Falling Definition and 1000 Threads

Hello: I have quite a few questions regarding objects free falling and the forces that they generate. I have been doing some reading on this topic over the last few days but I think that I am missing some of the concepts and how they apply in the scenario that I am trying them to. I think...

If you drop an object from a great height with no air resistance. e.g. 1000 km above the moon. How long will it take to hit the surface? (GM_{}1M_{}2)/r^{}2 = M_{}2a r^{}..=k/r^{}2 Hmm this is my first post, not quite getting the symbols. "The second derivative of r is equal to a...

Suppose we have two sticks held in a vertical plane, pivoted at one point (check the diagram). If we let go, why is the initial acceleration of the center of the mass not equal to g? Why does the pivot exert some force at the beginning? By contrast, if we keep the sticks in a horizontal...

...curvatures in spacetime being created by Earth's gravity? My understanding is that its speed offsets the gravity being created by earth, that it's freely falling towards Earth but never hits it because its speed somehow causes it to keep missing. If that's the case, wouldn't that suggest...

Hello, I've been trying to figure out the physica behind a collision of two objects due to the force of gravity. Here's the situation as I'm picturing it: A massive object A is falling due to gravity which impacts a stationary object B being held up by a structure. In this particular case...

The equivalence principle implies that it's always possible, by an appropriate coordinate transformation, to locally transform away the effects of gravity by going into a freely falling frame. Furthermore the local flatness theorem implies that it's always possible to but the metric ##g_{\mu...

Let us consider the case of a body falling down radially towards a Schwarzschild black hole. The velocity of the body is as high as it would be if it had been falling from standstill at infinity. When the body finally fuses with the black hole (get infinitely close to the Schwarzshild...

In a free-fall problem, 9.8 m/s^2 works fine as long as you stay close to the earth. However, if you are falling from very high up, the change in acceleration due to gravity is no longer negligible. Let's say there's an atmosphereless planet of mass M, and another object of negligible mass is...

I'm an author and I want to correctly portray a scene (with a bit of artistic license) in my next book. However, I don't think I understand the physics of the situation. Scenario: Passengers flying in a G6 going 450mph at 35,000 feet. Jet goes into a nosedive at let's say a 45 degree angle...

The solution of Einstein's field equations for a simple black hole show a slowing of time as you get close to the black hole. Time stops at the event horizon. An observer in flat spacetime far from the hole would see an astronaut fall slower and slower as he approaches the event horizon. It...

There are two objects, let's go with the classic cannon ball and football. These objects are both equal in size and shape but they obviously have different masses (the cannon ball being heavier). My question is, will these two objects fall and hit the ground at the same time if dropped from the...

I get the fact that a) electrons don't "like" each other so they force each other away and b) that this is why we don't fall through the floor. But my question is (since this is on the quantum mechanics section) since there is a probability that say the atom under your toe could pop up somewhere...

http://en.wikipedia.org/wiki/Ladder_paradox#Man_falling_into_grate_variation In the resolution it says: "It should be stressed that, since this bending occurs in the rod's rest frame, it is a true physical distortion of the rod which will cause stresses to occur in the rod." I wonder if...

http://i793.photobucket.com/albums/yy215/dweeegs/probability_zps12a67dfb.png The picture shows everything needed. This is a worksheet on the similarity of classical probability to the probability of finding a particle in a box (Schrodinger stuff etc) Basically there's a ball falling...

Hi, I'm designing a crane that is supposed to withstand forces due to a falling object attached to the crane with a non-elastic cable. I have some troubles to calculate what force that will be due to the falling object. I figured that one way is to simplify this system with a spring with...

Hi there everyone, Would like some checking of my work or comments. Would like the work done on a falling mass M as a function of time. To begin, the relation for work as function of distance.. w = Mgx but would like as function of time so substitute x this way, x = (1/2)gt2...

Homework Statement A penny is released from the top of a very smooth sphere of radius 1.3 meters. The sphere is fixed to a platform and doesn't move. The penny slides down from rest and leaves the sphere at a certain point. How far will the penny fall away from the point of contact of the...

