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. snate

    What Determines the Maximal Elongation of a Spring in a Pulley System?

    Homework Statement 2 bricks of mass m are located near the edge of a smooth horizontal surface, they are connected by an ideal weightless ,unstretched spring with a length of l0 and spring constant k. The brick which is closer to the edge is connected to another brick of the same mass by an...
  2. B

    A rocket on a cart is fired to go through a hoop

    Homework Statement A 300 g rocket is on a cart that is rolling to the right at a speed of 2 m/s. The rocket engine, when it is fired, exerts an 6 N thrust on the rocket. Your goal is to have the rocket pass through a small horizontal hoop that is 18 m above the launch point. At what horizontal...
  3. G

    With what minimal horizontal velocity can you throw a stone

    Homework Statement With what minimal horizontal velocity can you throw a stone from position A so it it manages to fly over position B. the distance between A and B is 40m the height of position A is 20m the height of position B is 10m Homework Equations [/B] The Attempt at a Solution...
  4. S

    Horizontal to tilted beam radiation

    Hello, the name's Mike and I'm a newbie here, I have a question pertaining to solar angles required to calculate a solar panel's hourly generation over one year. Total solar irradiance on a tilted surface equals the sum of the direct, diffuse and reflected component. In my case, reflection is...
  5. C

    Cannonball - time required to stop its horizontal motion

    Let's imagine that we fire a cannon located on a platform high above the ground and we want to compute the time after which the horizontal velocity of the cannonball will be zero. Let's assume that we shoot at 0 degree angle. 1. Air resistance force F = C_d \frac{\rho v^2}{2}S 2. Assuming that...
  6. L

    Investigating the Physics Behind Horizontal Damping of a Trailer

    I want to do an investigation on how the damping of a trailer when it is moved horizontally. I saw a video of a toy car with a trailer and someone changing the weight distribution on the trailer. This change led to a big difference in the oscillation patterns of the trailer when moved. (the...
  7. N

    Confusion about work performed by a horizontal push or pull

    Hello, Over the past couple of weeks I have been working my way through the basics of physics on my own. I've just arrived at work and energy and there is one thing that confuses me a little bit. Let's say I have a 25kg box on a sidewalk. I go to push it and I ultimately push it 5m east (lets...
  8. Maryam9

    Vertical and horizontal components,physics As level help :(

    Homework Statement This is paper from june 2016 , the link below; http://qualifications.pearson.com/content/dam/pdf/International%20Advanced%20Level/Physics/2013/Exam%20materials/WPH01_01_que_20160524.pdf Can someone pleeeeeze explain how to solve question 15 part B AND queation 16 part B . I...
  9. alex91alex91alex

    Solve Horizontal Spring Homework: T, A, V&Where Max V

    Homework Statement A 425 gram mass is attached to a horizontal spring. The spring is known to have a spring constant of 84.6 N/m. The mass is free to slide along a friction less surface. a) The mass is then pulled to the side a distance of 5.67 cm and released. Determine the period and...
  10. A

    Effects of Rolling Resistance on Tension and Acceleration in an Atwood Machine

    We had a lab using an Atwood Machine with block A being on the surface and block B as the hanging object with different masses each round. Rolling resistance was present. Question 1 asked whether or not the tension in the string was less than, greater than or equal to the magnitude of the...
  11. R

    How the launch angle affects the horizontal distance/range?

    Homework Statement I'm doing a lab report about how the launch angle affects the range of a projectile. Independent Variable Angle of Launch Dependent Variable Range or distance I did an experiment with three trials and here are my results: And then plotted the data. However, it's a...
  12. R

    Calculating mass of the horizontal leg of a L shaped lever

    Hey everyone, been stuck on this for over a day now, wondering if anyone is able to tell me if I am on the right track. 1. Homework Statement "In your calculations for M1 (bell crank lever), note that the mass of the horizontal leg is contributing to the anti-clockwise moment. Given the masses...
  13. B

