Center of gravity Definition and 172 Threads

Are there any realistic scenarios for which center of mass is not almost exactly equivalent to the c.o.g., i.e. they must be treated separately?

It just occurred to me that in the right gravitational field, say, in a low orbit 100 km from the core of a neutron star with a mass equal to that of the sun, an orbiting object's center of gravity is somewhat noticeably displaced from its center of mass. Specifically, 1 meter closer to the...

Dear forum, while standing, spreading your legs helps your stability because you have a wider base. but doesn't spreading your legs lowers your center of gravity, thus shortening the distance (r) from your center of gravity to the ground, and therefore lowering your moment of inertia = making...

On the diagram in the thumbnail,You could see A,B,C,D I read from somewhere that forces acting on the two sides should be equal to be in equilibrium But a person moving closer does not change the forces i.e the forces on the two sides is still equal and the center of gravity still lies on the...

Homework Statement This has a fairly long problem statement, so I'll condense it. There are two gates with 81 vertical pickets and two horizontal support bars. These are holo rectangular tubes. The pickets are 2" x 2" x 3/16" box beams and support bars are 4"x6"x3/16" Box Beams. One...

So I'm trying to find vehicle center of gravity, but i only have this information: full loaded vehicle weight(3200kg or 31392 N) empty vehicle weight(2000kg or 19620 N) maximum rear axle capacity(1500kg or 14715 N) maximum front axle capacity(1800kg or 17658 N) Is this possible? I have a book...

Hi, I have this problem that I'm trying to solve and it has been a few years since I've taken Physics. I want to know how you would approach and solve this problem, and what equations you would use. Hopefully somebody here can help me out. The Problem: A vehicle is on a road that is V inches...

Homework Statement An automobile with a mass of 1321 kg has 3.40 m between the front and rear axles. Its center of gravity is located 1.78 m behind the front axle. (a) With the automobile on level ground, determine the magnitude of the force from the ground on each front wheel (assuming equal...

Center of gravity and Center of mass different?? I was developing a test for my students and always look for a difficult question as the only bonus question. I came across the question in the book, "When are center of gravity and center of mass different?". I thought about it before looking at...

Homework Statement A large wooden beam weighs 820 N and is 3.2 m long. the beam's CG is 1.4 m from one end. two workers carry it away. If they lift the beam at its ends, what part of the weight does each worker lift? Homework Equations Tcw=Tccw F*l=F*l The Attempt at a Solution I...

Homework Statement If Bethany and Serendipity each exert a force of 350 N on each arm of a wheelbarrow with 1.25 m arms and carry Cardinal Glick in the bucket, who has a weight of 1,050 N, where is the center of gravity of the bucket and the Cardinal with respect to the wheel? Pointers would...

HELLO Can someone help me locate the center of gravity for my vehicle design? all the parts, dimensions and mass of the parts of the design are known. Is it possible to locate for the COG of it? Thanks!

Homework Statement Hey In my assignment I am writing about beamdeflection, but there's some things i really can find out how to do. I need to explain area moment, moment of inertia and the center of gravity, i need to explain this with the help of integration. Under her I've inertet...

Homework Statement I need to find the center of gravity of a horizontal cylinder that has water in it, the level of water changes so I need to determine a relation between the diameter occupied by the water and the masses, those are my guesses. I solved the problem where i have the standing...

I should say that while I've taken some physics courses, I should probably be considered a layman or hack as I haven't done any real world engineering. I'd love to hear some more expert feedback on this topic. I'm sure that there are many approaches to this concept. For this project, my goal...

Hi, I have some questions regarding on the locating of the center of gravity. I have read some txtbk regarding on finding the COG for structure/element that is homogeneous. Therefore, the COG will conincide with the centroid of the the volume. Am i right to say that homogeneous...

Homework Statement A carpenter's square has the shape of an L, where d1 = 19.0 cm, d2 = 2.00 cm, d3 = 2.00 cm, d4 = 9.0 cm. Locate its center of gravity. (Take (x, y) = (0, 0) at the intersection of d1 and d4.) Picture ---> http://www.webassign.net/pse/p12-07alt.gif Answer = (____...

Well, I spent literally 45 minutes typing an in-depth post explaining the problem, the variables, and my (probably incorrect) approach only to be logged out and having the post completely lost after pressing the preview button. Sigh... apologies if it's not as thorough now, but I've run out of...

Homework Statement The machinist's square shown in the figure consists of a thin, rectangular blade connected to a rectangular handle. Determine the x and y coordinates of the center of gravity. Let the lower corner be x=0, y=0. Homework Equations x_cg = (m_1 * x_1)+(m_2 *...

Textbooks all say that the center of gravity of an object is the point at which all it's gravitaional effects appear to be concentrated. But that seems to depend on who's checking. (see atachment) Imagine a small mass M some distance from the Earth. That mass is attracted simultaneously...

What is ceter of gravity concept and how to calculate it for a triangle

Homework Statement A uniform door(.81m wide and 2.1m high) weighs 140N and is hung on two hinges that fasten the long left side of the door to a vertical wall. The hinges are 2.1m apart. Assume that the lower hinge bears all the weight of the door. Find the magnitude and direction of the...

1. My professor explained this concept before, but I didn't quite understand. I need help with understanding how if two players jump for the ball with the exact same mass and body segment dimensions, taking off with the same vertical and horizontal velocity of the CoG, one can have an advantage...

Sorry if this is posted in the wrong section I'm trying to find out what would be a good pick point on a steel point instead of just winging it. There are two sections to the steel pole, both combined together to create a total of 78 feet. The first section is 40' and weighs 3,438.004...

