# 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

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

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

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