Apologies if this is in a FAQ somewhere. A is out in deep space. B is falling toward the planet. Does A need both SR & GR to calculate B's time/space dilation as determine by A's IRF?

Homework Statement There is a rod falling at a speed v that makes an angle θ with the x-axis as it falls. Is it possible for the intersection point to move faster than light as it falls. Homework Equations The Attempt at a Solution I have done the geometrical calculations and I...

Switched to a "tougher" school, grades falling Hey guys. This semester I made the switch to a "harder" nationally ranked university from a local university in order to knock out some pre-reqs for graduate school. However, I am kind of regretting it at this point because I have already made...

Homework Statement Q: A stone is thrown vertically upwards with initial speed of 5 m/s from edge of a cliff 30 m high. Find the time needed for the stone to reach the ground (in seconds). Homework Equations 1. (h= Vo t - 0.5 g t^2) 2. Quadratic equation: The Attempt at a Solution...

Homework Statement A D flip-flop is implemented using an S-R master-slave flip-flop that changes states on the falling edge of the clock. Assume that the circuit is fabricated using NAND gates and that each gate has exactly a propagation delay Tpd = 1ns. a) Determine the set-up (Tsu), hold...

Homework Statement After gathering data via ticker tape, of a falling object, I had the following information: Time (s), Displacement (cm) 0.0 - 0.1 , 6.2 0.1 - 0.2 , 16.0 0.2 - 0.3 , 24.5 0.3 - 0.4 , 33.1 0.4 - 0.5 , 43.0 0.5 - 0.6 , 49.7 The Question: Determine the average...

The cable of an elevator of mass M = 1640 kg snaps when the elevator is at rest at one of the floors of a skyscraper. At this point the elevator is a distance d = 36.4 m above a cushioning spring whose spring constant is k = 13600 N/m. A safety device clamps the elevator against the guide rails...

Homework Statement I'm currently new to Matlab and have just started trying to solve a few problems with it. So I have to make a program that will display the results of height and velocity of a falling object, as well as plotting the overall function. My main concern is I am using an...

It appears paradoxical because to an observer falling with the charge it is as though the charge is at rest and therefore should not radiate. Also, if we place a charge on a table, shouldn't it radiate as there is a normal reaction force from the table?

Homework Statement "A spring is hung from the ceiling. A pan of mass 100.0 g is attached to the end, which causes it to stretch 5.00 cm. Find the maximum distance the pan moves downward when a lump of clay of mass 120.0 g is dropped from a height of 40.0 cm onto the pan." The correct answer...

I have a bowl in the form of a parabola (say y=x^2, motion is in 2d! On the graph of the parabola) and i place an object on the edges of the bowl and let if fall in the bowl. I have gravity, and no friction. My question is plain simple: what are it's equations of motion? I know it has to...

First of all, do falling droplets have a final volume like falling bodies have a final velocity - in air? If so, is there a way to determine such volume for a specific liquid and a specific height? More specifically, the final volume of a semen droplet falling from a 1km height.

Homework Statement A penny is released from the top of a very smooth sphere of radius 1 m. The sphere is fixed to a platform and doesn't move. The penny slides down from rest and leaves the sphere at a certain point. How far will the penny fall away from the point of contact of the sphere...

Homework Statement There's a stick with a weight at the end standing straight up and I touch it slightly so it falls over. The stick is massless, the weight is 20kg and the length of the stick is 0.5 meters. How long will it take for the weight at the end to hit the ground? Homework...

Homework Statement A rock is dropped off the top of a building. On the way down, the rock passes a window. The window is known to be 2.00m tall and the stone takes 0.164s to fall past the window. 1)What is the velocity of the rock at the top of the window? 2)What is the velocity of the...

Homework Statement A steel ball bearing falls through a viscous syrup. The equation of motion is m(dv/dt) = mg - (alpha)v where g = 9.8 m/s^2. The terminal velocity is 0.2 m/s. (a) Determine the value of alpha. (b) Determine the speed at t = 0.04 s. [initial velocity = 0; mass m = 12.6E-3 kg]...

