Tuesday
March 31, 2015

Posts by Damon


Total # Posts: 20,745

maths
A work/day = 1/16 B work/day = 1/12 2(1/16) + x(1/16 +1/12) = 1
February 13, 2015

Physics Dynamics
work done against friction = Initial PE - final Ke = Force of friction * distance down slide = mu * normal force * distance Now where is your work?
February 12, 2015

Math
ds/dt = v = -4 (2t) /t^4 = -8/t^3 if t = a v = -8/a^3 if t = 1 v = -8/1 = -8 if t = 2 v = -8/8 = -1 if t = 3 v = -8/27
February 12, 2015

Algebra 1
6 a + 2 s = 40 5 a + 12 s = 85 multiply first one by 6 36 a + 12 s = 240 5 a + 12 s = 85 ------------------ subtract 31 a = 155 a = $5 now find s
February 12, 2015

Physics
so the magnitude is 3.31 kg m/s
February 12, 2015

Physics
-29 m/s - (+29 m/s) = -58 m/s velocity change change in momentum = -.057(58) kg m/s
February 12, 2015

Physics
Ac = v^2/R = 100/20 = 5 m/s^2 so F = m g + 5 m = (9.81+5)m = 14.81 m so F = 14.81*85 = 1258 Newtons f = change in momentum / time change in momentum = 85*10 = 850 kg m/s time = distance/average speed = 1.5/5 = .3 seconds so f = 850 kg m/s / .3 s = 2833 kg m/s^2 = 2833 Newtons
February 12, 2015

math
(1/2) x = 3 x = 6
February 12, 2015

Math
HE HAD 280 dollars. That is the answer. It is not a fraction.
February 12, 2015

Math
he started with x he spent 3/7 of x then he had 4/7 of x left he then gave his sister 1/4 of 4/7 of x so he was left with 3/4 of 4/7 of x that is 120 so 3/4 * 4/7 * x = 120 3/7 * x = 120 x = 40*7 = 280 =========================== NOW spend 3/7 * 280 = 120 280 - 120 = 160 left ...
February 12, 2015

Math
Look at this simpler problem: http://www.jiskha.com/display.cgi?id=1423783632
February 12, 2015

Math
He spent 3/7 which left him with 4/7 !!! 7/7 - 3/7 = 4/7 then he gave away 1/4 of his 4/7 1 - 1/4 = 3/4 so he is left with 4/7 * 3/4
February 12, 2015

math
HUH ? 120.25 + (7/28)^(3/7) ??? but 7/28 = 1/4 = .25 120.25 + .25^.42857 ??? 120.25 + 0.55 = 120.80
February 12, 2015

Physics
You have to tell us the angles from vertical or horizontal or what. if from horizontal T1 cos 45 = T2 cos 30 .707 T1 = .866 T2 T2 = .816 T1, so T1 is the one that will break m g = T1 sin 45 + T2 cos 30 m g = .866 T1 + .866 (.816) T1 m g = .866 T1 + .707 T1 = 1.57 T1 m g = 1.57...
February 12, 2015

Math
I am getting a bit bored with this question as well.
February 12, 2015

Math
he was left with 4/7 he gave 1/4 of the 4/7 to his sister so he was left with 3/4 of the 4/7 so (3/4)(4/7)x = 120 (3/7) x = 120 x/7 = 40 x = 280
February 12, 2015

math
1 - 3/7 = 4/7 is remainder (4/7) x - 3 = 120
February 12, 2015

TYPO ???
5 seconds up, 5 seconds down do vertical problem first with Vi = initial velocity component up v = Vi - g t at top v = 0 0 = Vi - 10 t but t = 5 seconds so Vi = 50 m/s IF YOU LAUNCH AT 10 m/s, YOU CAN NOT STAY IN THE AIR TEN SECONDS!
February 12, 2015

Science
If there are no mutations, there are no changes with generations, no adaptation of beak lengths or anything.
February 12, 2015

Science
You are welcome.
February 12, 2015

Science
n = 2 , 3, 4, 5, 6 ,7 ..... n^2 = 4 , 9 , 16, 25,...... 1/n^2 = 1/4 , 1/9 , 1/16 .....
February 12, 2015

Science
so did I :)
February 12, 2015

Science
1/n^2
February 12, 2015

math
100(3/4) = 300/4 = 75
February 12, 2015

math
sorry, slope intercept form is y = -(1/2) x + 1/2
February 12, 2015

math
2 y = -x + 8 y = -(1/2) x + 4 so slope = -1/2 -2 = -(1/2) 5 + b -2 = -2.5 + b b = .5 = 1/2 so y = -(1/2) x + 1/2 2 y + x = 1
February 12, 2015

Math
x in 1900 y in 2015 x = .64 y so y = 1.56 x so y now is 156 percent of x which is an increase of 56 percent
February 12, 2015

