Balls Definition and 541 Threads

Homework Statement Two balls with the same mass are dropped from the same height. After colliding with the ground, one of the balls "A" bounces higher than the other ball "B." Neglect air resistance. Is mechanical energy conserved ? Are they subjected to the same impulse after colliding with...

Homework Statement You received many steel balls of the same diameter d and container of known volume V. All dimensions of the container are much greater than balls diameter. How many balls can be placed in a container? Homework Equations (\frac{4}{3}\pi)(\frac{d^3}{8})\approx0,52d^3 The...

http://www.sciencedaily.com/releases/2016/01/160127053413.htm Researchers have solved an apparently overwhelming physics problem involving some truly huge numbers. In summary, the problem asks you to imagine that you have 128 tennis balls, and can arrange them in any way you like. The challenge...

Homework Statement Hello. Let be n integer and let's considere $$\mathbb{R}^{n} = E$$. Let be the distance $$d : (x; y) \in \mathbb{R}^{2} \rightarrow ||x - y||_{2}$$. We wright $$\forall p \in [1; \infty], B_{p}$$ the unit closed ball for $$||.||_{p}$$. Forall compacts A, B of $$E$$, we...

Hi. Assuming only one ball is pulled away and let go, it's fairly easy to show that momentum and/or energy conservation would be violated if this made two balls to bounce off on the other side (if the other ones remain still). So what happens if we glue the last to balls together or replace...

Homework Statement There are two problems: (A) Consider two identical billiard balls (spheres), each of mass M and radius R. One is stationary (ball 2) and the other rolls on a horizontal surface without slipping, with a horizontal speed v (ball 1). Assume that all the frictional forces are...

I know, this is a very stupid question, but it troubles me the whole day and i can't figure it out. Why can't water remains its shape if the cup is being removed and the water will spill all over the table ? And if you fill your car with full of small balls and when you open the door of your...

I would have thought the force of a persons arm being thrown downwards (with gravity) would essentially increase a balls initial downward acceleration immediately following the balls release. As compared to an upwards thrown balls initial acceleration; in which the persons upwards arm movement...

Homework Statement Why can we assume that atoms in a solid material act like hard balls? The Attempt at a Solution because they are tightly packed together when in a solid state[/B]

Homework Statement Two balls move toward each other. Ball one is moving in the positive direction, has a mass of m1, and a velocity of v initially. While ball two has a mass of m1/2, is moving in the negative direction, and has initial velocity of v2. Once the collision takes place ball one...

Hi all, There is a known formula for the number of solutions to ## x_1+x_2+...+x_k =n ## when ##x_1,x_2,...x_n ##are non-negative Integers. Question: Are there known formulas for the sum ##x_1+x_2+...+x_k =n ## when ## x_1, x_2,..,x_k ## are positive or negative Integers in a bounded...

Homework Statement Consider two small balls with charges +q and -q, connected by a spring with spring constant k. A homogeneous electric field E has been turned on. E is collinear with the line that connects -q to +q. By how much will the string stretch? Homework Equations Coulomb's Law...

Homework Statement A ball is thrown straight up from the edge of the roof of a building. A second ball is dropped from the roof 1.00s later. A) If the height of the building is 20.0m, what must the initial speed of the first ball be if both are to hit the ground at the same time? B)...

Homework Statement You throw one ball vertically (V0= 15m/s) on top of a 100m tower. Two seconds later you release another ball from rest from the same tower. Create a motion equation for both balls At what moment do they pass each other? At what height? Homework Equations s=vt+1/2at^2 The...

I have seen youtube videos where two balls of the same size and of different masses are dropped from the same height and they hit the ground at the same time. I understand why this is so: the increase in the mass of a body increases the force of gravity acting on the body, but also decreases...

How find $\frac{a}{b}$

Homework Statement Four balls are distributed randomly and independently into 4 cells. What is probability that: a) In every cell there is exactly one ball? b) All four balls be in one cell? c)Two balls in one cell ( any) , other two balls in other cell (any)? (assume that the balls are...

Homework Statement [/B] A white billiard ball with mass mw = 1.53 kg is moving directly to the right with a speed of v = 3.25 m/s and collides elastically with a black billiard ball with the same mass mb = 1.53 kg that is initially at rest. The two collide elastically and the white ball ends...

