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. Eclair_de_XII

    How to find the horizontal distance from projectile motion?

    Homework Statement "A projectile is fired horizontally from a gun that is 45.0 m above flat ground, emerging from the gun with a speed of 250 m/s. (a) How long does the projectile remain in the air? (b) At what horizontal distance from the firing point does it strike the ground? (c) What is the...
  2. S

    Horizontal circular motion problem, what am doing wrong?

    Homework Statement The County Fair Swing carries the mass of riders and chairs in a circular path in a horizontal plane while suspended by cables or chains. Let's assume that: Each chair with riders is supported by a single cable The tension in the cable equals 2 x the total weight riders...
  3. C

    Horizontal Range (arrow fired max speed off moving horse)

    Homework Statement A standing archer can fire an arrow from a bow with a maximum speed of 40.0 m/s. The archer rides a horse that can run at 12.0 m/s. The archer shoots an arrow at the maximum speed while riding the horse in the direction the horse is running and 10 degrees above horizontal...
  4. Y

    Horizontal Range Homework: 45° & 30° Angles

    Homework Statement A ball is thrown at angles 45° and 30° above the horizontal with the same initial speed. What multiple of the horizontal range at angle 30° is that at angle 45°? Homework Equations Trigonometry formula The Attempt at a Solution I think that first step is to divide the...
  5. G

    Horizontal Tangents in the Graph of y = 3x + 6sinx

    Homework Statement Does the graph of the function y = 3x + 6sinx have any horizontal tangents in the interval 0 ≤ x ≤ 2 If so, where? Homework Equations Derivative rules The Attempt at a Solution I tried finding the derivative and setting it equal to zero. y' = 3 + 6(cosx) 3 + 6(cosx) = 0...
  6. J

    Horizontal open channel flow -- Hydraulic jump calculation

    Dear Fellow Engineers I'm having an issues with my calculations. This case concerns a open channel flow that start off being supercritical on the left and turns into subcritical flow after a hydraulic jump. Given: Volume flow rate Q = 0.16m^3/s Width of the channel b = 1m Resulting...
  7. M

    Offset Cantilever Beam - Horizontal & Vertical Deflection

    Homework Statement The offset cantilever beam, ABCD, is fabricated from structural steel. Es = 30,000,000 lbs/in2, I = 60 in4. A load of 2000 lbs is placed at point D. Neglect the weight of the beam. Determine the horizontal and vertical deflection at D with respect to A in inches. Homework...
  8. nomadreid

    Horizontal tangent to wolfram alpha's heart-shaped graph

    On http://mathworld.wolfram.com/HeartCurve.html, the nicest heart-shaped curve is given by x=16sin3t y = 13 cos t-5 cos(2t) -2 cos (3t) - cos(4t) There are evidently two values of t, one in the first, one in the second quadrant, where you can get a horizontal tangent to this shape. Asking...
  9. R

    Angle made by arms with horizontal

    what would be the angle of a arms and how it is to be determined
  10. T

    Water Flow Through a Pipe w/180° Horizontal Elbow

    Homework Statement Water flows through a circular pipe with a 180° horizontal elbow and exits to the atmosphere through a nozzle as shown in Fig. Q3. The diameter of the pipe is 300 mm and the diameter of the nozzle exit is 160 mm. The density of water is 999 kg/m3 . The mass flow rate of...
  11. I

    Horizontal force on a bicycle dependent on center of mass?

    Hello! If I pedal a bicycle, where is the force that moves the bike forward horizontally applied? Is it the bottom of the back wheel or the center of the back wheel? When the force applied to that point is F, does all that force goes into horizontal acceleration, or does some of that force go...
  12. F

    Calculating horizontal difference in spring-ball situation

    1.Problem The problem is: calculate the horizontal distance the ball will travel if the same spring is aimed 25° from the horizontal. This is the second part. The first part was: a small steel ball bearing with a mass of 21 g is on a short compressed spring. When aimed vertically and suddenly...
  13. A

