# Posts by Scott

Total # Posts: 3,574

**Math**

D = k v^2 ... 90 = k * 70^2 ... k = 9 / 490 D = (9/490) * 71^2

**physical science**

force times distance equals work (energy)

**physical science-asap**

work (energy) = force * distance 10 J = 10 N * ?

**Math**

looks good

**Physics**

momentum is conserved the mass is doubled, so the velocity components are halved ... 1 m/s N and 5 m/s E magnitude of v ... v^2 = 1^2 + 5^2 direction ... tan(?) = 1 / 5 ... ? is the angle north of east

**Math**

R = .1639 V^2 R = .1639 * 215^2

**physics**

the tension in the string provides a horizontal force of 5.8 lb, and a vertical force of 10 lb tan(?) = 10 / 5.8

**Math**

A = k B^2 a) 45 = k * 3^2 ... k = ? b) A = ? B^2 c) A = ? * 6^2

**physic**

f = G * M1 * M2 / r^2 7.30E25 = 6.67E-11 * M1 * M2 / 1.50E12^2 solve for (M1 * M2) M1 + M2 = 6.00E30 substitute to find M1 and M2

**algebra 2**

f(x) = (x + 1)(x + 1)(x - 6) multiply the binomials

**Math**

yes

**Science**

the gravitational attraction of the masses is what holds the moon in orbit gravity provides the centripetal force for the circular (mostly) path

**Geometry**

you're doing fine plug in all the numbers you have, and solve for the missing side (the only non-number)

**Physics**

v = (96000 m/hr) / (3600 m/s) = ? m/s r = 70 kg * v^2 / 856 N

**Physics**

f = m v^2 / r ... r = m v^2 / f do the suggested conversion to get the right units

**Honors Geometry**

Steve ... since the problem says so

**Honors Geometry**

the diagonals of a kite are perpendicular the angles at the ends of the longer diagonal are congruent the right angle is at one end of the shorter diagonal, and is bisected by it ... this means there are two isosceles right triangles on the longer side of the shorter diagonal...

**physics please help!!**

f = k Q1 Q2 /r^2 = 9E9 * (3E-9)^2 / .1^2 F = 8.1E-6 N

**physics please help!!**

use the electrostatic force equation also, nano is E-9

**physics**

the electrostatic force equation will solve all your problems

**physics**

the charge gained by the balloon is lost by the denim so you have two opposite charges of known size, and you know the distance between them google "electrostatic force equation"

**Physics**

3600 s per hr convert one of the units

**Physics**

one MeV is 1.60E-13 Joules proton mass is 1.67E-27 kg 1/2 m v^2 = 1.25 * 1.60E-13 J = 2.00E-13 v^2 = 2 * 2.00E-13 / 1.67E-27 v = 1.55E7 m/s proton charge is 1.60E-19 C ... same as electron, opposite polarity current is charge per unit time past a given point ... C / s the ...

**Physics**

google these ... mass of proton, charge of proton, Joules to MeV

**Algebra 2**

[(14 - 2) / d] + [(14 + 2) / d] = 7

**Math**

dividing by A ... D/A + E/A = 1 ... E/A = .15 (N/A) / (E/A) = N/E = .18 / .15

**Math**

5 d = 20 ... d = 4 T5 + 11d = 3 T5 ... T5 = 22 T1 = T5 - 4d

**chem**

the diagonal of a face of the unit cell is equal to 4 times the atomic radius

**Math Algebra Help**

matches in nth round = 2^(7 - n) total matches = 64 + 32 + ... + 1 = 2^7 - 1

**maths**

8 s = 7.5 (s + 4) solve for speed (s) substitute back to find distance

**Geometry**

the Law of Sines says that the length of the sides is the same ratio as the sines of the angles opposite the sides angle 1 is 90º ... sine is 1 sin(angle 2) / 1 = side 2 / 5 mm do the same with angle 3 and side 3

**math**

.11 m + 11 < .08m + 23 .03 m < 12 m < 400

**chem**

P1 V1 / T1 = P2 V2 / T2 610 * 200 / (45 + 273) = 760 * V2 / (0 + 273)

**math, algebra, word problems**

it takes Gary two hours to catch up to Greg at the finish because Gary goes 12 miles/hour, Greg finished 24 miles ahead of Gary every hour, Greg travels 4 miles more than Gary ... so it took Greg 6 hours to get a 24 mile lead and finish the race Greg goes 16 miles/hour, so in ...

