# Posts by Damon

Total # Posts: 30,127

**math**

6(10) + 5(1) = 65

**Algebra**

-4 -2 +2

**algebra**

(-3)^2 -5(-3) + 1 = 9 + 15 + 1

**math**

65

**Math**

when you multiply by 10 in our conventional tens base number system, move the decimal point one place to the right. for example 0.27 * 10 = 2.7

**physics**

goes .5 Vi in the first half second for the rest of the trip the average speed is Vi/2 (because Vi at start, zero at end, and constant a) 5 = .5 Vi + (Vi/2) t = t is the time to deaccelerate from Vi to 0 v = Vi - 6 t so t = Vi/6 so 5 = .5 Vi +(Vi/2)(Vi/6) Vi^2/12 + Vi/2 - 5 = ...

**phy211**

first part final v = a t = 40 m/s average v = 20 m/s x = 0 + 20(20) = 400 m second part v = 40 x = 400 + 40(20) = 1200 m third part Vi = 40 average v = 20 time = 40/3 = 13.3 x = 1200+20(13.3) = 1466 m

**Math, Data Management**

google "permutations" p(12,2) = 12!/(12-2)! = 12!/10! = 12 * 11 = 132

**draw a flowchart wich genrates frist 50 items of t**

Well, not really :) But I have boxes of it in the attic.

**draw a flowchart wich genrates frist 50 items of t**

x(1) = 1 x(2) = 2 do 1 for n = 3 to 50 1 x(n)= x(n-1)+x(n-2) print or store the results the end

**physics**

v = 3 t x = 1.5 t^2

**Algebra**

No idea, please look at my reply to your previous question.

**Algebra**

(4x^5 y^6 z)^2 (5x^9 y^12 z)^3 ???????????????? if so 16x^10*125x^27 * y^12 y^36 * z^5 = 2000 x^37 * y^48 * z^5 note a^b * a^c = a^(b+c) (a^b)^c = a^bc

**Physics**

m g h 100 * 10 * 1.5 =1500 Joules

**math**

** v c s n| x x x f| x x x m| x x x p| x x x v = vanilla c = choc etc n = nuts f = fudge m = marshmallow sure enough, 12 x marks :)

**Maths**

first a boy, take him out to the principal's office, then a girl? m + 12 students boy first m/(m+12) now we have (m-1)+12 students pick a girl 12/(m+11) so the product is 12m/[(m+12)(m+11)] or 12m/(m^2 + 23m + 132)

**Physics**

u = 27 cos 45 forever Vi = 27 sin 45 at start h = Vi t -4.9 t^2 = t (Vi -4.9t) h = 0 at ground so at ground at t = 0 of course and at t = 27 sin 45 /4.9 range = u t max height at t = half that t h = Vi t - 4.9 t^2 second question nonsense, from where

**Physics**

Since this is physics, I assume you use SCI units, meters, seconds, newtons, kilograms ... x direction 31min * 60 s/min = 1860 seconds u = x velocity = 109000meters/3600 seconds =30.3 meters/second x displacement component = 30.3*31*60 = 56,358 meters y direction 83,000/3600...

**Physics**

north 990 sin 45 = y component west 990 cos 45 = NEGATIVE x component south is -990 y component and zero x component

**math**

88*20 = 1760 in^3

**huh? sin(2x) /5x maybe**

well the point is that sin x ---> x -x^2/2 + ....... as x------> 0 sin x ---> x so sin(2x) / 5x ----> [2x - 4x^2 ...]/5x as x---> 0 sin(2x) /5 ---> 2x/5x = 2/5

**mathematics**

ax + ab = c agree so far but ax = c-ab x = (c-ab)/a or x = c/a - b

**Math**

subtract 2 from both sides 2x = 2 multiply both sides by 1/2 x = 1 or just think from the start what plus 2 = 4 well, 2 of course so 2 of them is 2 so one of them is one

**Physics**

None if there is no friction. You could ask how much force to accelerate the cart. But if you do that, do in in kilograms and Newtons and meters and seconds. Pounds are too confusing.

**Physics**

u = 15.5 cos 53.5= 9.22 m/s forever Vi = 15.5 sin 53.5 = 12.5 initial h = Hi + 12.5 t - 4.9 t^2 h = 0 at ground Hi = 4.9 t^2 -12.5 t Hi = 4.9(5.37)^2 - 12.5(5.37) Hi = 82.1 meters v = Vi -9.81 t v = 12.5 - 9.81(5.37) = - 40.2 m/s

**American government**

enforce, not force otherwise ok, but if you google articles of confederation I am sure you will find more.

