What is Spinning: Definition and 579 Discussions

can someone explain to me how can it be proof that the spinning-room-artificial-gravity, actually works? i mean, that if you take a huge wheel-like room, and spin it in the right velocity, the people inside will experience something that feels like gravity. well, I've mange to understand...

Homework Statement A small puck is placed on a disk spinning with angular speed OMEGA around axis perpendicular to the disk and passing through its center. The coefficient of static friction between the disk and the puck is MU. At what distance(s) from the center of the disk will the puck...

Spinning "tornado" wheel - circumference and radius Another quote from my current lecture "elgant universe": Page 63, 3rd Paragraph This doesn't make much sense to me. While I can comprehend that the ruler must be shortened as it's layed out tagentially to the circumference, as it's moving...

If you are inside a box that is spinning, can u detect its motion? At first i was thinking you can't the same way as if the box is moving forward. However, I was thinking that moving in a straight line involves one vector while spinning creates different ones so that you CAN detect...

I've been wondering for some time and it seems I still have doubt on how friction works on spinning object. Assume a situation like this (top down view): http://img33.imageshack.us/img33/5889/physics.jpg Assume dimension of the box is w and h, ignore the thickness of the box for time...

Homework Statement Mass of ball=0.500kg string length=1.02m I have a motion diagram of a ball being spun in a counter clockwise direction. there are four points on the circular diagram this is the best I can do right now ......v= 4.0m/s ......| ......| v=6.0m/s ---------- v= 6.0m/s...

Spinning mass Homework Statement 1) A mass of 7.10 kg is suspended from a 1.21 m long string. It revolves in a horizontal circle as shown in the figure. The tangential speed of the mass is 2.90 m/s. Calculate the angle between the string and the vertical. Picture 1)...

Homework Statement I need to determine the average speed of a dot on a spinning motor and also the time it takes for teh dot to make on revolution. Using a strobe light I determined I needed to do 3959.2 flashes/min in order to make the dot stay in place. The dot is 6.9 cm away from the center...

consider two planets, planet X and planet Y with masses, Mx and My separated with distance, D and they orbits about the centre of mass of the system which remains stationary. we know that period of orbit for X and Y are the same because they are always collinear with the centre of mass...

I am trying to find the best way to determine whether a spherical shell would stabilize in a certain orientation when falling. Assumptions I need to take into account: The sphere is spinning with some random angualr velocity for each axis The density of the shell is higher at the +x extreme...

If there was a stick the length of the diameter of Earth spinning in space for the same amount of time at the same rate as earth, would it appear as a spiral?

Homework Statement So there's a sphere, and it has a positive charge on it. The sphere is spinning, and the angular velocity vector is pointing up through the top. What does the magnetic field look like inside & outside the sphere? Homework Equations none The Attempt at a Solution This is...

Homework Statement Hi guys, this question is from Kleppner and Kolenkow's mechanics book, problem 7.2: A flywheel of moment of inertia I rotates with angular velocity w at the middle of an axle of length 2L. Each end of the axle is attached to a support by a spring which is stretched to...

Homework Statement Problem statement: Please see the attached picture. A rigid rod rotates with constant angular velocity w. A rigid bar with length A is attached perpendicular to the rotating rod. A second rigid bar with length B is attached to the other end of bar A by a hinge. The...

hypothetical: If I were to spin with my arms outstretched, with the tips of my fingers moving at (or near) the speed of light the center of my head would therefore not be moving at all. Would the centre of me age faster than the extremeties?

Consider the following object: The exact dimensions are unimportant, but its x, y and z dimensions must not be too similar (so I'm told). I have been told that an object such as the one above will behave strangely when thrown up into the air whilst spinning. If it is sent spinning...

Homework Statement A spinning top has a moment of inertia of 0.0004 kg*m^2 and is initially at rest. It is free to rotate about a stationary axis. A string, wrapped around a peg along the axis of the top, is pulled in such a manner as to maintain a constant tension of 5.57 N in the string...

