Ball Definition and 999 Threads

BALL (pronounced "ball") is software consisting of the versatile C++ class framework Biochemical Algorithms Library (BALL), a set of algorithms and data structures for molecular modelling and computational structural bioinformatics, a Python interface to this library, and a graphical user interface to BALL, the molecule viewer BALLView.
BALL has evolved from a commercial product into free-of-charge open-source software licensed under the GNU Lesser General Public License (LGPL). BALLView is licensed under the GNU General Public License (GPL) license.
BALL and BALLView have been ported to the operating systems Linux, macOS, Solaris, and Windows.
The molecule viewer BALLView, also developed by the BALL project team, is a C++ application of BALL using Qt, and OpenGL with the real-time ray tracer RTFact as render back-ends. For both, BALLView offers three-dimensional and stereoscopic visualizing in several different modes, and applying directly the algorithms of the BALL library via its graphical user interface.
The BALL project is developed and maintained by groups at Saarland University, Mainz University, and University of Tübingen. Both the library and the viewer are heavily used for education and research. BALL packages have been made available in the Debian project in April 2010.

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  1. brainpushups

    Exploring the Physics of a Ball on an Infinite Plane

    A person asked this question of me recently and it generated some discussion amongst the people in the room (many of whom had a limited background in physics). The original question went something like this: suppose that a ball is initially at rest in a wagon and the wagon is given a horizontal...
  2. R

    Determine angle made by a ball inside a rectangle

    From the picture i.e attached. Can there be a formula, where the ball will strike after certain number of hit, say on side b, what will be the angle the ball will make after n successive hit. I think it is just not possible, one can only measure the next angle the ball will make, provided one...
  3. R

    Why is my time calculation for the ball's flight incorrect?

    1. A ball is thrown vertically upward with an initial velocity of 27.0 m/s. Neglecting air resistance, how long is the ball in the air?Homework Equations vf (v final) = v0 (v initial) + at[/B]The Attempt at a Solution I set final velocity equal 0. So.. 0 = 27.0 m/s (initial velocity) +...
  4. H

    What's the speed of ball when travelling over the fence?

    Homework Statement Two girls are playing baseball in a park. The batter hits the 400-g ball with a speed of 20.0 m/s. It travels over the park's fence that is 4.00 m high. Assuming that the ball loses half of its energy to air resistance, at what speed does the ball travel over the fence...
  5. G

    Finding the height of a ball with a geometric series

    Homework Statement A ball is dropped from one yard and come backs up ##\dfrac{2}{3}## of the way up and then back down. It comes back and ##\dfrac{4}{9}## of the way. It continues this such that the sum of the vertical distance traveled by the ball is is given by the series...
  6. D

    Velocity graph, a ball is thrown upward

    I don't get it, why is the graph always linear? Shouldn't its slope be zero when the ball is at the top and stops there for a moment? The way it is "explained" is that it's at the top for instantaneous moment. Okay, but, if let's say, ball was going upward for a 5 sec, then stopped for 1 second...
  7. C

    Determining a specific frequency to make the ball bounce

    So, here's the set-up: A small stereo speaker is connected to a function generator. A concave lens, bearing a ball is place over the speaker. Now, the frequency is slowly increased in the function generator. My question is, Will the ball really bounce at a certain frequency? Because I am not...
  8. G

    How High Does a Small Ball Rise After Colliding with a Superball?

    Homework Statement A small ball of mass m is placed on top of a “superball” of mass M, and the two balls are dropped to the floor from height h. How high does the small ball rise after the collision? Assume that collisions with the superball are elastic, and that m<<M. To help visualize the...
  9. P

    What would happen if you had a ball of antimatter?

    If you had a ball of matter and anti-matter in a vacuum and threw them at each other - would they just blow apart and go largely unreacted? What about in atmosphere - would the ball of anti-matter blow up or form a shell of exploding material around it insulating it like the boiling of liquid...
  10. K

    Calculating the Angle of a Stable Ball on a Charged Plane

    Homework Statement A single charge q1 = 1.10E-7 C is fixed at the base of a plane that makes an angle theta with the horizontal direction. A small ball of mass m = 1.75 g and a charge q2 = 3.30E-8 C is placed into a smooth frictionless groove in the plane that extends directly to the fixed...
  11. arpon

    Tennis Ball Dropped: Will It Ever Come to Rest?