Homework Statement <a href="http://www.flickr.com/photos/56362284@N04/6149231787/" title="untitled by redmond0991, on Flickr"><img src="http://farm7.static.flickr.com/6065/6149231787_e6230d69ab.jpg" width="407" height="229" alt="untitled"></a>...

I have a project to do and I have to make a demonstration about a physics phenomenon. I'n planning on doing a demonstration that explains one or all of Newton's Laws of Motion. I've chosen to do it on the center of gravity, but I want to know if it's related to Newton's 3 Laws of Motion or is it...

Hi there, so I'm a bit confused...I'm 14 years old and I'm living in Croatia.I heard for Hallow Earth theory one year ago so I wanted to research it, but I had no material i needed until today...data(material9 i needed is what is radius of Earth on poles and Equator and what g is there...

Homework Statement Calculate the center of gravity of this object: http://img638.imageshack.us/img638/8412/inddddd.jpg The Attempt at a Solution The bottom line turns out zero, so I get something over zero therefor error! http://img101.imageshack.us/img101/6995/theretherere.jpg

From some reason Yc's result is different than mine. But, the solution manual and me are using the same X axis to calculate Yc (we're using a different Y axis to calculate Xc, though). Can someone explain to me what's wrong here?The question: Calculate the center of mass of the material line...

Could anyone help me figure out a formula to calculate a Center of mass for a non uniform object. In my case it would be a "shell" that would go over a body of a solar car. If anyone could help me that would be great.

Homework Statement Find the problem of the centroid of each of the shapes http://img29.imageshack.us/img29/7563/64279412.jpg this makeshift diagram is not as accurate as it should be, but it is a plain T shape that is perfectly symmetrical. Homework Equations...

Hi, hope someone can help. I need to find the centre of gravity of a supermileage. Here is the dimensions: ~The maximum height must be less than 100 cm. ~ The maximum height measured at the top of the Driver's compartment must be less than 1.25 times the maximum track width between the...

Hi, I was wondering about an issue that we just started in my physics class: we learned that center of mass (CM) and center of gravity (CG) coincide in an object as long as the force of gravity is uniform over that object. So, for something near the Earth's surface we can say that CM and CG...

These questions apply to the act of pitching a professional horseshoe. I will use a 3 foot rod held horizontally, as an example. Q1. I assume the center of gravity would be 18" from each end. I would grip the rod at the pivot point. Is it true that there is no torque since I'm gripping the...

Homework Statement A uniform plank of length 4.7 m and weight 207 N rests horizontally on two supports, with 1.1 m of the plank hanging over the right support (see the drawing). To what distance x can a person who weighs 454 N walk on the overhanging part of the plank before it just begins to...

I am building a stand for my LCD/LED TV and Mount. See several pics below: Calculation Sheet, Mount Diagrams, and Side View of the TV. The Mount will be hanging on 2 poles, and the TV hangs on the front of the Mount. Am I computing the Center of Gravity correctly? in order to determine where to...

Homework Statement a person is doing pushups and its weight is 584 N, center of gravity is at waist and from waist to hands=.410m and from waist to feet=.840m. find the normal force on each hand and each foot Homework Equations The Attempt at a Solution do u have to find the...

Homework Statement What is the Relation between center of mass and center of gravity, please compare with simple example. Bco'z i am very confused about it Homework Equations The Attempt at a Solution

Center of gravity? A uniform board 20.0cm x 10.0 cm has a mass of 200g. Masses of 50.0 and 80.0 grams are attached at two corners at the ends of one of the longer sides. Locate the center of gravity. i have no idea how to solve this help me pls...

hello to all INTRODUCTION: i have created application that splits triangles (2d simplex) and tetrahedrons (3d simplex) to 1 triangle -> 3 quadrilaterals 1 tetrahedron -> 4 bricks (8 nodal elements) my application uses element center of gravity in both cases. and than splits...

Suspend all disbelief and imagine digging to the center of the Earth, there you dig out a small spherical chamber, you sit in the middle, do you float or are you depatched violently to the wall around you instantaneously.

Homework Statement Find the x- and y-coordinates of the center of gravity of a 4.00 ft by 8.00 ft uniform sheet of plywood with the upper right quadrant removed as shown in the figure below. The dimensions of the cutout are a = 3.50 ft and b = 2.10 ft. The Attempt at a Solution I made...

Homework Statement For the machine element shown, locate the x coordinate of the center of gravity. The picture of 2 different problems are attached Homework Equations V = 1/3*a*b*h The Attempt at a Solution I can figure out the coordinates fine for everything except the triangles...

A skateboarder with his board can be modeled as a particle of mass 73.0 kg, located at his center of mass (which we will study in a later chapter). As shown in the figure below, the skateboarder starts from rest in a crouching position at one lip of a half-pipe (point A). The half-pipe is a dry...

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Homework Statement Find the x- and y-coordinates of the center of gravity of a 4.00 ft by 8.00 ft uniform sheet of plywood with the upper right quadrant removed as shown in the figure below. The dimensions of the cutout are a = 4.30 ft and b = 1.70 ft. I found: xA= 3.7/2 cm...

Homework Statement Caution: Ignore the weight of the bucket itself. The bottom and the top of a bucket have radii rb = 15 cm and rt = 26 cm respectively. The bucket is h = 36 cm high and filled with water. Where is the center of gravity relative to the center of the bottom of the...

Hello I was wondering is it possible to figure out the center of gravity for a wheelchair through calculation alone and how is it done? Thanks!

Hi! I am new to the forum. I have a short question: I have uploaded drawings of two "speed boats" with fuel systems. Which boat got the best CG? The one with one, or the one with two fuel tanks? What do you think.

I was absent from school for 3 days and my teacher gave this worksheet to me. I have no idea what I'm doing on it. Can anyone please help me with this? Thanks.