**geometry**

h^2 = 20^2 - 4.5^2

**Algebra**

(fºg)(4) means f[g(4)] g(4) = -2(4) - 6 = ? f(?) = 3? - 7

**Math - binomial**

the "center or middle" term ... 7th

**Geometry**

Damon didn't mean radius, he meant half of the chord length draw the picture and you will see

**Math**

expected return per play ... (20 * 12/30) + (10 * 8/30) - (30 * 10/30)

**Chemistry**

(4.951 / molar mass CO2) = moles C = x (2.027 / molar mass H2O) / 2 = moles H = y k[x(molar mass C) + y(molar mass H)] = 56.11 molecular formula is ... C(kx)H(ky) divide kx and ky by GCF to find empirical formula

**Chemistry**

a liter of the wine has a mass of 930 g 14% is ethanol ... .14 * 930 = ? calculate the ethanol mass divide by the molar mass to find the moles in the liter of wine (molar concentration)

**Math - binomial**

an expansion of ... (a + b)^k for the nth term ... (k)C(n-1) a^(k-n+1) b^(n-1)

**Math - binomial**

x^40 + 40 x^38 + 780 x^36

**science**

m g h

**physic**

this seems like part of a series of questions ... the note about values from previous answers planetary orbits are elliptical, with the sun at one of the foci perihelion is the closest approach to the sun ... distance from vertex to focus aphelion is the farthest distance ... ...

**physics**

Earth radius is 6371 km ... google orbit radius ... 6371 + 616 circumference ... 2 ? r (a) speed = circumference / period (b) a = speed^2 / r

**physic**

9.11E-31 Kg ... from google the speeds are not close enough to c to worry about relativistic effects

**Math**

6 4/5 is greater than 1 ... so it's more than 100%

**physics**

v = dx/dt = 3A t^2 + 2B t + C solve for t=12 a = dv/dt = 6A t + 2B solve for t=0.5

**physics**

v = dx/dt = 3A t^2 + 2B t + C solve for t=12

**Math**

looks good don't know Ms. Sue

**Math**

volume = width * depth * length

**math**

the ratio of the sides must be ... 12:16 = 3:4 = 6:8 = 9:12

**6thMath**

time = speed / distance

**Math**

150 / 10 = 120 / 8 = ? / 1

**Science**

things external to the car move in reference to the car

**Math**

out of control spell check?

**Math**

repeating? yes

**Math**

they used a z-score table to find the portion of the population between 3/13 s.d below the mean, and 15/13 s.d. above the mean 3/13 = .231 s.d. ... z-score below mean 15/13 = 1.154 s.d. ... z-score above mean take the z-scores into the table, and it will give the portion of ...

**basic chem**

google "face centered cubic cell" the length of the diagonal of a face of the cube is two atom diameters the cube edge length is ?2 times the atom diameter the volume is the edge length cubed (^3)

**math in society**

google "annuity payments formula"

**Physics**

w = f * d the mass is accelerated ... a = f / m = 9.0 / 18.0 d = 1/2 a t^2 ... find the distances at the various times the 4th sec is from 3 s to 4 s

**math**

7% of 8250 is 577.50 ... yearly interest

**Math**

v = 1/3 * base area * height 4000 = 1/3 * 40 * ?

**Math**

The volume of a rectangular pyramid is 4,000 cubic feet. The area of the base is 40 square feet. What is the height of the pyramid?

**math**

better for what? a sphere is the most volume per surface area ... melts slowest

**Science**

google "earth axis wobble"

**Physics**

use the freefall equation to find the flight time ... h = 1/2 g t^2 + vo t + ho ... 0 = -4.90 t^2 + 0 + 12.0 (b) flight time * 8.50 m/s (a) the dog must run as fast as the horizontal component of the ball's velocity ... 8.50 m/s

**Physics**

the deflection is vertical AND horizontal ... two sets of plates the "thin air" in the question is basically vacuum ... check your epsilon value

**Math**

there are 36 possible outcomes 2 ways to get a 5 and a 6

**physics**

the string provides the centripetal force a. a = v^2 / r b. f = m v^2 / r

**science**

electric field strength follows the inverse square law f d^2 = (3f) D^2 D^2 = d^2 / 3 D = 8.5 / ?3

**Trigonometry**

sine function it starts at the median (average) day length and increases to the summer solstice, then decreases to the winter solstice, then increases back to the average at the vernal equinox the midline is the average ... (9 + 17) / 2 the amplitude is max minus average the ...

