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. G

    Horizontal Force on a Ramp required to Accelerate a Mass

    Homework Statement A 5.57 kg box sits on a ramp that is inclined at 38.0^\circ above the horizontal. The coefficient of kinetic friction between the box and the ramp is 0.28. What horizontal force is required to move the box up the incline with a constant acceleration of 4.30 m/s^2...
  2. B

    Block Collides With Horizontal Spring

    Homework Statement A moving 2.40 kg block collides with a horizontal spring whose spring constant is 478 N/m. The block compresses the spring a maximum distance of 13.00 cm from its rest position. The coefficient of kinetic friction between the block and the horizontal surface is 0.360...
  3. M

    Solving a Rocket's Motion: Max Height & Horizontal Reach

    Homework Statement For 6.5 s, a rocket rises in a straight line oriented at 70° from the horizontal axis with a constant acceleration module of 8m/s2. Then she is goes into free fall. Find: a) the maximum height b) its horizontal reach Homework Equations t = ( vfv - viv)/a d = viht +...
  4. T

    Tension of 10 m rope hung across 6 m horizontal distance with 50 kg box hanging

    Homework Statement A rope is 10.0 m long and is attached at points A and B, which are at the same elevation 6.0 m apart. If a 50.0 kg mass is attached to the rope 4.0 m away from point A, what is the tension in the two segments of the rope? Homework Equations W = ma ƩFy = 0 = T1 + T2 - W...
  5. O

    Projectile Motion with only the vertical/ horizontal height and angle given

    I need help! I understand regular projectile, but when it comes to using an angle it drives me crazy! The vertical distance is 15.01 m Horizontal distance is 21.84 m Angle is 45° I figured the time to be 2.1 sec I need the velocity And VsubF is 0...right? I just need the help guys, thanks
  6. D

    Isothermal compressible flow in horizontal pipe

    Homework Statement A compressor is required to drive acetylene gas at 1.85 kg/s through a horizontal pipe, 68.7 m long. The maximum pressure that may be developed by the compressor is to be found, and gas pressure at the delivery end of the pipeline must be 470 kPa. The system is to...
  7. P

    Mass attached to a horizontal spring

    A particle with a mass of 0.210kg is attached to a horizontal spring with a force constant of 0.84 N/m. At the moment t=0, the particle has its maximum speed of 5m/s and is moving to the left. (Assume that the positive direction is to the right.) Determine the particle's equation of motion...
  8. V

    A rope of 5m is fastened to two hooks 4m apart on a horizontal ceiling

    Homework Statement A rope of 5m is fastened to two hooks 4m apart on a horizontal ceiling. To the rope is attached 10kg mass so that the segment of the rope are 3m and 2m.Compute the tension in the string Homework Equations Sine rule The Attempt at a Solution I get stuck at the...
  9. V

    1) A rope 5m is fastened to two hooks 4m apart on a horizontal

    1) A rope 5m is fastened to two hooks 4m apart on a horizontal ceiling. To the rope is attached a 10kg mass so that the segment of the rope are 3.0m and 2.0m.Compute the tension in the string. 2) A uniform pole 7m long weighing 10kg is supported by a boy 2m from one end and a man 3m from the...
  10. B

    Horizontal Projectile Launcher

    I need to build a completely horizontal projectile launcher for my physics class. I started experimenting with a Gauss rifle, but the horizontal velocity was hardly even 1m/s, even with strong magnets. I'm looking into a few other propulsion mechanisms, such as pressurized air (like a spud gun)...
  11. M

    Horizontal / Vertical Motion, Parabolic Motion

    If this sounds ridiculously vague, I apologize - my physics teacher gave us this problem verbally and didn't want to clarify anything. Homework Statement A ball is thrown at a 45 degree angle to the ground and remains in the air for 2.35 seconds by an individual standing 1.81m. How far did...
  12. D

    Calculating Angular Acceleration of Horizontal Rod

    Homework Statement A uniform horizontal rod of mass 2.3 kg and length 0.32 m is free to pivot about one end as shown. The moment of inertia of the rod about an axis perpendicular to the rod and through the center of mass is given by I = (ml^2)/12 If a 4.6 N force at an angle of 76 to...
  13. F

