# Posts by Scott

Total # Posts: 1,998

**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 '?'

*March 4, 2017*

**maths**

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

*March 4, 2017*

**Chemistry**

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

*March 3, 2017*

**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

*March 3, 2017*

**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)

*March 3, 2017*

**Physics**

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

*March 3, 2017*

**Physics**

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

*March 3, 2017*

**Physics**

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

*March 3, 2017*

**Math help plz?!!**

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

*March 3, 2017*

**Math! Help Hurry!**

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

*March 3, 2017*

**Maths**

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

*March 3, 2017*

**maths trigonometry**

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

*March 3, 2017*

**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...

*March 2, 2017*

**Algebra**

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

*March 2, 2017*

**Physics**

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

*March 2, 2017*

**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

*March 2, 2017*

**Biomechanics**

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

*March 2, 2017*

**Algebra, Math**

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

*March 2, 2017*

**math**

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

*March 2, 2017*

**Science- Astronomy**

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

*March 2, 2017*

**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

*March 1, 2017*

**Álgebra**

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

*March 1, 2017*

**Math**

5C3 = 10

*March 1, 2017*

**Math**

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

*March 1, 2017*

**physics**

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

*March 1, 2017*

**Chemistry**

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

*February 28, 2017*

**Science**

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

*February 28, 2017*

**homework**

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

*February 28, 2017*

**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

*February 28, 2017*

**Chemistry**

Thanks

*February 28, 2017*

**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 ...

*February 28, 2017*

**Math**

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

*February 27, 2017*

**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

*February 27, 2017*

**Science**

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

*February 27, 2017*

**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 &...

*February 27, 2017*

**Physics**

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

*February 27, 2017*

**Pre-Algebra**

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

*February 27, 2017*

**Algebra1**

-8 * 6^2

*February 27, 2017*

**Algebra1**

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

*February 27, 2017*

**Science**

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

*February 27, 2017*

**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

*February 27, 2017*

**Math**

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

*February 27, 2017*

**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?

*February 27, 2017*

**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.

*February 27, 2017*

**Math**

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

*February 27, 2017*

**Math**

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

*February 27, 2017*

**Math**

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

*February 27, 2017*

**math**

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

*February 27, 2017*

**physics**

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

*February 27, 2017*

**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

*February 27, 2017*

**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

*February 26, 2017*

**Algebra**

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

*February 26, 2017*

**Math**

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

*February 26, 2017*

**word problem**

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

*February 26, 2017*

**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

*February 26, 2017*

**Math**

80 cubes long 8 cubes wide 13 cubes high

*February 26, 2017*

**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

*February 26, 2017*

**Maths**

z = 7/9 c

*February 25, 2017*

**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

*February 25, 2017*

**chemistry**

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

*February 25, 2017*

**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

*February 25, 2017*

**Algebra**

9 / .75 = x / 7.5

*February 25, 2017*

**College Algebra**

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

*February 25, 2017*

**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

*February 25, 2017*

**math**

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

*February 25, 2017*

**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

*February 25, 2017*

**math help now plez**

type the url (web address) for the figure

*February 25, 2017*

**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

*February 25, 2017*

**Math**

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

*February 24, 2017*

**Biomechanics**

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

*February 24, 2017*

**stats**

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

*February 24, 2017*

**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...

*February 24, 2017*

**math need help now**

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

*February 24, 2017*

**math**

you're looking for an area of 80 try C

*February 24, 2017*

**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

*February 23, 2017*

**math**

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

*February 23, 2017*

**Physics **

did your G have the right units? you are correct that either equation should work Fg = Fc ... in orbit ... recalculate, and watch your units

*February 22, 2017*

**Science**

blood comes from the body ... goes to the lungs ... comes back from the lungs ... goes back out to the body the blood drops off carbon dioxide and water in the lungs and picks up oxygen, which is carried out to the body look up the exact flow through the heart chambers ...

*February 22, 2017*

**physics**

the surface is frictionless, so T is providing acceleration to the boxes the accelerating force is transferred to the small box by friction between the boxes at some point (as T increases), the frictional force will not be enough to provide the necessary acceleration and the ...

*February 22, 2017*

**chemistry**

.100 L * .10 M/L = .010 M .010 M / 4.0 M/L = ?

*February 21, 2017*

**chemistry**

each mole of butane yields 5 moles of water a mole of gas at stp is 22.4 L 10/22.4 * 5

*February 21, 2017*

**probability**

this is a binomial result ... win or not win P(w) = .15 , P(n) = .85 (n + w)^10 ... you want the 3rd term 10C2 * .85^8 * .15^2

*February 21, 2017*

**Physics**

the acceleration is ... g sin(38.0º) d = 1/2 a t^2 ... t = ?(2d / a)

*February 21, 2017*

**Chem**

you need to combine the given reactions ... some partial and/or reversed ... to get the desired reaction 2CO2 + H2O --> C2H2 + 5/2 02 ?H = 1300 kJ 2C + 2O2 --> 2CO2 ?H = -788 kJ H2 + 1/2 O2 --> H20 ?H = -286 kJ add the 3 reactions, along with the ?H's ... cancel ...

*February 21, 2017*

**Math**

1 cm on the original is 20 cm on the transfer

*February 21, 2017*

**chemistry**

not enough nitrogen a mole of nitrogen is needed for every 3 moles of hydrogen

*February 20, 2017*

**math**

tan(?) = 250/170

*February 20, 2017*

**Math**

v = 24 (1 + .06)^385

*February 20, 2017*

**physics**

2 * vertical velocity / g 16.7 * ?2 / 9.81

*February 20, 2017*

**Algebra**

(a) m = 500 (1 + .015)^t (b) 800 = 500 (1 + .015)^t ... 1.6 = 1.015^t ... log(1.6) = t log(1.015) ... [log(1.6)] / [log(1.015)] = t

*February 20, 2017*

**Algebra - PLEASE HELP!**

231 = -17.5x2^ - 138.5x - 27 462 = -37 x^2 - 277 x - 54 0 = -37 x^2 - 277 x - 516 use quadratic formula to find x

*February 20, 2017*

**probability**

there are 9 pairs of cards that differ by one ... 1-2, 2-3, 3-4, etc. there are 10C2 possible pairs ... 45 so the probability of a pair differing by one is 9/45 or .2 ... by more than one is (1 - .2) = .8 3 cards contain 3 pairs .8^3 = .512

*February 19, 2017*

**physics**

m g h = 1/2 m v^2 ... v = ?(2 g h)

*February 19, 2017*

**physics**

it's a fraction of a mole ... 9.1E5 / 6.02E23 multiply the fraction by the molar mass

*February 19, 2017*

**physics**

60 sec in a min 2.54 cm in an inch 9.843E4 ft/min * (1 min / 60 s) * ... (12 in / 1 ft) * (.0254 m / 1 in)

*February 19, 2017*

**physics**

f = m a = 2E3 kg * ... [(20 m/s - 5 m/s) / 4 s] answer is in Newtons

*February 19, 2017*

**Algebra2**

an = 13n - 8

*February 19, 2017*

**Physics**

convert mph to m/s convert cg(?) to kg K.E. = 1/2 m v^2

*February 19, 2017*

**physical science**

Joules of energy required ... 202 * (95.6 - 22.0) * 4.18 divide by heater wattage ... 1 watt = 1 Joule per second divide by 60 ... sec to min

*February 19, 2017*