Tuesday
September 27, 2016

Posts by steve

Total # Posts: 44,101

Physics
Starting at the top of the ramp, the rider's height is h(t) = 1.60 sin23° t - 4.9t^2 So, find t when h=0 The rider's velocity when he hits the ground is Vx = 1.60 cos23° Vy = 1.60 sin23° - 9.8t So, the speed v at time t is found using v^2 = Vx^2 + Vy^2
September 24, 2016

maths
google is your friend: (a) https://answers.yahoo.com/question/index?qid=20131112055820AAxrUAf (b),(c) Check out Riccati equations y' = y^2 + q(x)y + p(x)
September 24, 2016

Maths Percentage
22/24 * 100 = ?
September 24, 2016

Math
If the length of AB is x, then AP = 2x/5 AQ = 3x/7 PQ = AQ-AP = 3x/7 - 2x/5 = 2 Now just solve for x
September 24, 2016

maths
infinitely many. Any point on the x-axis will do.
September 24, 2016

math
geez. How many ways are there to add 18 + 16?
September 24, 2016

Physics
340m/s * 2s = 680m
September 24, 2016

Math
48/(5+(11-8)) - 7
September 24, 2016

Maths - Woe Is Me!
fix the typos And what does p>+-24 mean. I get that +- means ±, but what does p>±24 mean? Also what are you supposed to do with 18x^2+2px+32 ?? factor it? solve for the roots? find p such that it is a perfect square? what, oh, what? Wooooeeee is meeee!!
September 24, 2016

Geometry
You know that AP+PQ+QB = a Now, AP = 2PQ = 2BQ That means that PQ = QB and that gives us 2PQ + PQ + PQ = a 4PQ = a PQ = a/4 Let M be the midpoint of QB Let N be the midpoint of AP AM = AP+PQ+ QB/2 = a/2 + a/4 + a/8 = 7a/8 NM = AP/2 + PQ + QB/2 = a/4 +a/4 + a/8 = 5a/8 Draw and ...
September 24, 2016

Geometry
first, recall that supplementary means they add to 180. So, now you know that A) The two angles are x and x-40 x-40 + x = 180 B) The two angles are 5x and 4x. So, 5x+4x = 180 So, just solve for x, and then you can work out the angles.
September 24, 2016

Trigonometry
see related questions below google can also help out
September 24, 2016

maths~log
just for ease of readability, let's say u = log5x v = log3y Then we have 2u+3v=8 6u+2v=2 This has the solution u = -5/7 v = 22/7 Unusual for a problem of this kind, but anyway... log5x = -5/7, so x = 5^(-5/7) log3y = 22/7, so y = 3^(22/7)
September 24, 2016

maths
I think your sum-to-product formulas will make this just drop out easily.
September 24, 2016

Maths
AB^2 + BC^2 = AC^2 1 + 1 = 2
September 24, 2016

Maths
assuming this is an isosceles triangle, I'd say they are both (180-65)/2
September 24, 2016

math
6 1/2 + 7 2/3 = 6 3/6 + 7 4/6 = ...
September 24, 2016

Algebra
plug in your data at http://www.gregthatcher.com/Mathematics/GaussJordan.aspx for the details, and confirmation of your answer >wink wink<
September 24, 2016

Math
DNE means Does Not Exist, so (a) is the choice of choice.
September 23, 2016

Physics
the range R = v^2/g sin2θ Now just plug in your values
September 23, 2016

Chemistry
25/800 = 1/32 = 1/2^5 so, it will take 5 half-lives
September 23, 2016

Math
Try plugging in you numbers here and see whether it is the same. The range is R = v^2/g sin2θ
September 23, 2016

Math
so, what do you get?
September 23, 2016

Math
√n is defined only for n>=0 So, the domain of √(2x+1) is (2x+1)>=0, or x >= -1/2 similarly for the other. There is always a domain.
September 23, 2016

