Tuesday
February 21, 2017

Posts by Scott

Total # Posts: 1,812

chemistry
not enough nitrogen a mole of nitrogen is needed for every 3 moles of hydrogen
February 20, 2017

math
tan(?) = 250/170
February 20, 2017

Math
v = 24 (1 + .06)^385
February 20, 2017

physics
2 * vertical velocity / g 16.7 * ?2 / 9.81
February 20, 2017

Algebra
(a) m = 500 (1 + .015)^t (b) 800 = 500 (1 + .015)^t ... 1.6 = 1.015^t ... log(1.6) = t log(1.015) ... [log(1.6)] / [log(1.015)] = t
February 20, 2017

Algebra - PLEASE HELP!
231 = -17.5x2^ - 138.5x - 27 462 = -37 x^2 - 277 x - 54 0 = -37 x^2 - 277 x - 516 use quadratic formula to find x
February 20, 2017

probability
there are 9 pairs of cards that differ by one ... 1-2, 2-3, 3-4, etc. there are 10C2 possible pairs ... 45 so the probability of a pair differing by one is 9/45 or .2 ... by more than one is (1 - .2) = .8 3 cards contain 3 pairs .8^3 = .512
February 19, 2017

physics
m g h = 1/2 m v^2 ... v = ?(2 g h)
February 19, 2017

physics
it's a fraction of a mole ... 9.1E5 / 6.02E23 multiply the fraction by the molar mass
February 19, 2017

physics
60 sec in a min 2.54 cm in an inch 9.843E4 ft/min * (1 min / 60 s) * ... (12 in / 1 ft) * (.0254 m / 1 in)
February 19, 2017

physics
f = m a = 2E3 kg * ... [(20 m/s - 5 m/s) / 4 s] answer is in Newtons
February 19, 2017

Algebra2
an = 13n - 8
February 19, 2017

Physics
convert mph to m/s convert cg(?) to kg K.E. = 1/2 m v^2
February 19, 2017

physical science
Joules of energy required ... 202 * (95.6 - 22.0) * 4.18 divide by heater wattage ... 1 watt = 1 Joule per second divide by 60 ... sec to min
February 19, 2017

Physics
friction
February 19, 2017

science
free fall...starting from rest d = 1/2 g t^2 ... plug in the times, and find the difference in the distances the 1st body will always be going faster than the 2nd, so the distance between them is always increasing
February 19, 2017

Math
the edge length is the cube root of the volume 8 in this case
February 19, 2017

Math
not enough information
February 19, 2017

Maths
the distance between the centers of the two outer circles is 4 they are in the diagonal corners, and their centers are ?2 from the corners so the diagonal of the square is ... 4 + 2?2 dividing by ?2 to find side length ... 2 + 2?2 squaring ... 4 + 4?2 + 4?2 + 8 = 12 + 8?2
February 19, 2017

Math
order counts 6P3
February 18, 2017

physics
the work ... 7.6N * 8.6m ... is equal to the block's KE 1/2 * 0.50 * v^2 = 7.6 * 8.6
February 18, 2017

Math 125
sometimes just using numbers will clarify for 2000 people ... 10 have the virus ... 8 will test pos ... 2 will not ... 1990 do not have the virus ... 199 will test pos a) 207 people test pos ... 8 of them have it ... 8/207 = .0386 b) 1793 people test neg ... 2 of them have it...
February 18, 2017

physics
20^2 = 10^2 + v^2 sin(?) = 10/20 ... north of west
February 17, 2017

College Chem
heat gained by water equals heat lost by metal 50.0 * (t - 20.0) * 4.182 = ... 1000 * (100.0 - t) * 0.50
February 17, 2017

Physics
you know the size of the disk, and the material (aluminum) calculate the volume and look up the density
February 17, 2017

Physics 202-help
15/3 = 5 ... storm distance in km 15s * 343m/s = theoretical distance the time for the light to travel is below the sig fig of the other measurements ... it can be considered instantaneous
February 17, 2017

backwards math
(6 + 6 - 5) * 4
February 17, 2017

Algebra
u = t + 7 10u + t = 3(10t + u + t + u) ... = 33t + 6u 4u = 32t solve the system by substitution or elimination
February 16, 2017

math
x (154) + (40 - x)(170) = 40 (160)
February 16, 2017

Math
v / 125 = [v / (125 + 25)] + 4/3
February 15, 2017

Physics
1) the sound goes over and back ... 2 w =5.7 * 343 2)velocity = frequency * wavelength ... v = (2.22 / 7.59) * .168 m
February 15, 2017