    Lagrangian about rolling disk on a horizontal plane

    Homework Statement Homework EquationsThe Attempt at a Solution This is the problem in Goldstein's classical mechanics exercise 1.11 I wonder why the solution doesn't consider rotational kinetic energy (1/2 I w^2) So, L= T = 1/2mx^2 + 1/2 I w^2 .
  14. physicsdude101

    A mass is free to move on a horizontal frictionless surface

    Homework Statement A mass m that is free to move on a horizontal frictionless surface, is attached to one end of a massless string that wraps partially around a frictionless vertical pole of radius r, as in the Figure below.You are holding onto the other end. At t=0 the mass has speed V0 in the...
  15. T

    Force of a block on an incline above a horizontal

    Homework Statement The block shown in figure #1 above has a mass of 4.30 kg. The applied force F has a magnitude of 31.2 N and is directed at 38.0˚ above the horizontal frictionless surface the block in on. What is the magnitude of the normal force that acts on the block? Homework Equations...
  16. J

    Can I design a horizontal cylindrical hollow turbine blade

    Hello everyone, I need the following but I am not sure if it is possible or not? I don’t have mechanical engineering background. Please advise me on feasibility of this project and any suggestion would be greatly appreciated. I am looking to design a horizontal cylindrical hollow turbine...
  17. P

    MHB Consecutive vertical and horizontal transformations of a function

    Dear all, I am stuck on this question: "If f(x)=(2^x)+1, give in simplest terms the formula for h(x), which is obtained from transforming f(x) by a vertical stretch, scale factor 8 relative to y=0 a translation by vector (1,4) a horizontal stretch, scale factor 1/2 relative to x=0" This is...
  18. J

    Impact Force of a Horizontal Moving Projectile

    What is the correct way to calculate the impact force of a 2"x4" flying through the air and hitting a solid cross beam? The knowns are: Velocity: 50 ft/sec Distance To cross beam: 12 ft 2" x 4" Weight: 9 lbs I don't know much the cross beam will deflect on impact, so the stopping distance is...
  19. G

    Splitting reaction into horizontal and vertical components

    Homework Statement In each of the diagrams (please see attached file (I am sorry for the rotated, the original was in normal form but when uploading it, it was somehow rotated)) and the description of each case below, a particle is moving on a smooth surface, so that the reaction force R acting...
  20. S

    Finding frequency of a specific mechanical oscillator -- horizontal rod on pivot

    Homework Statement There is a cyllinder with radius 0.5 m fixed on the wall. We put a 6 metres long thin rod with mass 0.3 kg on it, which does not slip. I would like to calculate the oscillating time. It is a part of a clock, so the oscillating time is probably 1 or 2 seconds, but I got...
  21. Clara Chung

    Question about circular motion on a horizontal road

    Homework Statement Homework EquationsThe Attempt at a Solution Why can't we take the moment on the left wheel? In this case, 2d(N2) - mgd = mgd + m(v^2)h/r - mgd =m(v^2)h/r ≠ 0 Shouldn't there be an anticlockwise moment about the left wheel?
  22. S

    Lagrangian for a rolling disk on horizontal plane

    for a disck rolling on a horizontal plane the kinetic energy should be the kinetic energy of the CM of the disk with respect to the origin plus the kinetic energy due to the rotation of the disc about his CM so T= 1/2 (M V^2) +1/2(I ω^2) where M is the mass of the disk and V is the velocity of...
  23. FallenApple

    How does pendulum go slack above the horizontal?

    So say a pendulum consisting of a non rigid string and mass bob is swung above the horizontal position. It's given an impulse at the bottom so that in the swing, there is nothing but tension and gravity acting. At above the horizontal, the gravity is pointing down while the tension can only...
  24. K

    Calculating Horizontal Forces in a Stream of Sand Impacting a Wall

    Homework Statement "A stream of sand moving at 4 m/s is directed horizontally eat against a wall at a rate of 120 kg per minute. If the sand falls vertically downward after impact, find the horizontal force exerted by the wall on the sand, and the horizontal force exerted by the sand on the...
  25. A

    What is the minimum horizontal force?

