Ball Definition and 999 Threads

Problem: You are playing soccer with some friends while some people nearby are playing hide and seek. When the seeker gets to '4', you kick the soccer ball high in the air. WHen the seeker says '5', the ball is 10 ft in the air. When the seeker gets to '7', the ball is 20 feet in the air. How...

Homework Statement:: Ball of mass mb and velocity vb hits rod of length L , Rod pivots about the center. What is the angular momentum aafter impact? Homework Equations:: I = 1/12 (mR^2) I = mR^2 See the attached figure. I understand the concept of linear and angular momentum separately but I...

My attempts involved using suvat equations to determine the rebound distance : S = 0.5 * (u + v)*t With u being 50 and v being 0 t being time taken to fall down (Height of impact / gravitational acceleration) t = 48.41 / 9.81 Plugging the numbers in gives S = 123.365m This is where i get...

Hello, How can I calculate the force that must be exerted on a ball inside a rubber tube? Thanks

To start off with, I can't seem to interpret the FBD here. Here are my drawing: and what I interpret as. From here, I feel like I can (it's wrong obviously but I'm not sure why) state that sin theta = o/h = o/mg = N/mg , so N= mg sin theta? Thanks

a) E(mech)=E(k)+E(g) E(mech)=1/2mv^2+(0.2)(9.8)(0) E(mech)=19.6 J b) E(mech1)=E(mech2) E(k)+E(g)=E(k)+E(g) E(g)=E(k)+E(g) 0=1/2mv^2+(mgh) *No height is given so I can't solve using this method. It says instantaneous velocity meaning the velocity at...

(L) = (radius) * (mass*velocity) velocity= 0+ (9.8m/s^2) (0.7s) = 6.86m/s (L) = (0.77m) * (2kg*6.86m/s)= 1.05 kg*m^2/s angular momentum points towards Polly

I don't know how to approach this question. This question is on my Midterm tomorrow and the teacher gave it to us without the values in order for us to get an understanding help

Let's say there is a train moving at 50 mph on the moon on a flat surface (say it's a perfect vacuum) and you are on the last cart where you throw a ball out the rear in the opposite direction the train is moving (directly away from it, parallel to the ground). The ball thrown is also...

How did you find PF?: social media The flight of a golf ball off the club face at the moment of strike would seem to be determined, among other variables such as elasticity, by the mass of the ball, the club's force vector, and the orientation of the club face relative to that force vector...

So to begin this question, I do know that volume =4/3 pi r cubed, while the surface area) 4 pi r squared. I will like to clarify some things about the question: 1) does the first sentence means dv/dt is proportional to 4 pi r squared? 2) given the second sentence how am I able to construct an...

Figure of the problem. There are many exercises like these, and I've read the whole chapter and I got no clue where to start here. Kinetic energy from gravity is: E = mgh = 39.3m I could try change v to ωr in the K equation but it will leave me nowhere because I don't have the mass nor the...

Hi all ! I wonder if I'm right. (From : Fundamental University Physics, Volume 1 (Mechanics) - (Marcelo Alonso, Edward J.finn) Addison Wesley 1967) This is my try: * I have the Greek version of the book and there is no answer.Thanks.

Hi all, I'm new to this but joined in the hope someone with more experience could provide some advice. In a personal project, I have a particular design dilemma where I am trying to pass a metal ball bearing (or any other spherical shaped solid) from a column of air into a column of water...

Did not know where to start so I tried A= v/t to find velocity then plug into equation to find g, but i got a huge g.

I am just not sure if I did this properly. My professor hasn't really gone over when to use the range equation but I would assume range would equal the distance traveled therefore can be used for this problem. If not the how would I go about solving this? I did 1/6*9.8=1.63 for g on the moon...

Hi all - I'm not an engineer or even very good at physics, but I was hoping to learn about something I'm interested in. I bought a ball pitching machine that I've outgrown and I'm wondering about either modifying it or even building my own and wanted to know about some of the key principles...