    Homework Statement A tennis ball is dropped from a point 4.9 m above the ground. Every time it hits the ground, it bounces back to ¾ of its previous height. How long will the ball take to come to at rest? [ignore the time required for hitting the ground and turning back] Homework...
  12. anubodh

    Effect on throwing a ball up in a car on it's efficiency

    I just wanted to know when we throw something like a ball up inside a moving car, the weight of that ball till it is air is 0 on the car.Does it mean that the car has become lighter and will take less energy to run.I know the effect is every small but please tell the answer.
  13. H

    Final velocity of a ball down a ramp.

    Homework Statement If a ball is dropped down a ramp of any shape, will the acceleration always be 9.8 assuming there is no friction. Homework Equations I know you can use mgh = 1/2mv^2 to solve for velocity, but can you use vf^2 = vi^2 + 2(a)(d) The Attempt at a Solution If you use both...
  14. K

    Does the ball clear the fence?

    Homework Statement A ball is thrown at 22 m/s at 45 degrees to the horizontal. A 5 foot tall fence is located 100 meters away. Does the ball make it over the fence? Homework Equations The Attempt at a Solution
  15. G

    Exploring the Mystery of Ball Lightning: A Physics Luddite's Journey

    Greetings from NZ...I'm a new member and a physics luddite. In 2008 I had a close encounter with what I eventually found out was Ball Lightning. I find it hard to believe that here we are 2015 and still no solution to this phenominon. Are there any researchers out there currently working on...
  16. L

    Static friction for a ball rolling without slipping

    Homework Statement A bowling ball rolls without slipping up a ramp that slopes upward at an angle β to the horizontal. Treat the ball as a uniform solid sphere, ignoring the finger holes. Explain why the friction force must be directed uphill. Homework Equations F=ma, torque=I(alpha)...
  17. M

    Speed of Ball: Wet Pitches Increase Horizontal Velocity

    Why does horizontal velocity of a ball increase when it pitches on a wet surface??
  18. B

    Circular motion problem -- A ball rolling down an incline

    Homework Statement A 1 kg ball with a radius of 20 cm rolls down a 5 m high inclined plane. Its speed at the bottom is 8 m/s. How many revolutions per second is the ball making when at the bottom of the plane? Homework Equations circumference = 2πr velocity = distance / time = circumference /...
  19. R

    Exploring Velocity at the Midway Point of Projectile Motion

    Homework Statement The velocity at the midway point of a ball able to reach a height y when thrown with a velocity v0 at the origin is:Homework Equations v2=v02+2ay The Attempt at a Solution I made y = 1/2 y and the simplified the equation to v=sqrt(v02+ay) But that is wrong because the answer...
  20. R

    Does the Golf Ball Land Before, In, or After the Lake?

    Homework Statement Golfer hits a golf ball so that it goes with initial velocity of 40 m/s at angle of 45 degrees. 100 m away is a lake that is 50 m wide. The ball will not bounce or roll when it lands. Where does the ball land? Before, in, or after the lake.Homework Equations Vertical: a =...
  21. R

    Ball Thrown Up: Constant Speed Despite Height

    When a ball is thrown up straight overhead. It just follows the curved space with the speed it is being released and seems as if the ball gradually slows down to zero at the top most and return to earth. If I'm right, according to Newtonian physics, the ball speed is zero at the top. And...
  22. A

    Maximum Angle for Non-Null Initial Velocity of Billiard Ball Hit by Cue

    Homework Statement A billiard ball of mass M and radius R is hit by a cue as shown in the figure. http://i.imgur.com/vJ7qB8W.png The blow can be thought as an impulse J of given value, and let μ be the coefficient of static friction. Homework Equations Find the maximum angle for which the...
  23. E

    Elastic Collision between ball and pivoted rod

    Homework Statement This is a solved problem-- http://web.mit.edu/8.01t/www/materials/InClass/IC_Sol_W13D1-10.pdf Homework EquationsThe Attempt at a Solution In the solution, they conserve energy and angular momentum. Can I conserve linear momentum? Also, can I use coefficient of restitution...
  24. dean barry

    Bowling Ball Problem: Is Friction Force All Absorbed in Rotation?

