What is Horizontal: Definition and 978 Discussions

The horizontal branch (HB) is a stage of stellar evolution that immediately follows the red-giant branch in stars whose masses are similar to the Sun's. Horizontal-branch stars are powered by helium fusion in the core (via the triple-alpha process) and by hydrogen fusion (via the CNO cycle) in a shell surrounding the core. The onset of core helium fusion at the tip of the red-giant branch causes substantial changes in stellar structure, resulting in an overall reduction in luminosity, some contraction of the stellar envelope, and the surface reaching higher temperatures.

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  1. F

    Constant, Horizontal Force on Swing

    1. Homework Statement This problem is connected to an example in the textbook. Here's some of the key info from the example, first of all: You are appointed to push your cousin Throckymorton in a swing. His weight is w, the length of the chains is R, and you push Throcky until the chains...
  2. L

    Understanding horizontal asymptotes of non-even rational functions

    I think the technique that is to be used for these types of problems, but I just am having trouble grasping why it is permitted. I have no problem with any homework, but it just doesn't seem right. Maybe my text is just not being clear (Larson, 9th, btw) Given a function...
  3. R

    Horizontal Spring Pulled from Equilibrium?

    I don't necessarily understand the explanation given to the solution. Is it basically saying: A (valley) --> 0 (equilibrium) --> -A (valley) --> 0 (equilibrium) --> A (valley)?
  4. F

    Horizontal spring oscillations

    Hey everyone. I have 2 relatively basic questions about horizontal springs. I feel like the questions are actually very simple (it's just high school physics) but I think I'm approaching it the wrong way. Any help would be greatly appreciated. 1. I'm supposed to find the spring constant when a...
  5. K

    Projectile montion Problem given the Inital Velocity and Angle to horizontal

    Hi All, I am struggling to work out the following: Q: A football is kicked at an angle of 32.50 to the horizontal, with an initial velocity of 42m/s. Assume air resistance is negligible. A) Find the Balls Velocity at max Height B) The Balls Acceleratoin Vector at max Height I have so far...
  6. S

    Pendulum suspended from Horizontal rotating hoop

    Homework Statement A massless hoop is suspended horizontally and is free to rotate about a vertical axis through its center with a constant angular velocity (omega). Attached to the edge of the hoop is a simple pendulum that is restricted to oscillate in only the radial direction. find the...
  7. P

    Maximum horizontal force F on ramp with friction?

    Homework Statement Assume the ramp and block make the following coefficients of friction: (μs=0.9 μk=0.3) and the 2 kg mass is placed at rest on the ramp and a horizontal force F is also applied. http://img69.imageshack.us/img69/4097/filepq.jpg What is the biggest magnitude force F...
  8. J

    Calculate Muzzle Velocity: Angle, Height, Horizontal Displacement

    I need help with my hw, bad. I've been screwing off in my physics class for awhile and I can't get afterschool help because I have sports. I need to pick my grade up in this class to keep playing...so here I am. I need a good walkthrough badly, i don't know a whole lot with physics, but a decent...
  9. beowulf.geata

    Bead attached to a spring and moving along a horizontal wire

    I'm self-studying an introductory book on mathematical methods and models and came across the following problem: 1. A bead of mass m is threaded onto a frictionless horizontal wire. The bead is attached to a model spring of stiffness k and natural length l0, whose other end is fixed to a...
  10. S

    Equation for translational equilibrium for horizontal components of force

    searching for equation for translational equilibrium for horizontal components of force
  11. ?

    The connection as a choice of horizontal subspace?

    Hi, I'm trying to understand the fiber bundle formulation of gauge theory at the moment, and I'm stuck on the connection. Every reference I've found introduces the idea of a connection on a principle bundle as a kind of partitioning of the tangent space at all points in the total space into a...
  12. P

    Toy car moving in a horizontal ring.

