1.5 = 2*10^8 m/s distance = 0.9 meters (really ? ) time = (0.9 /2) * 10^8 seconds 
Calc
What second line? What first line? That is a parabola. Its slope is df(x)/dx = 2x  12 
Calc!
distance / time for example from time 0 to 1.5 (660) / (1.50) = 44 
math;)
Hey, you try first. You are supposed to know how to take the derivative of a polynomial. if y = a x^n then dy/dx = n a x^(n1) and the derivative of a constant is therefore 0 because if y = a x^0 dy/dx = a * 0 * x^1 = 0 so if v = t^2+15 then a = dv/dt = 2 t + 0 and at t = 5... 
math;)
f'(x) = 2x at x = 1 f'(x) = slope m = 2 so y = 2x + b at (1,4) 4 = 2 + b b = 6 continue f' = 8 x + 2 so put in a for x what is your problem with this? 
math;)
f' = 12 x  1 so what is 12  1 ????? 
science
1 S + 1 N = 0 5 W = 5 W We are interested in his motion vector, not where he started so in the end his displacement vector was 5 W 
Calc
It would have made much more sense to ask you what is average velocity from t = t to t = t+h ? s(t+h) = 15 + 31 (t+h) 4.9 (t^2+2 t h+h^2) s(t) = 15 + 31 t  4.9 t^2 then distance moved is s(t+h)  s(t) = 31 h  9.8 t h  4.9 h^2 divide by time elapsed h [ s(t+h)s(t) ]/h = 31... 
Calc
at 0 it is 15 at (1+h) it is 15 + 31(1+h)  4.9(1+h)^2 subtract d moved = 31(1+h)  4.9(1+h)^2 divide by time (1+h) d moved/time = 31  4.9(1+h) 
Calc
if I go 4 miles from here to downtown at 30 miles/hour, then immediately come back at 30, my average velocity is ZERO. I went nowhere :) However my average SPEED was 30 
Calc
The reason I went into that detail is I am not sure your question is worded correctly. I wonder if they really want the average speed, not the average velocity. 
Calc
average velocity = displacement / time by the way NOT distance/time distance is scalar displacement is vector, might be  part of the time. if on earth and original height = 15 meters original speed up = 31 m/s and v = 31  9.8 t acceleration = g = 9.8 m/s^2 then h(t) = 15... 
chemistry
P V = nRT here V, n and R are constant so P/T = constant so P1/T1 = P2/T2 So I agree with you. 
Science
Yes 
Electron acceleration
Yes m a = q E so E = m a/q 
math:^]
work = Force * distance in direction of force = Force vector dot Distance vector = F D cos angle between the two vectors = 60 * 100 * sqrt 2 / 2 
science
You can assume for this problem that the speed of light is infinite, about 3*10^8 meters/second which is a lot bigger than 346. so in the two seconds between the flash and the noise the sound traveled 2*346 meters 
Sue
60/21.5 = h/19 
Orbital period
http://www.physicsclassroom.com/class/circles/Lesson4/MathematicsofSatelliteMotion T^2/R^3 = constant for any old star 
physics
when she crosses the bar she is moving in horizontal direction Ux = 1.16 the whole time. Now the vertical problem: (1/2) m Vi^2 = m g h so Vi = sqrt (2gh) {This is worth remembering} Vi = sqrt (2*9.81*1.89) = 6.09 so v = sqrt (1.16^2+6.09^2) = 6.20 sure enough 
math
You do not tell us what the question is but I could not do it anyway because I do not know if the 3 were caught in the first minute or the fourth or whatever. 
Maths
(1/3) long , x = (3/4) short , y x = y + 17.5 (y+17.5)/3 = 3 y/4 4 y + 70 = 9 y 5 y = 70 y = 14 
math
Five of the eight letters are not e. 
Physics
watts = volts * amps 
Math
3(22+20) = 3(42) 
Social studies
I agree. 