Homework Statement A body of some mass ##m## is thrown up from the ground with a speed of ##v_o##. Suppose that upon returning to ground level, the body enters into a deep well. What is the relation between the height of the well and the time it takes until the body hits the ground...

Homework Statement I have got a nice problem about free fall. Consider a free-falling bomb vertically down at the target. The movement starts from rest. Bomb is giving sound - speed c= 340 m/s (from friction of air). What is the maximum impact of the bombs to her target (people) to hear...

Homework Statement A friend of mine and me were walking through the city when he looked up at a tall building, let's say 25 metres, and said "I wonder how long it'd take to hit the ground if you jumped off". I was thinking about it and realized I didn't even know what the appropriate...

I am working on an animation, which involves a rigid, vertical tower falling (toppling) to the ground, and I am stuck at its core physics. Actually this is the same as the thin uniform rod initially positioned in the vertical direction, with its lower end attached to a frictionless axis...

I recently solved a question related to the problem below, but am having trouble getting an intuition for the problem. Suppose an automobile is traveling at a constant horizontal velocity, u, and it's raining. There is no wind, so the raindrops do not have an initial horizontal velocity, just...

Homework Statement Bronco dives from a hovering helicopter and finds his momentum increasing. Does this violate the conservation of momentum? Homework Equations p(before) = p(after) The Attempt at a Solution no, this does not violate the c.o.m, because it is a closed system of...

Homework Statement The drag force experienced by the spherical pebble in water is given by: (0.5)CpwAv2 mass of pebble = 83.8g radius of pebble = 2 cm C = 0.7 (a) Write down the differential equation governing pebble's descent. (done) (b) Derive an expression for terminal...

Is it correct to assume that two objects, with different masses, dropped from the same height at the same time will fall at the same rate until one of the objects reaches its terminal velocity? What are the applicable equation(s) used to calculate this?

Homework Statement We have got a ball of radius r, which is falling from the roof of the house. How is the radius r with respect to time? We are looking at the ball directly from above and ball is at the beginning of fall x from our eyes. Neglect air resistance. Homework Equations I'm...

Homework Statement The free end of a simple pendulum is attached to the ceiling of a box. The box is taken to a height and the pendulum is oscillated. When the bob is at its lowest point, the box is released to fall freely. As seen from the box during this period, the bob will a)continue...

You have this loop of water (or some other "incompressible" fluid) with a nuclear powered water pump that constantly pumps the water in a circle. This loop is slowly lowered near the event horizon of a black hole, let's even make it a super duper massive black hole to minimize tidal effects...

Homework Statement A mass-spring-damper subsystem is falling inside a container m1. The system is confined to the vertical direction. Use Lagrange’s equations to find the EOM. A. Use x1 and x2 as generalized coordinates. B. The linear spring is unstretched when x2 – x1 = l...

Hi everyone, I have read a few different ways of looking at this problem, and it's one of those things where I am happywith the answer, just not how to get there using proper mathematics. My lecturer described this with some complex integrals involving E (but I'm not sure what that is!) but I...

In a class at OCW 8.01 Professor Walter Lewin said... "...there are very prestigious physicists who even nowadays do very fancy experiments and they try to demonstrate that the time for an apple to fall does depend on its mass even though it probably is only very small, if it's true but they...

If you drop your shoe and a coin side by side, they hit the ground at the same time. Why doesn't the shoe get there first, since gravity is pulling harder on it?

Hello, I have recently conducted an experiment to measure the viscosity of some liquids using the falling sphere method and a high speed camera. For most of the measurements this is fine since the spheres reach terminal velocity and so it is easy to calculate the viscosity from: v =...

A meter stick is held vertically with one end on the floor and is then allowed to fall. Find the speed of the other end just before it hits the floor, assuming that the end on the floor does not slip. (Hint: Consider the stick to be a thin rod and use the conservation of energy principle)...