Saturday

January 21, 2017
Total # Posts: 28,805

**Calculus applications**

first go here http://www.jiskha.com/display.cgi?id=1480944543

*December 5, 2016*

**Math**

749 is bigger than 500 so 123,166---> 123,167 123,167,000

*December 5, 2016*

**Algebra**

3x+2y=34 x+y = 15 so y = 15-x 3x +2(15-x) = 34 3x + 30 -2x = 34 x = 4 y = 11

*December 5, 2016*

**which do you guess?**

NOT B

*December 5, 2016*

**Algebra 2**

I bet you mean x^2 + y^2 = 16 well we could do it right or we could cheat and say we want a circle with center at (-8 ,-3) (x+3)^2 + (y+3)^2 = 4^2

*December 5, 2016*

**URGENT 4TH GRADE MATH**

You are welcome.

*December 5, 2016*

**URGENT 4TH GRADE MATH**

733.2

*December 5, 2016*

**URGENT 4TH GRADE MATH**

you want 22 characters? 733.166666666666666666

*December 5, 2016*

**URGENT 4TH GRADE MATH**

well, I know 6*7 = 42 so 6*700 = 4200 but 6*800 is too big so use 700 and then we have 4399-4200 = 199 left over 6* 30 = 180 so use 30 and I now have 730 and 19 left over 6*3 = 118 so use 3 and I now have 733 and one left over so 733 1/6 733 with a remainder of one

*December 5, 2016*

**NO**

You do not have 49 teachers!

*December 5, 2016*

**VERY, VERY URGENT 4TH GRADE MATH!!!!!!!!!!!!!!!!!!**

so 6 groups of 7 would require 42 teachers but 7 groups of 7 needs 49

*December 5, 2016*

**VERY, VERY URGENT 4TH GRADE MATH!!!!!!!!!!!!!!!!!!**

Hurry please, I am waiting on pins and needles. I know that 7*6 is around 42 and 7*7 is about 49

*December 5, 2016*

**MATH URGENT!!!!!**

slope 1 = (3-3)/(4-0) = 0 slope 2 = 2 2-0 = 2

*December 5, 2016*

**wait a minute**

it PRODUCES 150 J of heat? Usually one must put heat into an engine to get work out (boil water, burn gas). This is either a typo or a magic trick.

*December 5, 2016*

**Physics**

100(work out/heat in) the heat out to the other system is lost to this problem. Note that it is 110 which is what is left over after you take 40 out of your 150 see http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heaeng.html

*December 5, 2016*

**whoops**

cos x =cos 2x cos 2x = cos^2x -sin^2 x where does cos^2x -(1-cos^2x) =cos x cos x = 2 cos^2x-1 2 cos^2x -cos x - 1 = 0 (2 cos x +1)(cos x -1) = 0 cos x = 1 or cos x = -1/2 x = 0 or 2 pi n or x = 2 pi/3 +2 pi n

*December 5, 2016*

**Calc**

why do you think the domain is from -pi to 3pi ? I think it is all real x df/dx = 2 cos x -2 cos 2x (hoping you did not mean sin^2x) at 7 pi 2sin 7pi = 0 in fact sin any number of pis is zero so we are looking for where the slope is 0 that is where cos x = cos2x well, that is ...

*December 5, 2016*

**what do you mean?**

What you typed y = a(x - h)2 + k, a ? 0 a line with slope 2a and y intercept 2 a h + k is VERY different from y = a(x - h)^2 + k, a ? 0 a parabola with vertex at (h,k) and upright (holds water)

*December 5, 2016*

**precalculus**

x 7-4 = 3 and directrix is above vertex (sheds water) so a = -3 (x+2)^2 =-4*3 (y-4)^2 = -12(y-4)^2 =

*December 5, 2016*

**you do this one**

Hey, I did the other one

*December 5, 2016*

**wait a minute**

I did the other one, you can find the x component of your speed around the circle.

