# Posts by Scott

Total # Posts: 2,571

physics problem
(2 * ? * 34 cm) / 39 m/s watch your units

Science
correct why the confusion?

Science
sounds like fermentation if there is oxygen, you get vinegar instead of wine

math
a- A = 12000 [1 + (.039/12)]^(6 * 12) b- subtract 12000 from a-

maths
no the ratio between the sides is not equal

math
A does 4/60 and B undoes 3/60 so 1/60 completed every 2 days after 112 days, 56/60 are done ... A completes the work on the 113th

algebra
6C3 ... 6! / (3! * 3!)

Math
it's a system of equations 5 V + 3 C + 2 M = 675 V = 2 C M = C + 75 substitute and solve

Math
x = 6 * 2^n

physics
cool the steam to 100ºC condense the steam cool the water to 0ºC freeze the water two specific heats heat of vaporization, and heat of fusion

Math
(300 / 500) * 250,000

Physics 1401
the center of mass of the stick is at the 50 cm mark ... 10 cm from the balance point the 6 g is 30 cm from the balance 10 * m = 30 * 6

Physic sucks 1401
the masses are linked by the string and have the same acceleration ... one upward and the other downward f = m a ... a = f / m (t - m1 g) / m1 = (m2 g - t) / m2 2t - 2g = 2g - t ... 3t = 4g ... t = 4/3 g the largest mass is 2 kg ... it gives about 20 N of force with the system...

Geometry Proofs
My teacher said she gave us everything.

Geometry Proofs
Trying to solve a proof. Triangle ABC. D is a point on side AC and E is a point on side BC. There is a line from Angle B to Point D and a line from Angle A to Point E. My Givens are AD = BE and BE>AE. I need to prove BC>AC. This is for my 7th grade geometry class. Thank ...

Chemistry
no some are not water soluble

math
look at 100,000 people 800 have it ... 56 will show negative ... 744 will show positive 99200 don't have it ... 2976 will show positive probability of accurate positive ... 744 / (744 + 2976)

math
(2 * 27.5) + 30/2

Math - combinatorics/ permutations
looks good

Chemistry
molarity is moles solute per liter of solution 0.05144 moles / .38 L = ? significant figures?

science
a + b = 29 a - b = 5 2a = 34 ... a = 17 ... b = 12 (17 + 3)^2 + (12 + 3)^2 = r^2

Physics
m g h + 1/2 m v^2 = 1/2 m V^2 (2 * 9.8 * 65) + 12^2 = V^2

Mathematics.
ER , 1/5 off , 4/5 normal , 80% normal ... normal = 64 / .80 MW , 15% off , 85% normal normal = 64.60 / .85

Math
the sides and angles must be congruent if they are "regular" octagons, the side lengths must be equal

math
looks good

physics
m g h / t ... 75 * 10 * 12 * .20 / 5

Physics
on the side of the -9 away from the +16 let d = distance from -9 16 (d + 8)^2 = 9 d^2

Math
the nearest point, the end of the chord, and the end of a diameter (opposite the point) form a right triangle the half of the chord forms the altitude of the triangle 4 / 7 = 7 / (d - 4) solve for the diameter (which is twice the radius)

Science
the product of force and time is 3 3 N for 1 s isn't realistic for golf, but it's easy to work with f = m a ... 3 = .05 a ... a = 60 m/s^2 t = 1 s , so the velocity is 60 m/s

Precalculus -- Systems of Equations
thank you, bob we all try to bring enlightenment where we can

Precalculus -- Systems of Equations
x^2 + y^2 = r^2 is a circle of radius r, centered at the origin x - 2y = 8 is a line the question is asking what r must be for the line to be tangent to the circle the radius is perpendicular to the line at the point of tangency ... it is the shortest distance from the line to...

Geometry
the radius of the tank is 36" (3 ft) looking a the tank in cross section the width of the gasoline surface is the base of an isosceles triangle the height is ... 36 - 18 the sides are ... 36 use the vertex angle to find the area of the sector of the circle then find the ...

math
6/7 = 0.857142857142... 6 digits repeating 327/6 = 54 R3 ... 3rd digit of 6

Math
A = 1/2 * b * h

Math
3 congruent triangles make up the 3 sides the area of a side is ... 198 / 3 cm^2 the slant height is the height of a triangular side you have the area and the height of a triangle ... how do you find the base length?

Math (Physics)

Solid figures
? * (d/2)^2 * 42 = 30 * 231

sale price = list price - discount

science
refraction is the quality that causes the bending (focusing) of light rays it's what allows lenses to function

Science
sure ... post them and someone will check

Science
looks good

Science
a mole of O2 gives 2 moles of ZnO the molar mass of O2 is ... ? 2.25 g is ? moles of O2 the molar mass of ZnO is ... ?

Maths
741 / (9 + 105) = 6.5 ... so there are 13 terms (105 - 9) / (13 - 1) = 8 ... the common difference is 8

Physics
f = m v^2 / r f = 43 N * (59/15.89)^2 / (.948/2.1)

math
check the sign

math
tan(?) = 8/10

physics
2) 2 sec up and 2 sec down 1) ave vel = 10 m/s 10 m/s * 2 s = ?