Math
3x+2 = x^2+3x4 x^2  6 = 0 x = +/ sqrt 6 if +sqrt 6 y = 3sqrt 6 + 2 = 6+3sqrt 6 4 check :) there are solutions but none of them are on your list 
History
I do not think it is C. 
math
https://www.mathsisfun.com/algebra/sequencessumsarithmetic.html 
math
arithmetic sequence, a = 14, d = 5 
math
Yes 
Math
20 = 4 * 5 
Computer
https://www.binaryhexconverter.com/binarytodecimalconverter You want decimal? 2824088250 
physics
original momentum = .050 * 0.6 + 0 = 0.03 final =0.03 = 0.050* 0.24 + 0.20* v solve for v 
science
gain of of kinetic energy at low spot = loss of potential energy coming down from top (m/2)(Vbottom^2  Vtop^2) = m g (meters down from top) or if stopped at top (1/2)m v^2 = m g h or (remember this) v = sqrt (2 g h) 
Calculus
You did not say how many rectangles. Here it is for ten: http://mathworld.wolfram.com/RiemannSum.html 
Calculus
graph it! You know how to find the area of rectangles and triangles. 
Chemistry
I would have .62 mols in a liter so I have .62 (.032 ) = .01984 mols .01984 mols /x liters = 0.3 mols/1 liter x = .01984/.3 = .06613 liters = 66.13 mL so add 66 32 = 34 mL of water 
Math
14! = 87?178?291?200 indeed 
Geometry
It was unclear to me which way the scale was supposed to go actually. 
Geometry
if the scale factor is s Like L' = s L and w' = s w and h' = s h then L'w' h' = s^3 L w h in other words volume scales as the cube of the length scale if the volume of one thing is twice another similar object then every length measure on the big one is... 
Chemistry
Yes, I should have said that :) 
Chemistry
there are 3 times as many Na+ ions as sodium phosphate molecules 3.3*3 = 9.9 
Math
Exactly Michael. 
physics
work done = F D = gain in Ke Now which of those has the same force times distance (time has nothing to do with it)? We are not doing power, just energy.) The heavier mass will just end up moving slower if they started at rest but will have the same gain in Ke. 
Science
work output = 30*2 = 60 Joules work input effort = 10*8 = 80 Joules well the time is the same so the velocity out is 2/8 = 1/4 the velocity in eff = 100 * work out/work in = 100(6/8) = 75% 
Algebra
four times a year so every 1/4 year multiply by 1 + .075/4 = 1.01875 do that for n years or in other words 4n periods so 3 = (1.01875)^4n log 3 = 4n log 1.01875 I suspect you can take it from there. 
History
You just want me to answer the questions for you? Read the excerpts carefully and try to answer before asking us to do your reading for you please. 
vectors
Somehow you can tell one of us does physics and the other does math :) 
vectors
x = a i + b j y = c i + d j a^2 + b^2 = 11^2 = 121 c^2 + d^2 = 23^2 = 529 xy = (ac)i + (bd)j (ac)^2 + (bd)^2 = 30^2 = 900 = a^2  2ac + c^2 + b^2 2bd + d^2 so 900 = 121+529 2(ac+bd) so 250 = 2(ac+bd) now x+y = (a+c)i + (b+d)j x+y^2 = a^2+2ac +c^2 +b^2+2bd+d^2 = 121+... 
vectors
I put A at lower left and B a lower right. AB = 1 i + 0 j AC = (1+cos 60)i + sin 60 j AD = 1 i + 2 sin 60 j AE = 0 i + 2 sin 60 j AF = cos 60 i + sin 60 j sum of x components = 3 sum of y components = 6 sin 60 = 6 (sqrt3 /2) = 3 sqrt 3 magnitude = sqrt(3^2 + 9*3) = sqrt 36 = ... 