Math
(4/7)(3/4) x = 120
February 12, 2015

Physics
d = (1/2) g t^2 6.9 = 4.9 t^2
February 12, 2015

Physics
horizontal x = 100 + 35 cos 35 vertical y = 35 sin 35 or sqrt(x^2+y^2) at tan^-1(y/x) above x axis
February 12, 2015

Physics
There is no force on the ball after it its release so it continues at 4,000 km/s while the ship accelerates away from it. Therefore: -6 m/s^2 Think, how does your head move when you accelerate a car as opposed to driving straight at constant speed.
February 12, 2015

math
3/2 is bigger than 1 4/9 = 13/9
February 12, 2015

linear algebra
well, we agree this time :)
February 12, 2015

linear algebra
I am going to call c1 = a c2 = b c2 = c +3a + 1b -11c = 0 +3a + 2b -13c = 0 -1a - 3b + 9c = 0 -b+2c = 0 from first 2 so b = 2 c +3a + 2b -13c = 0 -3a - 9b +27c = 0 from second 2 ---> -7 b + 14 c = 0 so -7(2c) = -14 c c = anything at all In your linear algebra using Cramer&#...
February 12, 2015

Physics
You must know the acceleration A of the shuttle F = m A + m g
February 12, 2015

physics
work = change in potential energy = m g h No work is done in the horizontal motion because the force, gravity, is perpendicular to the direction of motion during horizontal displacement.
February 12, 2015

math
A = x y cost = 75 x + 60 y = 1750 60 A = x (1750 - 75 x) maximize 60 A = z z = 1750 x -75 x^2 75 x^2 -1750 x = -z complete square to find vertex o parabola x^2 - 23.3 x = -z/75 x^2 - 23.3 x + 11.7^2 = - z/75 + 136 (x -11.7)^2 = -(1/75)(z-10,200) x = length = 11.7 A = z/60 = ...
February 12, 2015

Physical sciences
v = 0 + a t 12 = a (5) a = 12/5 Is that the whole question? Surely they ask about the deceleration as well? d = Vi t + (1/2) a t^2 so 24 = 12 t + (1/2) a t^2 v = Vi + a t so 0 = 12 + a t
February 12, 2015

algebra
if b is base 8 b + b = 36 9 b = 36 b = 4 then 4 b = 16 so 16 , 16 and 4
February 12, 2015

physics
(1/2) m v^2 = m g h v = sqrt (2 g h) = sqrt(2*9.81*4.03) average speed = v/2 5.00 = (v/2) t t = 10/v
February 12, 2015

Physics
tension - T inward force = T cos 30 so T cos 30 = m v^2/.6 downward force = mg = T sin 30 = T/2 T = 2 m g so 2 m g = m v^2/.6 v^2 = 1.2 g if you want angular velocity v = omega r omega = v/.6
February 12, 2015

Physics
power = V^2/Req = 9.8 = 26^2/Req so Req = 69 ohms so R = 2 Req = 138 Ohms new Req: 1/Req = 1/138 + 1/276 Req = 92 Ohms power = 26^2/92 = 7.35 Watts
February 12, 2015

physics
correct
February 12, 2015

GEO
7.5 * 5*10^4 cm (1 km/10^5 cm) = 37.5 * 10^-1 = 3.75 km
February 11, 2015

Physics
If there were a potential difference current would flow. i = V/R where V is the potential difference and R is the resistance In a perfect conductor the resistance is zero and and V ( potential difference) would lead to infinite current to wipe out the potential difference. ...
February 11, 2015

math(5th grade)
.375 = 3/8 (3/8)120 = 3*15 = 45
February 11, 2015

physics
m1 = 3 m2 = 4 F = m1 a1 = 3 a1 F = m2 a2 = 4 a2 so 3 a1 = 4 a2 3 * 6 = 4 * a2 a2 = 18/4 = 9/2 = 4.5 m/s^2
February 11, 2015

physics
40 = (1/2)(9.81) t^2 t = 2.86 seconds v = g t = 9.81 * 2.86
February 11, 2015

physics
13400 cm (1.72*10^-6) ohm cm /2.07*10^-2 cm^2 = [(1.34)(1.72)/(2.07)] * 10^(4-6+2) = 1.11 Ohms
February 11, 2015

physics
multiply
February 11, 2015

MATH
18 qt * 1 gal/4 qt = 2.5 gal 7 half gal * 1 gal/2 half gal = 3.5 gal 2.5 + 3.5 = 6 gal
February 5, 2015

