Conservation of momentum Definition and 751 Threads

[SOLVED] Conservation of Momentum problem-don't understand the solution Homework Statement The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of 0.025kg and is moving along the x-axis with a velocity of 5.5m/s. It makes a collision with puck B, which...

Homework Statement A 62.7-kg woman contestant on a reality television show is at rest at the south end of a horizontal 141-kg raft that is floating in crocodile-infested waters. She and the raft are initially at rest. She needs to jump from the raft to a platform that is several meters off the...

Homework Statement (understood: two air hockey pucks make contact--the x-axis is the table) Puck A has a mass of .025 kg and is moving along the x-axis with a velocity of +5.5m/s. It makes a collision with puck B, which has a mass of .05kg and is initially at rest. The collision is NOT head on...

OK this is about a bullet hitting a block on wheels (inelastic collision), no friction or energy losses in the problem. I'm trying to find Velocity of the system after collision Why is it that if I use conservation of momentum I get a different answer of V than if I used conservation of...

[SOLVED] Conservation of Momentum and Thrown Objects As part of our physics class, we've been given lots of problems typically solved by taking into account the law of conservation of momentum. I've had little-to-no trouble solving them, but one problem in particular is driving me nuts...

Homework Statement What can be said about the nature of collisions (elastic/inelastic) and the conservation laws that can be applied if...? Collision 1: Total kinetic energy before collision: 0.00503 J Total kinetic energy after collision: 0.00245 J Total momentum before: 0.0322 kg m/s...

Homework Statement A bullet of mass m and speed v passes completely through a pendulum bob of mass M. The bullet emerges with a speed of v/2. The pendulum bob is suspended by a stiff rod of length L and negligible mass. What is the minimum value of v such that the pendulum bob will barely...

The momentum of an apple falling to the ground is not conserved because the external force of gravity acts on it. But the momentum is conserved in a larger system. Explain? I am confused because gravity is the external force acting upward, so what's the force that is acting up on the apple...

Homework Statement An open top railroad car (initially empty and of mass M.) rolls with negigible friction along a straight horizontal track and passes under the sprout of a sand conveyor. When the car is under the conveyor, sand is dispensed from the conveyer in a narrow stream at a steady...

Homework Statement A man holding a gun ((mass of man)+(mass of gun)+(mass of bullet)=60kg)) skates on frictionless ice at an initial speed of +2 m/s and fires a 100 gram bullet with a speed of +500 m/s from the gun. a) What is the speed of the man after firing the gun? (be sure to include...

Homework Statement 2 automobiles of equal mass approach an intersection. One vehicle is traveling with a velocity of 13.0m/s toward east and other is traveling north with a speed of v_2i . The vehicles collide at the intersection become stuck together and leave parallel skid lines at an...

Homework Statement A spaceship of mass 2.00×10^6 kg is cruising at a speed of 6.00×10^6 m/s when the antimatter reactor fails, blowing the ship into three pieces. One section, having a mass of 4.60×10^5 kg, is blown straight backward with a speed of 2.10×10^6 m/s. A second piece, with mass...

Homework Statement We know that momentum is supposed to be conserved in this collision. We observe, however, that the pucks eventually come to a stop, at which point they have zero momentum. Give a solid explanation (using the law of conservation of momentum) for this apparent violation of the...

For the following problem: http://tinyurl.com/28xuwh The answer is a. What I understand is: The momentum of a system of two particles is conserved when the system is isolated. Can anybody explain to me, why a is the correct answer?

Homework Statement A 17.00kg sphere is hanging from a hook by a thin wire 3.60m long, it is free to swing in a complete circle. Suddenly it is struck horizontally by a 6.00kg dart that embeds itself in the sphere. What is the minimum initial speed of the dart so the combination makes a complete...

An electron collides elastically with a stationary hydrogen atom. The mass of the hydrogen atom is 1837 times that of the electron. Assume that all motion, before and after the collision, occurs along the same straight line. What is the ratio of the kinetic energy of the hydrogen atom after the...