    A bowling ball is released with no rotation (linear KE only) at a given speed, the friction between the ball and the lane creates a torque which tends to rotationaly accelerate the ball, robbing it of linear KE and reducing the linear speed until synchronous speed is reached. My question is ...
  25. P

    Acceleration, Uniform Ball on Incline

    Homework Statement [/B] A uniform solid ball of mass m rolls without slipping down a right angled wedge of mass M and angle θ from the horizontal, which itself can slide without friction on a horizontal floor. Find the acceleration of the ball relative to the wedge. 2. The attempt at a...
  26. R

    Ball Thrown Up Follows Curvature of Spacetime

    A ball thrown up comes down again because the ball follows the curvature of spacetime. So is it possible that the ball comes down and before hitting the surface, goes up again due to curvature of the spacetime,which now point upward.
  27. R

    What is the rebound height of a ball?

    If I have the velocity an object is moving up (lets make it v here), and the mass (m), how do I calculate the height it bounces to, and by using the efficiency of the ball 60% and gravity as 10 (for simplicity), how do i calculate the original height? Assume there is no wind resistance.
  28. S

    Circular Motion and Gravitation of tether ball

    Homework Statement There is a tether ball swinging around in a uniform circle on a rope that is 1.90m long. Marcus hit the ball so hard that the string holding the ball made a 20.0 degree angle to the horizontal. What is the tension in the rope if the ball has a mass of 1.40 kg? Assume that the...
  29. A

    Wireless power and lighting ball

    Hey guys.Is there some relation between wireless power and lighting balls
  30. C

    Work done on changing direction of a tennis ball

    Homework Statement [/B] A tennis player strikes an incoming tennis ball of mass m and speed v such that the ball leaves the racket at speed v as well. How much work was done by the tennis player to reverse the direction of the ball? Explain. Did the tennis player do any negative work? Homework...
  31. D

    De Broglie wavelength of a tennis ball

    This is a multiple choice question. The de Broglie wavelength of a moving tennis ball is calculated as 1x10^-33. This means that the moving tennis ball A)Diffracts through a narrow slit. B)Does not behave as a particle C)Does not display wave properties D)Is traveling at the speed of light The...
  32. D

    Solve Ball in Bowl Dispute: Get the Correct Constraint Equation

    Imagine a solid ball rolling around in a hemispherical bowl without slipping. The bowl has radius L and the ball has radius R. I need to write down the constraint relating the angular velocity of the ball, call it omega , to the angular velocity the center of the ball is sweeping out in the...
  33. lovethepirk

    What is the reflection angle of a golf ball after being struck by a putter?

    I'd like to begin by ignoring friction and center of gravity at the moment if that is possible...and throw out any other variables until I get the larger picture down and then I'd like to ask for a discussion including those items... The picture shows a block moving towards a ball...similar to...
  34. M

    Rolling ball in a enclosed cone problem

    Hello , I am new here , and at start id like to say that i`m lousy at formulas and math :) . I've been searching and googled my problem and i couldn't find any solution to it . So here it is. Ball and a cone are rubber coated .Ball is rolling inside enclosed cone, when ball reaches speed it...
  35. A

    Cannon Ball in Space: What Happens & How Much Does It Hurt?

    What would happen if you were shot with a cannon ball in space? How badly do you reckon it would hurt, compared to if you were shot with the same cannon ball on Earth?
  36. S

    Determine the magnitude of its radial acceleration for ball

    < Mentor Note -- Thread moved from the General Physics forum to HH > A ball swings counterclockwise in a vertical circle at the end of a rope 1.50 m long. When the ball is 36.9 degrees past the lowest point on its way up, its total acceleration is (-22.5i + 20.2j) m/s^2. For that instant, (a)...
  37. ximsooriginalx

    Conservation of Momentum of a ball

    Homework Statement A ball is thrown against a fixed wall where it bounces elastically. The mass of the ball is M and the velocity just before it hits the wall is U. Ignore the force of gravity in this question. a) Does the Principle of Conservation of Momentum apply to this situation? b) Obtain...
  38. Q

    Conservation of momentum and mass of a ball

    Homework Statement A 0.160 kg ball makes an elastic head-on collision with a second ball initially at rest. The second ball moves off with half the original speed of the first ball. a) what is the mass of the ball b) what fraction of the original kinetic energy gets transferred to the second...
  39. K

