# Posts by Scott

Total # Posts: 2,313

Physics
k = f / e k1 e1 = k2 e2 e2 / e1 = k1 / k2

chemistry
call the 2nd gas B 3 g of B is half as many moles as 2 g of A B / A = 3 / 1

Jar Marbles
a) one of the five red marbles has the number 3 on it, so the probability is 1/5 b) two marbles have the number 1 on them, one red and one blue ... so the probability is 1/2

Maths
u = 2t - 6 10u + t = 10t + u + 9 substituting ... 20t - 60 + t = 10t + 2t - 6 + 9 solve for t, then substitute back to find u

physics
gravitational force follows an inverse-square relationship inverse of 1/8 is 8 ... 8 squared is 64

math
The Holy Father sent a courier from Rome to Venice, commanding him that he should reach Venice in 7 days. The most illustrious Signoria of Venice also sent another courier to Rome, who should reach Rome in 9 days. And from Rome to Venice is 250 miles. It happened that by the ...

Physics
the average velocity during braking ... (13.1 + 0) / 2 divide the stopping distance by the average velocity to find the time

Math
take out a common factor

Algebra
common factor 5x (x + 2)

Chemistry
the reaction equation is written in MOLES 2 moles NO plus 1 mole O2 yields ... 2 moles NO2 so 5 moles of O2 uses 10 moles of NO find the molar (formula) weight of NO, and multiply by 10

Physics
the delay time is down and back ... twice the depth

Physics
yes

Physics
how about 4 by 2.9 ...

Physics
time = √(2 * distance / acceleration) initial velocity = 2 (distance / time)

Chemistry
there are about 55.3 moles of water in a liter the mean (average) concentration of chloride ions will be twice the arithmetic average of the MgCl2 concentrations (two Cl- for each MgCl2) I would be tempted to disregard the 175 value as a "flier"...but that's up ...

Science Check my work PLS
#8 ... a range of 5 in the 3rd digit is fairly precise the accuracy is substantially flawed

Science
a = f / m = 3 / 1

physics
the period is related to the mass and the spring constant the amplitude is inconsequential

physics
momentum is conserved the 2nd (larger) piece moves in the opposite direction at 1/3 the speed

physics
P = m g h / t = 100 * 10 * 6 / 120 answer is in Watts

Calculus II
If f(x) - x cos (x), how many intervals would be needed to approximate with the Trapezoidal Rule with an error of E<.01?

Math 115
a million is a thousand thousand (276.5 / 3150.4) thousand per mi^2

Physics
Tn = d / 40 Ts = d / 60 Save = 2d / (5d / 120)

Physics
.6 g = v^2 / r

Calculus
f(x) = x^2 has a critical point (and a MINIMUM) at x=0 f(x) = (x^3 + 3x^2 - 4x - 12) / (x+2) ... has a critical point (and a "hole" at x=-2)

College math
p(white) = 9/24 = 3/8 p(green) = 8/24 = 1/3 p(w then g) = 3/8 * 1/3

Math (Condensing logarithmic expression)
ln{5^2 * [x / (x^2 + 1)^2]^3}

ACT math
h + s = 10 ... s = 10 - h 12 h + 14 s = 128 substituting ... 12 h + 14(10 - h) = 128 ... 12 h + 140 - 14 h = 128 ... -2 h = -12

Physics
gravitational potential energy becomes kinetic energy m g h = 1/2 m v^2 v = √(2 g h) = √(2 * 9.81 * 15.0)

Chemistry
the sulfite ion has a -2 charge Pb(SO₃)₂ the hydrogen phosphate compound is missing a subscript 4 Pb(H₂PO₄)₄

algebra 2
3/5 (∛5)^2

Physics
compressing 0 cm to 6 cm is equivalent to compressing 0 cm to 3 cm, and continuing to compress 3 cm to 6 cm although the compression lengths are the same for the two parts, the 2nd part takes more work because the resistance of the spring increases with compression 0 to 6 uses...