Math Ms Sue please help me
We can not see your picture so have no idea how to help.
February 5, 2015

physic
420 rev/min = 420 * 2 pi /60 = 44 radians/second 120 rpm = 12.6 rad/s alpha = (12.6 - 44 ) /4 = -7.86 radians/s^2 (part A) angle = initial omega t + (1/2) alpha t^2 angle = 44 (4) - (1/2)(7.86)(16) = 113 radians 113/2pi = 18 revolutions 18 * 2 pi r =18 *2 pi * .2 = 22.6 cm but...
February 5, 2015

physics
d = u t for car d = 20.1 t d = (1/2) a t^2 for cruiser d = (1/2) 2.65 t^2 = 1.325 t^2 so 1.325 t^2 - 20.1 t = 0 t (1.325 t - 20.1) = 0 they are together at t = 0 and again at t = 20.1/1.325 = 15.2 seconds
February 5, 2015

physics
v = Vi - 9.81 t at top v = 0 t = Vi/9.81 at top Vi = 20.1 sin 33.4 = 11.1 so t = 11.1/9.81 = 1.13 seconds at top how far horizontal in 1.13 seconds? u = 20.1 cos 33.4 = 16.8 m/s 16.8 m/s * 1.13 s = 19 meters
February 5, 2015

algebra
2.5 pounds/month is a constant slope of weight as a function of age. Therefore we are dealing with a straight line, linear function. (eventually it will hopefully turn exponential as it approaches full grown weight but that is a later problem :) six weeks = 1.5 months weight...
February 5, 2015

chemistry
They are liquid.
February 5, 2015

Math
You are welcome.
February 5, 2015

Math
7/8 = .875 14/14 = 1 1 4/9 = 1.444444444...... 3.2 = 1.5 which is the winner
February 5, 2015

math
Hey, you are supposed to know how to solve simultaneous linear equations or would not have been given this problem: http://www.jiskha.com/display.cgi?id=1423159248#1423159248.1423161824
February 5, 2015

math
2.4 * 2.8 * 3 = 20.16 m^3 1 m^3 = 1000 liters so V tank = 20,160 liters we have 3,600 liters so must deliver 16,560 liters 16,560 liters / .5 liters/s = 33,120 seconds /3600 = 9.2 hours 9 hours and 12 minutes
February 5, 2015

math
p = 1040 - c L = c - 880 but p = 3 L 3 L = 1040 - c so 3 (c-880) = 1040 - c 3 c - 2640 = 1040 - c 4 c = 3680 c = 920
February 5, 2015

Latin I
Well, I took Latin in 1951 and 1952 but your work looks ok to me for what that is worth.
February 5, 2015

statistic
This might help: http://davidmlane.com/hyperstat/z_table.html
February 5, 2015

chemistry
Mg ion +2 Cl ion - 1 so I suspect MgCl2
February 5, 2015

math/algebra
s = a + 70 s+a=770 so (a+70) + a = 770 2 a + 70 = 770 2 a = 700 a = 350
February 5, 2015

physics
v = Vi - 9.81 t if it came down at 28 m/s, it started up at 28 m/s (symmetry) v = 28 - 9.81 t at the top, v = 0 0 = 28-9.81 t so t = 28/9.81 at the top, same time falling h = (1/2)(9.81) t^2 h = (4.9)(28/9.81)^2 h = 4.9
February 5, 2015

math - We do not do magic
If you do not give some sort of distribution of customer arrival times I have no idea when Tony's staff should be there.
February 5, 2015

math Huh ?
I do not have the slightest idea what you are talking about. Arithmetic sequences or series maybe ?
February 5, 2015

physics
Now you should be able to do them.
February 5, 2015

physics
in general if speed is s at A degrees above horizontal u = s cos A Vi = s sin A
February 5, 2015

physics
Now divide your problems up into vertical problems and horizontal problems if horizontal speed is u at start it is u to the finish so x = u t if initial vertical speed is Vi then v = Vi - 9.81 t (remember v=0 at top) h = Hi + Vi t - 4.9 t^2
February 5, 2015

physics
just a vertical problem Vi = 17.9 sin 36.0 h = 0 + Vi t - 4.9 t^2 0 = 0 + t (Vi - 4.9 t) so it is at ground level at t = 0 of course and at t = Vi/4.9
February 5, 2015

Algebra typo ???
a (b+c) = db a (b+c) = dc If you did not make a mistake than of course b = c but CHECK FOR TYPOS
February 5, 2015

physics
first do the horizontal problem with constant horizontal speed of 13 for 21.4 m to get time in air distance = speed * time t = 21.4 /13.0 now we know it fell for time t h = (1/2) g t^2 h = (1/2) (9.81) (21.4/13.0)^2 meters
February 5, 2015

