Sunday

February 7, 2016
Total # Posts: 25,136

**Physics**

LOL, they clung to each other after so after the crash the total mass is 89.5 + 81.5 = 171 kg now east, the fullback I call +x initial momentum = 89.5*5.7 - 81.5*2.58 = 431 kg m/s final momentum = 171*v Newton #1 say those are identical so 171 v = 431 v = 2.52 m/s
*January 14, 2016*

**algebra**

q(21) = 6 - 5*21
*January 14, 2016*

**Math**

(2j+1) / (j+1)^2 j^2 ??? (2j+1) / (j^2 + 2 j + 1)j^2 (2 j + 1) / (j^4 + 2 j^3 + j^2) (2 j + 1) / (j^2 + 2 j^3 + j^4) try 12 25/( 144 + 3456 + 20736)= 25/24336 = .001027 this is going to get small fast the denominator will be totally dominated by j^4 and what we really will ...
*January 14, 2016*

**i need your help damon**

12.5 ft (.5 in/2 ft) = 3.125 in 11.5 ft (.5 in/ 2 ft) = 2.875 in so 2*3.125 + 2*2.875 = 12 in
*January 14, 2016*

**i need your help damon**

first of all look at what I did a minute ago for someone else: http://www.jiskha.com/display.cgi?id=1452820078
*January 14, 2016*

**physics**

You did not say if your angle T is measured from across or from upstream. I will do it from across x - along walk y across walk Vc = cat running speed Vx = Vc sin T - .5 = 0 for result we want Vy = Vc cos T so 0 = 1 sin T - .5 sin T = .5 T = 30 degrees Vy = 1 cos 30 = .866 if ...
*January 14, 2016*

**Conceptual Physics**

learn to convert like a physicist (not math way) 106 mm * ( 1) does not change anything BUT I claim that 10 millimeters /1 centimeter) is ONE, because it is the same top and bottom so what I do is: 106 mm (1 cm/10 mm) = 10.6 cm mm cancel and left with cm and 106 mm (1 m/1000 ...
*January 14, 2016*

**i really need help but dont know how to do it**

I have a million people to help, look up and down :)
*January 14, 2016*

**i really need help but dont know how to do it**

3.25 in (1 ft/.25 in) = 13 ft 2.75 (1/.25) = 11 feet area = 13 * 11 = 143
*January 14, 2016*

**Algebra**

s^2 = (5x - 3)(5x - 3) = (5x-3)^2 so s = 5x-3 when in danger or in doubt: http://www.mathportal.org/calculators/polynomials-solvers/polynomial-roots-calculator.php
*January 14, 2016*

**math**

2 L + 2 w = 38 so L + w = 19 and L = 19-w w L = 90 w (19-w) = 90 w^2 -19 w + 90 = 0 (w-9)(w-10) = 0 9 by 10
*January 14, 2016*

**geometry**

41 1/3 / 2 1/3 = 124 / 7 = 17.7 yards^2 / gal 17.7 * 9 = 159 ft^2/gal 275 - 159 = 116 difference
*January 14, 2016*

**Physics**

sin w t + sin x t = 2 sin.5(w+x)t cos.5(w-x)t beat frequency is omega = 2 pi f = .5(w-x) assume gum decreases x thereby increasing w-x so w is our 200 Hz fork w = 200*2 pi = 400 pi radians/s w - x = 5*2 pi = 10 pi so x = 390 pi = 195 Hz I suppose that is more than you wanted ...
*January 14, 2016*

**Physics**

Also, from 1.95 s to 2.05 s this is set up so you can compare your calculated speed with the real speed at 2 seconds from calculus. By coincidence we already did that last part, v(2) = 9.18 m/s and your average from 1.95 to 2.05 should be very close to that, like really, ...
*January 14, 2016*

**Physics**

well, just for fun, let's see hat the form of the limit is v = dx/dt = b + 3 c t^2 = 1.5 + 1.92 t^2 ========================= now from 1 to 3 x(3)= 1.5*3 +.64*27=4.5+17.28 = 21.78 x(1) = 1.5+.64 = 2.14 so x(3)-x(1) = 19.64 delta t = 3 - 1 = 2 seconds so v during interval...
*January 14, 2016*

**History**

I agree with you. Once every living soul did not have to hunt or gather, someone could stay behind and make shoes.
*January 14, 2016*

**Science**

I think it is B, but what do I know :)
*January 14, 2016*

**math**

64497 = .31 S S = 64497 /.31
*January 14, 2016*

**chemistry**

P V = n R T in this problem n, R and T are constant so P2 V2 = P1 V1 or in other words V2 = V1 (P1/P2) now do it
*January 14, 2016*

**Give us the whole problem**

Are you talking about a sequence? If so is it arithmetic? is it geometric? or what
*January 14, 2016*