Summary: What could affect Magnus force's magnitude and direction except for speed and spin? Most golf flight simulators model the coefficient for drag (Cd) and lift (Cl) as a function of the relative spin ratio (rsr), where rsr = spin * radius / speed. In Figure 1, parameters of two similar...

Want to let the steel ball move upwards at a uniform speed, how is the torque of the spiral tube calculated? The parameters can be assumed by themselves. **The spiral tube is fixed on the central shaft, the central shaft is mounted in the ball bearing, and the thrust F acts perpendicularly on...

For part a I used conservation of energy. -m*g*cos(θ)*L+1/2*m*0^2=-m*g*L +1/2*m*v^2 => v = sqrt(2*g*L(1-cos(θ )). b) For b I was think that T = mg in the equilibrium point but that doesn't invole θ in the answer. So that's why I tought that T*cos(θ ) = mg. So that the tension is mg/cos(θ). But...

Hi all, Not sure on how to start this question in the first place, but from what I gathered from the data given I managed to derive this from the question: ##\theta = 53.13\deg## Let inside truck be t, final position be f, and ground be g ##D_{ft} = L## ##D_{fg} = xL## Also, for velocity...

Recently I chanced upon a video from the Royal Institution. The host has tried to replicate a piece of art by Jeff Koons (snapshot from video): At Ri, they have tried to produce the same thing by balancing the ball filled with water, in a tank containing saturated saline water at the bottom...

A steel washer is suspended inside an empty shipping crate from a light string attached to the top of the crate. The crate slides down a long ramp that is inclined at an angle of 37° above the horizontal. The crate has mass 180 kg. You are sitting inside the crate(with a flashlight); your mass...

if you put a fish in a plastic ball filled with water, can the fish make the ball roll by swimming. just like my hamster can make the ball roll by walking. thanx.

I am able to solve the problem for both cases (a) and (b) using ##\Sigma \tau = 0##. It is only when, stranglely, that I use ##\Sigma F=0## for the ball that I run into trouble. Let me provide the solutions. (a) Using ##\Sigma \vec \tau = 0## about the tipping point, ##mg R\cos\theta = F_C R...

This is based on "Concept Question 10.4" in Andrew Hamilton's General Relativity, Black Holes, and Cosmology. I have modified the question somewhat in order to focus on what seem to me to be the key issues. Suppose we have a spherically symmetric ball of stress-energy surrounded by vacuum. More...

I don't really know how to relate the effective and back focal lengths for magnification purposes. Literature review suggests that a lens of 1mm diameter can have a magnification of 350x-400x, but I don't really know the calculations behind it. Please advise.

=================== Now, I can get the solution in the book by writing and solving the force and the torque equations together with the non-slipping relation between the angular acceleration and the center of mass acceleration. However, the book solution only arises if there no friction between...

Summary: damage on glasses plate by hitting ball If a ball hit a rectangular plate of glass and it cause a damage "but it didn't broken" how can i represent this damage using mathematics? I'll tell you my idea about it: let the ball move horizontally and hit the plate perpendicularly with...

I was watching a game of snooker, and sometimes the cue ball bounces off the cushions with surprisingly high speed. Some people often say that it comes off the cushion faster than it went into it. And I started thinking - is that even possible? Does physics work that way?

New to the forums. Hoping to find a thread, forum, website dedicated to the discussion of/gathering of anecdotal reports of ball lightning. My mother's best friend witnessed what we believe is ball lightning in her home yesterday. She didn't get photos or video, but took some photos of odd...

I read Wikipedia's description of how a plasma ball works. Question: What kind of energy is the "radio-frequency energy from the transformer"? Is in the form of electric field energy, magnetic field energy, or both? Thank you! (from Wikipedia)... Although many variations exist, a plasma lamp is...