Physics
3 s measures the km to the lightning 5 s measures the miles
February 15, 2017

Algebra
(k - 10)(k - 2) (2x + 7)(3x - 2)
February 15, 2017

maths
45 * (1 + .10)^20
February 15, 2017

too-hard probability sir damon/reiny/steve help
"you can lead a horse to water...but you can't make him drink"
February 15, 2017

too-hard probability sir damon/reiny/steve help
this is binomial...with a twist P(b) = .4 , P(w) = .6 (b + w)^4 b^4 + 4 b^3 w + 6 b^2 w^2 + 4 b w^3 + w^4 P(w ? 0) = 1 - P(b = 4) = 1 - .4^4 P(b = 2) = 6 * .4^2 * .6^2 divide to find the conditional
February 15, 2017

Physics
the given data is unrealistic please check it
February 15, 2017

physics
the ball is uniformly accelerated by gravitational force the velocity is zero at the peak 1.5 s before the peak, the velocity is ... 1.5 * g upward 1.5 s after the peak, the velocity is ... 1.5 * g downward
February 14, 2017

PreCalc
18 t + 5 t - 5 = 12
February 14, 2017

Algebra 2
x y = k
February 14, 2017

Algebra 2
the job takes 96 people-hours so for 3 people... 96/3 hr
February 14, 2017

Exponential Equation
4E12 = 24 * e^388r ln(1.7E11) / 388 = r
February 14, 2017

Math
3 1/2 is 28 eighths
February 14, 2017

Math
the scale is logarithmic 10^(8.3 - 6.2)
February 14, 2017

Geometry
the four given sides sum to 24 so the 5th side is 6 ... 30 - 24
February 14, 2017

Algebra
x + 2y = 150 x + 4y = 260 solve the system
February 14, 2017

physics
the net force is ... f = m a ... f = 111.5 * 2.7 net force is tension minus gravity t = 111.5 (9.8 + 2.7)
February 13, 2017

Chemistry
2 KClO3 ---> 2 KCl + 3 O2 moles O2 = 3/2 * moles KCl moles KCl = mass KCl / molar mass KCl mass O2 = moles O2 * molar mass O2
February 13, 2017

chemistry
find grams of C in CO2 and grams of H in H2O convert the grams to moles (divide by the molar masses) the mole ratio will give you the empirical formula
February 13, 2017

college algebra
h = 1/2 g t^2 + v t + Ho 44 = -4.9 t^2 + 20 t + 37 solve the quadratic for t
February 13, 2017

Math! Please help!
15 ? -k/4 - 9 24 ? -k/4 96 ? -k ... -96 ? k
February 13, 2017

Chemistry
381 pm is the edge length of the cubic unit cell the atomic radius is the edge length multiplied by ... ?2 / 4
February 13, 2017

Math
2 is 12/6 so you need the lowest common multiple of 12 and 5 ... 60 60/6 = 10 ... five 2 lb bags
February 13, 2017

math
looking at the cross section, this is a circle in an equilateral triangle
February 13, 2017

math
looks good
February 13, 2017

math
plug the points into the general equation and solve the system P...1 = a - b + c Q...1 = a + b + c R...6 = 25a + 5c + c
February 13, 2017

math
P and Q are the same point need 3 DIFFERENT points
February 13, 2017

Chemistry
22.4 L/mole ... gas at stp octane is 114 g/mole 2 C8H18(g) + 25 O2(g) ---> 16 CO2 (g) + 18 H2O(l) (39.0 / 114) * 12.5 * 22.4 L
February 12, 2017

physics
work = force * distance f = 5497 / 22.1 a = f / m = 5497 / (22.1 * 3090) d = 1/2 a t^2 ... t = ?(2d / a) v = a t
February 12, 2017

Algebra
3a + 9c = 183 ... 6a + 18c = 366 6a + 13c = 276 subtract equations to eliminate a solve for c, then substitute back to find a
February 12, 2017

Algebra
(r + 3) / 79 = r / 15 15 r + 45 = 79 r
February 12, 2017

sciance
depends on the car
February 12, 2017

Physics
yes the up-thrust (bouyancy) is a function of the VOLUME of liquid displaced
February 12, 2017

grade7 math
the rectangle with the least perimeter is a square
February 12, 2017

Chemistry
you aren't given the atomic mass not enough data for a solution
February 11, 2017

