# Posts by Scott

Total # Posts: 2,123

**Math**

no ... is imaginary ... and irrational

**Math**

no ... is imaginary

**science**

a = f / m = 5224700 / 13500

**Algebra**

the corners are now three times farther from the origin just multiply each coordinate by 3

**Physics**

the beam weight is 50.3 N/m when Suki crosses a support to some distance (d), the equilibrium equation is ... (100.6 N * 1.00 m) + (595 N * d) ... = (251 N * 2.50 m) the distance from the end is ... 2.00 m - d

**Algebra2**

this is a circle, centered at the origin the domain and range are the same

**Math ASAP**

looks good

**Math**

180º - 65º - 65º = ?

**Calculus**

d = 2 r = 3 h ... r = 3/2 h v = 1/3 * ? * r^2 * h v = ?/3 * 9 h^3 / 4 dv = 9 ? h^2 dh / 4 dh = 4 dv / (9 ? h^2)

**Physics**

the incident angle is measured relative to the normal to the surface 90º - 60º = 30º

**Physics!**

.4 * 3000 = f (in Joules) 1) ma = 0utput / input = 3000N / 1000N 2) not enough info

**Math**

n, n+2, n+4 4(n+2) = n + n+4 + 2

**Physics**

that is the compression of the spring the more it's compressed, the greater the force

**Physics**

f = m a ... a = f / m a = (315 N * .15) / .00446 kg a is in m/s^2

**Physics**

ave speed = 1.4 rad/s stop time = 2 * ? * 60 / 1.4 acceleration = 2.8 rad/s / stop time ... negative ... wheel is stopping 30 * 2 * ? = 1/2 a t^2 + 2.8 t ... solve for t

**Precalc**

look at half the center 3rd it is a sector of the circle, with right triangles on either side the area of the sector is ... ? * r^2 * (?/360) ... ? being the central angle the combined area of the two triangles is ... r sin(?/2) * r cos(?/2) = r^2 tan(?/2) ? r^2 / 6 = r^2 [tan...

**math**

PEMDAS is the hierarchy of operations Parentheses...exponentiation ...multiplication...division ...addition...subtraction things in parentheses 1st ... 7^2 = 49 ...4 * 10 = 40 ...40 - 49 = -9 7 * -9 = -63 -63 + 4 = -59

**math**

.18 x + .40(10 - x) = .20 * 10

**Math**

like slicing bologna trees are cut on a "bias" to control the direction of fall

**Math - Trig**

Two buildings of equal height are 850 feet apart. An observer on the street between the buildings measures the angles of elevation to the tops of the buildings as 29° and 40°. How? high, to the nearest? foot, are the? buildings? I don't know how to set this up

**Trig**

the angle at the base of the pole is ... 90º - 8º the angle at the end of the shadow is the sun's angle the 3rd angle is opposite the 20 ft shadow use the law of sines to find the pole

**Physics**

the energy to lift the water is ... m g h = 10 kg * 10 m/s^2 * 10 m ... = 1000 J the kinetic energy of the water at delivery is ... 1/2 m v^2 ... = 1/2 * 10 kg * (10 m/s)^2 ... = 500 J 1500 J / s = 1500 watts = 1.5 kw

**math**

(1 - .75) * ? * 4 * r^2

**maths**

like the other one ... 5-12-13 tan = 12/5 sin = 12/13 cos = 5/13 cos(90 - ?) = sin (?) fyi ... holding down the 'alt' key while typing '233' will generate the '?'

**maths**

this is a 5-12-13 triangle cos = 5/13 tan = 12/5

**Chemistry**

don't know if sulfuric is moral or not ... however, it is diprotic (two H+) ?M = .16 * 25/17 * 1/2

**CIS**

1. you have 1GB and want to have 4 GB ... 2 open slots means a 1 GB and a 2GB module 2. 4 slots with 2GB each means max memory of 8GB

**Physic**

(a) w = m g (b) equal to weight (c) f = m a = 500 * 2.5 (d) moving (kinetic) (e) k = (7000 - 1250) / (m g)

**Physics**

some strike... impulse = change in momentum i = .34 kg (31.3 m/s - -6.18 m/s)

**Physics**

missed part (a) (a) voltage = [?(11.4/29.5)] * total R

**Physics**

I^2 = W / ? = 11.4 / 29.5 calculate I the resistors add in series power = I^2 * total R

**Math help plz?!!**

looks like your calculator is set on radians try again with degrees nearest hundredth is two decimal places

**Math! Help Hurry!**

same y-coordinates a vertical line length is the difference of the x-coordinates

**Maths**

think you are correct the question says p.a. (per annum) 58.7 is all four years ... divide it by 4

**maths trigonometry**

cos ? + 1 = 0 ... cos ? = -1 ... ? = ? tan ? - 1 = 0 ... tan ? = 1 ... ? = ?/4 , 5?/4

**Math(precalc)**

the logs are just (messy) numbers that you can distribute, add, subtract... [4 log(4)] x - 3 log(4) = ... [9 log(3)] x - 6 log(3) grind away...