Physics
Ke = (1/2) m v^2 + (1/2)I omega^2 you have everything there but omega, the angular speed, but you know that omega = v/R = 4.0/0.10 = 40 rad/second 
math
yes. 2/6 = 1/3 
math
The team shoots ?????????? goals in their sixth 
Physics
time to stop = t v = Vi  10 t 0 = 40  10 t t = 4 seconds to stop d = average speed during stop * time = 20 * 4 = 80 meters 
math
They run up and down like free range cattle. 
math
plug and chug (yk)^2 = 4a (xh) k = 8 given h = 9 given distance from vertex to directrix = a distance from 9 to  16 = 7 = a (positive for directrix to the left of the vertex) so (y8)^2 = 28 (x+9) 
math
9x^2 + 9y^2 + 72x ? 108y + 368 = 0 well put all the x stuff on the left first maybe 9x^2 + 72 x = 9 y^2 +108 y  368 divide by 9 x^2 + 8 x = y^2 +12y  368/9 complete square on left by adding(8/2)^2 = 4^2 = 16 to both sides x^2 + 8 x + 16 = y^2 +12 y  368/9 + 144/9 (x+4)^2... 
World History
Better Ulan Bator ? 
Chemistry
well, first, isotopes are different masses of atoms of the same element. In other words they have the same number of protons but a different number of neutrons. Now some such isotopes are unstable. Some like carbon 14 (regular carbon 12 with two extra neutrons) take a long ... 
math
well the middle is halfway between (8/2 , 12/2) = (4,6) center so (x4)^2 + (y+6)^2 = r^2 try a point like (1,7) (3)^2 + (7+6)^2 = r^2 9 + 1 = r^2 so r = sqrt 10 = (x4)^2 +(y+6)^2 = 10 ========================check with other point (7,5) (3)^2 + (1)^2 = 9 + 1 = 10 good... 
PreCalculus
like t = y/2 then x = t^2 = y^2/4 so y^2 = 4 x but y = r sin T x = r cos T so r^2 sin^2 T = 4 r cos T r sin^2 T = 4 cos T r =4 cos T/sin^2T = 4 cot T csc T 
PreCalculus
First you try. 
Physics
v = Vi  g t at the top, v = 0 and t = 1.6/2 = 0.8 s g = 9.81 m/s^2 approximately so 0 = Vi 9.81(0.8) Vi = 9.81(0.8) meters/ scond 
PreCalculus Help?
Then post your attempts. 
PreCalculus Help?
Hey, you try some now ! 
PreCalculus Help?
x(t) = e^t x^2 = (e^t)^2 = e^2t 3 x^2 = 3 e^2t = 3/x^2 = y 
math
now if f(x) = x^n f(x+dx) = (x+dx)^n = x^n + n x^(n1) dx + [n(n1)/2!]x^(n2) dx*2 ..... + ....dx^bigger f(x) = x^n still subtract f(x+dx) f(x) = n x^(n1)dx+[n(n1)/2!]x^(n2) dx*2 ..... divide by dx [f(x+dx) f(x)] /dx = n x^(n1) + [n(n1)/2!]x^(n... 
math
f(x+dx) = (x+dx)^2 = x^2 + 2 x dx + dx^2 f(x) = x^2  subtract f(x+dx)  f(x) = 2 x dx + dx^2 divide by dx [ f(x+dx)  f(x) ] / dx = 2 x + dx let dx > 0 = 2 x the end d/dx (x^2) = 2 x is now established in your mind forever. 
Calculus
typo, radius 2 I think 
PreAlgebra
Yes, although not since I was a young man lobstering and ground fishing out of Gloucester, Massachusetts. 
PreAlgebra
By the way this is a 3, 4, 5 triangle 9 + 16 = 25 
PreAlgebra
The hypotenuse is 20 one of the legs is 12 what is the other leg? 12^2 + x^2 = 20^2 = 400 x^2 = 400  144 x^2 = 256 x = 16 and yes, I am a fisherman. 
calclus
https://www.jiskha.com/display.cgi?id=1526514290 
calclus
Well, if you were a boat navigator you would use the 45 degree trick. Measure that distance from you to that road. That distance, d, should be perpendicular to the road. Now look 45 degrees right (or left). The distance along the road to that point on the road from your ... 