    Horizontal force due to tension from vertical wieght

    Homework Statement Block C (m= 4 kg) sits on a frictionless horizontal surface. Block B of (m = 2kg) sits on top of block C, and is attached to a rope that runs over the massless pulley as shown in the figure. Block A (m=1 kg) hangs vertically from the rope. With what horizontal force F must...
  14. P

    Horizontal Asymptote Question

    This is just a general concept question. Why is that an equation with a numerator to a greater degree than the denominator has no asymptote & the opposite does? Also why is the coefficient of the variable to the highest degree the horizontal asymptote? Maybe a proof would help here :P Anyway...
  15. P

    HELP ME PLEASE: A flea is at point A on a horizontal turntable

    A flea is at point A on a horizontal turntable 8.1 cm from the center. The turntable is rotating at 33.9 rev/min in the counterclockwise direction. The flea jumps vertically upward to a height of 4.11 cm and lands on the turntable at point B. Place the coordinate origin at the center of the...
  16. T

    Finding Angles Between Horizontal Planes and Multivariable Functions

    Homework Statement Suppose a mountain is described by the function z = 10x^2 * y − 5x^2 − 4y^2 − x^4 − 2y^4 and that you are standing at the point (1,1,−2). The positive x-axis points east and the positive y- axis points north. If you walk in the northeast direction what angle above the...
  17. D

    Horizontal Force to Hold Pendulum Perpendicular

    Friends: Recently I got this problem: what sustained horizontal wind pressure/force is needed to make a pendulum swing up and stay at a certain angle? To solve this problem, I imagined applying a horizontal force FH to the bob (of mass "m"). I learned that the angle that the pendulum makes...
  18. D

    Spring length hanging down and horizontal

    Homework Statement is a spring longer hanging down or horizontal Homework Equations The Attempt at a Solution i think that the spring is longer hanging down because then its own mass contributes to the force of gravity, making it stretch more.
  19. C

    Ball suspended in a horizontal electric field

    A table tennis ball of mass 10g carries a charge of 0.04 micro Coulombs. It is suspended at the end of a rine threa 25cm long and placed in a horiztonal electric field. The effect of the field is to move the ball's centre 1.5cm to on side of a vertical line through the point of suspension...
  20. M

    Pressure at points on the same horizontal plane

    As you know,pressure is the same at points on the same horizontal plane Okay,suppose two points A,B in a fluid are on the same horizontal plane [PLAIN]http://img197.imageshack.us/img197/1977/unledfhe.jpg the pressure on both points is the same but at A pressure=h2*ρg pressure at B=h1ρg...
  21. D

    Angular speed; horizontal circle

    Homework Statement A student ties a 400g rock to a 1.0m long string and swings it around her head in a horizontal circle. What angular speed does the string tilt down at a 10° angle? m = 400g = .4kg r = 1m Homework Equations F = \frac {mv^2}{r} \omega = \frac {|v|sin \theta}{|r|}...
  22. M

    What is the velocity of a car that falls off a cliff?

    Homework Statement A car drives straight off the edge of a cliff that is 53 m high. The police at the scene of the accident note that the point of impact is 139 m from the base of the cliff. How fast was the car traveling when it went over the cliff? Homework Equations...
  23. B

    Block pulled on horizontal surface -w/friction-

    Homework Statement A box weighing 80N is pulled along a horizontal surface by a force of 15 N which is directed at 20° above the horizontal. If the box started from rest and the coefficient of friction is 0.15, find the kinetic energy and velocity of the box after it traveled a distance of...
  24. T

    Horizontal Spring-Mass System with Friction

    I finished with my first semester of physics in Spring, and I thought that I had understood the unit on springs pretty well; however, today a friend gave me this problem to solve, and I’m drawing such a massive blank, it’s not even funny. I’m so frustrated with this problem. Homework...
  25. L

    Horizontal and vertical oscillations of a loaded spring

    Homework Statement Revered Members, I have attached two images which explain horizontal and vertical oscillations of a loaded spring. In horizontal oscillations the restoring force is taken as F = -kx. But in vertical oscillations the restoring force is taken as F = kdl. Homework...
  26. D

    Calculating the horizontal distance traveled of an object that was thrown.