Math
so, after t years, it is 41250 * 1.02^t
September 23, 2016

Physics
F = ma = 0.39 * 930√2
September 23, 2016

Math , trigonometry
h/20 = tan(47)
September 23, 2016

physics
F=ma plug in your numbers and evaluate a. Watch the units.
September 23, 2016

Newtons Cooling Method
-1.002 ≈ 1, so let's use T(t) = -53e^-t + 89.50 = 85.25 53e^-t = 0.25 e^-t = .004717 t = -ln .004717 = 5.3566
September 23, 2016

math
−2(x+2/3)+1=5 −2(x+2/3) = 4 x + 2/3 = -2 ...
September 23, 2016

math
.42
September 23, 2016

ODE Piecewise
y'-y = 1: y = ce^x - 1 for 0<=x<=1 y'-y = -1: y = ce^x + 1 for x>1 y(0) = 1 means c=2, so y = 2e^x - 1 for 0<=x<=1 If we want y to be continuous, then since y(1) = 2e-1, y = (2 - 2/e)e^x + 1 for x>1 Thus, y(2) = (2 - 2/e)e^2 + 1 = 2e^2-2e+1
September 23, 2016

Engineering Math
Start with Newton's Law of cooling. Using your numbers, with To the initial temperature, T(t) = 10 + (To-10)e^(-kt) Now you have T(1) = 10 + (To-10)e^-k = 40 T(2) = 10 + (To-10)e^-2k = 25 (To-10)e^-k = 30 (To-10)e^-2k = 15 (To-10)^2 e^-2k = 900 (To-10) e^-2k = 25 Now ...
September 23, 2016

5th grade math
14+2=6+2x(3+2)
September 23, 2016

Engineering Math, Newtons Cooling Method
Your DE yields v = c e^(-2t) + 4.9 v(0) = 0 means c = -4.9, so v(t) = 4.9 - 4.9e^(-2t) (a) plug in t=1.5 (b) v(∞) = 4.9
September 23, 2016

Physics
v = 30*sin30° - 9.8t it reaches max height when v=0.
September 23, 2016

maths
Man. some messy algebra! Clearly there are horizontal asymptotes at y = ±b and curve passes through (a,0). The shape seems to preclude any simple equation or parametric equations. Maybe more later.
September 23, 2016

Algebra
Treat it as you always do fractions. Multiply by the denominator to clear the fraction: -54/x = -6 -54 = -6x Now it's a cinch, right? |x| is the "size" of x, regardless of whether it is positive or negative. It is defined as |x| = x if x >= 0 |x| = -x if x <...
September 23, 2016

Algebra
shift left: x -> x+4 stretch: y -> 3y shift up: y ->y+5 g(x) = 3(x+4)^2+5
September 23, 2016

GEOMETRY
The change in coordinates from A(-6, -3) to B(3, 1) is (3-(-6),1-(-3)) = (9,4) 1/3 of the difference is thus (3,4/3) (-6,-3) + (3,4/3) = (-3,-5/3) (-3,-5/3) + (3,4/3) = (0,-1/3) (0,-1/3) + (3,4/3) = (3,1) The first two points divide AB into 3 equal parts.
September 23, 2016

science
adage: opposites attract
September 23, 2016

Math
well, 5+7 = ?
September 23, 2016

math
50 <= c <= 150
September 23, 2016

math
I'll just use x for ease of typing (note the use of parentheses to make things clear!) 1/(1+sinx) + 1/(1-sinx) =((1-sinx)+(1+sinx))/((1+sinx)(1-sinx)) = 2/(1-sin^2(x)) = 2/cos^2(x) = 2sec^2(x) By far the most useful trig identity is sin^2(x) + cos^2(x) = 1 It pops up in ...
September 23, 2016

Math
well, if they are not equal, one must be less than the other.
September 23, 2016