Math (Physics)

Math (Physics)
Rn = n^2 * R1 2.50E-3 m = n^2 * .53E-10 m En = (13.6 / n^2) eV

No one is helping me :/ ??
3 as an asymptote means that is the value that the function approaches as x goes to infinity

college algebra
only if the system is dependent ... which it isn't

college algebra
subtract the 2nd equation from the 3rd equation solve the two remaining x and z equations with substitution or elimination x + 2z = 5 3x - 4z = 15

Physics
a) 10/12 = (1/2)^(t/5700) [log(10/12)] / log(1/2) = t / 5700 b) use t from a) c = 12 * (1/2)^[(t+100)/5700] c / 12 = (1/2)^[(t+100)/5700]

math
2 log(x) + log(4) + 1 = 2 OR 40 x^2 = 100

physics
the resistance is directly proportional to ... length and specific resistance it is inversely proportional to the cross sectional area ... (square of the diameter) 4? * (2P / P) * (d / 2d)^2 * (3L / L)

Algebra 2
looks good

Math
the "degree" is the value of the largest exponent

Physics
the range formula is d= (v^2 / g) sin(2?)

Math
a = 24000 [1 + (.04 / 12)]^(30 * 12) 4% interest, compounded monthly

A = 1/2 b h solve this for b

Science
looks good

Physics
with g=10 the highest it gets is 5 m at t = 1 s

physics
force / distance

physics 10
the given explanation is reversed when the coefficient is changed by moving the decimal point, the exponent is changed to keep the overall value the same bigger coefficient means smaller exponent ... and vice versa

algebra
try fooplot online

MATHS
C is a right angle (corner of a rectangle) the bisector makes a 45º angle so CBX is an isosceles right triangle ... BX = BC

math
how many possibilities in each subgroup? ... 6Cn how many ways to combine the different subgroups?

physical science
speed is frequency multiplied by wavelength 250 waves per second each wave is 6.0 meters long

Physics
1 W·s = 6.24E18 ev

Physics
look up "heat of fusion" for lead it's like the specific heat, but for melting

math
let's say that the cube has an edge length of 3 units so the blue surface area is ... 6 * 3^2 each of the smaller cubes has an edge length of 1 unit so their collective surface area is ... 27 * 6 * 1^2

college algebra
w^2 + (180/2)^2 = (240/2)^2

story problem
the wires form a 30-60-90 right triangle, with the ground as the hypotenuse both of the smaller triangles are similar to the large triangle the length of the 2nd wire is half of the distance between the wires use Pythagoras or trig to find the height of the pole

Physics
cool steam to 100ºC condense steam to water cool water to 80ºC two specific heats (water and steam) ... one heat of vaporization

physics
heat ice to 0ºC melt ice heat water to 100ºC boil water heat steam to 125ºC specific heats - ice, water, steam ... heats of fusion and vaporization

math
feet, yards, meters

Science
m * g * h / t answer is in Watts

Math
complementary angles sum to 90º t < 2 s

Math
the (3x+12) term from Monica's factoring can be factored again into 3(x+4), leading to Ashely's result

Math
the numbers in the binary factors are factors of the constant term of the quadratic (-24) the sum of the numbers is the coefficient of the 1st order term of the quadratic (-5) the numbers -8 and 3 are factors of -24 that sum to -5 so the factors of the quadratic are ... (x - 8...

Algebra
they each do a fraction of the job (t / 40) + (t / 60) = 1

Science
don't know if you've seen video of a bouncing ball, but the bottom side flattens to provide the push for the bounce

physics
is relative mass the same as specific gravity? if the s.g. is 19, then the apparent mass (weight) in water is ... (19 - 1) g/cm^3 * 20 cm^3

Physics
divide the distance by c (speed of light) c = 3.00E8 m/s the frequency is not relevant

physics
heat lost by water = heat gained by unknown your method is fine

Physics
without knowing the speed of the train, there are no exact answers for b, c, and d you are correct for a b will hear a higher frequency c will hear a lower frequency d will hear the highest frequency ... the train (whistle) is moving toward the cliff, so the echo will be a ...

Math
The scores on the GRE are normally distributed with a mean of 541 and a standard deviation of 89. Use the 68-95-99.7 rule to find the percentage of people taking the test who score between 363 and 541

Linear Algebra
this should help p = 800 (1 - 0.13)^5

math
half of the numbers on the cube are even so a fair cube should have half of the outcomes even

Algebra
0 = -(x+2)^2 + 3 (x+2)^2 = 3 x + 2 = ±?3 x = -2±?3

Science
large nuclei split (fission) into smaller nuclei that have less binding energy the lost binding energy converts to heat through various processes

math
v = 4/3 ? r^3 through the magic of algebra... r^3 = 3/4 v / ? take cube root of both sides

Calculus
OOPS... missed the "anti" part that is the derivative

Calculus
4 (x^2 + 1)^-1 4 * -1 * (x^2 + 1)^-2 * 2x -8x / (x^2+1)^2

chemistry
diffusion rate is inversely proportional to the ? of the molecular weight CO2 / SO2 = ?(64.1 / 44)

pre-calc
inspection shows 1 as a root (zero) so (x - 1) is a factor dividing p(x) by (x - 1) will leave a quadratic that can be broken down

Chemistry
what reaction??

algebra