Calculus
points with the same x or y coordinate represent vertical or horizontal chords of the circle the perpendicular bisectors of the chords are diameters, and they give one of the coordinates of the center you can use the distance formula to find the other coordinate of the center ...

math
you don't show any of the data, but it's very likely that the line doesn't go through the origin (0,0) there is probably some base rental charge (represented by the intercept)

Chemistry
E = m g h ... h = E / (m g) h = 628 kJ / (70 kg * 9.81 m/s^2) 1 Joule = 1 kg m/s^2

Physics
the ball is uniformly accelerated by gravity average velocity = ... (final vel. + initial vel.) / 2 6.5 m / 3.1 s = (V fin + 0) / 2

Math (calculus 3)
the given height equation is incorrect ... the t^2 coefficient is -16, not -8 solve away...

MATH
try again when the bases are the same, just add the exponents 3^2 x 3^2 = 9 x 9 = 81 = 3^4 ... not 9^4

MATH
try again when the bases are the same, just add the exponents

help plzz asap
the trains are closing at 110 mph ... (50 + 60) t = d / r = 330 mi / 110 mph

Physics
the .410 coefficient means that the max acceleration is .410 g

v^2 / r = 5 g r = v^2 / (5 g) r = (288 km/h)^2 / 49 m/s^2 r = (80 m/s)^2 / 49 m/s^2

Math
Oops forgot one step Ignore my first answer Step 1.)5*15=x Step 2.)x*5=Answer

Math

Math~ Algebra 1
Thank You

Math~ Algebra 1
Two cars are traveling on the same highway. The first car is traveling at an average rate of 44mi/h. The second car leaves an hour late traveling at an average rate of 55mi/h. How long will the cars have traveled when the second car catches up with the first car?

Math
2 dived by 1/4= 8 banners

Science
the -256 C gas is hydrogen oxygen is -183 C they are both diatomic gases the volume of hydrogen (g) produced is twice the volume of oxygen (g)

Algabra
H < D < T H + 2 = D ... D + 2 = T 3 D = 2 T + 13 3 D = 2 (D + 2) + 13 = 2 D + 17

Math
draw a picture of the map for b they give you all the dimensions you need

Math
6 inches on the map equals 72 miles on the ground a. 1 inch equals 12 miles b. 2 inches on the map equals 24 miles on the ground

Math
L + P + N = 4050 L = P - 326 2 (L + P) = N L + P + 2L + 2P = 4050 L + P = 1350 (P - 326) + P = 1350 2 P = 1676

physics
the trains are closing at 50 kph (25 + 25) they start 150 km apart, so it takes them 3 hr to meet (and pass) the bird flies for 3 hr at 50 kph, so it flies 150 km

physics
the speed of sound in air is approximately 340 m/s the speed of light (from the flash) is approximately 3E8 m/s ... instantaneous for practical purposes so the distance to the bolt is ... 3 s * 340 m/s

Biology
if the dress absorbed red light, then red would not be reflected to your eyes ... the dress would not look red

chemistry
carbon dioxide is 32/44 oxygen by mass 3.70 g / (32 / 44)

physical science
weight is directly proportional to mass and gravitational acceleration ... w = m g w = 81.4 * (8.87 / 9.81)

Physics
f = m a m g - t = m a t = m g - m a = m (g - a) t = 2.45 (9.80 - 2.55) answer units are Newtons

physics
the free-fall equation is ... h = -4.9 t^2 + 12 t + Hb a. 0 = -4.9(3.4)^2 + 12(3.4) + Hb b. Tmax = -12 / (2 * -4.9) ... plug Tmax into the free-fall equation to find Hmax c. v = g(3.4 - Tmax)

PHY
h = 1.41 tan(34.7º)

physics
the increase in kinetic energy is from (equal to) the decrease in gravitational potential energy v^2 = 2 g h = 2 * 980 * 40 sin(.1 rd)

Physics
50 (5 + d) + 25 d = 200 (5 - d) 250 + 75 d = 1000 - 200 d 275 d = 750

PRE-CAL
2 = e^(11r) r = ln(2) / 11 1600 = P e^[10 ln(2) / 11]

Maths
a + b = 8 7 a^2 = 2 b^2 + 13 7 (8 - b)^2 = 2 b^2 + 13 448 - 112 b + 7 b^2 = 2 b^2 + 13 5 b^2 - 112 b + 435 = 0

Physics
from the general free fall equation 0 = -4.9 t^2 + 5 t + 98 v = -9.8 t + 5

Physics
see earlier post

Ashley
the distance equals the flight time multiplied by the horizontal component of the takeoff speed t = 2 {[s * sin(27.1º)] / g} d = t * [s * cos(27.1º)] 7.73 = 2 * s^2 * sin(27.1º / 2) / g

