Inertia Definition and 1000 Threads

Homework Statement A person grabs on to an already spinning merry-go-round. The person is initially at rest and has a mass of 29.5 kg. They grab and cling to a bar that is 1.70 m from the center of the merry-go-round, causing the angular velocity of the merry-go-round to abruptly drop from...

Homework Statement A uniform thin rod with mass 4.59 kilograms pivots about an axis through its center and perpendicular to its length. Two small bodies with a mass of 0.543 kilograms, are attached to the ends of the rod. What is the length of the rod such that the moment of inertia of the...

for part a I used the equation I=m*r^2 ---> 120(58/100)^2=40.36 kg*m^2 b)I know how to do this using the equation K=1/2Iw^2 but my moment of inertia is incorrect.

Pre-theoretically, we notice that objects have some property responsible for their varying dispositions to resist being pushed around in space, or to resist changes in motion given applied forces ("inertia"). So we introduce the term "inertial mass" to apply to the most physically interesting...

Homework Statement Water falls onto a water wheel causing it to rotate. Consider an instant when the water wheel is initially motionless and then 100 kg of water hits tangent to the wheel at a radius of 2 m (this water can be treated like a point mass). If the moment of inertia of the water...

In the figure, two skaters, each of mass 48.1 kg, approach each other along parallel paths separated by 2.90 m. They have opposite velocities of 1.61 m/s each. One skater carries one end of a long pole of negligible mass, and the other skater grabs the other end as she passes. The skaters then...

Homework Statement The thin rod shown has a length L = 100 cm, and a density that varies from 26 g/cm at the origin to 3 g/cm at the far end. Determine a) the moment of inertia about axis 1 (passing through the center of mass of the rod), and b) the moment of inertia about axis 2 (passing...

Homework Statement A compound disk of outside diameter 152 cm is made up of a uniform solid disk of radius 41.0 cm and area density 3.30 g/cm2 surrounded by a concentric ring of inner radius 41.0 cm , outer radius 76.0 cm , and area density 2.10 g/cm2 . Find the moment of inertia of this...

Homework Statement A thin walled hollow sphere of radius 16 cm is sliced in half. What is the moment of inertia of this hollow hemisphere about the x-axis if the areal density is 90 g/cm2? Homework Equations No idea The Attempt at a Solution I've had no luck with this. I've...

Homework Statement Two uniform square laminas are combined into a single body. One lamina ABCD has mass 5m and the other lamina PQRS has mass m. The lamina PQRS has side 2a, and its vertices are at the mid-points of the sides of ABCD, with P on AB and S on AD. The line PS meets AC at K, and...

Homework Statement Can i use "pyramid" method to derive the equation of Moment Inertia solid sphere? The pyramid is such we slice a watermelon. Sorry for my bad english. Regards. Homework Equations 2/5 MR^2 The Attempt at a Solution

Homework Statement You guys might recognize me from a post earlier. Yep, I'm still plugging away at rotation of rigid bodies and have another question. The flywheel of a gasoline engine is required to give up 500 J of kinetic energy while its angular velocity decreases from 650 rpm to 520...

Homework Statement A molecule similar to methanol is made by joining three flourine atoms (purple; m = 19 amu each) to one carbon atom (blue; 12 amu) to one oxygen atom (green; 16 amu) to one potassium atom (orange; 39 amu). The position of each atom is as follows: 1. The flourine atoms...

Homework Statement A wedge of a sphere of radius 14 cm (similar to one segment of an orange) is oriented so that the axis is aligned with the z-axis, one face is in the xz plane, and the other is inclined at an angle of α = 29o , as shown. The wedge is made of metal having a density of...

∂hi all. I sort of understand this question but not fully so here it goes: A shaft carrying a flywheel of diameter 565mm and mass 210 kg is required to run at a speed of 710 rev/min. If the working speed is to be reached in 16 seconds from rest and the coefficient of friction between shaft and...

Homework Statement If the fall height of the mass is doubled, the angular acceleration of the wheel will a. decrease by an unkown amount b. remain unchanged c. decrease by a factor of 2 d. increase by an unknown amount e. increase by a factor of 2 Homework Equations The...

