Center of mass Definition and 900 Threads

Homework Statement A 4.02 kg hollow cylinder with inner radius 0.19 m and outer radius 0.42 m rolls with- out slipping when it is pulled by a horizontal string with a force of 47 N, as shown in the diagram below. What is the acceleration of the cylinder’s center of mass? Its moment of inertia...

Homework Statement Find the center of mass for the following triange: http://www.ehow.com/how_5132033_calculate-hypotenuse.html above is a picture of a triangle, it is a right triangle the side labeled a in the picture is a length of 1 and side b is length of 2, the total weight of...

distance between front and rear wheels of the truck is 3.50m. total upward force on front wheels is 12300N and rear wheels is 9180N. (I have already calculated that the center of mass is 1.28 m behind the front wheels). Now a 4850N object is added to the tailgate 4.23m from the front wheels...

Homework Statement To get used to finding the center of mass of an object, I have decided to start with a uniform density square. The square is centered at the origin. The center of mass should be at the center of the square, and thus at the origin. When I tried to solve this however, my...

Homework Statement 2. The attempt at a solution I'm working on #49 ONLY. I know the top line equation is f(x) = x but I need to find the g(x), so how can I find with the point is given (4,3). Please help!

i have calculated the C.M. of semi-circular arc of radius r and mass m. How can i use this answer to calculate the C.M of semi-circular disk of radius r and mass m? thanks:) ps. how about the converse?

Homework Statement A uniform flat plate of metal with a circular hole, where it is a rectangle starting from -6 to 7 from the length, and the height is -3 to 3. The circle has a radius of 2, and it starts at 1 to 5. Calculate the x-coordinate of the center of mass xcm of the metal plate...

Homework Statement A 4.39 g particle is moving at 4.15 m/s toward a stationary 9.64 g particle. (a)With what speed does the heavier particle approach the center of mass of the two particles? Answer in units of m/s. (b) What is the magnitude of the momentum of the lighter particle...

Moment of Inertia of an object rotating about its center of mass?? Homework Statement An object is formed by attaching a uniform, thin rod with a mass of m = 6 kg and length L = 4 m to a uniform sphere with mass M = 30 kg and radius R = 1 m. What is the moment of inertia of the object about...

Homework Statement The coordinates of the center of mass for the extended object shown in the figure are (L/4, −L/5). What are the coordinates of m1? (Assume m1 = 4 kg, m2 = 2 kg, and m3 = 3 kg. Use any variable or symbol stated above as necessary.) Here is the diagram ...

Homework Statement The problem is asking to find the Acceleration vector before jack reaches the less steep section. the Ans from back of book says : (3.95)i + ( -2.29 ) j My answer does not match at all : ANY HELP PLZZZZ anyone know how to get this ? Two skiers, Annie and Jack...

I am floating in a canoe in still water. I carefully walk from one end of the canoe to the other. If my mass is M and the canoe's is Mc, how far does the canoe recoil? I've solved more complicated problems but this one confuses me. Isn't recoil the velocity of a body after collision? I would...

Homework Statement A key concept about the center-of-mass frame is that A. the total momentum in the center of mass frame is always zero. B. both the initial and final momentum vectors form pairs of equal magnitude and opposite direction C. this frame always moves at the same velocity...

Homework Statement A uniform sphere of radius R has a spherical hole of radius r removed. The center of the hole is at a distance d from the center of the original sphere. Locate the CM relative to the center of the sphere. Homework Equations The Attempt at a Solution Ok, so...

Ok this one is messing me up. I already got number one (1.28). The question now is: I thought it would just be simple-the distance across the boat. But apparently as the man moves, so does the boat. This is confusing me. How do I begin to solve this one?

This should be easy enough, but the fact that the guy is standing at x=0 is confusing me. The center of mass should be m[guy]*x[guy]+m[boat]*x[boat] / total mass But since x[guy] is zero, then its just 162*3.4/(163+53) which comes out to 2.55, which is incorrect, since it has to be less than...

I want to write a program that basically mimics the physics of seesaws. Part of a project I'm working on. I understand how equilibrium works and everything, but let's say that I have a mass on each end of the seesaw, and both masses are equal distance from the pivot. If both masses have the...

Hello, Can a closed system change the position of its center of mass if no external force is exerted on it?

Why is it that when an object moves both transitionally and rotationally the center of mass follows the path as if there was no rotational energy? My theory is that objects naturally rotate around the center of mass and since the center of mass is a point, rotation doesn't affect its...

Homework Statement im trying to find the center of mass of two identical strong square pizza boxes of dimension one inch deep by 18 inches wide one is placed on top of the other with the edge of the top box in line with the center of mass of the bottom box , Homework Equations n/a ...

Homework Statement I am trying to find the total energy of a twobody system (two planets orbiting each other) in the center of mass frame. And I was so wondering how to think about this problem.. I know that the kinetic energy in the center of mass is just the sum of the kinetic energies...

Asuming a uniform distribution, how can I find the center of mass of a planet such as Earth?

Suppose I perform an experiment, set up as follows: There is a rotating body which rotates around a vertical axis. The axis is at one end of the rotating body (denoted as the rotator) so that the axis is not through the center of mass of the rotator. The vertical axis is attached to a second...

Hi guys, recently I am reading Kleppner's Mechanics about center of mass, well, I am always a fairly fast learner, but I really got stick here. you see, in the page 119 example 3.3 (in short, a rod with nonuniform density ) let Q(x) be the function density of location vector it said...

In the following question, I'm unable to find the center of mass to do the Torque calculation: Two 59.0 N forces are applied in opposite directions to the 13.6 cm long figure shown. If the angle θ=37.0°, what is the net torque about the center of mass? Image...