    Finding Tension in Horizontal circular motion with friction

    Homework Statement A car of mass (m) is attached to a cable of length (L) to a rotating pole. The car will speed up and travel in a circle. If the maximum speed of the car is vmax, what should the minimum strength of the cable connecting the car to the pole be? Note the surface is not...
  14. tomdodd4598

    Pendulum with Pivot Moving in Horizontal Circle

    Homework Statement The problem is the following: Using a Lagrangian, find the equations of motion of a mass hanging from a massless string, with the pendulum pivot moving in a horizontal circle at constant angular velocity. I take the mass to be m, the length of the string L, the radius of the...
  15. O

    Transverse Oscillation of horizontal Mass-Springs system

    Homework Statement Mass M is supported by a smooth table and connected by two light horizontal springs to two fixed blocks. Each spring is of natural length L. Both springs are initially extended by L to get a total width between blocks of 4L. The spring constant of both springs is k. When...
  16. L

    Block on a spring on a horizontal surface with friction?

    Homework Statement A 3.0 kg block is held against a spring with a force constant of 125 N/m. The spring is compressed by 12 cm. The ice is released across a horizontal plank with a coefficient of friction of 0.1 A) Calculate the velocity of the block just as it leaves the spring. Assume the...
  17. P

    Box Pulled on Rough Horizontal Surface - Frictional Force

    Homework Statement A 100N box is initially at rest on a rough horizontal surface. The coefficient of static friction between the box and the surface is 0.6 and the coefficient of kinetic friction is 0.4. A constant 35N force is aplied to the box horizontally. Identify from choices (a) - (e)...
  18. vetgirl1990

    Finding launch angle from vertical and horizontal distance

    Homework Statement The mountain rescue officers trigger the avalanche by firing a gun at a distant mountain slope. The muzzle velcoity of the gun is 225m/s. The horizontal and vertical distance from the gun to the slope is x=1,072m and y=538m respectively. Find the lowest angle between the...
  19. gracy

    Horizontal asymptote:can be touched or not?

    I have gone through some sites. http://www.freemathhelp.com/finding-horizontal-asymptotes.html It says horizontal asymptote can not be touched or crossed http://study.com/academy/lesson/horizontal-asymptotes-definition-rules-quiz.html &http://www.purplemath.com/modules/asymtote2.htm According t...
  20. J

    Solving Giant Swing Horizontal Cable Tension

    1. Homework Statement In one of the versions of the "Giant Swing", the seat is connected to two cables, one of which is horizontal (Figure 1) . The seat swings in a horizontal circle at a rate of 33.0 rev/min . If the seat weighs 295 N and a 869-N person is sitting in it, find the tension in...
  21. Ygggdrasil

    Exploring the Ring of Life: Horizontal and Vertical Gene Transfer

    Since the time of Darwin, biologists have looked at the history of life as a tree showing how the common ancestor of all life gave rise to all extant species. However, as we have learned more about biology, we've found that organisms do not inherit genetic information from only their direct...
  22. M

    Horizontal velocity for projectile motion

    Homework Statement There was a plane with the height of 1 km above the ground. The plane is moving horizontally 200 m/s and can fire a bullet with the velocity of 400 m/s. At one time, the the gun form an angle of 37(degree) and fired the bullet. I was confused with the horizontal (x-axis)...
  23. A

    Horizontal Distance up Incline

    Homework Statement A spring with a spring constant = 1000 N/m is compressed 0.20 m then launches a block of mass 200 g. The horizontal surface is frictionless and the coefficient of kinetic friction with the inline is 0.15. What horizontal distance does the block cover while in the air after it...
  24. dodonaomik

    Px in horizontal direction (about fluid mechanics)

    1. Plot Px in horizontal direction about three quarters of cylndrical surface ABCD Px: horizontal force in unit length 2. formula: P=ρgh3. my question: ①Why does Px point at the right? ③What does the blank mean? Because ABCD is only 3/4 of a circle...
  25. V

    Block moving on a horizontal surface

    Homework Statement Homework EquationsThe Attempt at a Solution Working from the reference frame of block , a pseudo force Ma0 towards right need to be applied on the cylinder . Forces acting on the cylinder are pseudo force , weight Mg and normal force from the block (if any) . Since the...
  26. J

