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. A

    The smallest angle flashlight beam can make with horizontal

    Homework Statement At the aquarium where you work, a fish has gone missing in a 10.5m -deep, 9.45m -diameter cylindrical tank. You shine a flashlight in from the top edge of the tank, hoping to see if the missing fish is on the bottom. What’s the smallest angle your flashlight beam can make...
  2. T

    Height and horizontal distance of a projectile

    1. The problem: I need to find the height and horizontal distance reached by a projectile given only the vertical and horizontal velocities. Vv=120m/s Vh= 30m/s this is for an algebra based physics class, I'm very new to this stuff.Homework Equations : V=at+Vo X=1\2at^2 + Vo + Xo...
  3. S

    Lagrange for Rod/nail swinging from horizontal plane

    Hi! I need to figure out the Lagrange Equation for a rod or nail swinging from a horizontal plane. The thing is, that while it is swinging back and forth, the while nail is moving along the X axis as well. I was thinking to use 1/2mv^2+(1/2)Iø^2 . Any help would be appreciated! Thanks.
  4. C

    MHB Find Tension in Horizontal Rope DE | Cylinder Mass & Angle θ

    Hi there, I have a question I'm unable to get properly started on: A cylinder of radius R and mass m is lodged between cross pieces that make an angle θ with each other, as shown in the diagram below. The cross pieces of negligible mass are connected in point C, with lengths AC = BC = 2R and...
  5. P

    Calculating horizontal acceleration?

    Homework Statement The problem reads: Two forces act on a 5.0 kg block on a friction-less surface. (a) Draw a free-body diagram (b) Determine the magnitude of the normal force (Fn) (c) Determine net horizontal force (d) Determine the magnitude and direction of the horizontal acceleration I...
  6. liometopum

    Horizontal Branch Star: A Planet-like Object Found on ALADIN

    In researching a planned post about M87's globular clusters, I again have been diverted. Being a rank amateur, I was studying how to use Aladin. Looking at some YouTube videos, I found this odd one, "Planet Like Object Found on ALADIN". The object looks bizarre, like the guy drew it in the...
  7. Tim Allen

    Help with designing horizontal framework for UDL

    Hi, For my engineering project for college I am designing a rotating table/steel frame structure for supporting a mild steel panel which weighs 180kg. My previous experience with UDL's has only been in using a 2D beam like situation to calculate how the load is spread, bending of the beam and...
  8. C

    Magnitude of horizontal forces

    A child pulls an 11 kg wagon with a horizontal handle whose mass is 1.8 kg. This results in the wagon and the handle accelerating at 2.3 m/s^2. Find the tension forces at each end of the handle. Why are these different? Suppose that the mass of the child is 30 kg. What is the magnitude of the...
  9. R

    Horizontal Projectiles. Degree or Radian mode in calculator?

    Homework Statement It's a worksheet with questions like : 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 water below. What is the pelican's initial speed? Homework EquationsThe Attempt at a Solution [/B] So...
  10. R

    Acceleration question -- Deceleration of a baseball being caught by a player

    1. A baseball is traveling at +18 m/s and is caught by a player. The ball is brought to rest in 0.5 s. What is the acceleration of the ball?Homework Equations Maybe vf=vi+ at ?The Attempt at a Solution This is under a Horizontal Projectiles worksheet by the way...I'm not sure what to do on this...
  11. andyrk

    Rotating Horizontal Tube filled with ideal liquid

    A horizontally oriented tube is rotating with angular velocity ω about one end of the tube which is open. The tube has ideal liquid filled inside it as shown in the attachment. Why does there have to be a pressure difference between two points in the ideal liquid at the same horizontal level...
  12. C

    Horizontal ring water main pressure drop

    Homework Statement The accompanying figure shows a horizontal ring main consisting of a single loop of pipe, as might be used for supplying water to various points on one floor of a building. Water enters the main at A at 50 psig and is discharged at B and C at rates of 20 gpm and 60 gpm...
  13. L