*December 5, 2016*

**Calculus 1**

f(x,y) = x^3y^2 df = (df/dx) dx + (df/dy) dy df/dt=(df/dx) dx/dt + (df/dy) dy/dt but f is a constant = 2916 df/dx = 3x^2y^2 = 3*81*4= 972 df/dy = 2x^3y = 2*729*2= 2916 so 0 = 972 (dx/dt) + 2916 (2) dx/dt = -6

*December 5, 2016*

**Math**

y = cos (x)+ 3 x interchange x = cos y + 3 y if y = 0, x = 1 + 0 x' = -sin y + 3 but y = 0 at x = 1 dx/dy = 3 dy/dx = 1/3

*December 5, 2016*

**Math**

remember 1 worked for y, so not it works for x :)

*December 5, 2016*

**Math**

dy/dx = 5 x^4 + 6 x^2 + 1 but x is 1 here we know already dy/dx = 5+6 + 1 = 12 interchange dy/dx = 1/12

*December 5, 2016*

**try interchanging x and y**

y = x^5 + 2 x^3 + x - 1 exchange x and y x = y^5 + 2 y^2 + y - 1 now use 3 for x 4 = y^5 + 2 y^2 + y 1 works for y

*December 5, 2016*

**Vectors**

|a| = sqrt(3^2+4^2) about 5 I think. Now you do the other. Remember when you square a negative you get a positive.

*December 5, 2016*

**Calculus applications**

You are welcome.

*December 5, 2016*

**correction**

the shear, not the moment, changes instantly at the center

*December 5, 2016*

**Calculus applications**

If you want to draw it it is a seesaw with no one on it w pounds per foot of weight down (+) and a force up of wL = total weight at center :) Note that moment must be zero at both ends and will be maximum at the middle changing signs instantaneously M = w L (x/2) - w x^2/2 S...

*December 5, 2016*

**science**

ahh, which comes out to zero if he is not accelerating up or down :)

*December 5, 2016*

**science**

1500 * 9.8 Newtons down and if he is sitting quietly 1500* 9.8 N up from the ice on his frozen fur.

*December 5, 2016*

**Like ALWAYS**

Momentum after = Momentum before. Even when you get to relativity !

*December 5, 2016*

**Science Physics**

There is one thing you can really count on, Newton's First Law. If there is no external force on a system, the momentum remains CONSTANT Momentum before = Momentum after. If I could underline that PERIOD I would do so. You can not count on mechanical energy being the same ...

*December 5, 2016*

**Math**

w + L = 108 L = w + 30 so w + w + 30 = 108

*December 4, 2016*

**physics**

F = m a F = 3kg* 5m/s^2 = 15 Newtons a = F/m a = 15N/12.2kg a = 1.23 m/s^2

*December 4, 2016*

**statistics**

http://davidmlane.com/hyperstat/z_table.html

*December 4, 2016*

**math double check please**

yes, two 2s and a 3 yes, 420 * 3

*December 4, 2016*

**pre calculus**

http://www.jiskha.com/display.cgi?id=1480860809

*December 4, 2016*

**Calculus**

see the rope and the boat problem below.

*December 4, 2016*

**Calculus**

h height above bow (constant=7) y hor distance to bow (25 at moment) x = our rope length x^2 = h^2 + y^2 2 x dx = 0 + 2ydy dy/dx = x/y dy/dt = dy/dx dx/dt = 2 (x/y) x = sqrt (7^2 + 25^2) = 26 so dy/dt = 2 (26/25) = 2.08 m/s

*December 4, 2016*

**Calculus**

hint dA = 2 pi r dr so dA/dr = 2 pi r and dA/dt = dA/dr * dr/dt

*December 4, 2016*

**PHYSICS (REALLY DIFFICULT PLEASE HELP)**

18+273 = 291 K 0 + 273 = 273 K P V = n R T 103 * 23 = n R *291 n R = 103*23/291 same n R later 101 V = n R 273 V = n R (273/101cm^3) V = (103*23/291)(273/101) cm^3 22 cm^3 = .0022 Liters = 22*10^-6m^3 ================================== P V = n R T 101325 (22.4 liters)(1m^3/...

*December 4, 2016*

**Sequence and serice**

54/100 or 27/50 a rational number is any one that can be expressed as a ratio of whole numbers.