    Homework Statement What is the minimum horizontal force F needed to make the box start moving in (Figure 1) ? The coefficients of kinetic and static friction between the box and the floor are 0.25 and 0.46, respectively. Homework Equations Fs= mu * N The Attempt at a Solution So I know that...
  26. A

    How to find the minimum horizontal force?

    Homework Statement What is the minimum horizontal force F needed to make the box start moving in (Figure 1) ? The coefficients of kinetic and static friction between the box and the floor are 0.28 and 0.39, respectively. Homework Equations fk=mu N fs=mu N The Attempt at a Solution Im not...
  27. Haniah

    Calculating Toolbox Mass in Horizontal Pulley System

    Homework Statement A group of construction workers are building a house and want to lower down an excess bundle of 1400 kg bricks to ground. They tie one end of a rope to the bundle of bricks, loop it through a pulley, and tie the other end of the rope to a toolbox. If the coefficient of...
  28. K

    Rock thrown off a horizontal cliff

    < Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > The question states a stone is thrown off a cliff horizontal and it eventually hits the ground. A second stone is dropped from rest at the same height and it hits the ground too. The question...
  29. Vitani11

    What is the horizontal force exerted by the pivot on the rod

    Homework Statement A rod swings freely about a pivot. Is has mass M and length L. The average force and duration of hit are Fo and t respectively. A) What is the speed of the com of the rod just after It is hit? B) what is the horizontal component of the force exerted by the pivot on the rod...
  30. Cocoleia

    Time for a block to come to a stop on a horizontal surface

    Homework Statement I have a block of mass m on a horizontal surface, which is covered in oil. The tell me the viscous resistance force is a function of the velocity, F(v)=-cv1/2, where I am assuming c is a constant of some kind. I need to find the time that it will take for the block to stop...
  31. M

    Why electrons move up if the Magnetic field is Horizontal?

    <--Why electrons move up if the Magnetic field is Horizontal? at 0:14 <-- the Magnetic field is Horizontal but the electrons are also moving horizontally...
  32. V

    A Projectile Launcher (baseball hit at a 45 degree angle to the horizontal)

    Homework Statement [/B] A baseball player hits a ball 200.0m home run. The ball travels at angle of 45° with the horizontal just after being hit. Determine the initial speed. Assume the ball lands the same height it was hit. 2. Homework Equations The Attempt at a Solution I am not sure how...
  33. L

    A Unique separation of the vertical and horizontal spaces?

    I have trouble understanding how a connection one-form can separate and tangent space##{T_u}P## of a principal bundle uniquely into horizontal and vertical spaces ##{H_u}P \oplus {V_u}P## since from the literature I am learning (mainly Nakahara' book), the connection one-form is a...
  34. math4everyone

    What is the electric field at a point along the z-axis above a charged dome?

    Homework Statement Homework Equations The z component of the field: $$E_z = \frac{-Qh}{2\pi\varepsilon_0 (r^2+h^2)^{\frac{3}{2}}}$$ The Attempt at a Solution I tried to choose a cylinder for my Gaussian surface such that the radius of it matches with the distance d I am trying to find and...
  35. OrlandoLewis

    Why Is the Normal Force the Same on Both Blocks in a Frictional System?

    Homework Statement The two blocks (m=16kg and M=88kg) are not attached to each other. The coefficient of static friction between the blocks is us=0.38, but the surface beneath the larger block is frictionless. What is the minimum magnitude of the horizontal force F required to keep the smaller...
  36. E

    I Horizontal Noise Stripes in an Image

    What are the possible causes of the horizontal noise stripes in this image: http://dsp.stackexchange.com/questions/20061/removing-periodic-noise-from-image-using-fourier-transform I'm currently studying on these kinds of noise, and how to eliminate them. Can these be caused by diffraction...
  37. J

    A ball rolls on a horizontal table and drops. it hits the 0.