**Algebra**

seven three with one top three with 2 top one with three top

**Physics**

e = (wavelength / c) * h c = speed of light h = Planck's constant

**math**

a square has FOUR equal sides 4 * 1/3(x+2) = 4/3 x + 8/3 = P 4/3 x = P - 8/3 4 x = 3 P - 8 x = 3/4 P - 2

**Biomechanics**

so what is her vertical velocity after one second? you found the correct acceleration

**Algebra, Math**

.3 x + [.1 (500 - x)] = .25 * 500

**math**

(x + 5)^2 + (y - 2)^2 = 676 plug in the points to check if they lie on the circle

**Science- Astronomy**

venus is closer to the sun and has a shorter "year" earth has a moon but venus has none

**science**

because the moon is between the Earth and the Sun the sunlight reflected off the moon, that we normally see, is pointed away from us this is when solar eclipses can occur

**Álgebra**

2 * [(8 * 14) + (8 * 10) + (10 * 14)]

**Math**

5C3 = 10

**Math**

inverse ... y gets smaller as x gets bigger x y = 10

**physics**

the KE of the bullet e = 1/2 * .02 kg * (150 m/s)^2 answer is in Joules

**SAT Math**

4/3

**Chemistry**

these values are negative logarithms of the concentrations so a bigger number means a lower concentration

**Science**

work = f * d = 60 * 2 = 120 J power = work / time = 120 / 10 = 12 W work is in Joules and power is in Watts

**homework**

36 m times 4 lengths per day times 7 days per week times 4 weeks

**Science**

the mass (in kg) multiplied by the gravitational acceleration (in m/s^2) gives the weight in N (Newtons) w = .0585 kg * 9.8 m/s^2 w = .04593 kg * 9.8 m/s^2 the g value is 2 sig fig, so that is what the answer will have

**Chemistry**

Thanks

**Chemistry **

Tooth enamel consist mainly of hydroxyapatite (Ca5(PO4)3(OH). When tine (II) Flouride is added to toothpaste it reacts with the enamel to product a more decay-resistant material fluorapatite (Ca(PO4)3F. The by-products of this reaction are tin (II) oxide and water. What mass ...

**Math**

adding the equations ... to eliminate y 3x = 3 solve for x, then substitute back to find y

**Calculus**

h = highway distance from intersection d = auto-to-farmhouse distance by Pythagoras ... d^2 = h^2 + 6^2 differentiating implicitly ... 2 d dd/dt = 2 h dh/dt dd/dt = h / d * dh/dt

**Science**

barium carbonate in the same family as calcium carbonate (chalk)

**pre calculus**

(a) time up = time down ... = 320 fps / 32 ft/s^2 (b) the velocity at a given height is the same upward and downward EXCEPT for the direction the max height is 1600 ft, which is reached in 10 sec ... the velocity is zero at this point 1584 ft is one sec below the max ... 9s &...

**Physics**

the time to fall is ... t = ?(2 * 54 / g) speed off cliff = 130 m / t

**Pre-Algebra**

4/3 * ? * r^3 = ? * r^2 * 3 4/3 * r = 3

**Algebra1**

-8 * 6^2

**Algebra1**

100,350,000 * (1 + .017)^15

**Science**

t = 8.9 / 4.57 stopping distance = (8.9 / 2) * t

**Physics**

t = d / r across ... t = d / 2 back ... t = d / 8 total time ... d/2 + d/8 = 5d/8 total distance ... d + d = 2d average speed ... 2d / (5d/8) = 16d / 5d

**Math**

50h + 25(3h) + 10(12h) + 5(12h + 2) = 925 50h + 75h + 120h + 60h + 10 = 925 305h = 915

**Chemistry **

Silicon Carbide, SiC, is prepared by heating silicon dioxide in the presence of graphite. Carbon dioxide is the by-product of the reaction. How many grams of silicon carbide can be formed from the reaction of 50.0 grams fo graphite with 50.0 grams of silicon dioxide?

