Falling Definition and 1000 Threads

Homework Statement A ball was dropped through a known vertical distance with the time of drop also recorded. The aim of the task is to create a numerical model in excel in order to approximate the drag coefficient. Homework Equations This is my method. 1. FBD for the ball falling. (assume...

Homework Statement A uniform chain of length l and mass M contains many links. It is held above a table so that one end is just touching the table top. The chain is released freely. What is the force between the links? What is the time for the topmost link to fall to the table? Homework...

Hi! So i have been having this discussion with a friend. we have an old shaft going down about 100meters and we want to tie a 100kg sand bag and use it to generate electricity as it falls. (we will simply pull it back up) if my understanding is right, then: i can either generate 980kw for 1...

An object with a mass if falling with a force that is equal to its own weight of 25 pounds. The air resistance causes a decelerate force equal to 1/2 the velocity of the object at any time. If the object falls from rest, what is the velocity of the object after 8 seconds? I'm just confused at...

I used a ticker to measure to measure the acceleration of falling object. And and now I am writing report about it and the problem is what symbol is used for the marks on the ticker tape? Like for grams (g). What would you use for marks(?) ?

Homework Statement A magnet of mass 0.10 kg is dropped from rest and falls vertically through a 35.0 cm copper tube. Eddy currents are induced, causing the copper to warm up. The speed of the magnet as it emerges from the tube is 1.50 m/s. How much heat energy is dissipated to the environment...

Here is an unsettling question from a practice set that I've been working on today. Unsettling because the answer key contradicts my answer so I need a second thought. A pingpong ball and a golf ball are dropped in a vacuum chamber from the same height and at the same time. When they have...

Homework Statement A person can just survive a full-body collision (either to the front, back, or side) which results in a deceleration that is up about 100 g's. (One g is 9.8 m/s/s). At greater deceleration fatal brain damage will likely occur. If a 66.4 kg man falls of a cliff of height 37.8...

Homework Statement After performing a quadratic curve fit tool in Pro Logger, I was given the values: A = -1.426E-05 +/- 2.386E-06 , B = 0.02193 +/- 0.001581, C = 0.4785 +/- 0.1905. With this information, how is “g” for Planet X determined from the parameters of the curve fit equation...

Hi, My first post here, hope it goes well. I wonder if someone of you skilled persons could help me and my friend calculate the energy in a falling tree. I´m no good at maths neither good in english but I will try to explain what I´m after. If you cut down a tree that is 25m heigh and weighs...

There is a conducting circular loop with resistance R falling in the magnetic field \vec{B}=B_\rho(\rho,z)\hat\rho+B_z(\rho,z)\hat z and gravitational field \vec g=-g\hat z. How does z and the current in the loop change in time?(assume the loop remains horizontal!) The flux through the loop...

As a non-scientist, this question has been bothering me, but probably has a laughably simple answer. In high school physics (which, for me, was long time ago) we were taught that 2 objects dropped from a height fall toward Earth with the same acceleration regardless of mass (the so-called Tower...

Hello, This is a quick question that I want to know, When an object falls, does the vertical falling speed stay the same with any horizontal speed? To be more clear about this question, this is an example: There is a bullet. 1. The bullet falls from 10 meters above the ground without any...

I know that there is the equation to capture work of falling water using dams (power= head*flow*gravity constant*efficiency). But let's just say that there is an empty basin in the middle of a large body of water that is 100 meters deep. If the basin is 30m * 30m and we have a conduit that is...

Please excuse me for being a complete and utter pleb, my meager knowledge of Leonard Susskind's holographic principle comes from the second episode of the documentary "Through the Wormhole" [SIZE="2"](which is available online but I won't link to in case it is copyright infringement?). He...

Please watch this video (link: http://www.youtube.com/watch?v=JN-A3RryOC8) for reference. As you can see, the magnet does not slow down (at least, not appreciably) when falling through the copper coiled around a PVC pipe, and I can't figure out why.

Homework Statement A solid cylinder of radius R is spun and then placed on an incline having coefficient of friction μ=tanθ (θ is the angle of the incline). The solid cylinder continues to spin without falling for time: (A)Rωo/3gsinθ (B)Rωo/2gsinθ (C)Rωo/gsinθ (D)2Rωo/gsinθ The Attempt at a...

