Balls Definition and 555 Threads

TL;DR Summary: Almost as difficult as the Physics Olympics semi-finals or finals The coefficient of friction of the two arcs is the same.The radius of the ball is not taken into account.The roll of the ball is ignored.Can it be calculated or estimated quantitatively?The difficulty is estimated...

I'm guessing this question can be solved using the law of conservation of momentum Vi = 5 m/s (5 m/s) M = (4.33 m/s) cos30 M + V sinθ M I don't know what to do after this... I'm also not sure if I use the sin and cos correctly.

Hi There! I am quite a beginner at physics and my aim is to apply physics to a computer program which I'm coding. The program consists of 2 balls of equal mass colliding into each other and demonstrating the trajectories after an elastic collision. I have already coded a more basic model...

First of all, all the physical quantities presented in this topic are unknown variables, and I require a functional relationship between these unknown variables. In a vast space that does not consider gravity , there are many ideal rigid balls moving freely. And in equilibrium. The ball is...

I'm a little confused as to what the answer could be. This was one of my homework questions that I got wrong as I chose 0.5 v as the answer. Would someone be able to tell me what the correct answer would be?

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...

Along w/ Elvis, Buddy Holly, Little Richard, and many other founders of rock and roll, Jerry Lee Lewis really was a great ball of fire. https://www.cnn.com/2022/10/28/entertainment/jerry-lee-lewis-dead/index.html

This thread is meant to discuss a topic that arose in https://www.physicsforums.com/threads/is-there-a-theoretical-size-limit-of-a-planet.1045983/ in a more precisely specified, idealized way. Further details: 1) Standard model + GR assumed, no other theories intended for this...

My attempt for part (a) is as given below. I will attempt part (b) after getting part (a) correct. (a) Based on what is asked, we can identify 3 independent events as follows: (i) select any 2 bags followed by (ii) select a ball from one bag followed by (iii) select a ball from the other bag...

I think because both are launched with same speed so both have same KE. Since one is Thrown downwards it’s KE will increase but not that much as the body which is thrown upwards. Because it covers more distance so it gains more energy(the body thrown up). So 3rd option must be right.

If each ball rises two meters, then the time is in the air is equal to around 1.28 seconds. After this, what am I supposed to do? I feel really stuck. If all of the balls are released at different times, how am I supposed to find the answer?

I got curious about firearm ballistics and googled something similar to "bullet momentum vs kinetic energy". IIRC, momentum P = mv (checked); and kE = (mv^2)/2 (also checked). So I essentially wondered if it's worse to get hit by a bullet with greater kE than by one with lesser kE, presuming...

Hi guys, I have a maths question about Probability, hope somebody can help me out, thank you very much. There are 5 red, 4 blue and 3 green balls in a bag. Two balls are taken from the bag, one after the other. If the first ball is not replaced, and it was not green. What is the probability...

I don't understand why the answer is B. Here's my thinking: Since it wasn't mentioned that there's any other force aside from the drag force, then Fnet = Drag force I know that Fnet = ma, and since they have different masses, Fnet must be different for both balls? Acceleration cannot be...

Without this test,using only math, would you prove that left ball will comes first?

I am not sure how to even start this problem.

If there are N distinguishable boxes and M indistinguishable balls, the answer is easy as it is equivalent to the combinations of arranging N 0s and (M-1) 1s in a queue. $$\binom{M+N-1}{N}$$ However, if the boxes are themselves indistinguishable (which I name them "piles" instead), how should...

In the figure below Ball 2(B2) is hanging and attached to a square lever. B1 drop from gravity and hit the lever as shown. Calculate velocity of B1 and B2 with gravity influence right after collision. The mass of B1 and B2 is identical. Using energy equation E1=E2, therefore VB2 final = VB1...

I am stuck on problem presented about putting golf balls. A stationary golf ball (mass=45g, dia=42mm, solid & homogeneous) is struck by a horizontal force (putter) and ignoring sliding immediately starts rolling on a level putting green. The ball eventually stops due to rolling resistance...

Ball A of mass 2kg, is moving in a straight line at 5 m/s. Ball B of mass 4kg is moving in the same straight line at 2 m/s. Ball B is traveling directly towards Ball A. The balls hit each other and after the impact each ball has reversed its direction of travel. The kinetic energy lost in the...

I used the concept of electrostatic induction, which would cause the charges in metal ball near the ebonite rod to have +ve charges on end next to rod and a -ve charge on the end touching the other ball. What confuses me is how charges separate on the second ball. The only way these balls can...

Could you point me to interesting videos about plasma ball?

Performing force balance on the two balls, I obtain ## T+\frac{4\pi}{3}g \rho_3 R_1 ^3 = \frac{4\pi}{3}g \rho_1 R_1^3 ## ## T+\frac{4\pi}{3}g \rho_2 R_2^3 = \frac{4\pi}{3}g \rho_3 R_2^3 ## from which I obtain ## \rho_3 = \frac{\rho_1 R_1^3 + \rho_2R_2^3 }{R_1^3 + R_2 ^3 }## and ## 2T...

Since in an elastic collision, both momentum and energy is conserved, P(initial)=P(final) m1(3v)=m1v+m2v m2/m1=2 Which was the given answer but if we use conservation of energy, K.E(initial)=K.E(final) 1/2*m1*(3v)^2=1/2*m2*v^2+1/2*m1*v^2 m2/m1=8 Why do we get two different answers and why...