Help me!A spinning blue plastic object made me sleepless. I've seen the mit online vedio course Physics I: Classical Mechanics Lecture 21 Torques, Oscillating Bodies,near the end 44:19.There is a spinning blue plastic object,the teacher spun it, it revolved then it stoped,then it revolved...

How would I calculate the speed of a spinning wheel (using forces in Newton and anything else required)?

I would like to be able to calculate the forces on a spinning disk to determine the rpm it will fly apart given its dimensions and the mechanical properties of the material it's made of. I understand centripital and centrifugal forces. However, I'm not understanding how I to set up the problem...

Why a spinning top won't fall to the ground? yes I know this question must have been asked before right? tried looking for it on here but I couldn't find it.

We've heard of the water pipe analogy for electric circuit. It says that the current produces magnetic field and that the "pipe" is irrelevant - only the amp-turns are relevant. So I was wondering, is it possible to increase the amp-turns of a electromagnet by rotating it in the same direction...

well this is a really good question which i just thought while playing cricket. A sphere of mass m and radii r(a tennis ball) falls freely from a height of H and angular velocity(clockwise) about its axis omega.Coefficient of restitution is e The coefficient of friction is mu. After the...

spinning disk torque? Homework Statement A uniform solid disk with radius 10 cm has mass 0.7 kg (moment of inertia I = ½MR2). A constant force 12 N is applied as shown. At the instant shown, the angular velocity of the disk is 40 radians/s in the -z direction (where +x is to the right, +y...

Spinning Disk A disk with a diameter of 0.06 m is spinning with a constant velocity about an axle perpendicular to the disk and running through its center. a) How many revolutions per second would it have to rotate in order that the acceleration of the outer edge of the disk be 15 g's...

A spinning object such as a gyroscope is known to maintain its orientation. I am wondering *what* it maintains its orientation with respect *to*. One answer is itself. Something else I have read is "with respect to the distant stars". If it is not with itself but with "distant stars", one can...

Homework Statement I have three metal blocks evenly spaced in a 0.3m circle that attach to a rod in the center of the circle. The rod requires 15HP to keep rotating at 1200RPM. What would the mass of the three blocks spinning at 1200RPMs need to be in order to produce 15HP? My physics class...

Homework Statement A disk with a diameter of 0.07 m is spinning about an axle perpendicular to the disk and running through its center. a) How many revolutions per second would it have to rotate in order that the acceleration of the outer edge of the disk be 14 g's (i.e., 14 times the...

Homework Statement A solid ball of mass M and radius R is spinning with angular velocity \omega_0 about a horizontal axis. It drops vertically onto a surface where the coefficient of kinetic friction with the ball is \mu_k. Find an expression for the final angular velocity once it has...

Homework Statement A string 44 cm long will break under a tension of 24 N. Two such strings are tied to a 670 gm rock, their ends 60 cm apart. The rock is spun between them. What is the maximum speed it can spin before the string breaks? (Using pythagorean theorem, you can determine the radius...

Homework Statement a long, thin rod of mass M and length L is standing stright up on a table. its lower end rotates on a frictionless pivot. a very slight push causes the rod to fall over. as it hits the table, what are (a) the angular velocity and (b) the speed of the tip of the rod...

Several years ago there were widely reported claims that gyroscopes and the like became lighter.Although these claims have generally become discredited could there be any truth to them and could proof come from theoretical reasoning?

Good day. This is a reformulation of another post which I made with the physics guys at the Forum ;) OK. Here's the scoop: Through some helpful input from another source, I have found that the following handy equation Fc (N) = 4 m pi2 n2 r / 602 can be used to determine the restraining...

If a two dimensional object (say a circle) spins, their is a zero dimensional 'point' that stays in the same place as it spins. If a three dimensional object (sphere?) spins on its axis, there is a one dimensional 'line' (its axis) such that any part of that sphere that lies on that line...