Math
Not that I know of.
February 5, 2015

Math
(5/12) s = 10 c + 20 (7/12) s = 15 c well we have two linear equations with two unknowns. We can do it. 7 s = 180 c so c = (7/180) s (5/12) s = (7/18)s + 20 (5/4) s = (7/6) s + 60 (15/12)s = (14/12) s + 60 s/12 = 60 s = 720 kg
February 5, 2015

physics
speed east = 1.65 cos 18.8 t = 21.0 / ( 1.65 cos 18.8 )
February 5, 2015

Maths
5 f + 10 t = 500 f + t = 90 f + 2 t = 100 f + 1 t = 90 ------------- subtract t = 10 then f = 80 check 400 +100 = 500 80 + 10 = 90 ok
February 5, 2015

chm
water is 1 g/mL so we have 0.105 g of H2SO4 per mL How many mols is that H2 = 2 g/mol S = 32 g/mol 4 O = 64 g/mol total = 98 g/mol .105/98 = .0011 mol /mL which is 1.1 mol/Liter
February 2, 2015

Math
4 * (13/5) = 10.4 which is more than 10
February 2, 2015

math
Oh, sorry, assumed that if you were deciding what was a function you also were doing inverses of functions. You will be :)
February 2, 2015

math
Just watch out if you are asked for the inverse next.
February 2, 2015

math
It IS a function ! (I said that)
February 2, 2015

math
there is only one value of y for every x so it is a function (a parabola in fact) The inverse of this however is NOT a function
February 2, 2015

Physics
Gravity is not in this because it says in a HORIZONTAL circle (it must be on a table top or something but 625 is much bigger than g anyway))
February 2, 2015

Physics
Your problem only has two significant figures accuracy to two significant figures w = 25 so r w^2 = 625 F = m a F = 2 kg * 625 m/s^2 = 1250 N
February 2, 2015

money
1 small + 1 medium = $20 so $60 left we can only buy one large for $32 60 = 32 = $28 left (3 bought so far) One medium for 16 leaves 12 (4 so far) finally 3 smalls leaves $0 (7 total)
February 2, 2015

4th grade math fraction
4 * 6 = 24 juice boxes gave away 2 * 3 = 6 24 - 6 = 18 are left
February 2, 2015

5th grade math
to divide fractions invert the one on the bottom and multiply (8/11) / (4/1) = (8/11)(1/4) = 2/11 (3/8)(10/3) = 10/8 = 5/4 = 1 1/4 (6/1)(4/3) = 24/3 = 8 (1/6)(6/5) = 1/5 etc etc etc
February 2, 2015

algebra
5 b (6b+5) + 6 (6b+5) = (5b+6)(6b+5)
February 2, 2015

algebra
no (s + 7)(s - 4 )
February 2, 2015

algebra
********2 b + 8 (b-3) | 2 b^2 + 2 b - 9 ********2 b^2 - 6 b ------------------------ ************** + 8 b - 9 ************** + 8 b - 24 ------------------------- *****************R = + 15 In other words I suspect you have a typo or you have a remainder of 15
February 2, 2015

maths please help
x^2 = 2 x = +/- sqrt 2 2. not sure what is denominator 3. x^2/2 + 6 x + 10 = 0 x^2 + 12 x + 20 = 0 (x+10)(x+2) = 0 x = -10 or x = -2 4. x^2 - 7 x = 0 x (x-7) = 0 x = 0 or x = 7
February 2, 2015

Science
The jellyfish, which I suspect is actually a squid (I gather your teacher is not a fisherman), moves forward as the water moves aft. I suppose you could say that this is due to the third law (action---> equal magnitude opposite direction reaction). However I consider this a...
February 1, 2015

Physics
F = k Q1 Q2 /d^2 due to right one, +force because opposite sign due to middle one, -force because of same sign F = k(10^-6)(10^-6)(65) [ 95/1.2^2 -48/.6^2 ]
January 31, 2015

Physics
force up = 25 sin 25 force down = 5(9.81) normal force = 5(9.81) - 25 sin 25 pull force = 25 cos 25 back friction force = 4 so 25 cos 25 - 4 = 5 * a
January 31, 2015

Physics
force up from left wire = 106 sin 5 force up from right wire also 106 sin 5 total force up = 212 sin 5 = weight down = m g = 9.81 m m = (212/9.81)sin 5
January 31, 2015

physics
u = speed * cos 27.1 7.72 = speed *cos 27.1 * t where t is time in air h = Hi + Vi t - (1/2) g t^2 0 = 0 + speed*sin 27.1 * t - 4.9 t^2 but we know t = 7.72/(speed*cos 27.1) call speed s 0 = 0 + 7.72 tan 27.1 - 4.9*7.72^2/(s^2cos^227.1) solve for s do it again for s = 1.05 s
January 31, 2015

math
j = dan + 30 dav = 3 j j + dan + dav = 400 (dan+30) + dan + 3 (dan+30) = 400 5 dan + 120 = 400 5 dan = 280 dan = 56 j = dan + 30 = 86 dav = 3 j = 258
January 31, 2015

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