    Normal force of a bead moving around a horizontal ring

    A bead of mass m is threaded on a metal hoop of radius R. There is a coefficient of kinetic friction µk between the bead and the hoop. It is given a push to start it sliding around the hoop with initial speed v0 . The hoop is located on the space station, so you can ignore gravity Find the...
  14. J

    Find First Place Where F <= 0 in O(log n) Time

    Homework Statement Consider a strictly decreasing function F: ℕ → ℤ. We want to find the "first place where f is at or below the horizontal axis." Assume we can compute ƒ(i) for any input i in constant time. Clearly, we can solve the problem in O(n) time by evaluating ƒ(1), ƒ(2), ƒ(3)...
  15. T

    Projectile motion -- launched 60° above the horizontal

    Homework Statement A projectile is launched at an initial speed of 30 m/s at an angle of 60° above the horizontal. Calculate the magnitude and direction of its velocity (a) 2s and (b) 5s after launch Homework Equations x=v*t in the x dimension x= x+vt+(1/2)at^2The Attempt at a Solution I...
  16. IDespisePhysics

    Finding average horizontal force?

    Homework Statement A car is traveling at 60.0mph when it collides with a stonewall. The car comes to rest after the first foot of the car is crushed. What was the average horizontal force acting on a 150lb driver while the car came to rest? Homework Equations I'm not a hundred percent sure...
  17. S

    Horizontal range questions help

    Homework Statement A ball rolls off a table at an initial velocity of 2.5 m/s. The table's height is 3 meters. Similarly another question asks for the same thing except this time it's a rifle shooting a bullet with a velocity of 250 m/s with a height of 3 meters. Homework Equations The...
  18. G

    Hinged door lowering below the horizontal

    Hi all, This is not a homework question it is trying to get brownie points from my boss. I have a ramp (mass 2015kg of uniform size) hinged at one end lowered by cables (2) through a sheave 2.7m Vertical. The anchor point on the ramp is 2.7m from the hinge. The overall length of the ramp is...
  19. J

    Pretension wire with horizontal load

    I have a wire used for cutting cheese that gets pushed horizontally into the wire repeatably. Naturally the wires break as the wear. Currently, we just tighten the wire until it seems good but I am unsure how much the pretension in the wire influences the rate the wire breaks. I was looking to...
  20. R

    Constant horizontal force and friction

    Homework Statement A 50 kg is pushed across a floor by a constant horizontal force of 200 N. What is the force of friction? Homework Equations Ffr = coeff*Fn The Attempt at a Solution I'm not sure how to find it as I don't know the coefficient. The answer says the answer is 200 N, but I don't...
  21. R

    Horizontal velocity over an uneven surface

    Homework Statement A small ball of m=1kg at height hp = 8m at point p, is given an initial horizontal speed vp = 10 m/s. It slides over an uneven frictionless surface. What is speed vq of the ball at height hq = 3m at point q? Homework Equations Ui + KEi = Uf + KEf The Attempt at a Solution...
  22. GiantSheeps

    Object on horizontal surface practice question please?

    So I have a physics midterm tomorrow that will have a five part, 10 point question about the following "an object pushed across a horizontal surface. You should be able to calculate net force, frictional forces from the coefficient of friction, acceleration, velocity, momentum, impulse, and...
  23. I

    Finding horizontal force using mass and static friction?

    Homework Statement There is a box that has a mass of 30 kg. The coefficient of the static friction is 0.75. Find the horizontal force. Homework Equations Fs=muFn F=ma The Attempt at a Solution Fs=(.75)(.98)(.30)=.2205 N That is probably way off... I am very confused right now. Could someone...
  24. Z

    Fluid Statics: Find vertical and horizontal forces in tank

    Homework Statement The tank shown in the figure is filled with water and fastened to the ground. There is a small opening on top of the semi-spherical part of the tank. a) What is the magnitude of the horizontal force on the screws? Explain using a free body diagram. b) Consider the proper...
  25. B