A 9700 kg boxcar traveling at 18 m/s strikes a stationary second car. The two stick together and move off with a speed of 8.0 m/s. What is the mass of the second car? p=ma is 21825 m/s the answer? sig figs?

Question: A shell is fired with an initial velocity of 20 m/s at an angle of 60° above the horizontal. At the top of its trajectory, the shell explodes into two fragments of equal mass. One fragment, whose speed immediately after the explosion is zero, falls vertically. How far from the gun...

a runaway toboggan of mass 8.6 kg is moving horizontally at 23 km/h. as it passes under a tree 15 kg of snow drop onto it. ___ isn't the ans 13.88 if we use conservation of momentum equation (.5mv1 initial + 0.5mv2 initial) = (0.5mv1 final + 0.5 mv2final) --> (0.5 (8.6) (23^2)) = (0.5...

Can someone explain to me the vector nature of momentum in a case where two objects collide and stick together?

Homework Statement A pendulum consists of a 0.5 kg bob attached to a string of length 1.6 m. A block of mass m rests on a horizontal frictionless surface. The pendulum is released from rest at an angle of 53° with the vertical and the bob collides elastically with the block. Following the...

Homework Statement A hockey puck B rests on a smooth ice surface and is struck by a second puck A, which was originally traveling at 40.0m/s east and is deflected 30 degrees from its original direction. Puck B acquires a velocity of -45 degrees with the original velocity of A. THe pucks have...

Homework Statement THe expanding gases that leave the muzzle of a rifle also contribute to the recoil. A .30 caliber bullet has a mass of 0.00720kg and a speed of 601 m/s relative to the muzzle when fired from a rifle that has a mass of 2.50kg. The loosely held rifle recoils at a speed of...

Homework Statement Two carts, each with a mass of 1kg, are moving along a track towards one another. One cart is moving to the right at 4m/s and the other is moving to the left at 2m/s. Write down the momentum vector for each cart in column vector notation. Add these together to get the...

If you have a proton and an anti-proton traveling in the same direction with momentum from A to B but during the flight time they become attracted due to their opposite charges and annilhilate, the momentum I would guess is transferred to the resulting unstable K particles mesons etc, which, as...

I have two similar questions. 1. Show the relationship between invariancy of hamiltonian to translation and conservation of momentum. (In QM) 2. Show the relationship between invariancy of hamiltonian to rotation and conservation of angular momentum. (In QM) I have no idea how to prove this...

Homework Statement there is this requirement in my textbook that states: show an understanding that, whilst momentum is always coneserved in interactions between bodies, some change in kinetic energy usually takes place. Can anyone explain to me why this is so? If the momentum of a...

For my physics assignment i have a question on conservation of momentum that i am completely unsure of and have heard mixed answers to from teachers and fellow students. Here is the question and can ai have nice detailed answers please. Thanks in advance. Section A - conservation of momentum...

Problem: A 20.0 kg wood ball hangs from a 1.50 m-long wire. The maximum tension the wire can withstand without breaking is 300 N. A 0.900 kg projectile traveling horizontally hits and embeds itself in the wood ball. What is the largest speed this projectile can have without causing the cable...

Homework Statement Tony (45kg) coasts on his bike (5kg) at a constant speed of 1 m/s, carrying a 5kg pack. Tony throws his pack forward, in the direction of his motion, at 5 m/s relative to the speed of bike just before the throw. What is the bike speed immediately after the throw...

The law of conservation of momentum has never been observed to be violated.In quantum mechanics conservation laws relate to symmetries.So is the existence of the law of conservation of momentum due to the fact that a symmetry exists, or does a symmetry exist because the law of conservation of...

Homework Statement so, i have a problem. see the pic http://img255.imageshack.us/img255/4628/aughhm9.png the question is. if we have, for example 10 balls standin like that, if we move the ball which is on the right, only one will move, the left one. if we move two of them from the right...

Hey Everyone, I've just signed up for this forum because I'm currently taking a correspondence course and there's one problem in particular that I'm having problems with and there isn't really anybody I can ask. Can anybody here help me with this? Two spacecraft s from...