**math**

first one y = -2x + 4 which is B m = -2 b = 4 second one y = 5 x + 8 which is A
*January 14, 2016*

**x and y reversed**

sorry, you have x and y reversed in the second one.
*January 14, 2016*

**math**

slope of -2. !!!!!!!!!! THAT means m = -2 in y = m x + b y = -2 x + b moreover you are told that when x = 0, y = +4 The second one is correct
*January 14, 2016*

**geometry h**

draw it y 4 --> 2 --> 0 because 4 to 2 is 2 which is 2 to 0 x 1 -->-3 --> -7 because 1 to -3 is -4 which is -3 to -7 (0, -7)
*January 14, 2016*

**Math**

1 2/4 + 1 3/4 = 2 5/4 = 3 1/4 5 - 3 1/4 = 4 4/4 - 3 1/4 = 1 3/4
*January 14, 2016*

**math**

y = (1/2) x + b 5 = (1/2) 0 + b b = 5 so y = (1/2) x + 5 which I guess you mean for A) but what you typed was y = 2/(2x) + 5
*January 14, 2016*

**Physics**

How long does it take to fall 0.52 meters? .52 = (1/2) g t^2 1.04 = 9.81 t^2 t = 0.326 seconds
*January 14, 2016*

**Science**

Sounds like here might be some steam with the Hydrogen Ions reacting with O2 :) However the scenario does not sound very likely.
*January 14, 2016*

**C s s oberkom**

frequency of 6 revolutions/second is a period of 1/6 seconds
*January 14, 2016*

**Do you mean?**

2 Na + 2 H2O --> 2 NaOH + H2 If so, what do you want to know?
*January 14, 2016*

**better grid to avoid error**

xx 1 2 3 4 5 6 -------------------- 1| 2 3 4 5 6 7 2| 3 4 5 6 7 8 3| 4 5 6 7 8 9 4| 5 6 7 8 9 10 5| 6 7 8 9 10 11 6| 7 8 9 10 11 12
*January 14, 2016*

**whoops 1/9 is right**

2. b is 4/36 = 1/9 you were right (I added in the top label five)
*January 14, 2016*

**Math**

1. a (1/2)^10 = 9.77*10^-4 = .000977 indeed 1/1024 b yes c yes 1 - 1/1024 = 1023/1024 2. lay the grid out x 1 2 3 4 5 6 1 2 3 4 5 6 7 2 3 4 5 6 7 8 3 4 5 6 7 8 9 4 5 6 7 8 9 10 5 6 7 8 9 10 11 6 7 8 9 10 11 12 a. yes, no up there :) b. 5/36 c. yes, lower right :)
*January 14, 2016*

**calculus 1**

first let's look at the derivative (slope at a point) y = 1/(1-x) dy/dx = slope = [-1(-1)]/(1-x)^2 bottom always + so the slope is always positive now secant from (2,-1) to ( x , 1/(1-x) ) secant slope P to Q = (1/(1-x) +1) / (x-2) (1 + 1 - x )/ [(1-x)(x-2)] = (x-2) / (x^2...
*January 14, 2016*

**general physics**

net push = 18 - 7 = 11 N so 11 = m a = 25 a so a = 11/25 m/s^2 v = a t so t = 2.3 * 25/11 = 5.23 s and average v = (0+2.3)/2 = 1.15 m/s so d = 1.15 * 5.23 = 6.01 meters power = force * distance/ime = 18 *6.01/5.23 = 20.7 Joules average power
*January 14, 2016*

**physics**

mass per unit length = rho = (m/L) this is exactly like a rope hanging from a hook. The tension is zero at the bottom and m g at the top just below the hook. Here g is replaced with a where a = F/m so the tension is T = rho (L-y) a or T = (m/L) (L-y) (F/m) T = (1-Y/L)F
*January 14, 2016*

**MATH HELP FAST AND I MEAN NOW I NEED THE ANSWER!!!**

Yes, needed fast !
*January 14, 2016*

**history**

Oh come on, look at map or globe. B
*January 14, 2016*

**Science**

I can not do this in five minutes. Try: http://www.sciencemadesimple.co.uk/activity-blogs/lightning
*January 14, 2016*

**math**

12 cables length of one = L L^2 = 144 + 25 = 169 L = 13 (just in case you do not know about 5, 12, 13 triangle) 12 * 13
*January 14, 2016*

**Physical science and math**

2*3 = 6 a^2*a^3 = a^5 anything^0 = 1
*January 14, 2016*

**Physical science and math**

do you mean? 2x^2 y 4x^4 y^3 / (6x^6 y^6) ??? (8/6) x^(2 +4-6) y^(3-6) (4/3)/y^3 or 4/(3y^3)
*January 14, 2016*