Homework Statement A uniform rod of mass M and length L is placed vertically on a flat surface. The coefficient of friction between the rod and the surface is μ. The rod is beginning to fall, initially without slipping. To describe the motion of the rod during this stage: (a) Write down the...

Hello everyone! If a ball is released from the top of a very tall building, would it land ahead in the direction Earth is rotating (to the east) or would it lag behind i.e the Earth "moves out" from underneath it so it lands to the west? I think it should land ahead to the east since its...

Homework Statement I'm not sure if this is the right place to post this but I need help understanding this question... Discounting air friction, approximately how far will the boulder have fallen in 2 seconds? a. 20m b. 45m c. 30m d. 90m Homework Equations x-x_0 = v_0t + 1/2at^2...

Homework Statement Prove that the enrgy of a falling body remains constat using the derivate of a function Homework Equations We need to prove that: \frac{mv^2}{2} + mgh is constant, trhat is its derivate equals 0 The Attempt at a Solution Let the positive direction be...

Hello! I am trying to think of ways to generate significant amounts of heat through the motion of a falling object? Let's say we have a heavy ball and a structure that enables it to fall from a height of 30m for instance, how would you go about creating heat? I suppose you would have to use...

What would be seen if a ball were projected at an angle to the horizontal in a falling elevator? Would the path be parabolic as always? And why?

Homework Statement Pls help me with the (d) option of the question asked in the link https://www.physicsforums.com/showthread.php?t=724332&page=1 Correct expression for tension is ρgx/6 (as given in the answer sheet) Homework Equations The Attempt at a Solution...

Homework Statement This is elementary level stuff and I am pretty much past this, and yet I can't seem to find a suitable way of explaining this.I was thinking about Potential Energy of a particle of mass m falling freely under gravity(ignoring air resistance, again, beginner stuff :P) from...

Homework Statement A rigid rod of length ##\ell## and mass ##m## has its lower end in contact with a frictionless horizontal floor. Initially, the rod is at an angle ##\alpha_o## to the upward vertical when it is released from rest. The subsequent motion takes place in a vertical plane...

Homework Statement Homework Equations See below The Attempt at a Solution My book derives the period of oscillation through the tunnel: T = 2pi/w = 2pi*sqrt(m/k) = 2pi*sqrt(3/(4pi*G*p)) = sqrt(3pi/(G*p)) Where p is the density of the asteroid, and G is the Newton's gravitational...

Homework Statement A chain of mass M and length ##\ell## is suspended vertically with its lowest end touching a scale. The chain is released and falls onto the scale. What is the reading of the scale when a length of chain, ##x##, has fallen? (Neglect the size of individual links.)...

Hi All! This is my first question/post here, so I will try to make it work! Homework Statement Ok, so the question is simple-ish. Homework Equations Faradays Law (ε=-NΔΘ/ΔT) The Attempt at a Solution Now, I understand the concept that as the magnet is falling towards the coil, the coil...

I have a question pertaining to objects falling through the event horizon of a black hole. It is my understanding that due to the immence gravity of a black hole and the way gravity affects the flow of time, that from the point of view of an observer at a safe distance from a black hole...

Homework Statement If Earth stops rotating Sun suddenly , how long would it take for Earth to collide with Sun ? G = gravitational constant m_s = 2e30kg m_e = 6e24kg where m_s is the mass of the sun and m_e , mass of earth x = 1au =1.5e11m 2. The attempt at a solution Gravitational...

Homework Statement Assume your arm is a solid rod, 0.740 m in length, free to rotate about your shoulder (so its moment of inertia is (1/3)ML^2). If you hold your arm out sideways, and then completely relax your muscles, what is the initial downward angular acceleration of your arm? Homework...

Greetings, I've been learning about special relativity and most of the learning media included a part of general relativity. From that I learned that space-time is curved and orbits are nothing more than an object following a path in 4D. However I do not understand how those objects may rotate...