**Math**

Left side (cos/sin)/(1/sin -1) cos /(1-sin) multiply top and bot by (1+sin) cos(1+sin)(1-sin^2) or (1+sin)/cos right side (1/sin +1) /( cos/sin) (1+sin)/cos same

**Math**

a + s = 90 so a = (90-s) 3 a + 2 s = 250 so 3(90-s) + 2 s = 250 etc

**solar science physics**

ah come on. After overwhelming Hoover dam, it starts getting those nuc plants lined up: "An ideal grid-tied inverter works as a perfect voltage source, and changes the grid voltage and frequency to match its own. "

**Huh**

a = F/m if the force is the same and the mass is the same, then the acceleration is the same.

**Math**

(sin/cos + cos-/sin-)/[sin/cos-cos-/sin-] sin -x = -sin x cos -x = cos x (sin/cos - cos/sin)/[sin/cos+cos/sin] multiply top and bottom by sin cos (sin^2 - cos^2)/(sin^2 +cos^2) but sin^2+cos^2 = 1 sin^2-cos^2 but sin^2=1-cos^2 1 - cos^2 -cos^2 1 - 2 cos^2 well, that is what is...

**Physics**

If the velocity versus time is straight, then its slope, the acceleration, is constant a = change in v/change in t = (29.3 - 0)/29.9 calculate a v = Vi + a t but Vi = 0 so at t = 19.9 v = 0 + a (19.9)

**Maths Probability**

ppo 4/11 * 3/10 * 7/9 = a pop 4/11 * 7/10 * 3/9 = b opp 7/11 * 4/10 * 3/9 = c add a+b+c for the answer to (1) =============================== first is p = 4/11 second is p = 3/10 third is o = 7/9 answer to (2) is 4/11*3/10*7/9 for ( 30), Bayes try http://en.wikipedia.org/wiki/...

**Algebra**

Now let me see in F, 32 to 212 = freeze to boil in C, 100 = freeze to boil so change of 180 F is change of 100 C so change of F = (180/100) change of C = 9/5 now when C = 0, F = 32 so F = 32 + (9/5) C that settled, what is 52 F 52 = 32 +(9/5) C 20 = (9/5) C C = 100/9 = 11.1 ...

**Science**

Nah, the zero part counts total distance/total time

**Algebra**

It is particularly helpful if you have a whole string of them.

**Algebra**

You are welcome.

**doing units science way**

Yes, but people in science have a particular approach, Type the units in such a manner that the ones you do not want cancel we can use 6 meters / 1 minute or we can use 1 minute / 6 meters (both are the same top and bottom, just different units. For this problem one minute IS ...

**Algebra**

60 mi/h (1.6 km/1 mi) = 96 km/h 4 h( 96 km / h) = 384 km

**Maths**

100 p + 30 g + 5 c = 1,000 p+g+c = 100 so c = 100 - p - g 100 p +30 g +5(100-p-g) = 1,000 95 p +25 g = 500 we know p+g < 100 or we have <1 c p and g must be integers, no half goats allowed well 95 times what is a multiple of 25 95 = 5*19 so 95*5 = 19*5*5 =475:) try 5 ...

**Physics**

Where to start? My experience is with the earlier egg drop projects but there are some ideas here: http://www.google.com/search?q=egg+car+crash+project+ideas&ie=utf-8&oe=utf-8 What you can do depends on the ground rules for your particular project, specifically what materials ...

**Math**

1 meter/20,000 meters is 1 meter/20 km square that for area instead of length 1 meter^2/400 km^2 so (3/400) square meter or in centimeters 1 sq meter = 10,000 sq cm so 30,000/400 = 300/4 = 75 cm^2

**Huh?**

Let me get this right: You want me to type an entire linear algebra course into this tiny box on my screen?

**Physics**

weight = m g normal force = m g cos 37 friction force up slope = .15 m g cos 37 proulsion force down slope = m g sin 37 net force = m g (sin 37 - .15cos 37) = m a so a = g(sin 37-.15 cos37) calculate a from that now v = a t = 5 a

**math**

(87+75+93+85+x)=88*5

**Science Please Help**

They all look true to me.