    Need Help Projectile Motion - Hitting Target with toy gun

    Hey, I need help with a lab I'm doing in class. The goal is to hit a target on the ground by shooting a bullet from a toy gun. Our distance from the target will be assigned to us by our teacher and I need to calculate the initial velocity of the gun and then hit the target by only changing the...
  26. P

    Horizontal circular motion problem

    Homework Statement I have this question to solve for homework : " An object of mass 10 kg is whirled around a horizontal circle of radius 4m" If the uniform speed of the object is 5m/s Calculate a) tension in string b) angle of inclination of string to the vertical.Homework EquationsThe Attempt...
  27. T

    MHB What values of x make the graph of f(x) have a horizontal tangent?

    For what values of does the graph of have a horizontal tangent? f(x) = x + 2sin(x) I get this: $f'(x) = 1 + 2 \cos(x)$ And I understand that I need to set this to zero. $1 + 2cosx = 0$ $cosx = 1/2$ How do I isolate x in this situation?
  28. J

    Composite object resting on a horizontal plane

    A solid hemisphere has another, smaller solid hemisphere attached to each other at their plane, circular faces, so that the centre C of the circular bases of either coincide. A particle P is then attached to the edge of the plane circular face of the larger hemisphere. The composite object is...
  29. K

    Calculating Max Speed of a Car on a Horizontal Road

    1. "A car moves along a horizontal road against a resistance of 400 N. What is the greatest speed in kph that the car can reach if the engine has a maximum power of 16.0 kW?"Homework Equations : P= W/change in time P= F x v (dot product) Please help ): [/B]
  30. CivilSigma

    Why do we interpret this vertical angle to be a horizontal angle?

    At the point B, there is supposed to be a force B that is perpendicular to the angled piece of metal. Why is the angle that the force makes with the horizontal 20? Should it not be 70?
  31. K

    What is the difference between above and below the horizontal?

    Homework Statement Some of the questions in my homework list the velocity either above or below the horizontal. I am confused as to what the difference is. This is the question: "A child sitting in a tree throws his apple core from where he is perched (4.0 m high) with a with a velocity of...
  32. Satvik Pandey

    Find Velocity of Rod Center of Mass When Making 30° Angle with Horizontal

    Homework Statement A thin rigid rod of length ##l## is placed perfectly vertical on a smooth ground. A slight disturbance on the upper end of rod causes lower end of rod to slip along the ground and rod starts falling down. Find velocity of center of mass of rod when the rod makes ##30## with...
  33. K

    Frictional Force and acceleration

    Homework Statement The force applied to a cart is 10.5 N. The cart now moves toward the right at an acceleration also toward the right of 1.75m/s2. What are the magnitude and direction of the frictional force? The attempt at a solution I found that my mass is 6kg. I have F, m, and a, but I am...
  34. S

    Degree of freedom of a block of wood sliding on a horizontal plane

    Homework Statement Find out the degrees of freedom of a block of wood sliding on a horizontal plane. Homework Equations DoF=Nn-k N=no. of dimensions. n=no. of particles.k= no. of constraints. The Attempt at a Solution I am considering the block of wood as a rigid body made of n no. of...
  35. jk22

    Horizontal Photon Vertical Lift Acceleration

    supposing a constant acceleration Vertically a horizontal incoming photon is considered. We know that in the frame of the lift the vertical speed of the photon will increase, hence its horizontal one will decrease and then the photon trajectory has a vertical asymptote ?
  36. N

    How Do Horizontal and Vertical Movements Differ in Subducted Plates?