**math**

5/5 ------ = 1/4 20/5 5*5 ---- = 1/4 20*5
*January 14, 2016*

**Math**

(5/8) 6
*January 14, 2016*

**I mean 60**

60 km/hour
*January 14, 2016*

**math**

v t = 240 so t = (240/v) (v-12) (t+1) = 240 ==================== v t - 12 t + v - 12 = 240 or v + vt -12 t = 252 substitute v +240 - 12(240/v) = 252 v^2 - 12 v - 2880 = 0 (v-60)(v+48) = 0 v = -48 simply will not do so v = 48 km/hour
*January 14, 2016*

**Physics**

Force = rate of change of momentum = mass * acceleration if the mass is constant. Here you can ignore any change of mass due to fuel exhaust and simply use F = m a
*January 14, 2016*

**Math**

oh 2 and 2 and 3 any more?
*January 14, 2016*

**Math**

12= 2*6 = 2*2*3 so 1, 2 , 3 , 12 12 and 1 2 and 6 3 and 4
*January 14, 2016*

**Math**

LOL, the simpler the more advanced :)
*January 14, 2016*

**Math**

1. I can not imagine how. 2. no, the lowest is itself and one 3. How many ways can you divide up 12 cookies?
*January 14, 2016*

**math**

n is number of tickets 11 n > 250
*January 14, 2016*

**Science HELP**

I agree with your answer.
*January 14, 2016*

**Science HELP**

Suspect so, like humans and dogs and cats.
*January 14, 2016*

**Math**

sl^2= [(1/2) base]^2 + h^2 so sqrt (36+64) d = sqrt [36 + 25 + 81]
*January 14, 2016*

**No idea**

for distance(scalar) you need a ruler but for displacement(vector) you need a compass and a ruler Force is a vector so we not only need the magnitude but also the direction to do this.
*January 14, 2016*

**math,**

26 + 20 - 17 = 29 35 - 29 = 6 play neither
*January 14, 2016*

**Math**

2 w + 2 L = 154 L = 55 so 2 w + 110 = 154 2 w = 44 w = 22
*January 14, 2016*

**science**

If in SERIES the SAME CURRENT passes through all three and the voltages add up to the battery voltage. 10 i + 8 i + 5 i = V or 23 i = V i = V/23
*January 14, 2016*

**Civics**

Read Bill of RIGHTS
*January 14, 2016*

**chemistry**

4.5/13.9 = .323 not 3.32 x = Xo (1/2)^n log (x/Xo) = n log .5 = .323(-.301) = -.09723 x/Xo = 10^-.09723 = .799
*January 14, 2016*

**physics**

same magnetic field through each coil so voltage is in the ratio of the number of turns secondary/primary 60/120 = 1/2
*January 14, 2016*

**Science**

orbital motion is key, merry-go-round
*January 14, 2016*

**Science**

matter moves in accordance with Newton's laws (momentum is conserved, force is rate of change of momentum, action causes equal and opposite reaction) heat moves from hot to cold Electro magnetic energy follows Maxwell's equations.
*January 14, 2016*

**Science**

polar bears have long fur
*January 14, 2016*

**Science**

No,seeing as how I live beside the Gulf of Maine, it is increased flooding that worries me most immediately.
*January 14, 2016*

**math**

area of square = 32.5-7.5 = 25 so it is 5 by 5 = 25 like s = 5
*January 14, 2016*

**Physics**

4*10^-6 C*1 electron/(1.6*10^-19C) = (4/1.6) 10^13 electrons
*January 14, 2016*

**math**

4*8 = 32 3 * 32 = 96 ft^2
*January 14, 2016*

**math**

I see no picture so have no idea what your angles are.
*January 13, 2016*

**Civics**

Here in Massachusetts there are both state and local police forces so I suppose that is the right answer. However both the state and local governments provide funds for building schools. Here at present the state provides half and the city provides half the cost.
*January 13, 2016*

**Physics - equal and opposite**

Google Newton's Third Law.
*January 13, 2016*

**PHYSICS**

v at top = 0 v at two seconds down = Vi 0 = Vi - g t so Vi = 9.81 * 2 average speed during those two seconds is Vaverage = (0 + 2*9.81) /2 so average speed = g = 9.81 9.81 m/s * 2 s = 19.6 meters By the way that was quite a throw :)
*January 13, 2016*

**Physics**

v = Vi + a t stops so 0 = Vi + a (2.8) and -2500 = m a = 1350 a a = -1.85 m/s^2 0 = Vi - 1.85*2.8 Vi = 5.19 m/s
*January 13, 2016*

**Geometry**

same as the angle from the horizon to the top of the lighthouse from the ship tan T = 50/750 T = 3.81 degrees
*January 13, 2016*

