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.
"bubbles are ball" is called isoperimetric problem in serious mathematic. In this topic, many essay were written. Here's my serious essay about "why earth ball", which has been rejected by arxiv and my mentors...... I would want to know if physicists are interest?
I really think that is...
For this,
Can someone please tell me why they integrate the impulse over from ##t_i## to ##t_f##? Why not from ##j_i## to ##j_f##? It seems strange integrating impulse with respect to time.
Many thanks!
I have watched a few videos about how to use a 3 ball incentive spirometer for lung rehabilitation. Most of them are about inhalation, which you exercise with the device held right side up.
I also saw a couple of videos where they hold the device upside down to test and strengthen exhalation...
Here is the problem statement along with the figure.
Here, I take the right-ward and anti-clockwise directions to be positive.
After the ball collides with the wall, its angular velocity remains the same and its velocity changes direction while remaining the same in magnitude.
Using the...
Say I have a magic way to exert lateral forces on a free-rolling ball on a plane, with no slipping. Say I apply a force for a given period from the South, the ball starts rolling to the North and attains a constant speed. Then I suddenly apply the same force for the same period but from the...
I understand that it is a 2D momentum problem with an elastic collision;
Looking at the vector diagrams below, I notice that the velocity vectors initial and final in the y direction are in the same direction, indicating that momentum does not change, whereas the velocity vectors initial and...
Question: A ball is hit with a certain force and it starts with an initial velocity of V m/sec decelerating due to friction along a flat path and then up an inclined ramp coming to stop at the top of the ramp where the ramp becomes flat again (as per diagram A). The total distance traveled along...
I understand that when a tennis ball is in motion, the velocity vectors and acceleration vectors are pointing in the same direction. When the ball slows down, it is decelerating and comes to a stop. In the above statement, I understand that from the given angle, both vectors are pointing in the...
Here's the full code:
When a ball collides with bat or walls, I want the ball to be reflected with an angle, how do I do it?
I suspect there's lots of physics to it. So, should I stop this project here? I'd have to probably build a part of game engine…Can anyone help here?
Hi everyone,
i have been trying to find an answer to this problem I have but couldnt find any good answers...
(I dont know much about this stuff, but need a formula for a Project I am currently working on).
So The problem goes as follows:
Assuming we have a ball with a mass of m which is...
https://www.physicsforums.com/threads/choosing-a-ball-at-random-from-a-randomly-selected-box.1034377/
First of all, I would like to point out that this is the same exact question from what is being discussed in the thread above.
In that thread, the problem is solved by adding the probability...
What have mistakes/wrong assumption have I made in solving this question?
I tried to solve the problem this way
N.B. I assume that the j hat direction is up.
For part (a) of this problem,
The solution is,
However why did say show the motion is periodic, but then the solutions don't show it, instead explain how it is periodic?
Is there a way to prove that the motion is periodic other than the solution to part (b)?
Many thanks!
For school I'm trying to write some code to calculate the height of how high a ball would bounce given its mass, height, and the gravity of where it was dropped. I know there are more variables to consider, like wind resistance and the surface it was dropped on, but for now I'm trying to keep it...
The classic shape of a soccer (football for everyone outside of North America) is a Truncated Icosahedron. (And yes, all the shapes here are "rounded" forms. :rolleyes: )
https://fivethirtyeight.com/features/the-world-cups-new-high-tech-ball-will-change-soccer-forever/...
Problem:
In a box there are ##120## balls with ## X ## of them being white and ## 120 - X ## being red for random variable ##X##.
We know that ## E[ X] = 30 ##. We are taking out ## k ## balls randomly and with returning ( we return each ball we take out, so there is equal probability for each...
A 0.045 kg golf ball is hit by a driver. The head of the driver has a mass of 0.15 kg, and travels at a speed of 56 m/s before the collision. The ball has a speed of 67 m/s as it leaves the clubface. What is the speed of the head of the driver immediately after the collision?
I'm not sure...
I need a method to accelerate a ball bearing down a pair of wire tracks, and to generate a consistent amount of force on every activation. Please critique my tentative design:
I want to use an inductive coil activated by a proximity sensor to generate a transient EM field to accelerate the ball...
For some reason I'm having trouble understanding relative velocity problems. I know how to solve this, but I keep guessing at random methods until my answer matches the solution in the textbook.
I solved it correctly by breaking the velocity of the ball into x- and y- components, then solved...
I drew a FBD but I feel like it's wrong because there are too many missing values. I tried this:
Fy = 0
Tcosθ - Fg = 0
Tcosθ = mg
T = (1.2)(9.8) / cos(25)
T = 12.98 N
Fx = ma
Fwind - Tsinθ - Fdrag = ma
Fwind - (12.98)(sin25) - Fdrag = ma
I don't know how to find these missing values. I feel...
I have a wrecking ball with a mass of .5kg traveling at 3.03 m/s that hits a stationary block .9 meters high, weighing .06kg. I calculated the ball's exit velocity after it hits the block to be -3.00 m/s .
I calculated the final velocity of th block to be 4.2 m/s
Vf = Sqrt 2(g)(h) = sqrt...
This is the question:
A ball is thrown with a speed of 6m/s at an angle of 25° above the horizontal from the top of a cliff. The ball strikes the ground 15 m from the bottom of the cliff.
How long does it take the ball to strike the ground?
How long is the cliff?Here's a visual representation...
We have a weekly fun random chat to break from the routine of WFH. A science quiz poped up. There is no consensus on the good answer. We need 3rd party opinion.
You are at the equator, dropping a steel ball into a dry well, the depth is 100 meters, the mass of the ball is 1kg. The starting...