Chemistry
the volume of hexane is ... 338 g / .66 g/mL the height of the liquid is ... (hexane vol) / (? *2.91^2)
February 11, 2017

physics
energy = 1/2 m v^2 energy / time = power
February 11, 2017

Algebra 2
a^b = 3^3 3^(1/2)^x = a^(1/6) 3^3^x = a 3^3 = a^(1/x) x = 1/b
February 11, 2017

math
the slope is the same everywhere on the line slope = (-5 - 7) / (-5 - 4)
February 11, 2017

math
the distance is constant, so speed and time are inversely proportional t / 28 = 65 / 78
February 11, 2017

Math
c (100% - 56%) = 202.92
February 10, 2017

Math
m = [(91 - 44.39) / 44.39] * 100%
February 10, 2017

physics
how thick is the ice?
February 9, 2017

math
adding equations to eliminate e ... 3d = 12 solve for d, then substitute to find e
February 9, 2017

Math
3.36E6 poeple / 3 per household = ... 1.12E6 households 2 bags per month = 24 bags per year ... 10 lbs per bag 1.12E6 * 24 * 10 = ?
February 9, 2017

Math
a square m is 10000 square cm
February 9, 2017

chem
it will appear that there are more moles of solute than are actually present you will be dividing the mass of added solute by too large a number ... this will result in the molar mass being too low
February 9, 2017

geometry
the two angles sum to 180º x + (4x + 50) = 180
February 9, 2017

Chemistry
that's what you start with ... some of it is precipitated out also, the volume of the solution is more than doubled (remaining PbCl2) / solution volume
February 9, 2017

Science ms sue please help
the question specifies "chemical property"
February 9, 2017

Science ms sue please help
if there is no reaction...what are you observing?
February 9, 2017

algebra
c + r = 4.5 14c + 8r = 51 solve by substitution or elimination
February 9, 2017

Mathematics
x = -3 (y + 1) x^2 = 9 (y^2 + 2y + 1) substitute and solve for y there will probably be two solutions ... the intersection(s) of a circle and a line
February 9, 2017

Algerbra
the vertex is on the axis of symmetry ... x = -b / 2a f(x)=x^2+2x-3 ... x = -2 / 2*1 = -1 f(x)=x^2-3x+1 ... x = - -3 / 2*1 = 3/2 plug the x's into their functions to find the y's for the vertex coordinates
February 8, 2017

math
sin(0) = 0 ... sin(90) = 1 so ... sin(50) > sin(40) cos(0) = 1 ... cos(90) = 0
February 8, 2017

Chemistry
there are 1000 L in a cubic metre so the density is 3000 g/L the molar mass is 44.956 g so one L contains ... 3000 / 44.956 moles the number of unit cells is half the number of atoms the volume is ... 1 L / [(3000 / 44.956) * 6.02E23 / 2]
February 8, 2017

math
d = 3 q 10 d + 25 q = 385 solve the system using substitution or elimination
February 8, 2017

Further Mathematics
11th term is 10 cr from 1st term 7 * 3^10
February 8, 2017

Math
-5 = -a + b - c y' = 3a x^2 + 2b x + c ... 4 = 3a - 2b + c y" = 6a x + 2b ... 0 = -6a + 2b 3 equations, 3 unknowns ... solve the system
February 8, 2017

mATH
520 X [1 + (0.04/12)]^60 IS THIS RIGHT WAY TO DO THIS just clarifying
February 8, 2017

Physics
150 kN to pull 12 cars to pull one car ... 150/12 kN
February 8, 2017

physics
momentum is conserved (75 * 2) + (50 * v) = 0
February 8, 2017

Math
x * x * (x - 3) * (x + 1)
February 7, 2017

Chem
reacts with water to form sulfuric acid this is the "acid rain" reaction
February 7, 2017

Math
it's an even power regardless of the sign of x, f(x) will always be positive
February 7, 2017

Math
h + c = 160 ... 200 h + 200 c = 200 * 160 500 h + 200 c = 369 * 160 subtract equations to eliminate c solve for h, then substitute back to find c
February 7, 2017

Mathematics
the area of the bottom of the box is ... 3456 / 6 = 576 (x + 12) [(576 / x) + 12] = 1500 x is one dimension, 576/x is the other
February 6, 2017

Physics
800 N * 20 m = 16000 J per second means 16 kilowatts
February 6, 2017

Math
h(g(x)) = 9 - (x + 3)^2 ... = -x^2 - 6x the max is on the axis of symmetry ... x = -b / 2a = 6 / -2 = -3 plug in -3 to find the maximum
February 6, 2017

science
v = mass/density = 2.4 kg / 2.70 g/cm^3 2.4 is only 2 sig fig
February 6, 2017

  1. Pages:
  2. 1
  3. 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. Next>>