    Hi, I sincerely hope one of you could please help me with the equations in the following problem. Homework Statement A toy car is forced to move along a circular ring placed on a table with no friction. The friction coefficient between the ring and the car is given as μ. At t=0 the car...
  13. L

    Just a question about vertical and horizontal line tests

    There's no real question per say. I've been looking in books and on the internet i can't find anything. I don't know when to use the vertical and horizontal line test to test for injective functions and surjective. Let's say if I was to sketch the graph of x2+4x - 5 I would get a...
  14. H

    How to find horizontal asymptotes?

    Homework Statement f(x)=(8-4x)e^x Homework Equations The Attempt at a Solution I know you can usually compare the top and bottom and determine that way but how can you do it when it's like this? I know the answer is 0 already i don't know how to get it though
  15. S

    Velocities with a resulting horizontal component

    Homework Statement Romeo is chucking pebbles gently up to Juliet's window, and he wants the pebbles to hit the window with a horizontal component of velocity. He is standing at the edge of a rose garden 8m below her window and 9m from the base of the wall. How fast are the pebbles going when...
  16. B

    Pressure difference in a horizontal constant area pipe

    Homework Statement see attachment Homework Equations not sure if these are applicable because i don't think its steady state anymore mass flow in=mass flow out sum of forces in x direction= rate of momentum in-rate of momentum out bernoulli's p+0.5ρ(v^2)= constant The Attempt at a...
  17. P

    Accelerating wedge at angle above the horizontal with friction

    Homework Statement http://imageshack.us/a/img594/4821/fileeq.jpg So, the problem is to find the minimum acceleration required to keep the block on the ramp, when the ramp is being pushed at an angle to the horizontal (so going diagonally) I know that the coefficient of static friction...
  18. Q

    Horizontal lift, or parallel transport

    Hello, everyone! I'm studying Nakahara's book, Geometry, Topology and Physics and now studying the connection theory. I come across a problem. Please look at the two attachments. In the attachment , Nakahara said we could use the similar method in the attachment to get \tilde X, but why...
  19. P

    Motorcycle horizontal acceleration-front wheel rise

    Motorcycle horizontal acceleration--front wheel rise The distance between the centers of the wheels of a motorcycle is 171 cm. The center of mass of the motorcycle, including the rider, is 95.0 cm above the ground and halfway between the wheels. Assume the mass of each wheel is small compared...
  20. B

    Pushing a box across a horizontal floor

    Homework Statement A man wants to push a cardboard box 60 kg along a floor by applying force F in a direction 40 degrees above horizontal. Coefficient of static friction between box and floor is .7. a) Determine F if box is on verge of moving. b) Based on part A, determine acceleration...
  21. C

    Center of Gravity in a Horizontal Cylinder with Water

    Homework Statement I need to find the center of gravity of a horizontal cylinder that has water in it, the level of water changes so I need to determine a relation between the diameter occupied by the water and the masses, those are my guesses. I solved the problem where i have the standing...
  22. M

    Determining max horizontal force using friction coefficient

    Homework Statement A 0.5 kg wooden block is placed on top of a 1.0kg block. The coefficient of static friction between the two blocks is 0.35. The coefficient of kinetic friction between the lower block and the level table is 0.2. What is the maximum horizontal force that can be applied to the...
  23. E

    Does a horizontal line have horizontal asymptotes?

    For example, y = 7. Are there an infinite number of asymptotes at any y value that isn't 7? If so, how would I format this statement on my homework? *edit* oops sorry, I meant to post this in homework help
  24. A

    A pelican flying along a horizontal path

    a pelican flying along a horizontal path... A pelican flying along a horizontal path drops a fish from a height of 5.4 m. The fish travels 8.0 m horizontally before it hits the watwe below. What was the pelican's initial speed? Well I'm guessing that y =-5.4m and x= 8.0 m...what do I...
  25. S

    A sled is being pulled accross horizontal, snow covered ground

    Homework Statement A 16-kg sled is being pulled along the horizontal snow-covered ground by a horizontal force of 24 N. Starting from rest, the sled attains a speed of 2.0 m/s in 8.0 m. Find the coefficient of kinetic friction between the runners of the sled and the snow. Homework...
  26. L

    Combination of freefalling and constant horizontal movement

    Homework Statement At the height of H, from a plane with the speed of V, there is an object "thrown off". H = 10km = 10 000m V = 300m/s To be determined: - total distance from the plane to the falling point - S - the time the fall takes - T do not have to take aerial friction into...
  27. N

    Horizontal or vertical strips when solving c.o.m. of functions problems?