Homework Statement If we shift the rotation axis from the center of mass of an object, with no change in the orientation of the axis, what happens to the rotational inertia of the object around the axis? Homework Equations Calculating the Rotational Inertia The Attempt at a Solution Does it...

Homework Statement 25-2-EX9 The time rate of change of the displacement (velocity) of a robot arm is ds/dt = 8t/(t^2 + 4)^2. Find the expression for the displacement as a function of time if s = -1 m when t = 0 s. 26-5-9 Find the moment of inertia of a plate covering the first-quadrant region...

Does light have inertia? Suppose a light pulse is emitted in a moving train in the direction of train’s movement. Should it move at its constant speed even in the moving train? And if there is a front window in the path of the light pulse, should it shoot out through the window to go ahead of...

[b]1. Homework Statement [ How do I get I1( the moment of inertia of the picture b) ?is just a math problem but really no idea. Homework Equations I=mr^2 The Attempt at a Solution maybe centre of mass . Guide will do . please help , thank

I'm trying to figure where I've gone wrong in my calcs. the physics of the inertia dyno are simple enough however I can't seem to get the proper results. I=1/2*m*(r_{1}^{2}-r_{2}^{2}) \alpha=\frac{d\omega }{dt} \tau =I*\alpha these are some of the equations I'm using, the torque should be in...

Homework Statement An object is formed by attaching a uniform, thin rod with a mass of mr = 6.91 kg and length L = 4.88 m to a uniform sphere with mass ms = 34.55 kg and radius R = 1.22 m. Note ms = 5mr and L = 4R. What is the moment of inertia of the object about an axis at the left end...

[b]1. The

I was taught there was two types of inertia. The translational inertia and the rotational inertia. If in the Earth for example, that has a translational motion around the Sun, and a rotational motion around itself, all forces disappeared, it would follow an uniform rectilinear motion tangent to...

Hi, So I came across this article on the internet, and it was about the Equivalence Principle. So I were interested and read it all, and in the article it said that the EP might be only approximately true. What interested me more about the article was it said that any theory of quantum...

Hi all, It is really a history question. I read that Galileu developed the concept of inertia, but today I knew it from Newton's 1st law. So my question is: Both of them arrived at the idea independently? Was Newton aware about Galileu's work and used the law because it is the basis for his...

Hi Guys, I am trying to calculate a starting torque required to move the drum at 6rpm that weights 2000kg and has 1200mm in diameter. There would be no problem to do this calc in normal circumstances as I can find a moment of inertia formula for a pipe in my book. But in this case there...

In the bicycle industry, there is a lot of marketing saying that rotational weight is more important than static weight when it comes to accelerations and competition. I understand I=mr^2 but how do you compare differences. Keeping the the hub/spokes constant, how much advantage would you get...

What formula do I need here?Starting from the sum $I = \sum\limits_{\alpha = 1}^Nm_{\alpha}\rho_{\alpha}^2$ and replacing it by the appropriate integral, find the moment of inertia of a uniform thin square of side $2b$, rotating about an axis perpendicular to the square and passing through the...

Homework Statement http://i45.tinypic.com/hwcsy0.png The Attempt at a Solution I'm not sure how to find the rest; Ixy, Iyz and Izx... Usually for integrals such as moments of inertia you will be able to reduce it to only one variable. However, there are 2 variables here; xy, yz and zx. How do...

Homework Statement Starting from the sum: I=Ʃ mα*ρα2 and replacing it by the appropriate integral, find the moment of inertia of a uniform thin square with side length 2*b, lying in the x-y plane, rotated about the x-axis. Calculate its moment of inertia. Homework Equations The integral form...

Two masses, 300 g and 400 g, are connected by a cord that passes over a pulley with a radius of 6.64 cm (an Atwood's machine). When released from rest, the 400-g mass falls 60 cm and the 300-g mass rises 60 cm in 4.00 seconds. Find the rotational inertia of the pulley. Four 100-g ice cubes at...

Homework Statement Derive the formula for rod's moment of inertia: I = ml2/12 Homework Equations I = ml2/12 The Attempt at a Solution The only one derivation I know of is dividing the rod into two parts and then integrating from 0 to l/2. However' I'd love to know if there's some...