Vvertical=15sin30
= 7.5m/s
d=Vvertical*t+0.5atsquared
0=(7.5m/s)t+0.5(-9.81m/s)t squared
0=t(7.5m/s-4.9t)
t= 1.53s
t=1.53/2
t= 0.76s to reach the maximum height
Is this correct?
Hello there, I don't understand what I'm doing wrong I don't get the correct answer, but have done the same analysis 3x already and still get the same...
Some input would be appreciated thanks in advance.
Note: y-axis is upwards and x-axis is to the right.
3 unkowns i.e. 3eqs.
##x = x_0 +...
I have a question regarding the collision of two objects, specifically something heavy falling on something with a point. For example, if a 50lb ball of clay fell from 10 meters onto the point of a knife, would the knife's point have to withstand the entire force of the clay before the blade...
Hi, I have this kinematics question I am struggling with. There is a building from which a ball is dropped and it takes 5 second to reach the ground. Then they say that the same building is on a planet w/o atmosphere where g= 6 m/s^2 . What is the height of the building ?
I approached this...
Summary: Finding the transition matrix of a paint ball game where only 3 probabilities are given.
We have the following question:
Alice, Tom, and Chloe are competing in paint ball. Alice hits her target 40% of the time, Tom hits his target 25% of the time, and Chloe hits her target 30% of the...
Well, the problem is that, someone told me that a ball won't roll when sliding down a frictionless slope because the resultant force mgsinx is parallel to the slope which means that the ball will slide down the slope. Now, replace the ball with a round headed rod, does this means that the rod...
Hello, I'm not sure if this is the right place to post my question, however I still want to know. Recently, my teacher asked me the following question:
"In which of the cases will the cooling time be the least:
1. the ball is suspended from the ceiling
2.the ball lies on a stand with a thermal...
We know x = R =max range (28m) on level ground. Need to find v()^2. Subbing y=0 into (1) above, get v(0)^2 = (gR^2/)/(2*cos (theta)^2 * tan (theta). ... (2)
This didn't seem right, since this means v(0)^2 is a negative number ... maybe my orientation or algebra wrong?
Anyway, didn't see...
26.6m/s = v0
36.5º = θ
g = 9.81m/s^2
A) Find Range:
(v0^2)/g *sin2θ = (26.6^2)/9.81 * sin2(36.5)
= 89.99
I double-checked with the other Range equation (2v0*cosθ * (v0sinθ)/g) so I know I'm doing something wrong. Please help! Thank you
edit: A) Correct answer is 69.0
Summary:: I'd like to check my understanding of standard problems where a billiard ball resting on a plane is hit horizontally at some height above its center
So the situation is that a ball of mass ##m## and radius ##r## is at rest on a horizontal surface. There is friction between the ball...
Let's say there's an object floating in liquid. The depth of the object below the surface is 𝑑 and its height above the water is ℎ. The density of the ball is 𝑝𝑏 and the density of the liquid is 𝑝𝐿. The pressure above the water is 𝑃𝑎𝑡𝑚.
I understand this situation when only the density of the...
A=Cueball start position
CP=Centre Point where balls collide
B=The pocketHey guys, I was asked this question that seems completely obvious but I keep second guessing myself over it, I have included a basic picture to explain what I’m about to describe
Say you were to take the above pool...
a) Assuming it is inelastic as it is accelerating and therefore kinetic energy is not conserved? Intuitively this doesn't feel right...
b) change in momentum = p initial - p final = force x time
p initial = 0 as at rest
p final = 0.25 x v2
force x time = area under graph = 0.1
therefore 0.25 x...
I'm trying to build a DIY metal leaf or pith ball electroscope. I want to provide it with a circular arc voltage scale visible directly behind the (deflected) ends of the leaves. To calibrate the scale with ballpark accuracy, I want to determine the charge density upon the leaf pair (or pith...
Question:
Galileo released a metal ball from rest so that it could roll down a smooth inclined
plane. The time t taken to roll a distance s was measured. He repeated the
experiment, each time recording the time taken to travel a different fraction of the
distance s.
Write an expression for the...
Ei = 1/2 K (x)^ 2
K = .0152N/m
x = .0375 m
Ei = 1.06x10^-5
Ef= 1/2mv2 + mgh
m = .164kg, v is unknown, h is .0375sin(8.3)=.00541, Ef set equal to Ei
1.06x10^-5=1/2(.164kg)(v^2)+ (.164kg)(9.8)(.00541)
v = .3254m/s
I have gotten this answer multiple times but it is not correct. I am going...
If we throw a ball with initial velocity v0, and the ball progresses in a projectile motion, ignoring air resistance, will there be a force in the x direction? If so, what is that force in the x direction's value mathematically? I know there is a force in the y direction due to gravity.
(This is the diagram from the problem.)
My professor assigned this as extra practice and I don’t understand why the answer is (C) instead of (B). Why would sharp bends be the correct answer? Isn’t the curved diagram more accurate for movement on a slope?
Vertical components:
dy = 0m
ay = 9.8m/s^2 [down]
t = 1.34s
V1y = required
V2y = 0
i first tried to find V1y
dy =vi t + 1/2 a t^2
and got V1y = -6.566
then i solved for time of flight
dy =vi t + 1/2 a t^2
0 = -6.566t + 4/9t^2
and for 1.34 seconds
does this mean the time of flight is the...
the v before hitting the ground immediately=4.85m/s
the v after hitting the ground immediately= 3.96m/s
I considered the down positive, then
v= u+at
3.96= 4.85+ (a*0.16)
so a= -5.56m/s*s
The answer is 55m/s*s
The parts that I don't get are why it must be -3.96 and why that velocity becomes...
What is going on when the ball is thrown up in the sky. It is pushed by a force F for some distance d. Then the object travels a distance s up in the sky before finally coming to a stop. So what is going on here? Is the force doing work for distance d or distance s (s>d)?
I think change in...