Calculus
if you don't know that the slope of the curve is given by the derivative, I suggest more study, or google will provide many discussions. Assuming that you believe that the derivative of a function gives the slope of the curve at any point, then you just have to remember ...
September 23, 2016

Operating System
once you get past the sloppy English, you might provide a little more information, doncha think?
September 23, 2016

12
well, the numbers are 2k 2k+2 2k+4 2k+6 multiply them and you have 2^4(k(k+1)(k+2)(k+3)) Now, two of those numbers must be even, so the product is divisible by 2^6 In addition, the product of 3 consecutive numbers is divisible by 6, so 2^7*3 = 384 divides
September 23, 2016

math
original fraction: (x-3)/x (x-3+4)/(x+4) = 3/4
September 23, 2016

value
each hour, 1/2 - 1/3 = 1/6 of the tank is filled. That should help some...
September 23, 2016

Maths, science
maximum volume is achieved when the box is a cube. The area of the box is c^2, so each face has area c^2/6 That means the side has length c/√6. v = (c/√6)^3 = c^3/(6√6) Hmmm. Better double-check my math.
September 23, 2016

Chemistry
figure the moles each mole fills 22.4L at stp
September 23, 2016

dosage calculations
looks ok to me
September 23, 2016

Calculus
f'(a) = R means f(a) = Ra + C But, if f is odd, C=0 So, f(-a) = -f(a) = -Ra
September 23, 2016

Algebra
reflected: y = |-x| stretched: y = 1.5|-x| shifted: y = 1.5|-x| - 4 However, since |-x| = |x| the reflection has no effect.
September 22, 2016

Math
48,136.47 / 7
September 22, 2016

Math
40 + 32.60*8
September 22, 2016

geometry incomplete
no information on the relative placements of the points.
September 22, 2016

Msth
300+300
September 22, 2016

taxation
no, it isn't.
September 22, 2016

Math
1in : 8ft = 1in : 96in = 1:96
September 22, 2016

Algebra
oops. Forgot to multiply the 4
September 22, 2016

Math
you have (almost) listed them in order of distance from zero, but smallest means farthest to the left. And even then, 2.4 is closer than 2 1/2
September 22, 2016

Algebra
by the time you get to algebra, you should know about fractions ... -2x+1/3y=4 -2(-3) + 1/3 y = 4 6 + y/3 = 4 y/3 = -2 y = -6
September 22, 2016

Math (Plz Help ASAP)
-7 -7(10*60)
September 22, 2016

math
the difference is 25 km/hr so, 25*12 km
September 22, 2016

Math
sloppy use of the = signs, there.
September 22, 2016

Algebra
|n-0| < 6
September 22, 2016

Math
well, y = 6x-12 plug and chug 6(-3)-12 = -30 ...
September 22, 2016

PHYSICS
if the acceleration is in the same direction as the velocity, the object speeds up. Otherwise, the acceleration opposes the velocity, so it slows down.
September 22, 2016

Math
since ln8 = 3ln2 is just a number, you have ∫(2x^2 ln⁡8)dx = ∫2x^2*3ln2 dx = 6ln2∫x^2 dx = 2ln2 x^3 = ln4 x^3 + C Maybe you had a typo, I'm guessing... If so, recall how to do integration by parts: ∫x lnx dx u = lnx du = 1/x dx dv = x dx v = 1...
September 22, 2016

Physical Science/ Chemistry
reading down the column, they become more reactive.
September 22, 2016

Math
so, what two numbers add to 9 and one is twice the other? Come on - there aren't that many pairs that add to 9.
September 22, 2016

Math
x = amt at 4% x-2000 = amt at 5% Now just compare the interest: .05(x-2000) = .75*.04x
September 22, 2016

MATH
#1A is correct, but it is not scientific notation for the value. #2B is also correct, but not S.N. #3 is 0.593 x 10^4 But, to make it S.N., you need to have 5.93 x 10^3 #4 5.2 x 10^8 / 25 = 0.208 x 10^8 That is 2.08x10^7 Looks like you need some serious review on how to move ...
September 22, 2016