**slight clarification (physics)**

a = -9.8 m/s^2 = g (1/2) a = -4.9 m/s^2 so distance = (1/2)g t^2 +48 t + c distance = -4.9t^2 + 48t + c, where c is the initial height

**Physics**

1. b right 2. AhhhgggHHH a is 1 g downward the whole time whatever is airborne 3. b right 4. sqrt(10^2+10^2) =10sqrt2 = 14 c 5. c! when you reach steep enough it goes to zero 6. B ! the forces are ALWAYS equal and opposite (Law 3) however unless the friction on the ground or ...

**Chemistry**

CH4 = 12+4 = 16 g/mol O2=32 g/mol CO2 = 12+32 = 44 g/mol CH4 + 2O2 ---> CO2 + 2H2O I guess we want just the CO2 gas, although that H2O is initially steam same mols of CO2 as mols of CH4 1000 grams / 16g/mol = 1000/16 mols of CH4 so 1000/16 mols of CO2= 62.5 mols quick ...

**Chemistry**

quick esstimate: CO = 12+16 = 28 g/mol about 22.4 liters/mol at stp so we are talking around 28*20/22.4 = 25 grams of CO +10 grams of rubber = 35 grams total will the air lift that? 1.17*20 = 23.4 grams of buoyancy no way, not close

**Physics**

1 d

**Physics**

4. It is stopped, but the acceleration is STILL -9.81 m/s^2 from the time it is launched until it hits the ground or something.

**Physics**

3. The acceleration of g = -9.81 m/s^2 is CONSTANT, even if the speed is zero !

**Physics**

2. 45 - 10*3 = 15 which is c

**Physics**

1. c is not correct. a particle moving at constant velocity has no acceleration. However how could a particle with constant acceleration stay stopped?

**You try first**

Hey, I already took 8:01, freshman physics. I am here to help if you get stuck, not to do the problems for you. These are very basic questions

**Physics**

acceleration and velocity are vectors. They have magnitude and direction. In your car, speedometer gives speed but you need a speedometer AND a compass for velocity acceleration is the rate of change of velocity. If you go in a circle at constant speed your velocity changes ...

**No idea**

sorry, do not know

**physics**

Hey, do some yourself. I already took the course. (in 1955)

**physics**

friction force = mu m g = m *(centripetal acc) so mu g = Ac = v^2/R car A .222 g = 19.5^2/R so R g = 19.5^2/.222 car B R g = v^2/.670 so v^2 = .670 [ 19.5^2/.222 ]

**physics**

Ac = v^2/R = omega^2 R omega in radians/second Ac = 9.81*2.28*10^3 (good grief!) omega^2 = 9.81*2.28*10^3/.0297 omega = 868 radians /second 868 rad/s (1rev/2pi rad)(60s/min) = 8287 rpm

**physics**

omega = v/R is the same for each Ac = omega^2 R = v^2/R 284 = omega^2 (.0302) SO Ac = [284/.0302](.0803)

**ELA**

or listen to the cat walking :)

**physics**

Ac = v^2/R 2.48 * 9.81 = (87.5)^2/R

**Geometry**

y = -(7/17)x + some old constant slope m = -7/17 slope of perpendicular = -1/m = 17/7 y = 17 x/7 + b 7 = 17*8/7 + b 49 = 136 + 7 b 7b = -87 b = -87/7 7 y = 17 x - 87

**Physics**

t = 19.7/41 h = 0 + 0 - 4.9 t^2

**Physics**

Vi = 27 sin 45 u = 27 cos 45 h = Vi t - 4.9 t^2 at ground h = 0 0 = Vi t -4.9 t^2 = t (Vi-4.9t) t = Vi/4.9 then range = u t

**Physics**

average velocity = displacement vector / time Hypotenuse/time and angle average speed = distance scalar/time sum of x and y distances/time

**Physics**

hey, you try.

**Physics**

x = 77*(55/60) + 96(28/60)cos 60 y = -96(28/60)sin 60 distance=sqrt(x^2+y^2) tangent of angle south of east = |y|/x

**Physics**

tan 39 = h/27

**Math**

a pint is a pound the world around ( about half a kilogram :) (assumes fresh water :) a gallon is about 8 pounds of water so 3 gallons is 24 pounds of water or 24 pints ====================== The more conventional way 2 pints = 1 qt so 8 pints = 4 quarts = 1 gallon so 24 pints...