In a recent thread we discussed the idea that an object slowly dropped into a black hole, can have its rest mass recovered, as energy, if slowly brought to a halt at the event horizon. Once the object is dropped, it would be unrecoverable, and the BH would gain no new mass. I am under the...

The solution to the problem simply states: "Use of mv^2/r = 2000. T = (2000 + 7500) = 9500N". I don't understand this solution. Nothing more is provided. I don't know how you are supposed to find the radius (in order to use the centripetal force formula) merely from the information provided...

What I'm here to find out: I am in the early stages of a physics project to build a electric circuit or use an electrical source to power the force that will carry a marble throughout the mechanical portion of the project, going through linear acceleration and circular motion. I'm not sure what...

I know that the height before the first bounce will be ##y = g * t * t + v_0 * t + y_0##. After the first bounce, I can find y by pretending the ball was thrown from the ground with velocity ##e * -v_f## with ##v_f## being the velocity of the ball when hitting the ground, but I have to reset the...

I know this question has been asked before but I really need some help finishing this final piece of the puzzle.. I have attached an image of my work to show how far I have gotten towards the solution but my unfamiliarity with trigonometry equations has gotten my stuck. Please assist! thank you

I am a beginner and I know a little bit of Math. Can anyone tell me what concepts in Math do I need to know to see one ball jumping in space? I need names of the concepts which let's me realize this Jumping Ball. Thanks.

Hi all! I was attempting the following question but my answer differed from the given answer. Please help me to solve it. Thanks. My answer = 2.45 m/s Given answer = 3 m/s

I have a project which consists in making a tennis ball launcher for training kids (6-12 years), but there is a catch, the mechanism can't have any elastic parts (springs, bands, rubber). It has to be purely mechanical. I need help

I already have a and b, but want to see if anyone is willing to verify my answer for part c. I get 0 for the frictional force between the ground and ball, which would lead d and e to be 0 as well. Physics is rarely that easy so I wanted to make sure I didn’t miss anything.

Why is there a difference in force required throwing a ball horizontally on the moon and pushing it horizontally it in the spacestation Thanks

I tried to substitute 1/2T in for T, because 1/2 T is when the ball is at H. With that, I found Vo, which was (H-1/8gT^2)/(1/2T). I plugged in Vo into h=vot+1/2gt^2 and put 1/4 T for t, but I could not get an answer in terms of H

I'm working on a planet that is earth-sized, but has been essentially a dead stone for millions of years: no volcanic activity, the core has completely cooled down, the atmosphere has long since drifted off. In turn it has been mined for so long that a sixth of its mass has been dug up and...

Answer is C.

Hi PF! When proving a closed ball in ##L_1[0,1]## is not compact, I came across a proof, which states it is enough to prove that the space is not sequentially compact. Counter example: consider the sequence of functions ##g_n:x \mapsto x^n##. The sequence is bounded as for all ##n\in \mathbb N...

Homework Statement A 200 g ball attached to a spring with spring constant 2.40 N/m oscillates horizontally on a frictionless table. Its velocity is 20.0 cm/s when x=−5.00cm. What is the amplitude of oscillation? Homework Equations f=√(k/m) /2π x(t) = Acos(2πft) v(t) = -2πfAsin(2πft) The...

Homework Statement Find the initial velocity for the above soccer kick. Note that ball must cross the 2 points in the diagram within the two walls. Linked below is the diagram Homework Equations dx = v1(cos theta) * t dy = v1(sin theta) * t - 0.5at^2 The Attempt at a Solution I tried using...

Homework Statement A 0.500 kg ball is dropped from rest at a point 1.20 m above the floor. The ball rebounds straight upward to a height of 0.700 m. What are the magnitude and direction of the impulse of the net force applied to the ball during the collision with the floor? Homework...

What is reason that ball do not falls down,curved water jet low pressure because of centrifugal force or? How water jet transfer force to the ball,through pressure? As I know fluid can only moves object through pressure...