I have a question regarding Inertia. Exactly how much force, in Newtons, is required to overcome the inertia of exactly one kilogram of mass? It seems to me there must be some sort of quantity for it.

The experiment is the following: First part - The demonstrator puts an egg in the table, and places a heavy block resting above the egg, then he applies a force in the heavy block using the hammer, and the egg doesn't break. Second part - Now he takes the heavy block away, and instead...

Homework Statement Hi there. Im trying to find the moment of inertia for a 2/3 empty cylinder, could anyone see if I solved this correctly? Someone told me it's wrong, but I don't know why exactly, so any thoughts would be much appreciated. (I added the question and the attempt to solve it in...

Homework Statement I have a physical pendulum that is rotating about an fixed axis. The period is: T=2\pi \sqrt{\frac{I}{mgd}} I = moment of inertia d = distance between the center of mass and the axis. The problem is: If you add a mass in the end of the pendulum. The period is going...

Hi, Homework Statement Will the moment of inertia of a two dimensional rectangle (with sides a, b) whose axis is parallel to one of its sides and passes through its center of mass, be (1/12)M(a2+b2)? Homework Equations The Attempt at a Solution

Homework Statement Four particles with masses 2 kg (top left corner), 3 kg (bottom left corner), 4 kg (bottom right corner), and 5 kg (top right corner) are connected by rigid rods of negligible mass. The origin is centered on the center of the rectangle of sides 0.8 length and 0.6 breadth. If...

Getting ready for linear algebra exam. One question that I got right but not exactly sure why is this: --- Consider the quadratic form Q(x,y,z) = 3x^2 + 3z^2 + 4xy + 4xy + 8xz a) Decide if Q is positive definite, indefinite, etc. b) What point on the surface Q = 1 lies closest to...

Homework Statement A)Find the moment of inertia tensor for a system of 4 particles of mass 1kg at A=(1,1,0), B=(1,-1,0) C=(-1,1,0) D=(-1,-1,0) in Cartesian coordinates. B)Rotate the coordinates 30 degrees around the z axis and find the tensor in the new coordinates. Homework Equations...

Homework Statement The question is from a lab. The lab used an Atwood Machine with two masses suspended string looped over a pulley. The time for one mass to reach the ground was measured and acceleration of the mass was calculated. The results were plotted on a graph of weight difference...

Homework Statement A solid rod of mass M = 1.35 kg and length L = 83 cm is suspended by two strings, each with a length d = 71 cm (see Figure), one at each end of the rod. The string on side B is cut. What is the magnitude of the initial tangential acceleration of end B...

Homework Statement Hiya boys, Sorry i don't know how to proceed with this problem can anyone help me solve these two questions? In preparation for building a space station, an astronaut removes a self-telescoping uniform rod from the cargo bay and releases it, not noticing that he gave...

Homework Statement Problem with diagram here Homework Equations I=(1/3)MR2 (I believe the formula given in the problem is incorrect since it is pivoting on one end rather than the center of mass) KE=(1/2)Iω2+(1/2)Mv2 L=Iω=MvR The Attempt at a Solution a. True, the velocity is still going in...

The puzzle is: "The figure below represents a small, flat puck with mass m = 2.24 kg sliding on a frictionless, horizontal surface. It is held in a circular orbit about a fixed axis by a rod with negligible mass and length R = 1.03 m, pivoted at one end. Initially, the puck has a speed of v =...

Hello, I was curious to know if there was some intuitive out-look on why rotational inertia depends on the distance of the mass from the axis of rotation; and why is this distance have to be squared?

Homework Statement A sphere and a cylinder of equal mass and radius are simultaneously released from rest on the same inclined plane and roll without sliding down the incline. Then: A. the sphere reaches the bottom first because it has the greater inertia B. the cylinder reaches the bottom...

What is the origin of inertia? This is a question asked by many people. I believe even Einstein pondered on this and did put some of his thoughts in a paper, but nothing really conclusive. In Newtonian gravity, inertia appears to be just something that is inherent to mass. However, given...