Center of mass Definition and 916 Threads

Homework Statement Give the X, Y, and Z coordinates of the center of gravty of a half cubical block of uniform density. The diagram below shows how the block was cut. The diagram depicts a cube with sides of length 1 cut diagonally in half. the six vertices are as follows: (0,0,0) (1,0,0)...

[b]1. A composite slab has dimensions of d1=11.0cm, d2=2.80cm, and d3=13.0cm. Half the slab consists of aluminum (density=2.70g/cm^3) and half consists of iron (density=7.85g/cm^3). What are the x coordinate, y coordinate, and z coordinate of the slab's center of mass? There's a figure in...

General Question-- Compuing velocity of a center of mass Homework Statement A ball of mass 0.198 kg has a velocity of 1.47 i m/s; a ball of mass 0.309 kg has a velocity of -0.401 i m/s.They meet in a head-on elastic collision. (a) Find their velocities after the collision. (b)...

http://www.fileden.com/files/2006/11/15/381656/My%20Documents/problem%2013.jpg The figure above shows an arrangement with an air track, in which a cart is connected by a cord to a hanging block. The cart has mass m1 = 0.600 kg, and its center is initially at xy coordinates (-0.500 m, 0 m)...

A stone is dropped at t = 0. A second stone, with twice the mass of the first, is dropped from the same point at t = 250 ms. (a) How far below the release point is the center of mass of the two stones at t = 600 ms? (Neither stone has yet reached the ground.) (b) How fast is the center of...

Hi, sorry stuck again! Here is the problem: A projectile of mass 19.4 kg is fired at an angle of 57.0 degrees above the horizontal and with a speed of 81.0 m/s. At the highest point of its trajectory the projectile explodes into two fragments with equal mass, one of which falls vertically...

Hi there, I have a question about what I'm doing wrong with the following problem: A 45.0-kg woman stands up in a 60.0-kg canoe of length 5.00 m. She walks from a point 1.00 m from one end to a point 1.00 m from the other end. If you ignore resistance to motion of the canoe in the water...

Hi, I've been working on the following question for a little while. I've looked it over several times and I can't find any obvious (to me anyway) errors in my work. Would you please scan it through and let me know if I am correct or, if not, please guide me in the right direction so I can try...

this question has really stumped me. 23 people on a boat rest on water without friction. Each person has an average mass of 70 kg, and the boat itself weighs 10^4 kg. The entire party walks the entire 8 m distance of the boat from bow to stern. How far (in meters) does the boat move? i know i...

The Earth and moon are separated by a center-to-center distance of 3.85x10^8m. The mass of the Earth is 5.98x10^24kg and that of the moon is 7.35x10^22kg. How far does the center of mass lie from the center of the earth? I know you have to use the equation Xcm=m1x1+m2x2/m1+m2 I don't...

I really don't understand the concept of center of mass but i have a conceptual question that i am really not sure about. Where would you expect the center of mass of a doughnot to be located? Why? I mean gut instinct would tell me the center of the doughnut but there is no mass located...

If a particle of mass 5.30 kg is moving east at 10.0 m/s and a particle of mass 18.0 kg is moving west at 10.0 m/s, what is the velocity of the center of mass of the pair? I used the equation Vcm = P/M Vcm = [(5.70)(10) + (15)(10)] / [(5.70)+(15)] Vcm = 10 ms however, it says that...

A 50 kg person at the left end of a 75kg boat is 6 m from shore. The person walks to the other end of the boat 3m away. How far is the person from the shore now? The system center of mass fixed in space so as the person moves right, the boat moves left. I know that the person moves 3 m to...

After finding the center of mass of a pentagon with five equal sides a but one triangle missing, then iam asked to find the CM of uniform square a with one quadrant missing. I dont' really grab the idea of CM, please help..

Please check my answers. A 1200-kg station wagon is moving along a straight highway at 12.0 m/s. Another car, with mass 1800 kg and speed 20.0 m/s, has its center of mass 40.0 m ahead of the center of mass of the station wagon. a)Find the position of the center of mass of the system...

