# 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)**

did you google Hubble's Law?

**Solid figures**

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

**6th Grade Math (Please Help It's Getting Late)**

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)**

the answer is asking for nanometers units?

**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

**Math- PLEASE HELP. I DONT UNDERSTAND THIS QUESTION**

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**

your solution looks fine

**Physics**

figure??

**Pre calc**

sin(?) = -5/13 , cos(?) = -12/13 cos(?) = .3?10 sin(? ? ?) = sin(?)cos(?) - ... cos(?)sin(?)