    What will be the horizontal acceleration

    Homework Statement a 4.00-kg block is sliding up the plane on a 30 degree incline. If the coefficient of kinetic friction between the block and the inline is .700. What will be the acceleration of the block if a 50-N horizontal force pushes on the block? Homework Equations 50 - mgsin(30) -...
  27. Skilen

    A man hangs from a hole, Horizontal pulley

    I 1. A man of mass m = 80.0 kg hangs from a rope down into a hole. The rope goes over a massless pulley and is connected to a block of rock of mass M = 200 kg, which is lying on a frictionless horizontal surface. The distance between pulley and man is 5.00 m; between pulley and block 20.0 m...
  28. wein7145

    A horizontal force of 100 N is applied a block solve this

    Homework Statement 1) A block lies on a horizontal friction-less surface. A horizontal force of 100 N is applied to the block giving rise to an acceleration of 3m/s^2. (a) Determine the mass of the block. b)Calculate the distance the block will travel if the force is applied for 10s...
  29. Paulene Gueco

    For what angle is horizontal speed fastest -- How measure ramp angle?

    Hi! I'd just please like to know the most efficient way to conduct my experiment. See, my research question is "for what angle is horizontal speed the fastest?" We all know that the steeper a hill is, the faster an object accelerates. Obviously a 90 degree angle won't do much. I will try to...
  30. ToonBlue

    Horizontal and vertical component for electric field

    Homework Statement At the video length 1:25 , why does the vertical component cancel out ? At the video length 3:55 , why does the horizontal component cancel out? Homework EquationsThe Attempt at a Solution I don't seem to understand this part very well for the vertical and horizontal...
  31. Roman Kozak

    I Load on a Horizontal Wire (Zip line)

    I am creating a horizontal zip line, in which a rider will be pulled with a rocket engine. Completely serious. One end of the wire will be secured to a tractor and the other to a large tree. The zip line will be made from 12.5 gauge (2 mm) galvanized class 3 200 KPSI minimum tensile strength...
  32. K

    Trajectory of raindrop with horizontal wind

    Hi all, This question just occurred to me: Whether a falling raindrop in presence of a uniform horizontal wind (ideally speaking) has a curve trajectory or a straight line? Assuming the wind force is constant, the velocity of the raindrop in horizontal direction will keep on changing since there...
  33. I

    Find the frequency of the oscillation of a horizontal beam.

    Homework Statement A uniform meter stick of mass M is pivoted on a hinge at one end and held horizontal by a spring with spring constant k attached at the other end. If the stick oscillates up and down slightly, what is its frequency? [Hint: Write a torque equation about the hinge.] The length...
  34. J

    Angle below horizontal projectile question

    Homework Statement a ball rolls off an incline on top of a 9.0m building at a velocity of 22m/s 32° below the horizontal how far from the base of the building will the ball hit the ground? [ANS = 11m) Homework Equations vf^2 = vi^2 + 2ad d = ((vf+vi)/2)t d = vt The Attempt at a Solution x...
  35. F

    Solving Horizontal Tension: Step-by-Step Guide

    Hi guys, I came across this question and I was wondering if someone could explain how we get: TLsinO - mg(1/2LcosO) = 0 Your help would be much appreciated.
  36. A

    10 m dive. Time and horizontal displacement is known.

    Homework Statement A diver jumps from a 10 m platform.Time in air is 2.3 s. Horisontal displacement is 4 m. What is the divers initial velocity and angle? Homework Equations No idea :'( The Attempt at a Solution No idea :'(
  37. caters

    Speed, altitude, and horizontal distance

    I have thrown several things from balls to paper airplanes and I have noticed that the faster I throw something the longer it stays at any given altitude. The slower I throw something the shorter it stays at a given altitude. Also I have noticed that fast objects slow down faster than slow...
  38. Tana-ami