Statistics
see earlier submission

Math
p(not correct) = 1 - .797 p(at least one) = 1 - p(none) p(none) = (1 - .797)^3

Chem
g/ml * ml ---> g

Physics
one cycle (rotation) in 12 hrs (12 * 60 * 60) sec per cycle (1 / 43200) hz

chemistry
c - 44 = f f = (9/5 c) + 32 substituting ... c - 44 = (9/5 c) + 32

precalc
w^2 + (π/2) (w/2)^2 = 240 ft^2 w^2 [1 + (π/8)] = 240

chemistry
the ratio of NH3 to H2O is 4:6 or 2:3 NH3 / 2 = H2O / 3 NH3 = 2/3 * H2O 2/3 * 8 = ?

math
5 + 4i

RPS
6a + 5d = 6 ... a = 1 - 5d/6 (2a + d) (5a + 4d) = -80 ... 10 a^2 + 13 ad + 4 d^2 = -80 substitute for the value of a solve for d substitute back to find a

math
looks good

physics
looks like gravitational potential energy the energy equals the mass of an object, multiplied by the gravitational acceleration, multiplied by the height of the object

Physics
100 N * sin(45º) * 10 m = ? Joules

Physics
the height of the tree is ... 54 tan(30º) m

algebra 2
mary has a two hour head start she is 120 mi (2 * 60) ahead when tom starts tom catches up at 10 mph (70 - 60) it takes tom 12 hr (120 / 10) to catch up 12 hr from 8 am is 8 pm

physic
speed = wavelength * frequency so, the speeds are in the same ratio as the wavelengths sglass = sair (wglass / wair)

SCIENCE
you're multiplying 3 sf by 4 sf the result will have the smaller number of sig figs a trailing zero without a decimal point is not significant

Math
this is a Pythagorean triple ... 3-4-5 times 2 ... 6-8-10 x^2 + (x + 2)^2 = 10^2 2x^2 + 4x - 96 = 0 x^2 + 2x - 48 = 0 (x + 8) (x - 6) = 0 x = 6 ... x + 2 = 8

Chemistry
distributing on the right ... 3.6 v = 2.7 v + (2.7 * 4.9) subtracting 2.7 v ... .9 v = 2.7 * 4.9

Chemistry
How did the left side of the equation went from 3.6*V to .9V?

Chemistry
p₁ v₁ = p₂ v₂ 3.6 * v = 2.7 * (v + 4.9) .9 v = 2.7 * 4.9 ... v = 14.7 the evacuated flask means that no additional air was introduced into the system ... just a volume increase with a corresponding pressure decrease

Chemistry
A flask of known volume was filled with air to a pressure of 3.6atm. This flask was then attached to an evacuated flask of known volume and the air was allowed to expand into the flask. The final pressure of the air (in both flasks) was 2.7atm and the volume of the second ...

physics
a slingshot launches a rock straight upward at 25 m/s, how high does the rock go, how long is it in the air, what is the velocity and the acceleration of the rock at its highest point

physics
a greyhound is capable of running at 40 mph, how many meters could the greyhound run in 3 minutes at this speed, how many seconds would it take the greyhound to run 1 km at this speed

Chemistry
so the concentration of H⁺ from the HCl is ... 1 mole in 6 moles of water pH is based on moles of H⁺ per liter of solution water's volume is 18 mL per mole (based on the molar mass) so 6 moles is 108 mL so, [H⁺] = 1 mole / .108 L pH is the negative log of...

Physics I - Modern
the momentum is the product (multiply) of the relativistic mass and the velocity the relativistic mass is the rest mass multiplied by gamma (the relativistic "fudge factor") gamma = 1 / sqrt[1 - (v² / c²)] p = gamma * rest mass * v hyperphysics (web) is a ...

math
that is the number for all correct (or incorrect) see the answer to your other posted question

math
(a) it is a normal distribution (bell curve)n with the most likely score being half right (or wrong) you could plot the points using your binomial distribution from part (b) (b) the exponents in an individual term should sum to 15 only your last term does that otherwise, looks...

Chemistry
H₃BO₃ is triprotic (3 H⁺ per molecule) 29.15 * .025 = M * 3 * 25.0

Algebra
x (7 - 2x) (12 - 2x) = 33 4x³ - 38x² + 84x - 33 = 0 (9 - √15) / 2