Could somebody check my solution in this task? Is it correct?

Since there is no friction, there is no radial force acting on Ball B after the pin is remove. Therefore the radial acceleration of Ball B is zero. I don't know how to determine the transverse components of the acceleration of Ball B. I looked at the textbook solution. It takes moment about the...

https://www.asi.edu.au/wp-content/uploads/2015/03/PhysicsASOE2014solutions.pdf Do not understand the q 13 c) ii), iii) logic at all.

Consider this scenario: two astronauts are floating in outer space with no other frame of reference other than themselves. Relative to one another they are stationary and have no motion between them, except that one astronaut is spinning at one revolution per second. The astronaut that is...

i tried with conservation of energy. ##E_i = 0 ## ##E_f = 2 m v^2 - 2mgh - 2mg(\sqrt{h^2 + l^2} - l) ## ## v = \sqrt{g(h - l + \sqrt{h^2 + l^2})} ## Is it right?

I did energy conservation, considering that the final velocity of the largest mass would be zero and I used moment conservation. But I am not finding the answer . Where I maked a mistake?

I defined the angle ##\beta## as the angle from the right horizontal to the ball C, from B, and ##\alpha## as the angle from the left horizontal to the ball A, from B. I also work in the CM frame, which has a velocity downwards of magnitude ##\frac{v}{3}## w.r.t. the lab frame. The positions of...

Given the total angles in the x direction, I set up this: (mg/cos(x))*sin(x)-Fe=0 then isolated for x: mgtan(x)=(kq^2)/(2*sin^2x) sin^2(x)*tan(x)=(kq^2)/(2mg) From here I am stuck. How do I go forward when x is contained in two different trig functions on the left?

If I have 237 buckets, and there are n green balls distributed randomly over those buckets, and I put 34 new red balls randomly in those 237 buckets, what is the formula for the probability that x green balls share a bucket with a red ball? Any help appreciated.

I actually found most of it out I'm just struggling with how to find the mass of the balls. I'm not sure how you would do that since could only derive two equations from the information given or are we assuming the mass is so small that it doesn't matter? Q = charge of one pith ball d =...

Hello all, I am trying to solve this problem: r balls are randomly assigned into n urns. The assignment is random and the balls are cannot be distinguished. What is the probability that exactly m urns will contain exactly k balls each ? I know that the probability of each ball to be in each...

I'm looking for recommendations for a relatively low-budget launching mechanism design for launching ping pong balls with high accuracy and high precision (able to consistently land within a 0.5 cm radius of a fixed point located about 30 cm away from the launcher). I've tried constructing a...

Firstly I deduced that in this situation the moment of inertia I, is not going to be parallel to w. And I calculated it as a matter of the angle, for the rod and the two point particles attached (with a mass 'm'), and the total moment of Inertia ended up being: I=((R²*sin²α)/2)*(M/6 + m) Being...

We have 27 balls in the container, some of which are white and some black. How many white balls in the container must be at least, so that the probability that two black balls were drawn at random without a return was less than 23/30?

My attempt- a) used equation { MV + mv = (M+m) V' } and got the right answer. b) I assumed that potential energy was asked for when the two balls were moving together with velocity 9.3m/s, so I used that when before the collision K.E( of m) + K.E( of M) will be equal to K.E(of M+m) +P.E(...

We have a 2D box (billiard table) which have size of Width = 600 and Height = 300. We have two identical ball a radius of 20. Also the balls decelerate with a rate of 5 m/s^2. The problem is to find the position of the ball after 10 second. ( The balls may have collide) from math import...

The Definition of a Neighborhood and the Definition of an Open Set ... Carothers, Chapters 3 & 4 ... I am reading N. L. Carothers' book: "Real Analysis". ... ... I am focused on Chapter 3: Metrics and Norms and Chapter 4: Open Sets and Closed Sets ... ... I need help with an aspect of...

Answer says, 'any (x, y) satisfying 2(a^2)x = (x2 + y2)^(3/2)

I am reading N. L. Carothers' book: "Real Analysis". ... ... I am focused on Chapter 3: Metrics and Norms ... ... I need help Exercise 32 on page 46 ... ... Exercise 32 reads as follows: I have not been able to make much progress ... We have ...B_r(x) = \{ y \in M \ : \ d(x, y) \lt r \}...

Which formula do I have to use? and why?

Plasma balls. Knowing that... 1. Neon lights are filled with noble gas and light up when current goes through them. 2. The equations, ##V=Ed##, ##F=qE ##, and Coulomb's Law could be used to design these. Are you actually seeing a random electric field or is the plasma real...

I'm continuing to struggle when it comes to objects that are dropped at different times. At height h, a ball is dropped at rest. Also at height h, another ball is dropped one second later. For the first ball, time=t. For the second ball, time=t+1...but this is wrong? The answers show it...

I have never felt comfortable about trying to explain gravitational attraction to children by using heavy balls running around elastic rubber sheets. After all, it is using gravity to explain gravity. It would be so much better to explain it more like it really is, thanks to that originally...

In a recent thread, @sweet springs asked: I pointed out that the claim about Newton is only strictly true in a uniform gravitational field, and proposed an approximation in GR. The idea was to take a Schwarzschild spacetime, restrict the "acceleration due to gravity" to some specified value, and...