    Discontinuous at horizontal axis, U and K points, in energy

    I have a question about horizontal axis of energy band. In band structure of FCC lattice, like Si, GaAs, the horizontal axis have discontinuous at U point and K point. But other region have continuous like from Gamma to X or to L. I cannot hit on an idea about this discontinuous. Would anyone...
  39. D

    Finding the horizontal range without initial velocity

    Homework Statement A locust jumps at an angle of 43.8 degrees and lands 1.0 m from where it jumped. If it jumps with the same initial speed at an angle of 62.4 degrees, how far would it jump then? X-component knowns: Initial velocity = v(cos(43.8)) displacement = 1m angle = 43.8 degrees...
  40. K

    Friction on a particle on rough horizontal rotating disc

    A particle is attached to an inextensible string. The other end of the string is attached to the centre of a rotating rough disc. The string is shorter than the radius of the disc so the particle remains on the disc and moves in uniform circular motion. I don't remember the quantities but the...
  41. P

    Projectile Motion- Incline vs. Horizontal Surface

    Homework Statement Two identical metal blocks, H and A, are placed at equal heights on frictionless ramps as shown above. The blocks are released at the same time, travel down the ramp, and then slide off their respective ends of the table. Block H leaves the table from a horizontal surface...
  42. J

    Density of a liquid in a horizontal pipe

    1) Alright, so the problem reads, "The liquid in a horizontal pipe of diameter d1 before a constriction is at pressure P1 and flowing with the speed v1, and then in the constriction with diameter d2 the gauge measures pressure P2. What is the density of the liquid?" 2) I'm assuming the...
  43. jonny23

    Pressure in horizontal rotating tube

    Homework Statement If there is a horizontal tube rotating on axis in horizontal plane. it is filled with an ideal gas , So which end will the pressure be higher ? the end on axis?? or the free end Homework Equations P.A= m .w^2 .r The Attempt at a Solution i think the free end should have...
  44. D

    How do I know which direction the horizontal force acts

    Homework Statement I am to find the reactions of a 3 pin frame. Homework EquationsThe Attempt at a Solution So how do I know which direction to label the horizontal reactions? In the diagram HA and HF are in the same direction, I was under the impression that reactions are opposite to applied...
  45. Yam

    A wheel rolling on a horizontal flat or inclined surface

    Homework Statement A wheel rolling on a horizontal flat surface at a constant velocity experiences no friction force. Why? A wheel rolling on an inclined surface at a constant velocity experiences friction force. Homework EquationsThe Attempt at a Solution A wheel rolling on a horizontal flat...
  46. T

    Calculate horizontal and vertical force components

    I have a construction containing two force sensors. http://postimg.org/image/3zv76lo3b/ The sensors are not able to divide the force into components. If a force is applied that ´tips´ the upper plate, I was wondering if it was then possible to divide the force into horizontal and vertical...
  47. J

    Determine the horizontal distance that the ball traveled

    My teacher never taught us any of this. She just gave us a worksheet, and told us to solve it. I need to know how to solve this for a quiz tomorrow. Problem: Matt hits a baseball with an initial speed of 125 feet per second at an angle of 40 degrees to the horizontal. The ball was hit at a...
  48. A

    Horizontal & vertical angle of antenna beams & UE position

    Hi this is my first post here. Sorry for this naive question xD I want to calculate antenna gain for which I need the horizontal Φ and vertical θ angle of an antenna beam. The formula for gain is. is it ok to convert the rectangular coordinates of antenna into spherical coordinates and compute...
  49. A

    How does length affect the bending of a horizontal beam?

    Homework Statement We were shown this image ^ We were later told that it is suggested that the depression (y), is directly proportional to the length of the beam cubed (L3). We were asked to give reasons why this is so. EDIT: The 1kg mass is placed at L/2 Homework Equations y is directly...
  50. T

    A mass inside a horizontal spring

    Homework Statement We have a spring of length l0 tied to two vertical non moving sticks. We place a mass m at 0,45l0 and let it oscillate. If we measure the period of an oscillation, we can find the angular frequency and calculate k. The question is, how can I calculate k1 and k2, the constants...
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