**Math**

(n+1) n 9 n+1+n = 11 n = 10/2 = 5 659

**Physics**

easy to use kinetic energy (1/2)m v^2 + 7.31 = (1/2)m Vfinal^2 .324 (1.31)^2 + 14.62 = .324 Vf^2

**Math-algebra**

now in b we get the slope first yes, -3/4 so the slope we want is -1/m = 4/3 now 4/3 = (3-1)/(k-4) 4 k- 16 = 6 4 k = 22 k = 11/2

**Math-algebra**

a. 9 y = -8x + 18 y = -(8/9) x + 2 slope = -8/9 so (3-1)/(k-4) = -8/9 2(9) = -8(k-4) 18 = -8k+32 8 k = 14 k = 7/4 ----------- check -8/9 = ? (3-1)/(7/4 -4) = 2/(7-16)/4 = 8/-9 sure enough

**Simple interest it says**

about 73

**Math**

Well, you have to go look at a morning glory. There are not many around here in January. The ones I see seem to have five points in the flower coloring which would be a pentagon. http://www.google.com/search?q=morning+glory+picture&ie=utf-8&oe=utf-8

**hard to say**

I do not see any measurements usually scale factor is just the ratio of any length on one to the corresponding length on the other. Of course they must be similar or the term has no meaning.

**Algebra**

it is simple, not compound, interest 3*.045*540 = 72.9 or about 73

**Algebra**

g(-5) = 25-3 = 22 f(22) = 22-10 = 12 yes

**Math**

7/12 foot = 7 inches :) 7*7*7 = 343

**interesting perhaps relevant**

I just ran into a story about Neanderthals in Europe which might be relevant :) I hope others can open it: http://blogs.discovermagazine.com/crux/2017/01/24/neanderthals-underrated-genius/?utm_source=SilverpopMailing&utm_medium=email&utm_campaign=News0_DSC_170126_000000_Final%...

**earlier discussion**

http://www.jiskha.com/display.cgi?id=1485466841#1485466841.1485473989

**Needs attention from Social Science teacher**

I tried but not my thing :)

**social**

link: http://www.cartoonstock.com/directory/a/amercians.asp I think you are doing fine with it. The immigrant Europeans are assuming that because they have gunpowder they are more important and valuable. They offer the locals something of no value in return for centuries of ...

**Physics-Momentum**

initial momentum = 1500*15+2500*9 final momentum = -1500*2 + 2500 x initial = final :) 15*15+25*9 = 25x - 30 25 x = 225+30+225 = 480 x = 19.2 =============== check 45,000 = 45,000 ok

**Math**

20 inches/305 feet = 20 inches/3660 inches = 1 inch/183 inches or 1 inch/15.25 ft

**Trig**

You mean for the slope of that line? y = -4x slope = -4 in quadrant 2 x = -1 y = 4 hypotenuse = sqrt(17) sin = 4/sqrt17 cos = -1/sqrt17 tan =-4 in quadrant 4 x = 1 y=-4 h = sqrt 17 again sin = -4/sqrt17 cos = 1/sqrt17 tan = -4 again

**Math**

easier to factor top and bottom that way

**Math**

That is why I wrote 45 not 4.5 and 2700

**Math**

45 inches/2700 miles = .01666.....inch/mile or 5 inches/300 miles or 1 inch / 6 miles :)

**math**

8x + 24 = 8(x+3)

**Trig**

1/cos T = -5 cos T = -1/5 = -0.20 the absolute value is between 0 and 1 so sure, in quadrant two or three about 101 degrees or 360-101 =259 degrees

**Evaluating algebraic expressions**

Hey, draw number lines !

**Evaluating algebraic expressions**

http://www.jiskha.com/display.cgi?id=1485468814

**Evaluating algebraic expressions**

46 > 42 46 is to the right of 42 on your number line. if you move left n units from each, 46 - n is still to the right of 42 - n

**Math**

(4x + 5)(7x + 7) = 28x^2+63x+35 (10x+10)(2x + 6) = 20x^2+80x+60 ---------------subtract---------- 8x^2 -17 x -25 = remaining roof which is (8x-25)(x+1)

**Math**

she doubled speed so took half the time ! half of 50 minutes is 25 minutes

**Math please check**

assume you mean: [ f(4)-f(2) ] / (2) f(x) = x(2-x) if x = 4 4(2-4) = -8 if x = 2 2(2-2) = 0 so we have -8/2 = -4