*December 4, 2016*

**maths**

2n + 24/6 = 25/6 n = 1/12

*December 4, 2016*

**pre calculus**

2 1 2 4 2 2 0 5 2-1 6 2 1 0 2 3/2 0 1-2 1 0 0 0 0 (3/2, 1, 0)

*December 4, 2016*

**pre calculus**

http://www.gregthatcher.com/Mathematics/GaussJordan.aspx

*December 4, 2016*

**Maths**

The diagonal sqrt(24^2 + 18^2)

*December 4, 2016*

**Where are you stuck?**

So what did you do?

*December 3, 2016*

**Math**

(1/2)(40 + 3/8) = 20 + 3/16 20 3/16

*December 3, 2016*

**Math**

2/12 = 1/6 24 * 1/6 = 4 or 12/24 = 2/x 12 x = 48 x = 4 or the original width was twice the length twice 2 is 4

*December 3, 2016*

**Math**

Then count the number of one inch by one inch square boxes. You will get 50 of them, 5 times 10 :)

*December 3, 2016*

**Math**

Because to find the area of a rectangle you multiply the length by the width. To figure out why, draw a picture 10 inches by 5 inches and divide it up into columns one inch wide and rows inch high.

*December 3, 2016*

**Math**

yes, multiply

*December 3, 2016*

**CSC**

(2s-44)+(s+22)+ s = 5858 4 s -22 = 5858 4 s = 5880 s = 1470 etc

*December 3, 2016*

**Physics**

vertical problem Vi = 25.8 sin 20 = 8.824 m/s v = Vi - 9.81 t at top v = 0 t = 8.824/9.81 = .900 seconds at top (therefore 1.8 seconds in air by the way) h = Vi t - (9.81/2) t^2 = 8.824(.9) - 4.9(.81) = 7.94 - 3.97 = 3.97 meters high horizontal problem u = 25.8 cos 20 = 24.2 ...

*December 3, 2016*

**Math**

multiplying by 5/2 should not give the same answer as multiplying by 2/5(which is dividing by 5/2)

*December 3, 2016*

**Math**

21 7/8 * 2 1/2 one way is to use distributive property (21 + 7/8)(2 + 1/2) =(2 + 1/2)(21) +(2 + 1/2)(7/8) = 42 + 21/2 + 7/4 + 7/16 = 42 + 168/16 + 28/16 + 7/16 = 42 + 203/16 = 42 + 12 + 11/16 = 54 11/16

*December 3, 2016*

**Physics**

yes,your table is for a = dv/dt = 4 so dv = 4 * dt dv/dt = a = 4 v = a t = 4 t x = (1/2) a t^2 t a v x 0 4 0 0 1 4 4 2 2 4 8 8 3 4 12 18 4 4 16 32 5 4 20 50 It is that v column you want, how far it moves PER SECOND not how far it moved total.

*December 3, 2016*

**Physics**

so dx/dt = a t dx = a t dt at t = 0, dx = 0 at t = 1, dx = a at t = 2, dx = 2a at t = 3, dx = 3a at t = 4, dx = 4a etc in other words you are looking at v(t), the velocity, which is linear with time (the CHANGE in position, not the position) v = a t the POSITION itself will be...

*December 3, 2016*

**College Calc**

sqrt 576 = 24 24*4 = 96

*December 3, 2016*

**College Calc**

LOL,square min P, given A A = L w so L = A/w P =2L+2w P = 2A/w + 2 w 2 w^2 - w P = -2 A w^2 -(P/2)w = A w^2 -P/2 w + P^2/16 = -A + P^2/16 (w-P/4)^2 = -(1/16)(16A-P^2) vertex when w = P/4 (that is a square :) Area = P^2/16 = (P/4)^2 of course P given, max A A = L w P =2L+2w so ...