Homework Statement A .2kg block from rest slides down a frictionless ramp that is .5 meters long. The block lands on a flat surface and moves towards another block that is 1.4 meters away. The other block is not moving and it has a mass of .8kg. The Miu (sp?) of the flat surface is .1...

Homework Statement "Relative" is an important word. Block L of mass mL = 1.90 kg and block R of mass mR = 0.500 kg are held in place with a compressed spring between them. When the blocks are released, the spring sends them sliding across a frictionless floor. (The spring has negligible mass...

Homework Statement In an inelastic collision, momentum is conserved but kinetic energy is not conserved. How can this be true in the situation where a car runs into the back of a stationary truck, since after the collision neither are moving and so cannot have momentum? Homework Equations...

I have a fundamental question regarding conservation of momentum (not homework). So if we have a system of 2 balls, identical in size and weight, one of which is initially stationary until hit by the other ball. We have the following: m1v1 + 0 = 0 + m2v2 or v2 = v1 and therefore...

Homework Statement So I have one of these trippy toys http://www.spacehall.com/shop/images/AstroBlaster.JPG ,[/URL] and have a question. Basically the way that it works, is that all the balls bounce, and the top one that isn't secured on rockets off very high while the others are...

First of all I would like to explain that this is the last question I need to answer to complete an assignment that consisted of 20 University of Waterloo SIN Contest questions. This question is from the 1999 SIN contest. I would ask my Physics teacher for help but it is now the weekend and the...

Can someone help me to prove the law of conservation of momentum using an example?

The issue of the New York Times had a mass of 5.4 kg. Suppose a skateboarder picks up a copy of this issue to have a look at the comic pages while rolling backward on the sakteboard. Upon realizing that the New York Times doesn't have a "funnies" section, the skateboarder promptly throws the...

The larges grand piano in the world is really grand. Built in London, it has a mass of 1250 kg. Suppose a pianist finishes playing this piano and pushes herself from the piano so that she rolls backwards with a speed of 1.4m/s. Meanwhile, the piano rolls forward so that in 4.0s it travels 24 cm...

An object, with mass 16 kg and speed 19 m/s relative to an observer, explodes into two pieces, one 4 times as massive as the other; the explosion takes place in deep space. The less massive piece stops relative to the observer. How much kinetic energy is added to the system during the explosion...

A barge with mass 1.50 X 10^5 kg is proceeding downriver at 6.2 m/s in heavy fog when it collides with a barge heading directly across the river (see the poorly drawn image, in link)http://img.photobucket.com/albums/v638/ravenatic20/untitled4.jpg ... The second barge has mass 2.78 X 10^5 kg and...

hello i have a question... I have two objects going towards each other (in 2 dimensions) I know the mass, initial speed and direction... I want to know how to figure out what the final speed and direction of the two objects will be after a collision assuming there is not friction...

Heres the question: A car of mass m = 1200 kg and length l = 4 m is positioned such that its rear end is at the end of a flat-top boat of massM = 8000 kg and length L = 18 m. Both the car and the boat are initially at rest and can be approximated as uniform in their mass distributions and the...

Hi, could you please help me with following: ---------- two boats traveling in opposite direction with speed v1 and v2 when they are passing by they interchange a parcel of same mass M=50kg as a result second boat stops and first boat continue traveling in same direction with speed...

Here's the problem: An atom of mass 2mp with an anitial velocity vo undergos an elastic collision with an atom at rest with mass 3mp. After the collision, the first atoms trajectory deviates 30 degrees from the initial. What angle does the second atom travel from the first atoms initial...

How are inertia (Newton's first law) and the law of conservation of linear momentum related? Also, how does Newton's first law for rotation (rotational inertia or moment of inertia) related to the law of conservation of angular momentum?

I'm not sure if i did this problem correctly. Could someone check it over. A 730-N man stands in the middle of a frozen pond of a radius of 5.0 m. He is unable to get to the other side because of a lack of friction between his shoes and the ice. To overcome this difficulty, he throws his 1.2...