Physics
v(t) = Vo + at = 85 - 13t It stops when v=0.
September 22, 2016

Algebra
stop guessing and start working 1/r * s = s/r, so p=s/r + d p-d = s/r Now what do you think?
September 22, 2016

maths
depends on the value of y. But, since 12y-12 = 12(y-1) it is certainly not prime.
September 22, 2016

Math
2.3(4.5-9.6)+3.1 = 2.3(-5.1)+3.1 = -11.73+3.1 = -8.63 you are correct. If your input on the calculator is as accurate as your typing here, it is no surprise that is sometimes wrong...
September 22, 2016

Algebra
the slope of the perpendicular line is -1/7 So, knowing that the line through (h,k) with slope m is y-k = m(x-h) what do you think?
September 22, 2016

Computing
I think you mean virtual memory. If so, just google it for many discussions.
September 22, 2016

Math
incorrect writing as a ratio is just one way of expressing rational numbers. Terminating or repeating decimals is another way.
September 22, 2016

Math
sorry - you wanted the bearing of Q from X. Just subtract 180°.
September 22, 2016

Math
since Q to P is 140°, P to Q is 320° P to X is 315°, so angle QPX is 5° using the law of cosines, |QX|^2 = 36^2 + 55^2 - 2*36*55*cos5° = 376.1 So, |QX| = 19.39 km 55^2 = 19.39^2 + 36^2 - 2*19.39*36*cosQ So, Q = 165.7° The bearing of X from Q is thus 140...
September 22, 2016

Physics
it stops going up when v=0. So, since v = 15 - 9.8t v=0 at t=1.53 So, at t=2.5 it is coming back down: http://www.wolframalpha.com/input/?i=15t+-+4.9t%5E2
September 22, 2016

Physics
t is 2.5 Vi is 15 m/s up a = -9.8 m/s^2 up (or, 9.8 m/s^2 down) d = Vi * t + a/2 t^2 = 15*2.5 - 4.9 * 2.5^2 = 6.875 m Vf is Vi + at = 15 - 9.8 t^2 (though it does not matter for this question)
September 22, 2016

Math
x = 2 A = {2}
September 22, 2016

Math - eh?
{x: x 3x=6} ?? Do you mean {x: 3x=6} ?? Then you ask Does A? Does A what? However, you are correct in saying that {2} is not 2
September 22, 2016

Computer science
https://en.wikipedia.org/wiki/Virtual_memory
September 22, 2016

math
(72+84+90)/6 + 90/2 = 86
September 22, 2016

math
also check out the way the coefficients are sums of subsets of the roots: http://mathforum.org/library/drmath/view/61024.html
September 22, 2016

Mathematics
list a few how far apart is each from its neighbor?
September 22, 2016

math
think of the factors of 18 which two differ by 3?
September 22, 2016

Algebra
x = x/3 + 8 + 52
September 22, 2016

Math
(1 hr 54 sec) * 7 And yet, I suspect you meant 1 hr 54 min.
September 22, 2016

Algebra
900/(300+250) hours later
September 22, 2016

Math
6:8:15 * 7/5 = 42/5 : 56/5 : 21
September 22, 2016

calculus
x^2+y^2 = 10^2 so, when x=6, y=8 2x dx/dt + 2y dy/dt = 0 Now just plug in your values to find dx/dt
September 22, 2016

math
14250 * 1.02^3
September 22, 2016

United States History
thank you
September 22, 2016

  1. Pages:
  2. <<Prev
  3. 1
  4. 2
  5. 3
  6. 4
  7. 5
  8. 6
  9. 7
  10. 8
  11. 9
  12. 10
  13. 11
  14. 12
  15. 13
  16. 14
  17. 15
  18. Next>>