*December 3, 2016*

**Physics**

R is speed of rain r is angle of rain to vertical horizontal rain we see = Rsinr+bike speed vertical rain we see = R cos r case 1 hor = R sin r + 20 ver = R cos r tan 45 = (R sin r +20) /Rcos r case 2 tan 19deg48 min = (R sinr +12)/R cos r

*December 3, 2016*

**Algebra**

It is as if she got 89 on 5 of the 6 tests! (89*5 + x)/6

*December 3, 2016*

**Physics**

http://formulas.tutorvista.com/physics/doppler-shift-formula.html

*December 3, 2016*

**Physics**

As the ambulance approaches, the pedestrian will hear a higher frequency. As it recedes a lower frequency. Add the absolute values of the changes. For the formula, Google Doppler shift (classical not relativistic)

*December 3, 2016*

**chemistry**

4/2 = 2 mols of CO2 for every mol of C2H6 mol of C2H6 = 2*12+6 = 30 g mol of CO2 = 12+32 = 44 g 7500 * 2 * 44/30

*December 3, 2016*

**history knowledge**

I guess I would have to go along with that but wonder if it would have lasted if he had lived. The last few years of scooting around the Middle East and western Asia did not seem to be aimed at establishing any sort of permanent government but rather putting people in titular ...

*December 3, 2016*

**Physics**

Fup = m (9.81 + v^2/R) 2*265 = 30 (9.81+v^2/1.4) (b) 2*265 up assuming the seat has no mass :)

*December 3, 2016*

**Math**

55% is Cu and FE so 45% is zinc .45 *720 = 324 grams That is assuming this is a MATH, not a Chemistry problem. If it were Chemistry they might be looking at 1/4 of the molecules are Cu, not 1/4 of the mass.

*December 3, 2016*

**Math**

2^n

*December 2, 2016*

**Math**

5(.07)(8000)=2800

*December 2, 2016*

**Calculus**

Yes, of course -4-1 = -5 :)

*December 2, 2016*

**Calculus**

where do they hit? 4 x^2 = 45 - x^2 x^2 = 9 x = +/- 3 cylinder height = 45-x^2 - 4 x^2 = 45 - 5 x^2 cylinder thickness = dx cylinder circumference = 2 pi x so V=?[0,3]2 pi x(45-5x^2)dx

*December 2, 2016*

**So what?**

no question is asked.

*December 2, 2016*

**physics**

Vertical problem: at max height (half the trip) 600 = Vi t - .5*9.8 t^2 .5*9.8 t^2 - Vi t + 600 = 0 also v = 0 so 0 = Vi -gt t = Vi/g = Vi/9.8 so .5*9.8(Vi^2/9.8^2) - Vi^2/9.8 +600 = 0 600 = .5*VI^2/9.8 Vi = 108 m/s initial up speed t = rising time = 108/9.8 = 11.1 s total ...

*December 2, 2016*

**Finite Math**

A (1.0465)^6 = 15,000 A = 15,000/1.313516 = 11,419.73

*December 2, 2016*

**physics**

Ke = (1/2)(1260)(14.8^2) Joules go ahead and integrate m a dx if you want but energy is a lot easier.

*December 2, 2016*

**Physics**

total weight = (251+350)(9.81) + rhogas 9.81(4/3) pi (9.5)^3 where rhogas is the mass per unit volume of the gas in the balloon weight must = weight of air displaced = rhoout g (4/3)pi(9.5)^3 rho gas = kg/mol * n = .029 n where n is mols in PV =nRT T = 273 + T that we want rho...

*December 2, 2016*

**Pressure in Physics**

60 *9.81/10 N/m^2 or Pascals if you mean on the floor on earth and 10 is the floor area

*December 2, 2016*

**maths**

2 pi Ro = 44 solve for Ro then Ri = Ro - 2 so inner circumference = 2 pi Ri and Path area = pi(Ro^2-Ri^2)

*December 2, 2016*

**math**

16 = 4*4 12 =4*3 so 4*4*3 is LCM = 48 of each 3 packs HD 4 packs buns

*December 2, 2016*

**Physics**

google Bernoulli constant= v^2/2 + g z + p/rho in your units v in m/s p in Pascals(N/m^2) rho = 1000 kg/m^3 for water g about 9.8 v at bottom = 1.2 m/s v at top = 2 v at bottom =2.4 m/s z at top = z at bottom + .2 meters p/rho bottom =143000/1000 so 2.4^2/2 + 9.8(.2)+ 143 = 1....

*December 2, 2016*

**Math**

B yes C 128(0.5)^3 128*.125 = 16 yes D 128*.5^8 = 128* .00390525 = 0.5 YES !!!!!