Homework Statement Is a spinning frame of reference an inertial frame of reference? Homework Equations net torque, net force = ma, equilibrium --> net force = 0, net torque = 0 I've learned that an inertial frame of reference is a frame of reference which is not accelerating. The...

Homework Statement Suppose you are standing on the center of a merry-go-round that is at rest. You are holding a spinning bicycle wheel over your head so that its rotation axis is pointing upward. The wheel is rotating counterclockwise when observed from above. For this problem, neglect...

a bucket is filled with water and tied to a rope with a length of "L=1m", the bucket is then spun in a verticle circular motion , what is the minimum frequency the bucket can be spun at in order for the water to not spill? i realize that i need to find the centripeutal force. is it mv^2/r...

Hi, I am trying to work out the result of a collision between two rotating particles if you knew all initial speeds, initial rotation speeds, masses etc. There is no friction or anything complicating. COM: m1v1initial + m2v2initial = m1v1final + m2v2final. COAM: I1w1initial +...

Homework Statement There are two balls with masses m_a and m_b connected by a string. m_b is moving at a velocity v upwards (perpendicular to the string) and it asks for the Tension (T) in the string. Homework Equations a=(v^2)/R delta Energy of system = 0 T = m((u^2)/r) u is...

Hi all, I'm a science fiction writer working on a scene in which a character in EVA, approaching a cylindrical, spinning space station. He fires a grapple and attaches to the side of the station. What would he experience? Is this so unrealistic that no editor would ever buy the story...

Homework Statement In an old-fashioned amusement park ride, passengers stand inside a 4.6m diameter hollow steel cylinder with their backs against the wall. The cylinder begins to rotate about a vertical axis. Then the floor on which the passengers are standing suddenly drops away! If all goes...

Homework Statement You swing a 6.5 kg bucket of water in a vertical circle of radius 1.2 m. (a) What speed must the bucket have if it is to complete the circle without spilling any water? m=6.5 r=1.2 Homework Equations maybe f=ma f=m(v^2/r) The Attempt at a Solution What I did...

Spinning Disk problem. Due tomorrow! Help please! A disk with a diameter of 0.1 m is spinning about an axle perpendicular to the disk and running through its center. a) How many revolutions per second would it have to rotate in order that the acceleration of the outer edge of the disk be 14...

Hi, I'm just trying to find out if there is a calculation to that relates deviation from a straight line to the forward velocity and the rotation of a circular object. Essentially i have a small project that i get to prepare and work on and was thinking of trying to find the optimal bowling...

If you are reading this thread chances are you are familiar with Bruce Depalma's work and publishing's. If you are not i will briefly fill you in on the " Spinning ball Anomaly ". ([ crackpot link deleted ]) Back in the 70's Bruce Depalma did a series of tests involving spinning...

Homework Statement A person stands at rest on a 5.0kg, 50cm diameter frictionless turntable. He receives spinning bicycle wheel, 180rpm counterclock wise, diameter 64cm, and the rim weighs 4.0kg. The wheel was held in a horzontal plane, the handles extend outward from the center...

Actually I have a couple of questions. First of all, I'm new here so hello to everyone. 1) Is it possible for an object or something to rotate at the speed of light? For example, with a special record player, can a record spin at or near the speed of light or does c only refer to a straight...

Why is a space probe spinning around its own axes, when flying through space?

Ok, so the Earth spins around its axis, and around the sun; and the sun spins around the black hole at the center of the Milky Way galaxy; and that center spins around some other monster black hole at the galactic center of a cluster of galaxies, which, in turn spins about another monster...

Hi to you all, May I just say I am not a physicist or the like so my questions may seem a bit green to you all, I wish to make something and need a little bit of info please. With regards to a vacuum sphere, if I was to spin an item within it would it spin freely or would there be forces...