    Homework Statement it hits the ground 0.5s after dropping and at a 40cm distance from the table. what is the table height? what is the ball initial speed? in what speed (with direction) did it hit the ground Homework EquationsThe Attempt at a Solution solved thee first question stuck on the...
  38. M

    B Understanding the Horizontal Component of Normal Force in Banked Curves

    Why during a banked curve is the horizontal component of the normal force considered as the net force and the centripetal force? The horizontal component of Normal force, N·sinθ, is not even ponting towards the centre of the curvature.
  39. S

    Design -- horizontal I-beam with center loading....

    I have an i-beam placed horizontally and i want to apply 1 ton point load on its center. Now i will run a stress analysis on ansys on it and will get the displacement in the beam on the mentioned load. How will i know tht the displacement value i am getting is good or bad?
  40. R

    B Finding Horizontal Force in a Crank at 10N

    I'm trying to establish the force in the horizontal direction of a crank when the force that is tangent to the crank is 10N. Zero degrees is on top of a circle. Clearly, when the crank is vertical which corresponds to it being at zero degrees, the force in the horizontal plane is normal to the...
  41. Kloud

    Minimum horizontal force needed so book does not fall?

    Homework Statement Part C of problem Please see attachment : What is the minimum horizontal force needed to keep the book from slipping. Note that P=515N, and P=normal force, Fs=131.32N, Us=.255, M=9.85kg Homework Equations Fn=(m*g)/Us The Attempt at a Solution My answer is 378.549N, which...
  42. steroidjunkie

    Metal sphere on a thread in a horizontal electric field

    Homework Statement Charged metal sphere hanging on an isolated thread of negligible mass is put in a homogeneous horizontal electric field so that the thread makes a 45 degree angle with the el. field. What angle does the thread with the sphere close with the el. field after we remove 40% of...
  43. S

    Three/four sprockets in horizontal line can be run by chain?

    Hello people, I have a serious design problem for designing a sprocket-chain system. I want to know that can three sprockets as in picture (in attachment) can be rolled by a chain? The main concern is for middle sprocket it have few teeth above and few teeth in bottom connected to chain. The...
  44. JulienB

    Pendulum on a horizontal spring (Lagrangian)

    Homework Statement Hi everybody! I'm back with another lagrangian problem :) Although I think (or hope) I have made progress on the topic, I always learn a lot by posting here! A pendulum with point-shaped mass ##m_1## hangs on a massless string of length ##l##. The suspension point (also a...
  45. C

    Horizontal Force in Bottom Member of a Truss

    Hello, I've been studying for the FE, and this question in the Statics section of the review I am going through has really tripped me up for some reason. I understand Statics, and how to determine forces in X and Y directions, determining X and Y components using trig, etc, etc.. Maybe I am...
  46. Parsifal1

    Horizontal force across a partition

    Homework Statement Find the horizontal force across the partition in a water tank with two compartments, one filled with water to x height and the other with water to y height. I've worked out the thrust acting on the partition as a result of density, height, gravity and average depth, so I...
  47. E

    B How can gravity have a horizontal component?

    In the above case, mgcos(theta) is the component of gravity perpendicular to the surface of the wedge. Considering all surfaces to be frictionless, the horizontal component of the normal force would cause the wedge to accelerate towards the right, and the horizontal component mgcos(theta)-the...
  48. H

    Rolling friction on a horizontal surface

    Suppose a cylindrical rod is given a push such that it rolls without slipping on a horizontal plane. Am I right to say that rolling friction is only required at the start when the push is applied to initiate the rolling motion? Once the push is removed, the only forces acting on the rod are its...
  49. F

    I Understanding Falling with Horizontal Velocity

    In the book I'm reading, there is a discussion about how a person inside a "box" falling in a gravitation field would see himself as compared to someone on the ground. It is as follows "While the guy is asleep, put him in a spacious box elaborately furnished inside to look exactly like his...
  50. M

    MHB Vertical and Horizontal Asymptotes

    In an inverse variation equation, what are the asymptotes and how do you find them? For example, I was given the equation: y= [1 \ (x - 3)] - 6 and asked to find the vertical and horizontal asymptote. I don't really understand what they are and why y= -6 and x=3. Thanks for any help!
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