*December 1, 2016*

**Math**

Gabby drove t-3 hours she drove 2 hours so t-3 = 2 and Ryan drove 5 hours D = Ryan speed * 5 D = Gabby speed * 2 so 5 R = 2 G but G = R+42 so 5 R = 2(R+42) 3 R = 84 R = 84/3 = 28 HUY - The DIFFERENCE is 42

*December 1, 2016*

**Calculus 1**

v = x^3 dv/dx = 3 x^2 dv/dt = dx/dt * dv/dx dv/dt = 4 * 3(121) cm^3/s

*December 1, 2016*

**math**

1000-850 = 150 interest 150 = 850 (.08) t

*December 1, 2016*

**Pre-Calculus**

satellite position is likely to be x, y , z of t :)

*November 30, 2016*

**science**

1. I disagree with you. People just assumed we were at the center. Partly religious 2. agree 3. agree 4. I agree with you. A and B are obvious. D is the sun and moon working together to produce spring tides when the moon is full and new and neap tides when the moon s half moon...

*November 30, 2016*

**Algebra**

v = dh/dt = 32 -32 t at top, v = 0 t = 1 h = 9+16 = 25 ====================== now with algebra 16 t^2 -32 t =9 - h complete square t^2 -2 t = (-1/16)(h - 9) t^2-2t+1 = (-1/16)(h - 9)+16/16 (t-1)^2 = -(1/16)( h-25) t = 1, h=25 same answer

*November 30, 2016*

**precalculus**

1 x +1 y = 2 1 x +1 y = 3 1 1 2 1 1 3 subtract top one from this 1 1 2 0 0 1 oh my! 0x+0y=1 ?

*November 30, 2016*

**College alegbra**

I assume this does not mean the perimeter but the total length of fencing. I assume x is the length and there are 3 y fences P = 2 x + 3 y x y = 1500 so y = 1500/x then P = 2 x + 4500/x x P = 2 x^2 + 4500 2 x^2 - xP = -4500 x^2 -xP/2 = -2250 x^2 -xP/2 + P^2/16 = -2250 + P^2/16...

*November 30, 2016*

**Calculus**

the function climbs uphill 15 from -3 to +12 in its jaunt of +5 from -1 to +4 that means that somewhere in between there the slope of the function is slope = 15/5 = 3 so at some x = c between x = -1 and x=+4slope = f'(c) = 3 so a)

*November 30, 2016*

**Physics**

(1/2) m v^2 = m g h or use Bernoulli (1/2) rho v^2 + rho g h + P = constant here P = 1 atm on top of the tank and at the outflow so the two ways are the same v = sqrt (2 g h ), just like the water fell amount that comes out per second = Q = Area*v = pi r^2 v = pi*10^-4 v so Q...

*November 30, 2016*

**Physics**

F/m = 2/60

*November 30, 2016*

**physics**

a = F/1 = i + 2 j -2 k v = Vi + a t x = Xi + Vi t + (1/2)a t^2 v at 5 = i+0j+2k + 5i +10j -10k = 6i + 10j - 8k x at 5, well assume start at (0,0,0) x = 0 +(i+0j+2k)5 +(1/2)(i + 2 j -2 k)25 = 5i+0j+10k+(1/2)(25i+50j-50k) =17.5 i +25 j -15 k check my arithmetic !

*November 30, 2016*

**Physics**

yes, both in watts or Joules/second

*November 30, 2016*

**Math**

same as when tan = -1 which is when theta = 90+45 =135 = 3 pi/4 or when theta = 360 - 45 = 315 = 7 pi/4

*November 30, 2016*

**Physics**

m v^2/r = 50 * 64 / 8 = 400 m/s^2

*November 30, 2016*

**Calculus AB**

-(x^4 - 5 x^2 + 6) / (x +3^.5) -(x^2-3)(x^2-2) /(x+3^.5) OH LOOK! -(x-3^.5)(x+3^.5)(x^2-2)/(x+3^.5) = -(x-3^.5)(x^2-2) when x is -3^.5 = -(-2*3^.5)(1) = 2 sqrt 3 Now there is a limit and I am at it without you doing some.

*November 30, 2016*