    A ball is thrown up onto a roof, landing 3.70s later at height h = 21.0m above the release level. The ball's path just before landing is angled at θ = 54.0˚ with the roof. Find the horizontal distance it travels. Answer: 33.5m Related Equations: Xf = Xo + 1/2(Vf + Vo)t...
  27. A

    Law of Motion: Horizontal Force

    Physics: Newton Law of Motion Question? I am a bit confused about this elementary question. If anyone can guide me in the right direction, I would appreciate it. Picture: http://tinypic.com/r/14w84g1/7" 2 boxes are placed next to 1 another on a horizontal surface. The box on the left has...
  28. G

    Conservation of energy to find horizontal displacement?

    Homework Statement This probably seems really obvious but what formula do you use to find velocity with conservation of energy? Once you find the velocity, is it the velocity of the object at the bottom of the height? Homework Equations This is what I'm not sure about. Is it mgh=0.5mv^2?
  29. W

    Calculating Displacement and Landing Position of a Horizontal Projectile

    Homework Statement A tennis ball is thrown horizontally from an elevation of 13.03m above the ground with a speed of 24.0m/s. a)where is the ball after 1.50 seconds (both horizontally and vertically)? b) if the ball is still in the air, how long before it hits the ground? c) if...
  30. X

    Finding the expression for the horizontal acceleration

    Hey folks its me again! The problem at hand gives me a potential energy function ( V(x) ) that defines the height of a particle in motion. Next to the problem is a picture of a curvy graph that is y vs x. It asks to find the expression for the horizontal acceleration. This is what I did...
  31. C

    Engineering Calculating how fast a motor can move something in horizontal motion

    Homework Statement So I need a motor for a project. The motor I'm looking at creates circular motion. I want to make the motor move some object in a horizontal motion but I want to know how fast it can move the object horizontally before getting it. How can I find out how fast the motor can...
  32. P

    Work pumping oil out of partially filled horizontal tank

    Homework Statement "Oil weighing 9000N/m3 is to be pumped out of the top of a horizontal cylindrical tank of radius 5m and length 15m. Set up an integral to find the work required to pump out the oil to the top of the tank if the depth of the oil is 4m." Homework Equations I used y =...
  33. C

    I'm having trouble with horizontal line problems and I'd love some help

    Homework Statement During an Apollo moon landing, reflecting panels were placed on the moon. *This allowed earth-based astronomers to shoot laser beams at the moon's surface to determine its distance. *The reflected laser beam was observed 2.52 s after the laser pulse was sent. *What was the...
  34. G

    Projectiles: Launch speed and horizontal distance

    New to the forums, just starting a physics 11 course online and having some troubles with formulas. Homework Statement Projectile shot straight upwards, flight time = 4.70 sec Second Launch at 45 degrees (horizontal range approx. 50-60 meters A) Find Launch Velocity B) Find...
  35. G

    Physics projectile problem - finding vertical range using the horizontal range

    Homework Statement What is the maximum vertical height to which a baseball player can throw a ball if his maximum throwing range is 54 m? vertical: a=9.8 m/s/s, Vyo=0 m/s, d=?, t=? horizontal: d=54 m, a=0 m/s/s, Vxo=?, t=? Homework Equations d=Vo*t+.5*a*t^2 The Attempt at a...
  36. Q

    Finding the horizontal range of a projectile when maximum height is not known

    Homework Statement A projectile is launched with an velocity of 40 m/s and crosses a tower of height 20.4 m after 2 seconds. Find the angle of projection with the horizontal and the horizontal range. Homework Equations S = ut - 1/2 gt2 where S is the distance, u = 40 Sin\Theta and g...
  37. J

    Does hooke's law account for the force of friction on a horizontal spring?

    Homework Statement Whether or not the spring is vertical or not, assuming that the spring is ideal, is Fnet always equal to -kx? Is it incorrect to write the sum of the forces of a vertical spring as Fnet = -kx - mg? And does hooke's law account for the force of friction on a horizontal...
  38. K

    Me Find Horizontal Distance?