    Is there any decent way to quickly spot if I should divide a 2d figure defined by functions into horizontal or vertical strips when solving centre of mass problems? Or does it come down to experience and/or math-talent? Problems like the1 in this video is what I'm on about...
  28. M

    Centripetal Motion along the horizontal with an angle

    Homework Statement A 0.20 kg stone attached to a 0.8 m long string is rotated in a horizontal plane. The string makes an angle of 25° with the horizontal. Determine the speed of the stone.Homework Equations V= √(Fr/m)The Attempt at a Solution find the vertical component, call it y, then say...
  29. S

    Finding the Initial Velocity and Angle of a Cannon Ball Launched from a Cliff

    Homework Statement Classic cannon ball launched with an initial horizontal velocity from an elevated position. Initial hvelocity: v Final velocity (when hits the ground): 4v High of the cliff: 16m Find the initial velocity and the angle at which the ball strikes the ground. Homework Equations...
  30. H

    Period for harmonic motion (horizontal)

    Consider a light flexible rod placed on a horizontle table with part of the rod (length say "x") hanging freely (ie without support of the table) see attachment for clarity A mass is also hung from the rod t one end. Are there any equations that relate the Period T of the end of the rod to...
  31. H

    Projectile motion - horizontal seperation of two points

    Homework Statement A projectile is fired with velocity v0 and passes through two points, both a distance h above the horizontal. The angle of the barrel of the gun is adjusted for the maximum range, find the horizontal separation of the two points. Homework Equations Max range for projectile...
  32. K

    How can I find Horizontal and Vertical velocity, given distance and time?

    Homework Statement I need to find the horizontal vectors and vertical vectors at launch, maximum height and at final catch of a projectile. I know that the distance between point A and point B is 5 and the total time is 1. Homework Equations How can I also find the maximum height and the...
  33. L

    Discover the Influence of Horizontal Centripetal Force on Spinning Motion

    Imagine you are spinning a weight at the end of a string horizontally. As one increases the speed with which the weight is being spinned, the motion becomes more and more horizontal. I understand this occurs because the centripetal force (tension of the string) is increasing but at the same time...
  34. P

    Horizontal force on frictionless ramp

    A 100 N box is being pushed with a horizontal force F at 30 degrees on a frictionless ramp. Determine F and N (normal force). I got about 57.74 and about 115 for the second part (I don't know if it is right) Fcos(theta) -mgsin(theta)=0 for part A N-Fsin(theta)-mgcos(theta)=0 for...
  35. R

    How do I find the horizontal force/traction force of this?

    8. A setup similar to the one shown in the figure below is often used in hospitals to support and apply a traction force to an injured leg. (a) Determine the force of tension in the rope supporting the leg. F = mg F = (8.00)(9.81) F = 78.48 F = 78.5 N Is that all I had to do? It...
  36. C

    Fortran Fortran: determine the horizontal distance of a ball

    Im writing a program to determine the horizontal distance of a ball but getting this error: Y(t)=Y0+VY0*t+(1/2)*g*t^2 1 Error: Unclassifiable statement at (1) Distance=(X(t))^2+(Y(t))^2 1 Error: Unclassifiable error at (1) My code is as follows: PROGRAM...
  37. I

    How to find the horizontal range of the car rolling off an inclined cliff

    Homework Statement A car is parked near a cliff overlooking the ocean on an incline that makes an angle of 14 with the horizontal. The negligent driver leaves the car in neutral, and the emergency brakes are defective. The car rolls from rest down the incline and has a velocity 5 m/s...
  38. B

    Horizontal Force Required to move a box up a ramp

    Homework Statement A block with a mass of m is initially moving up the incline and is increasing speed with an acceleration of a. The applied force F is horizontal. The coefficients of friction between between the block and incline are μs=S and μk=K. The angle of the incline is θ. What is the...
  39. H