**Chemistry **

A scientist studying the reaction between decaborane (B10H18) and oxygen mixed 1.00 x 10^2 grams of decaborane with 2.75 x 10^2 grams of oxygen. Compute the masses of all substance present after the reaction went ot completion, generating B2O2 and water as the only products.

**Math**

you've got x and y switched ... and the rate of ascent is the slope the right equation will give the right answer

**Math**

1st one is correct the division hint is for the 2nd

**Math**

one out of two if something goes into something else "evenly" (wholly), then ...

**math**

dh/dt is the velocity (1st derivative) v(t) = -32t

**physics**

hydraulics? the force multiple is the ratio of the piston areas f * (180 / 2)^2 = 2400 * g

**Physics**

the density of air decreases with altitude the balloon stops rising because the density of the gas inside is close to the ambient air density the weight of the balloon itself also contributes to the loss of bouyancy

**ADVANCED LEVEL PHYSICS**

after 4 s, the velocity is 4*a after 5 s, the velocity is 5*a the average velocity in the 5th sec is ... (5a + 4a) / 2 = 4.5a 4.5a = 36 ... a = 8 m/s^2

**Algebra**

w + j > 18 w/3 + j/6 < 5 ... 2w + j < 30 walk 1 hr, jog 3 hr

**Math**

no 27 + 33 = 60 they will end up with two lengths of fence with no space in between

**word problem**

(49 - 9) / 4 = (85 - 9) / 4 =

**Math**

2 sin^2 - sin - 1 = 0 (2 sin + 1)(sin - 1) = 0 2 sin + 1 = 0 ... sin = -1/2 sin - 1 = 0 ... sin = 1

**Math**

80 cubes long 8 cubes wide 13 cubes high

**maths**

n^2 + 1/n^2 = 7 n^4 + 1 = 7 n^2 ... n^4 - 7 n^2 + 1 = 0 let k = n^2 k^2 - 7k + 1 = 0 use quadratic formula to find k n = ?k

**Maths**

z = 7/9 c

**math**

the east component is ... 10 cos(30º) the north component is ... 10 sin(30º) - 4 speed = ?[(east)^2 + (north)^2] tan(?) = north / east ? is degrees north of east

**chemistry**

the molar mass of Fe is 55.8 g [98.7 / (2 * 55.8)] * 852 kJ

**physics**

the ball is pulled back from the lowest point, and gains gravitational potential energy this energy becomes kinetic energy when the ball is released ... it is maximum at the low point m g h = 1/2 m v^2 ... v = ?(2 g h) use trig to find the height above the low point

**Algebra**

9 / .75 = x / 7.5

**College Algebra**

(x * .05) + [(10000 - x) * .06] = 550

**Chemistry**

hydrogen and hydroxide ions are neutralizing each other acid vol * molarity * hydrogens = ... base vol * molarity * hydroxides 26.3 * x * 2 = 17.45 * .425 * 1

**math**

p log(8.2) = q log(10.5) p / q = log(10.5) / log(8.2)

**Math :(:( Totally stressing ouuut ned help now.**

translation moves the object, but it maintains its orientation reflection or rotation can result in the point being up

**math help now plez**

type the url (web address) for the figure

**High School Geometry**

this is a 30-60-90 triangle m?L = 30 ° ... AK is the side opposite AL (the hypotenuse) is twice AK KL is AK times ?3 the area is 1/2 the product of the two perpendicular sides

**Math**

9 m x 6 m = 54 m^2 4 m x 4 m = 16 m^2

**Biomechanics**

1.5 laps is 600 m 600 m / 77 s = 7.8 m/s it's a straight forward calculation typo somewhere?

**stats**

the dice are independent chance (probability) of a 5 is ... 1/6

**physics help please**

the difference in the path length between the direct and reflected sound should be an odd half wavelength to facilitate cancellation ... 1/2, 3/2, 5/2... the speed of sound is 340 m/s so the wavelength is 340/440 m the diagram is an isosceles triangle with an altitude of 2 m...

**math need help now**

as bob says "all REGULAR n-gons are similar" C for sure (they're regular) D doesn't say "regular"

**math**

you're looking for an area of 80 try C

**Physics**

vol = m / d = 20 kg / 20Mg/m^3 = 1 L the stone displaces 1 L of water with a mass of 1 kg the stone's weight is ... 19 * g

**math**

pay = [$.01 * 2^(day)] - $.01