    A ball is thrown with an initial speed of 4.6m/s at an angle of 15(degrees) below the horizontal. It is released 0.80m above the floor. What horizontal distance does the ball cover before bouncing? I keep getting 2.4m as my answer, but it's wrong! Here's what I did (Please correct...
  39. N

    Solving for Height in Horizontal Projectile Motion: 41 m/s, 23 m, g = -9.8m/s

    This was an even numbered problem from the book so there are no answers to make sure I've done this correctly or not. Homework Statement An arrow fires horizontally at 41 m/s travels 23 m horizontally. From what height was it fired? Vi = 41 m/s a = g = -9.8m/s x = 23m Homework...
  40. H

    Horizontal Distance For Guy Landing onto a running horse

    Homework Statement The man is 3m high from the saddle on a tree limb. The horse is running at 10m/s. A) What is the horizontal distance necessary for the men to land on the horse B) How long is he in the air Homework Equations I used y/accel to get the amount of time for him...
  41. J

    Determining vertical or horizontal fuel atomized

    I need a little help understanding which method would be the best way to keep fuel atomized for the longest period of time. I have a CV carb (more specifically a Keihin CV 40) and I'm wanting to install a Dial A Jet. *If you'd like to learn more about the Dial A Jet, go here...
  42. jaumzaum

    Calculate the biggest horizontal distance that can be reached

    An object is thrown of a given H height by a given Vo initial velocity. Calculate the biggest horizontal distance the object can reach from the starting point. It was a questioon from the national physics olympiad in my country. I tried to solve, but I was not able toif the object is thrown...
  43. J

    Tension in a string attached to a bob moving in horizontal circles

    Homework Statement Calculate the tension in a 2m string attached to a 2kg bob that is moving in horizontal circles of 0.5m radius. Homework Equations I thought it was F=MA but the working out shows all sorts The Attempt at a Solution I know the answer is 78.4N but don't know...
  44. X

    Question involving moment of inertia, rotation about a horizontal axis.

    Homework Statement A uniform cylinder, of radius 2a and moment of inertia $2Ma^2$ is free to rotate about its horizontal axis. A light, inextenzible string is wound round the cylinder and a particle of mass m is suspended on its free end. If the system is released from rest, find the...
  45. M

    Horizontal water rocket thrust calculations - HELP

    Horizontal water rocket thrust calculations - HELP! Hi All, I want to accelerate a 90kg body at a rate of 2 m/s2 for a period of 1 second using thrust developed from a number of water bottle rocket jets. Based on the drag coeff calculated I believe I need to develop 190N of force. A...
  46. Femme_physics

    Solving for Horizontal Projectile Motion: Mechanics Final Question

    This is one of the questions at the mechanics finals that I skipped. Homework Statement http://img155.imageshack.us/img155/1702/mecccs.jpg In the drawing is described the trajectory of a stone cast from a cliff at point A in an initial horizontal velocity V. During its motion the stone...
  47. A

    About air resistance in horizontal direction

    Hello, I was playing with formulas on air resistance and derived formula for velocity in horizontal direction after object was thrown. It looks reasonable but I started have confusion about it, i'd like for you great experts check on its derivation, so here it goes every v is v in x direction...
  48. M

    Difference between Vertical and Horizontal shaft rotordynamics

    Hello all, I am new to physics forums so please excuse my posting mistakes (if any). I wanted to know how different is the rotordynamics when one is analysing a vertical machine v/s a horizontal machine ? Is it substantial or we can analyse it as a horizontal machine and extend the results...
  49. Femme_physics

    Solving Horizontal Beam & Cable System: F, W & T1, T2

    Homework Statement http://img864.imageshack.us/img864/8066/graspcc.jpg the uniform horizontal beam AC, is held at tip A by a circular joint, and at point B it's held by 2 cables, BD and BE, as described in the drawing. At tip C of the beam acts a vertical force, F: Given W = 1 [kN] F = 4...
  50. Y

    Frictionless, horizontal table radius and speed ?

    Frictionless, horizontal table...radius and speed...? The 0.20 kg puck on a frictionless, horizontal table is connected by a string through a hole in the table to a hanging 1.20 kg block. With what speed must the puck rotate in a cicle of radius 0.50 m if the block is to remain hanging at rest?
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