physics
first 250 km/hr = 250,000 meters / 3600 seconds = V acceleration = rate of change of velocity = change in V / change in time = (250,000/3600) / 2.2 meters/ second^2 
physics asap
second one Again the mass does not matter (1/2) m v^2 = m g h v = sqrt (2 g h) (remember that) 
physics
his mass has nothing to do with it. Vi = 4.7 how long to reach top? v = Vi  g t 0 = 4.7  9.81 t t = .479 seconds up H = 3.8 + Vi t  4.9 t^2 h = 3.8 + 4.7(.479)  4.9 (.479^2) h = 3.8 + 2.25  1.12 h = 4.93 meters stopped above ground, falls from there 4.93 = 4.9 t^2 t = 1 ... 
maths
You are welcome. 
maths
I read even numbers so increased by 2 each time. Just do increase by 1 same system, same answer 
maths
[ n+ (n+2) + (n+4) + .....(n+12) ] /7 = 16 [ (n+2) + (n+4) + .... (n+12) ] = 108 ==================================== well, multiply the first one by 7 [ n+ (n+2) + (n+4) + .....(n+12) ] = 16*7 = 112 [ (n+2) + (n+4) + .... (n+12) ] = 108... 
math
You are welcome. 
math
y distance = 40 x distance = 30 d = sqrt (40^2 + 30^2) the hypotenuse = 50 I suspect (3,4,5 triangle) 
physics
How about 4184 J/kg deg C ? https://water.usgs.gov/edu/heatcapacity.html 
Physics
https://www.jiskha.com/display.cgi?id=1526419154#1526419154.1526420002 
Math
https://www.mathsisfun.com/algebra/sequencessumsarithmetic.html a = 4 d = 4 and do you not have a text book ? 
Physics
Well, they usually follow some sequence, generally something like a geometric sequence. 2 4 8 16 32 64 ..... If you left 8 out you would notice. 
Quadratic Functions and Equations
well, (100+2w)(25+2w) = 3 (100*25) 2500 + 250 w + 4 w^2 = 7500 w^2 + 62.5 w  1250 = 0 agree with bobpursley 
Probability
possible outcomes 1  1 2 3 4 5 6 2  1 2 3 4 5 6 3  1 2 3 4 5 6 4  1 2 3 4 5 6 5  1 2 3 4 5 6 6  1 2 3 4 5 6 of those 36, 5 of them add to 8 
PreAlgebra
....and by the way, Google distributive property of multiplication for example: http://www.mathworksheet.org/multiplying the way I think of it is (a+b+c)(d+e+f) = a(d+e+f) +b(d+e+f) +c(d+e+f) = ad+ae+af+bd+ ....... get it :) 
Math
3 years = 36 months .07/12 = .00583333.... 1.00583333...^36 = 1.232925587 1.232925587 p = 30,000 p = 24,332.37 
math
So do it. 10 = m (1) + b 2 = m (7) + b  subtract 
math
d = k x + b by the way b is un stretched length 12 = 2 k + b 18 = 5 k + b  subtract 6 = 3 k k = 2 then b = 8 25 = 2 m + 8 
math
(12t^6  8t^8) ÷ (2t^3) 2 t^3 ( 6 t^3  4 t^5) ÷ (2t^3) so ( 6 t^3  4 t^5) agree 
Math
3,3 3,6 6,3 6,6 is 4 out of 36 = 1/9 
Math
6 taken 4 at a time with no order 6!/[4!(2!) ] = 6 *5 / 2 = 15 
physics
Hg is about 13.5 times water density of about 1 gram/cm^3 50 mL = 50*10^3 Liters liter is 10^3 cm^3 so we have 50 cm^3 13.5 g/cm^3 * 50 cm^3 = 675 grams = .675 kg if you want weight not mass m g = .675 * 9.81 Newtons 
Math
agree first one 9/36 = 1/4 agree second one 3/36 = 1/12 
Physics
(1/2) rho v^2 + p = constant Q = volume flow rate = 275 kg/min * 1min/60 s * 1 m^3 / 1200 kg = 0.00382 m^3/second so v skinny pipe = 0.00382 / .068 = 0.0562 m/s v fat pipe = 0.00382 / 0.083 = 0.0460 m/s p fat pipe  p skinny pipe = (1/2)*1200 *(.0562^2  .0460^2) = 600*0.00104...