Centre of gravity Definition and 73 Threads

could anyone help to answer the questions below?thank you! 1.where are the c.g and c.m of a uniform circular disk when it is placed in the outerspace? 2.the c.g of a car tyre is adjusted to coincide with its geometric centre .Explain why this is important. 3.some chopsticks have a metal...

Solved, thank you.

Homework Statement Find the centre of gravity of this system of particles Homework Equations attached image showing diagram http://www.zshare.net/image/7209360586277b98/ The Attempt at a Solution Taking moments about a, 4*0+6*30 = 184 then not sure Any help is greatly appreciated Thanks...

Homework Statement Hi, Imagine a patient lying down on a bed , you want to weigh her without moving her, but the scale can only support the pair of legs of the bed at one end - or the pair at the other end , but not simultaneously. So he puts the scale at point X (the pairs of bed legs...

Homework Statement Hi, Imagine a patient lying down on a bed , you want to weigh her without moving her, but the scale can only support the pair of legs of the bed at one end - or the pair at the other end , but not simultaneously. So he puts the scale at point X (the pairs of bed legs...

may i know what is the difference between centroid,centre of gravity and centre of mass of a body?is it necessary that all the points coincide?

Hi, hope someone can help. I need to find the centre of gravity of a car (x,y and Z). I know the length of the car (5.390m) the distance between the axils (3.116m) and the height of the car (1.515m) I also no the loading on the fronat axil (151.5 N) and the rear axil (111.9 N) and the total mass...

Can anyone tell me that if centre of mass and load centre of gravity of a heavy vehicle doesn't concide,what vl be its effect on vehicles acceleration?

Hi all. I was presented today with a question that I think I know the right answer to but I just want to confirm it. Imagine that a cylinder is removed from the earth, the cylinder being inside the earth, like the height of the cylinder is the diameter of the earth. The cylinder goes right...

Homework Statement This is the case: We going to decide the centre of gravity to a flagstaff with length 10 m We saved up the flagg staff in the thick end. We then need to use a vertical force F in the thin end to keep the flagstaff in horizontal balance. We then saves up the flagstaff in...

i am presently working on a model hovercraft(prototype).The problem with which i am stuck is that the power supply(battery) i am using weighs around 2.5 kg.My lift motor is to be placed on the center of the hull as it is a rectangular one.Because of this i have to place the battery on one of the...

Hi All, If I have block measuring 2m wide by 2m high and 3m long sat on the ground which has a centre of gravity 0.3m from the base how can I calculate the force required to cause the block to topple over. I am trying to calculate wind speed(force) required and how much effect Cog has...

Homework Statement Three uniform rods OA, OB, and OC, each of mass 3m and length a, lie along the x, y and z axes, respectivley. Show that the inertia matrix relative to Oxyz is Io = 2ma^2 \left(\begin{array}{ccc}1&0&0\\0&1&0\\0&0&1\end{array}\right) Determine the inertia matrix with...

consider a symmetrical solid body. we say its centre of mass is at its geometric centre. that is, for uniform density we've taken mass to vary exactly as volume. now when the same body is taken from a place of gravitational field A to gravitational field B. say from the Earth to jupiter, this...

Homework Statement A small ball of mass m is dropped at a height of 50 metres. At the same time, a second ball with twice the mass of the first one is launched at an initial velocity of 10m/s from the ground. Where is the centre of gravity in this system? Homework Equations The...

Homework Statement I'm doing a coursework on ''Gender differences in whole body centre of Gravity position using the Reaction Board Method of measurement.'' Homework Equations I want to find out what other methods can I use to find the center of gravity so I can put it in my evluation to...

Homework Statement A uniform disc A of radius 2m is cut as shown in the figure. The cut out is also a disc of radius 1m. O is the centre of gravity of disc A before cutting and O' is its centre of gravity after cutting. Find the distance between O and O' Homework Equations The...

centre of mass There is a mass at a position vector r1 from origin. like wise there are different masses at different r from the origin. the centre of mass is the distance in which the entire mass can be concentrated at some distance R which will give the same EFFECT as that of the...

hello , could anyone explain to me the difference between a.) the centre of mass b.) the centre of gravity much aprreciated =) Cheers

Hi, I would like some clarification on the following. Suppose I have a unit square A, symmetric about the xy plane. In addition to this, suppose that I cut a square B from A so that I am left with a lamina (A - B). Where B is a (1/4) * (1/4) square which is symmetric about the x-axis and lies in...

in a dynamics problem the example in a book shows a circular rod rotating about a pin at the end. Now the author says that the cg of the rod is at a point and he draws an acceleration vector from cg towards the pin and says that it is the normal acceleration and a perpendicular component called...

How to find centre of gravity for a hemisphere shell?? Can someone show me how to calculate centre of gravity for a hemisphere shell??

why do bottles or any other things thrown up with a twist always spin about their centre of gravity? Also if all forces pass through centre of gravity of a rocket in space, it will not rotate , even though there is a net moment about any other point except the cg. why