If I have 8 jars, each jar contains 5 unique ball types. However, I know that I have 20 unique ball types out there. So, I have balls labelled from B1, B2, B3, ...B20 to put into 5 jars. Let's say Jar 1 : B1, B3, B4, B7, B12 (5 unique balls) jar 2 : B9, B7, B11, B15, B18 (5 unique balls) jar...

Here's a physics question that's been giving me trouble. At a height H ,a ball A is thrown upward with a velocity of 20m/s and another B one is thrown down with a velocity of 20m/s and a third ball C is just dropped. Note that it's the same height for all three.I need to find the relation...

Homework Statement A 2.0 kg ball moving with a speed of 3.0 m/s hits, elastically, an identical stationary ball as shown. If the first ball moves away with angle 30° to the original path, determine the speed of the first ball after the collision. the speed and direction of the second ball...

Suppose you have a box with 10 balls, the 4 are red, the 5 are blue and the 1 is white. The probability of dragging each ball is 0.4~,~0.5~,~0.1 respectively. Now if I ask what is the probability of getting 3 balls in the order: red -> blue -> white, what is the right answer if balls are...

My knowledge about this kind of problems is almost zero, so I need some help. I know that if we have 20 balls in a urn, 1 to 20, the probability to extract 1 to 5 in a extraction is 5/20=1/4 But what if we have 4 extractions with the balls extracted put back in the urn? How do I calculate that ?

Homework Statement Two small plastic balls hang from threads of negligible mass. Each ball has a mass of 0.14 g and a charge of magnitude q. The balls are attracted to each other and the threads attached to the balls make an angle of 20.0 degree. with the vertical. The balls are 2.05 cm apart...

Homework Statement A 500 g billiard ball is going at 10 m/s [E] when it impacts 2 other identical billiard balls. Afterwards, you observe 2 of the balls moving at 2 m/s [30 W of S] and 3 m/s[45 N of E] respectively. Calculate the Energy lost in the collision. Homework Equations KE = 1/2mv^2...

Homework Statement Two masses are placed on top of a building. The mass of one is twice the mass of the other. Both are dropped at the same time. Neglecting air resistance, which statements are true? 1. Both objects have the same potential energy at the top 2. Both objects fall with the same...

What are the number of ways in which 3 different boxes can be filled with 5 different balls so that one box gets 3 balls and the other two get 1 ball each? Each box has the capacity to hold 5 balls at most. The answer to this is 5!/(3!1!1!) x 1/2! x 3! = 60 But when I do it, I think of it this...

Homework Statement Two smooth balls of radius 10[cm] and weight 6[kg] are inside a tube of radius 16[cm] that's on the table. what are the reactions from the walls and what is the minimum mass of the tube to be in equilibrium Homework Equations Disassembling of forces using trigonometry The...

Homework Statement I am not asking you to help me solve this, so i won't put in any usefull relevant equations or attempts at a solution. The nature of my problem is more of an understanding this collision - it is more of a thinking thing to process here. The problem goes like this. Ball is...

Homework Statement In the figure, two conducting balls of identical mass m = 20 g and identical charge q hang from nonconducting threads of length L = 100 cm. If x = 5.9 cm, what is q? Since x is much smaller than L approximate sin(θ) by θ. Homework Equations Tcos theta = mg Tsin theta =...

If we drop two balls same heights.One ball reaches higher height after bouncing than other then has that ball experienced larger impulse?

Hello, I'm working on a personal project that requires a very precise, but not very powerful, ping pong ball launcher. Would it be possible to coat a ball in metallic conductive paint, and then fire it from two rails like a railgun? Would I still get a constant net force in the correct...

1. You have one platform (1.2m high and 0.12m wide) and a few small balls of a different mass (0.09, 0.14, 0.25, 0.38, 0.57, 0.9 kg) that slide across the platform without friction and you have 4 springs with various stiffness (556, 918, 1110, 1546 N/m, ignore the mass of the spring). You can...

Problem Statement Two identical spheres of radius r are placed inside a cylinder of radius R as shown in the diagram below. You are given that R/2 < r < R and that each ball has a weight W. All surfaces are smooth. Show that there is a minimum mass, m, of the cylinder which will allow it to...