Chapter 7, Problem 56 The drawing shows a sulfur dioxide molecule. It consists of two oxygen atoms and a sulfur atom. A sulfur atom is twice as massive as an oxygen atom. Using this information and the data procvided in the drawing, find the y coordinate of the center of mass of the...

The drawing shows a human figure approximately in a sitting position. For the purposes of this problem, there are three parts to the figure, and the center of mass of each one is shown in the drawing. These parts are: (1) the torso, neck, and head (total mass = 41.5 kg) with a center of mass...

I'm having a hard time with these center of mass problems. The lecture that my professor gave on this wasn't very descriptive. Could someone show me the whole process of finding the center of mass? A uniform plate of height 0.720 m is cut in the form of a parabolic section...

If a particle of mass 5.3 kg is moving east at 10 m/s and a particle of mass 19 kg is moving west at 10 m/s, what is the velocity of the center of mass of the pair? This one should be simple, here is my work: Vcm = (m1v1 + m2v2) / (m1 + m2) (-5.3kg*10m/s + 19kg * 10m/s) / -5.3 + 19 =...

I am having a tough time with this one... Body A of mass 4 kg is moving in the +x-direction with a speed of 15 m/s. Body B of mass 5 kg is moving in the -y-direction with a speed of 8 m/s. What are the x- and y-components of the velocity of the center of mass of the two bodies? How do I relate...

For some reason I can't seem to figure this question out. I get the feeling it's much easier than I'm making it. But here it is: Ball 1, ball 2, and ball 3 have masses 1 kg, 2 kg, and 3 kg respectively, and are initially arranged at x = 1 m, x = 2 m, and x = 3 m respectively. y = 1 m for...

Dave Johnson, the bronze medallist at the 1992 Olympic decathalon in Barcelona, leaves the ground at the high jump with vertical velocity component 6 m/s. How far does his center of mass move up as he makes the jump? I've got nothing for info how do I solve this?

Lets say I have some convex shape defined by a set of points in a clockwise direction. How do I calculate the MOI and the COM?

Can someone explain how center of mass changes? We haven't actually learned about the center of mass, so I don't know how to even approach this homework question. ok so here's the question: If you stand with your back against a wall, you find you can not bend over to pick something up...

On earth, under the influence of gravity, when an object is spun/rotated and then released, it will find its center of mass and rotate around that as it falls. So, if you spun a very straight uniform stick at its exact center of mass say 1 meter off the ground and then released it, it will drop...

A big olive (m = 0.11 kg) lies at the origin of an xy coordinate system, and a big Brazil nut (M = 0.82 kg) lies at the point (0.99, 2.1) m. At t = 0, a force Fo = (4i + 4j) N begins to act on the olive, and a force Fn = (-4i -3j) N begins to act on the nut. What is the (a)x and (b)y...

A big olive (m = 0.11 kg) lies at the origin of an xy coordinate system, and a big Brazil nut (M = 0.82 kg) lies at the point (0.99, 2.1) m. At t = 0, a force Fo = (4i + 4j) N begins to act on the olive, and a force Fn = (-4i -3j) N begins to act on the nut. What is the (a)x and (b)y...

1) A force F = A/t^2 acts on an object. At time t = t_o its momentum is 0. What is its momentum after a very long time? First I used Newton's second law: dP/dt = A/t^2 Then t^2 dP = A dt dP = A/t^2 dt And I took the integral of both sides, the left from 0 to P, the right from t_o to t...

centroid ("center of mass") of cardioid I'm having trouble calculating the centroid of the cardioid (and various other polar-coordinate-defined lamina), i.e., r = 1 +\cos \theta I can see how it's symmetric over the x-axis, so y-bar is zero. So to calculate x-bar, then I do...

A 1470 kg automobile has a wheel base (the distance between the axles) of 2.70 m. The center of mass of the automobile is on the center line at a point 1.20 m behind the front axle. Find the force exerted by the ground on each wheel. A bit confused here. Were going to use the sum of the...

:cry: been wonderin' for an hour already nac somebody please answer if there is a difference between the center of gravity and the center of mass if there is, what is it?