    For my homework I was given a velocity diagram of the Juan de Fuca plate similar to this: The first question is as follows: Measurements indicate that the Juan de Fuca plate is moving at a speed of ~40 mm/year. Calculate, and draw diagrams that show, the horizontal and vertical components...
  37. T

    MHB Solving Limit for Horizontal Asymtotes

    We had to solve this limit $$\lim_{{x}\to{\infty}} \frac{1}{x}$$ the answer is y= 0 is the Horizontal Asymptotes. I get the y = 0 but how do we know that it is the horizontal asymptote?
  38. M

    Block held at rest against a vertical wall by a horizontal force

    Homework Statement A 5.00-kg block is held at rest against a vertical wall by a horizontal force of 100 N. (a) What is the frictional force exerted by the wall on the block? (b) What is the minimum horizontal force needed to prevent the block from falling if the static coefficient of friction...
  39. T

    Vertical and horizontal circular motion: How to identify the centripetal force?

    I made notes on this in class, but I did not understand everything about it. So, what I know is that vertical motion is when the object goes around in a circle like this: And horizontal I guess it is like this: But then I am very confused regarding what my teacher told me for horizontal...
  40. C

    Solving the Horizontal Light Clock Puzzle: Length Contraction & Frame Shifting

    Consider a Horizontal light clock of length ##L_0## lying at rest in a frame K. There are two important events: (A) a photon gets emitted from the left mirror and (B) it gets reflected at the right mirror. Another frame K' is moving by at velocity v and the frames are in standard configuration...
  41. P

    Projectile Motion, only given horizontal distance

    Homework Statement The longest pass in history is 85.8m. Ignoring any air resistance effects, calculate the initial speed of football.Homework Equations Vx=Vo cosΘ x=VcosΘt Vy=VosinΘ -gt y= VosinΘt - 0.5gt^2 The Attempt at a Solution I really don't know what to do here. I've looked through all...
  42. T

    How can a horizontal component be of sin? Error in book or my brain?

    I've learned that the horizontal component is F cos angle not F sin angle, but I'm looking right now into the aqa physics a student book from nelson thrones, chapter 2.3 page 27, and it says that the horizontal components going to be made up of sin and the vertical out of cos... This is about...
  43. S

    Flux above a flat horizontal surface

    So my question is, am I missing any key thing in answering the question below? Question: An electric flux of 149 N.m2/C passes through a flat horizontal surface that has an area of 0.67 m2. The flux is due to a uniform electric field. What is the magnitude of the electric field if the field...
  44. I

    Finding an expression for a projectile's horizontal range

    Homework Statement A projecticle launced at an angle of θ to the horiz
  45. F

    Fluid Dynamics Question - Pressure Difference in Horizontal Pipe

    Homework Statement The Trans-Alaska Pipeline System (TAPS) carries around 100,000m3 of oil per day from the Northern Alaskan oil fields to the nearest ice-free port of Valdez, around 1300km away. The pipe has an outer diameter of 1.22m and a wall thickness of 12mm. Eleven pumping stations...
  46. B

    Horizontal Vs Vertical Steel tube

    How does the orientation affect how much a steel tube can hold? or does it not really have an effect?
  47. C

    Mass of a rubber stopper being swung in a horizontal circle

    Homework Statement Homework Statement [/b] The purpose of this lab is to determine the mass of a rubber stopper being swung in a horizontal circle. I made an apparatus that resembles the picture attached, with a string (with a rubber stopper on one end, and a weight on the other end) put...
  48. skulliam4

    Weight of Horizontal Projectile

    Hi, I am 12 years old and sort of a noob to physics due to, well, me being in the 8th grade. I need to find the weight of this spherical projectile given just about every other factor, I know the Angle in which it was fired (32.2°), the gravity of the planet this takes place on (12m/s2), the...
  49. marellasunny

    Catia, measuring just the horizontal distance in side view

    In CATIA V5R19, when I switch to the side view, how do I measure just the horizontal distance between 2 points that are not exactly in the same horizontal plane? When I use the tool 'Measure distance between' , I get a inclined measurement line which is exactly what I do not want. How do I...
  50. matineesuxxx

    Speed of conical pendulum at angle alpha to horizontal

    Homework Statement Assuming we know the length of the string L, radius of the swept out circle r, angle formed by string and centre of circle, \theta, and angle the swept out circle is to the horizontal, \alpha, what is the speed, v, of the mass if it is constant? picture...
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