**SIERRA**

watch your signs east defined as + initial v = +4.5 final v = -1.5 we want final - initial or (-1.5 - 4.5) impulse = change in momentum 90 (-1.5 - 4.5) = -90(6) = -540 kg m/s or 540 west F = rate of change of momentum = -540/1.2 = - 450 N or 450 N west
*January 13, 2016*

**Physics**

8.2 UP and .5(9.81 ) down = 3.295 Newtons up Work done =Force * 1.5 meters = 3.295*1.5 = 4.9425 Joules so (1/2) (.5) v^2 = 4.9425 v = 4.45 m/s
*January 13, 2016*

**Been there - done that**

http://www.jiskha.com/display.cgi?id=1452713165
*January 13, 2016*

**Civics**

http://worldpopulationreview.com/states/nevada-population/
*January 13, 2016*

**civics**

My son borrowed my chain saw :(
*January 13, 2016*

**Math Help!**

If the forces are in the same direction they add, yes
*January 13, 2016*

**Math**

yes yes
*January 13, 2016*

**Maths**

yes, yes
*January 13, 2016*

**16 no**

NOT MORE </= 30 You knew that
*January 13, 2016*

**biology**

all different acts of the same screen play. I do not think you should have a comma between continental and drift :)
*January 13, 2016*

**math**

volume = dimension^3 to double volume multiply dimensions by 2^(1/3) = 1.26 so 2.52 * 3.78 * 5.04 ================== check: 2*3*4 = 24 2.52 * 3.78 * 5.04 = 48.006 close enough to 48 :)
*January 13, 2016*

**Math**

do #7 more carefully
*January 13, 2016*

**Math**

5.5.4 + 0.2x =-1.4x + 8.6 2 --2 .2*** 20 ======================== 1.6 x = 3.2 16 x = 32 x = 2 I get
*January 13, 2016*

**PHYSICS**

a = change in v / change in t t1 = 1 Y1 = 2 V1 = 2 Dv = 2 t2 = 2 Y2 = 6 V2 = 4 Dv = 2 t3 = 3 Y3 = 12V3 = 6 Dv = 2 change in V = 2/1 = 2 m/s^2
*January 13, 2016*

**Physics**

fb = frequency heard then emmitted by blood particle fb = (c+v) f /c fl = frequency heard back at the source f receiver = fr = fb c/(c-v) so the result is: fr = f * (c+v)/(c-v) which is B (sort of, parenthesis missing)
*January 13, 2016*

**Physics**

You are welcome.
*January 13, 2016*

**Physics**

LOL, figured you knew how to do all that initial bullet speed = V that is what we want we know final speed is 4.7 conservation of momentum: .15 V = (.15+1.85)(4.7)
*January 13, 2016*

**Physics**

at the top of the circle: v^2/r = g v^2 = g r = 9.81 * .45 = 4.4145 so at top v = 2.1 m/s so Kinetic energy at the bottom must be enough to get up there at that speed (1/2) m v^2 = m g h + (1/2) m (4.4145) (1/2) v^2 = 9.81(0.90) + 2.207 v = 4.7 m/s at bottom after crash NOW do...
*January 13, 2016*

**SCIENCEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE**

23. The number of protons in the nucleus of an atom is its ___. (1 point) ============================= HEY - I am happy to help a student who is stuck on something but I will not do your work for you. If you even read this question before posting it you would have answered ...
*January 13, 2016*

**physics**

F = M A = 1500 * 10 = 15,000 NEWTONS
*January 13, 2016*

**Physics**

17 min = 1020 seconds coulomb = amps * seconds so coulombs = .526 etc * 1020 or about 536 coulombs so answer = (536 / 1.602) 10^19
*January 13, 2016*

**chemistry**

(1/2)^ 6 = 1/64 so we are talking six half lives for A is 12 hours so one half life for A is 2 hours Now I will read the problem :) well half life of B is 3 hours 1/32 = 5 half lives 5 * 3 = 15 hours Not hard, just keep your wits about you and think ! (and check my arithmetic :)
*January 13, 2016*

**physics**

define + is up Draw a picture x = 0 at A , Fa up x = 80 at C , Fc up x = 50 at CG, mg =4*9.81=39.24 down so Fcg = -39.24 N sum of forces = 0 Fa + Fc + Fcg = 0 so Fa+Fc = 39.24 N now do moments about 0 for example Fc * 80 = 39.24 * 50 Fc = 24.5 N so Fa = 39.24 - 24.5 = 14.7 N
*January 13, 2016*

**chemistry**

Oh my. How many electrons? Nickel is 58.7 grams per mole or 6*10^23 atoms which here is 6*10^23 electros so 6 g * 6.022*10^23 electrons/58.7 g = .6155 * 10^23 electrons 1.602*10^-19 coulomb/electron so the product is .986 * 10^4 Coulombs a coulomb is an amp second so .986*10^4...
*January 13, 2016*

**physics**

.3 * 55 * 9.81
*January 13, 2016*