As a first-order approximation I can simply calculate the location and radii of an ellipsoid that contains the center of mass, but that's not good enough. Doing a Google search for "center of mass earth" doesn't pull up anything.

Will the velocity V2 be greater than or less than velocity V1 in the attached sketch? Yes and why or No and why not.

Homework Statement A toy manufacturer wants to create a toy ice cream cone by fitting a sphere of radius 4 cm inside a cone with a height of 8 cm and radius of the base of 3 cm. The base of the cone is concave, but the rest of the cone is solid plastic so that with the sphere attached...

Homework Statement Find the center of mass of the 2-dimensional plate which occupies the region inside the circle x^2 + y^2 = 2y, but outside the circle x^2 + y^2 = 1, and for which the density is inversely proportional to its distance from the origin. Homework Equations m =...

I hope this is the right section. consider the CM of a uniform ring. Suspend that ring by light cables above the earth, by a crane maybe? Where is the rings center of mass now? If this system was in space (crane, cables, ring), the CM would be somewhere else right? If the ring was...

Homework Statement In using a ladder where the wall is smooth but the floor has a coefficient Us, why is it necessary to make the angle large? Homework Equations The Attempt at a Solution I'm a little confused by this, because I would think that you would want to make the angle...

Gravity towards Center of Mass?? Conceptual question: Does gravity always act from the center of mass, regardless of shape of source of field, for finite mass distributions?

Homework Statement A uniform rod of length 1.25 m is attached to a frictionless pivot at one end. It is released from rest from an angle θ = 23.0° above the horizontal. Find the magnitude of the initial acceleration of the rod's center of mass. I keep getting the wrong answer...

Homework Statement Lets image the following a boat has three people in it A has a mass of 120lb B has a mass of 180lb C has a mass of 160lb and the boat has a mass of 120lb also distance from person A to the front of the boat is 2 feet and distance from person A to person B is...

Homework Statement The thickness of the object is 2 cm. The density of the material (pronounced row) is 7800. The angle (theta) is pi/6. The radius is .75 meters. What is the moment of inertia and the center of mass? Here is what the object looks like...

Homework Statement http://screencast.com/t/ZTk3NDUxNjU I need help with understanding number 18. Homework Equations Center of mase formula: m1x1+m2x2/(all masses) The Attempt at a Solution How do you tell if adding the weight will make the truck tipover. I calculated that...

Homework Statement 1. Verify the given moments of inertia and find the center of mass. Assume each lamina has a density of p=1. The problem gives a circle with a radius a. 2. Find the area of the surface of the portion of the sphere x^2 + y^2 + z^2 = 25 inside the cylinder x^2 + y^2 = 9...

Homework Statement A thin wire has the shape of the first quadrant part of the circle with center at the origin and radius a. If the density function is rho(x,y)=kxy, find the mass and center of mass of the wire. Homework Equations My parametric equation of the circle was x=a*cos(t) and...

The boundary of a lamina consists of the semicircles y=\sqrt{1-x^2} and y=\sqrt{4-x^2} together with the portions of the x-axis that join them. Find the center of mass of the lamina if the density at any point is proportional to its distance from the origin. I drew a graph that looks like...

Homework Statement I'm confused about how to find the center of mass http://www.screencast.com/users/ntrinh3/folders/Jing/media/a9773d23-38f1-4d28-a6f8-3b681d42d4c2 and http://www.screencast.com/users/ntrinh3/folders/Jing/media/bfb40c40-0068-41e8-ac83-2146e1df3330 Homework...

Not sure if this is in the right subforum but: A chain of uniform mass density, length b, and mass M hangs in a loop from the ceiling (both its ends are adjacent to each other) At time t = 0, one end, end B is released. Find the tension in the chain at point A after end B has fallen a distance...

give answer to this question

Hey Folks, i just wondered if there is a direct connection between the rapidity parameter y and the center of mass energy squared s (for example in the case of two colliding massless particles (aka high energy approx). I tried googling it, but failed to find any satisfying answer. Thank...

Homework Statement A man is standing 1 meter in from the left of a 4 meter long beam. The beam is held up by two wires perpendicular to the beam. The beam is 750 N and the man is 100kg what are the tensions of the two wires. Homework Equations F = ma Torque = F x d The Attempt at...

[The subject should say "adjusting center of mass"] Hello, I am trying to make a machine that "pairs" two object's center of mass and weight. I was trying to figure this out myself but with barely primary school completed, I obviously could not figure it out. Any help is very much appreciated...

A wire of uniform density is bent into the shape shown in the figure below. The value of L is 0.740 cm. Answer the following questions assuming that the origin is at the bottom left corner. What is the value of xcm? cm What is the value of ycm? cm Attempt xcm = 2*.74 = 1.48...

Homework Statement Find the x-coordinate of the center of mass of the composite object shown in the figure. The sphere, cylinder, and rectangular solid all have a uniform composition. Their masses and dimensions are: sphere: 200 g, diameter = 10 cm; cylinder: 450 g, length = 11 cm, radius =...

A being is on a sphere like planet. Sudently hey grabs a GPS and starts diging straight on a diemeter, heading to the center. We can theoretically say tha he is carrying a level with him. Then tha sphere is theoretically cut in two section , A and B. I have(well...with help) found the volume of...

momentof inertia and center of mass! in book of serway : he says moment of inertia of a body is m(r^2).---->(1) is mass of the body and r is the distance of the body. but for a rigid body we will divide into particles of very small masses so i = E(Mi * (Ri)^2) E() is submission function to...

Isn't the inertial frame defined by the center of mass of the universe somehow special? To get to any other frame an object must experience a force and be accelerated to a new velocity. In this case the CMB shows us the inertial frame of the CM of the universe. I understand that velocity is...