Finding the center of mass of a two dimensional object of constant density is a question that frequently occurs on my Mu Alpha Theta tests. I know of a long way to find it which I'll show in a moment using single integrals. I'm wondering if using double integrals can shorten this considerably...

Does the center of mass between the Earth and the moon follow an elliptical path around the sun? Does it wobble a little bit?

We have a block of un-uniform density of mass m suspended by two massless wires, against gravity. The left wire makes an angle phi_1while the right angle makes an angle phi_2. The block has length L. They want me to find the center of mass. THis is what I've done: We have tension in the wires...

hi,Center of mass is supposed to be this one particular point that behaves as if the whole body mass was located there. Since human body is not rigid does its center of mass change when for example person raises his/her arms or leans forward? thank you

hi, I am finding the center of mass in this problem. I have it as an attachment. Please take a look, thanks.

Hey, There is a question in my textbook that I don't understand the answer too. THey show a diagram of a baseball bat and say if the baseball bad it cut at the location of its center of mass, do the two pieces have the same mass? They say no, the piece with the handle will have less mass than...

To determine the location of his center of mass, a physics student lies on a lightweight plank supported by two scales L = 3.90 m apart. http://forums.cramster.com/answer-board/image/b34f433113a2369128cc61ed29304ffd.jpg If the left scale reads 250 N, and the right scale reads 106 N, find the...

hey everyone, I am stumped as to finding the x and y coords of the center of mass of this picture. it is supposed to be a uniform sheet of steel in increments of 6. please help, i have an exam tomorrow.

Hello A cable is attached at two (nonemoving)fixpoints. Now the cables midpoint is pulled downward, thereby destroying the catenary curve. Question: How will the cables center of mass (CM) move: op, down or stay fixed? My thoughts: I find it intuituitive that the CM will assume the...

I am trying to understand this example of finding the center of mass of a uniform solid cone. please refer to the attached figure. We know for obvious reasons that the center of mass will be on the z-axis. I will be referring to the integral that my book used to find the center of mass which is...

I don't understand how to approach this question, I'm lost in where energy gets involved. Any help would be appreciated :smile: A 110kg person is traveling at 3 m/s on a frictionless surface toward a wall, then stops themselves by pushing against the wall. During the push, the person's...

ok here is the problem <br>A uniform meter stick of mass M has a half-filled can of fruit juice of mass m attached to one end. The meter stick and the can balance at a point 33.0 cm from the end of the stick where the can is attached. When the balanced stick-can system is suspended from a...

I am having difficulty solving the first part of this problem. I have tried to many ways to find the ratio of m_a/m_b but I can't seem to get the correct answer. Can someone point me in the right direction. Thanks.

The ratio of the mass of the Earth to the mass of the moon is 77.6. Assume that the radius of the Earth is about 6404.0 km and that the distance between the center of the Earth and the moon is 380604.0 km. Determine the distance of the center of mass of the earth-moon system from the center of...

I'm sitting in my car on a flat road while it is stationary. The only forces acting on my car for this exercise are gravity and the normal force, which add up to give no net external force on my vehicle and me. My center of mass is at a fixed point somewhere in the vehicle, and according to the...

1. The ratio of the mass of the Earth to the mass of the moon is 77.6. Assume that the radius of the Earth is about 6404.0 km and that the distance between the center of the Earth and the moon is 380604.0 km. Determine the distance of the center of mass of the earth-moon system from the center...

Hi, Ok so we were told to find our center of mass using the reaction board method, but modified. We just do a pushup position with our hands on a scale, I have a electronic one and toes on the floor. My values obitained are: weight=68kg the scale reading in a pushup position=48.9kg...

A dog, with a mass of 12.0 kg, is standing on a flatboat so that he is 25.5 m from the shore. He walks 6.0 m on the boat toward the shore and then stops. The boat has a mass of 46.0 kg. Assuming there is no friction between the boat and the water, how far is the dog from the shore now? i used...

A 44 kg woman leaps vertically from a crouching position in which her center of mass is 48 cm above the ground. As her feet leave the floor her center of mass is 81 cm above the ground; it raises to 124 cm at the top of her leap. What average force was exerted on her by the ground during the...