Homework Statement Two balls, of masses mA=45g and mB=65g, are suspended as shown in figure 9-53. The lighter ball is pulled away to a 66 degree angle with the vertical and released. (a.) What is the velocity of the lighter ball before impact? (b.) What is the velocity of each ball after the...

I’m working on a chemistry problem, which essentially translates to finding the answer to a related probability problem. However, my knowledge in probability is very limited and I'd be grateful if someone could help me out with it. The following is the problem:- Suppose I have a bag containing...

I joined the forum to hope for an answer to a question that has been bugging me for a while. If I hit a tennis ball in a vacuum with no other forces acting upon it and another chap hits a ball from the other end of the court - at the moment the balls cross if you could freeze time what...

Homework Statement The first ball collides with ##v_1## collides with the second two as shown in the picture. All balls are identical and the second balls have no speed at the beginning. Find the transform matrix and find the covariation matrix after the collision if it is ## \begin{bmatrix}...

Homework Statement suppose in a box there are 20 red, 30 black,40 blue,and 50 white balls.what is the minimum numbers of balls to be drawn, without replacement,so that you are certain about getting 4 red, 5 black, 6 blue and 7 white balls? Homework EquationsThe Attempt at a Solution so there...

Homework Statement I can't believe it how my brains stopped cooperating today. We have the first ball with ##m_1 ## and ##v_1## and of course the second one with ##m_2## and velocity ##v_2##. Covariance matrix before the collision is ##M= \begin{bmatrix} \sigma _1^2 & 0\\ 0& \sigma _2^2...

Problem Statement: Moe Mentum and Ken Ettik are playing pool. Moe hits the cue ball, sending it towards the 6 ball at 2 m/s. It strikes the stationary 6 ball off-center, moving off at a 60 degree angle from the original direction after a perfectly elastic collision. Both balls have a mass of...

I´m working on a physics hand-in and found the relative angle between the two balls after collison(where one is stationary before the collison) to be exactly 90degrees, is this random or is it always so? It´s worth mentioning that total momentum and kinetic energy is conserved. The hand in is...

Consider the pith balls in the diagram: Both of them has mass 'm' and charge 'q'. The question asks for the charge on both the pith balls. The concept is a bit straightforward. But I am confused at the force distribution experienced by the pith balls. My text tackles the problem with...

Homework Statement Two spheres of mass M1 and M2 are arranged one above the other as shown. They are separated by a fraction of a mm. They are released from rest and allowed to fall to the ground, a distance h = 5.0 m below. Mass M2 collides elastically with the ground and then elastically...

Homework Statement Two identical balls are interconnected with a massless and inextensible thread. The system is in gravity free space with the thread just taut. Each ball is imparted a velocity v, one towards the other ball and the other perpendicular to the first, at t=0. Then, (A)The thread...

Homework Statement Standard pool balls have a mass of 0.17kg. Before a collision, ball A is at rest and ball B is traveling at 4.5 m/s [N]. After the collision, ball B is traveling at 1.6 m/s [N20E]. What is the velocity of ball A? Homework Equations pinitial = pfinal m1v1 + m2v2 = m1v1 + m2v2...

Homework Statement While rolling balls down an inclined plane, Galileo observes that the ball rolls 1 cubit (the distance from elbow to fingertip) as he counts to 10. How far will the ball have rolled from its starting point when he has counted to 20? The answer I get is supposed to be 4...

Start with an existing black hole and an event horizon radius R at time T. Say the black hole is being "fed" an infinite series of golf balls, one after the other, which are all stamped numerically such that the current golf ball external to the event horizon is 1.0 * 10^32. See linked img...

Homework Statement Ball A is dropped from the top of a building. One second later, ball B is dropped from the same building. As time progresses, the distance between them A) increases. [<-- Correct Answer] B) remains constant. C) decreases. D) cannot be determined from the information given...

Homework Statement Two students conduct physics experiments on a balcony 19.6 m above the street. One student throws a ball vertically downward at 14.7 m/s. At the same instant the second student throws a ball vertically upward at the sam speed. The second ball follows the same path as the...