Hello, my question id the following: when using Tsiolkovsky's equations to determine the velocity of a body after certain period of time, when the engine of a (space)craft is running, life is simple. But how do you calculate the falling rate of an object that is constantly falling, and then...

Falling matter of supernova does "work" heating the core? A supernova core collapses and the rest of the star follows, inner layers arrive first, a shock wave wave forms? As outer layers continue to collapse and slow down is there a large radial time rate change in momentum as rapidly...

Hi, I am wondering if total momentum of the system is conserved in this case. Our system is consisted of two balls: one is falling vertically down to ground, another is thrown vertically up, so they collide in air. Is total momentum of the two balls conserved after the collision? Now I...

This is my first post but just as it says in the title I'm curious about the physics behind falling objects. Specifically if you could examine this video which despite the title is not actually graphic and school me on why we heard what we did, Thanks. http://www.youtube.com/watch?v=0ABGIJwiGBc

Homework Statement I'm doing a lab and getting very confused. A cart is on a table. It is attached to a string which goes over a pulley. The pulley is on the edge of the table. On the end of the string there is a mass. When the mass falls straight down, it pulls on the string and makes...

Homework Statement This problem is very easy, but there is some conceptual point of view I am missing. There is a vertical rod of length L without mass on its own that has two masses, m1 and m2, attached at each end standing on point P at a table. The rod is at unstable equilibrium at first...

Homework Statement A pencil of length l = 0.2 m is balanced on its point. How much time does it take to fall? Assume that the pencil is a massless rod and all of its mass is at the tip. To make the math easier, assume the small angle approximation. Homework Equations theta (double dot)...

Homework Statement A chain with length ℓ is held stretched out on a frictionless horizontal table, with a length y0 hanging down through a hole in the table. The chain is released. As a function of time, find the length that hangs down through the hole (don't bother with t after the chain...

Homework Statement A uniform, solid cylinder of mass M = 4.22 kg and radius R = 0.36 m with I=1/2(M*R^2) is attached at its axle to a string. The string is wrapped around a small frictionless pulley (I=0) and is attached to a hanging block of mass 1.69 kg. You release the objects from rest...

Homework Statement Let the angle of the block(slope) to be 30°. height=0.6m, length=1m. Breadth=1m Smallest height on diagram is 0m Let the red line to divide the block by 2(when viewed from the top) The two wheels are of equal diameter and is connected by a rod. The total mass of two wheels...

How do I calculate the acceleration of the falling weight? It is hanging from a string which goes through a wheel, and is attached to a sphere with thin walls. The string doesn't stretch and the wheel and the sphere spin without friction. The fact that the weight is connected to multiple...

Mod note: deleted image that was way too large.[/color] Homework Statement I want to know the time flowed while the stick falls. gravity = g density of the stick is same so it's center of mass is l/2. what is the T? Homework Equations The Attempt at a Solution failed to do torque.

Homework Statement If you are worried about safely driving after a party, I recommend you just not drive! But if you want to see when you are finally okay to drive, here is a test to see if you are still too “impaired”. Take a dollar bill and have a friend hold the bill from one of the short...

Problem goes like this.. body falls toward a planet with acceleration of -g0*R^2/s^2. where R is the radius of planet 4000 miles, g0 is 30 ft/s^2, s is the distance of the body from the planets center. the initial distance of the body from the surface is 400 miles. find the impact velocity...

Homework Statement You throw a baseball at a 45 degrees angle to the horizontal, aiming at a friend who's sitting in a tree a distance, h, above ground. At the instant you throw your ball, your friend drops another ball. a) Show that the two balls will collide, no matter what your ball's...

I was reading The History of Physics by Isaac Asimov, and I came across this passage. "Imagine a body dropped first from a height of 1000 kilometers, then from 2000 kilometers, then from 3000 kilometers, and so on. The drop from 1000 kilometers would result in a velocity of impact v_{1}. If...

I've been asked to research D'Alembert's principle and solve a question. I've looked up quite a lot of different explanations on the internet of D'Alembert's Principle and I'm not quite grasping how to use it. I understand that you rearrange formula so that they equal 0 (e.g. f - ma = 0 or PE -...