**Physics**

f = m a ... 110 = .5 a a = ?v / ?t 110 = .5 (9.2 + 4.9) / t

**physics**

a mmHg equals 133.3 Pa (google conversion) find the pressure difference (in kPa) a Pascal is a Newton per m^2 ... 10^4 cm^2

**physics**

1) the horizontal velocity stays constant ... the vertical velocity is decreased by gravitational acceleration ... 9.8 m/s^2 ... 22 - (1.7 * 9.8) ... add the two velocity vectors to find the resultant 2) you have the vertical velocity at 1.7 s ... average it with the initial (...

**Chemistry Hess’s Law**

multiply 3rd eqn by 4 ... 2 N2 + 6 O2 + 2 H2 —> 4 HNO3 -696kJ reverse 2nd eqn and multiply by 2 ... 4 HNO3 —> 2 N2O5 + 2 H2O +154kJ reverse 1st eqn and multiply by 2 ... 2 H2O —> 2 H2 + O2 +572Kj add the the three eqn, cancel identical items on both ...

**math**

it is free the sum of the EXTERIOR angles of a polygon is 360º decagon has 10 sides (and angles) each exterior angle is ... 360º /10 each interior angle is ... 180º - (360º /10)

**Pre Algebra (8th)**

v = base area * length = 1/2 * 2 * 12 * 18

**Maths**

(x^2 - 3y)(x^2 + 2y)

**Algebra**

p + w = 720 / 2 p - w = 720 / 3 add the equations to find p substitute back to find w

**Chemistry**

the Cr atoms are not balanced in the 1st equation ...probably the source of your trouble chromate vs. chromite

**Physics**

work = force * distance units are Joules (same as energy)

**math**

Determine whether a figure with the given vertices is a parallelogram. Use the method indicated. A(3, ? 9), B(10, 1), C(4, 10), D(?9, 3); Distance and Slope Formulas

**math**

a^2 + b^2 = c^2 ... (?7)^2 + 3^2 = 4^2 construct a 3" segment with a perpendicular at one end at the other end strike a 4" radius arc the arc intersects the perpendicular ?7" from the right angle

**math**

a square, with an edge length of one unit a square is a subset of all the other figures it is a parallelogram, rhombus, and rectangle

**math**

Given the set of vertices, determine whether parallelogram ABCD is a rhombus, a rectangle, or a square. List all that apply. A(5, 10), B(4, 10), C(4, 9), D(5, 9)

**AP Chemistry**

convert the 4.7 g to moles by dividing by the molar mass you have the L (convert to mL if needed) then go for it

**Chemistry**

[(molar mass of N)^2 / (molar mass HNO3)] * .025

**math**

a square tile with a 2 ft perimeter is 1/2 ft on each side you can fit 16 tiles on the 8 ft dimension, and 12 on the 6 ft dimension 16 * 12 = ? 2/3 * 1.4 * 1.5 = ? w = 3 b r = 2 w = 6b b + 3b + 6b = 10b fraction r = 6b / 10b = 6/10 = 3/5 so, not r is ... 1 - 3/5 1 out of 3 for...

**Algebra 2**

(goh)(0) ... g[h(0)] h(x) takes the place of x in g(x) h(0) = 0^2 + 4 = 4 g(4) = 2 * 4

**Algebra 2**

(2x^2+x-3) / (x-1) = 2x - 3 you can use "long" division or synthetic division the domain is all real numbers except 1 ... x = 1 makes the denominator of the fraction zero ... a big no-no

**Chemistry/Science**

ALWAYS add acid to water water to acid may flash to steam if the acid is concentrated enough

**Chemistry/Science**

add one part of the 6M acid to five parts of water

**Pre-Cal**

17000 = 12000 (1 + .05)^y log(17/12) = y log(1.05)

**calculus**

1 to 5 is 4 units, so each rectangle is one unit wide the height of each rectangle is x^2 ... x equals one to four ... under the curve find the combined area

**Maths**

(3x+ 1)^2 = (3x - 1)^2 + x^2 9x^2 + 6x + 1 = 9x^2 - 6x + 1 + x^2 x^2 - 12x = 0 ... x = 12

**Physics**

energy (kinetic) is ... 1/2 * 2 * 3^2 work done by friction equals initial energy frictional force * distance = K.E. frictional force = weight * coefficient m g * ? * 2.5 = K.E. solve for ?

**PreCal**

[3 (360/25)] / (2 ?) your answer looks good

**Please help MATH**

perpendicular means slopes are negative-reciprocals easiest to see in point-slope ... y = 2x + 3 so -1/2 is the new slope ... A or D plug in the point (8,2) to check which one