    A charged ball on a string between two charged plates

    Homework Statement A charged ball of mass 0.2[gr] and q=6E-9[Coulomb] hangs on a string between 2 plates that are 5[cm] apart. the ball makes 300 with the vertical. what is the voltage difference of the plates. Homework Equations Electric field: $$E[\frac{N}{Coulomb}]=\frac{V}{S[m]}$$ The...
  40. V

    Angular velocity of a ball after change of direction

    Homework Statement A ball with radius, R, and moment of inertia, I = 2/5 mR2 is rolling on a horizontal plane with angular velocity ω0. At point A the ball rolls onto an incline with the angle θ wrt the horizontal plane. No air resistance and ω0R = V, where V is the velocity of CM. What is the...
  41. Ritzycat

    Bouncing ball - How many times does it bounce

    Problem statement: I have a 0.0506kg bouncy ball that will I drop at 1.75m. I must predict how many times it will bounce before it comes to a rest. My work: We did a lab to predict the percent of energy "lost" from each bounce. After doing some calculations with my data, I found that, on...
  42. I

    Force on Ball Bearing: Should Torque be Included?

    I'm trying to work out the free body diagram for a router tool (which is basically used to cut wood sideways and create grooves and interesting shapes). I need to work out the free body diagram in order to find out the bearing load but I'm having difficulty with the aforesaid. The shaft that...
  43. S

    Bowling ball sliding & rotating

    Relative equations: F_net = ma a = F_net/m f = N = _net/I Problem Statement: A spherical bowling ball with mass m = 6.50 kg and radius R = 0.680 m is thrown down the lane with an initial speed of v = 9.00 m/s. The coefficient of kinetic friction between the sliding ball and the ground is μ =...
  44. T

    Projectile Motion ball is launched

    Homework Statement A ball is launched with initial speed ##2\sqrt{}gh## such that it just clears two walls of height 'h' separated by a distance 2h .What is the time taken by the ball between the two walls ? Ans: ##2\sqrt{\frac{h}{g}}## Homework EquationsThe Attempt at a Solution...
  45. B

    What factors affect the trajectory of a soccer ball in projectile motion?

    Homework Statement A soccer ball is kicked 27.43m away from the goal and 9.15m away from the defensive line with a initial velocity of 36 m/s, when the ball reaches the goal is 1.92m from the floor [/B] I'll leave a little diagram of the problem, thanks for your time. P.D: I apologize for my...
  46. F

    Circular Motion Ball on a String

    Homework Statement https://www.dropbox.com/s/slpu1p8jplmxzmy/Screenshot%202014-11-18%2020.11.58.png?dl=0 Homework Equations Fnet = ma ma = (mv^2)/r The Attempt at a Solution ai) Ft up, mg down /\Ft I m I \/mg aii) both down m I I \/mg \/Ft aiii) Ft right, mg down m - >Ft I \/mg b)...
  47. M

    Another vector problem -- A ball suspended from 3 wires

    Question A ball with a mass 4 kg is suspended from 3 light in-extensible wires (diagram given) Given that the ball is in equilibrium, calculate the tension in each of the wires. My attempt T1 is equal to the weight of the ball which is 4g so T1 = 4g From there I don't know what to do but for...
  48. AdityaDev

    Air Drag & No Drag on a Ball Projected Vertically

    < Moderator Note -- thread moved from General Physics to Homework Help forum > If a ball is projected vertically upwards say with a velocity V. Case 1: Without air drag Case 2: With air drag What will be the difference in v-t graphs and the motion of the ball Air drag D=bv (b is a constant,v...
  49. I

    How far from the foot of the cliff does the ball land?

    A solid, uniform ball rolls without slipping up a hill. At the top of the hill it is moving horizontally; then it goes over the vertical cliff. V= 29 m/s and H= 22.0m A) How far from the foot of the cliff does the ball land? B) How fast is it moving just before it lands? Been stuck on this...
  50. D

    Is K.E. Conserved During an Elastic Collision in Billiard Ball?

    The question is, Is the K.E. energy conserved during the collision ? Given Data : Collision is elastic, ball of same mass. P.S. It is asked if the K.E. is conserved DURING the impact; not before or after it. After the collision & before it, I know the K.E. is conserved.
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