    Horizontal Acceleration of a Stone

    Homework Statement A stone is thrown horizontally from a cliff 25 m high and lands on the ground 22 m from the foot of the cliff. What is the horizontal acceleration on the stone? Homework Equations a = Δv/Δt = (vfinal - vinitial) / (tfinal - tinitial) The Attempt at a Solution...
  40. K

    Calculating horizontal distance using angle and max height

    The froghopper, Philaenus spumarius, holds the world record for insect jumps. When leaping at an angle of 58.0 above the horizontal, some of the tiny critters have reached a maximum height of 58.7 above the level ground. A)What was the takeoff speed for such a leap? I got 4.00 m/s which was...
  41. K

    Horizontal and Vertical Velocity

    A rookie quarterback throws a football with an initial upward velocity component of 16.5 and a horizontal velocity component of 18.3 . Ignore air resistance. A)How much time is required for the football to reach the highest point of the trajectory? I got 1.68s which is correct B) How...
  42. M

    Why does rotating a ball on a string faster makes it horizontal

    Hi suppose i had a ball on string and started to rotate it in a circle around my hand. When i increase the speed of the ball it becomes more and more horizontal. The only forces i can think of at play is centripetal and centrifugal forces and the force exerted by my hand and gravity. Is somehow...
  43. C

    Finding Horizontal & Vertical Asymptotes Of A Curve

    Homework Statement Homework Equations None The Attempt at a Solution I was able to find a vertical asymptote at x=-3/8 by setting the denominator to 0 and using the quadratic formula to find the roots. However, I am unsure of how to find the horizontal asymptotes, and I am not...
  44. N

    30º above the horizontal with initial velocity problem

    Homework Statement A basketball player throws a ball at an angle of 30º above the horizontal. If the ball in has an initial velocity of 29.4 m/s, how far does it travel? Homework Equations Vyf^2 = Vyi^2 + 2(Ay)(Dy) solve for Dy and get [Vyf^2 - (Vyi^2)] / (2(Ay)) = Dy The Attempt at a...
  45. L

    Horizontal Lift vs Parallel Transport in Principal Bundle & Riemannian Geometry

    I am a physicist trying to understand the notion of holonomy in principal bundles. I am reading about the horizontal lift of a curve in the base manifold of a principal bundle (or just fiber bundle) to the total space and would like to relate it to the "classic" parallel transport one comes...
  46. P

    Horizontal Asymptote by Long Division?

    Homework Statement Find the horizontal asymptote Homework Equations The Attempt at a Solution There are two ways I did this problem. One way seems to be a coincidence and the other the "proper way" 1. I used long division, and got 2+(9x-3)/(x^2-2x) 2 seems to be the horizontal asymptote...
  47. Darth Frodo

    Projectile on horizontal surface

    Homework Statement A particle is projected with a speed of 98 m s−1 at an angle A to the horizontal. The range of the particle is 940·8 m. Find (i) the two values of A The Attempt at a Solution U = 98cosAi + 98sinAj i direction s = ut 940.8 = 98cosAt j direction s = ut...
  48. W

    Horizontal + Celestial Coordinates to Geographic Coordinates

    Hey everyone, I cannot seem to figure this out and I'm having a hard time finding any guides online for this stuff. All I can find are calculators. I was wondering if it would be possible to calculate my Geographic Coordinates on Earth if I had the Horizontal and Celestial coordinates of a...
  49. T

    Maximum vertical and horizontal forces.

    Homework Statement https://dl.dropbox.com/u/64325990/math.PNG The Attempt at a Solution So what I did was set up an system of equations such that the sum of the horizontal forces = 0 and the sum of the vertical forces = 0. I ended up solving for the tension in the rope BC and then found...
  50. Philosophaie

    Horizontal Parallax Correction

    Parallax is a way of measuring the distance of one object to another. By taking the distance of an already known object, say the Sun, and drawing a line to the object. Then drawing another line between you and the object in question. The angle you get is the Horizontal Parallax angle...
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