Conservation of momentum Definition and 757 Threads

Homework Statement A 238U nucleus is moving in the x direction at 4.5*10^5 m/s when it decays into an alpha particle 4He and a 234Th nucleus. 1.) If the alpha particle moves off at 34degrees above the x-axis with a speed of 2.0*10^7 m/s, what is the speed of the thorium nucleus? 2.)What...

Homework Statement A hollow box, mass M, rests on a frictionless surface. Inside the box is a spring, spring constant k, attached to one wall. A block, mass m, is pushed against the spring so that it is compressed an amount A. a. If after leaving the spring the block has velocity of...

Homework Statement A tennis ball of mass m is held just above a basketball of mass M. Their centers are vertically aligned. Both are released at the same moment, and fall a distance of h until the basketball hits the ground, which it rebounds from elastically, and then undergoes an...

Homework Statement a) At t=1 second, a 0.5 kg cart is at x=0.5 m, traveling at 0.5 m/s. At t=3 seconds, the cart is at 1.4 m, traveling at 0.4 m/s. What is the acceleration due to friction, the frictional force and the work done by friction? What is the change in kinetic energy of the cart...

Homework Statement A 56-kg woman contestant on a reality television show is at rest at the south end of a horizontal 147-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 An object at rest explodes into three pieces. Two of them are equal in mass and break off at an angle of 85.3° to each other, both with a speed of 33.2 m/s. The last piece has 4 times as much mass as each of the other pieces. What is the magnitude of the velocity of the last...

a) At t=1 second, a 0.5 kg cart is at x=0.5 m, traveling at 0.5 m/s. At t=3 seconds, the cart is at 1.4 m, traveling at 0.4 m/s. What is the acceleration due to friction, the frictional force and the work done by friction? What is the change in kinetic energy of the cart? b) If a cart of mass...

Homework Statement A spherical asteroid of mass m_0 is moving freely in interstellar space (no external forces) with velocity v_0 . It runs into a dust cloud whose uniform density is \rho_d Assume that every particle of dust that hits the asteroid sticks to it and that the asteroid remains...

A cat stands on a skateboard that moves without friction along a level road at a constant velocity of 2.00 m/s. She is carrying a number of books. She wishes to stop, and does so by hurling a 1.20 kg book horizontally forward at a speed of 15.0 m/s with respect to the ground. (a) What is the...

Conservation of momentum problem and kinematics!? Hi, I've been working on this problem for the last three hours, I hope someone can help. In fact, the solution I keep getting is double the correct answer (the answers are in the back of the book, but not the how). An 80 kg astronaut is...

Homework Statement A nucleus originally at rest splits into two fragments of unequal mass. The fragment with smaller mass has a larger 1.momentum 2.speed 3.Kinetic energy A. 1only B. 3only C. 1&2 only D. 2&3 only E. 1,2 &3 The Attempt at a Solution well, i can figure out the...

Homework Statement Tarzan mass M swings from a vine from rest at height H. At the bottom of the arc he picks up Jane of mass m in a perfectly inelastic collision. They reach a vertical height h. How far vertically above h is H?Homework Equations Pi = Pf R = \Sigmamr/\Sigmam The Attempt at a...

If a car crashes into a solid unbreakable wall, how is momentum conserved (I know it must be). To me, it seems that the car will just "stop" and the wall will not move. If momentum is to be conserved, the car should either move through the wall, (which doesn't happen) or the wall should move...

A car with mass M1,with a box upon it of mass M2 moves with constant speed v.(there is no friction).If the box is shot vertically with speed v1 relative to the car then the final speed of the car will remain orizontial?or it will be floating downwards in relation to an observer that is at rest?

The law of conservation of momentum states that all momentum is conserved in a collision. Momentum is defined as p = mv. When a collision occurs, most of the time a lot of velocity is lost and most of the mass remains. For example, a fast moving trolley runs into a brick wall, after hitting the...

Okay here goes... I'm having a hard time trying to logically understand how momentum is conserved for inelastic collisions, even though energy is lost. Since energy is lost (in the form of kinetic energy) how can the initial momentum be the same as final momentum. I know I may be confusing...

Homework Statement This question is related to an in-class experiment. The lab involves bouncing a ball and using a motion sensor which creates a graph representing the motion. The question is: Is the principle of conservation of momentum violated in this collision (the ball colliding with...

I'm not very confident with my final answer for this question, wondering where I might have gone off track... 2 spacecraft are thrust apart, what was the original speed of the 2 craft when they were linked together? Mass spacecraft 1 = 1.9 x 10^4kg Velocity spacecraft 1 after...

Homework Statement In a conservation of momentum lab, two objects were collided together, velocity before and after the collision were measured. The problem asks how the momentum compares before and after I'm really confused about the variables here... In the hypothesis it asks to...

I developed a propulsion system...a propulsion system which has no interactions from the environment...i.e the force in completely internal. The principle that I used was that when you propel a mass (suppose a ball) on a heavy body and make it hit the heavy body, the impulse that was given to...

I reading a physics book on my own right now and I appear to be stuck. The problem is as follows: A 10 m long glider with a mass of 680 kg (including the passengers) is gliding horizontally through the air at 30 m/s when a 60 kg skydiver drops out by realesing his grip on the glider. What is...

The law of conservation states that if two objects have a net force of zero, and if they were to collide with one another, the change in momentum of one object is equal in magnitude, but opposite in direction, to the change of momentum of the other object. Knowing this, what would happen if...

Homework Statement An empty freight car of mass M starts moving from rest with a constant applied force F0. At the same time, coal runs into the car at steady rate b from a hopper above the car at rest along the track. Calculate the velocity of the car as a function of time. GIVEN: M =...

If say, a object such as a ball with velocity v m/s and mass m kg collides with a stationary solid wall, and the ball rebounds back with a velocity of v' m/s while the wall remains stationary, is momentum conserved? Since the wall is stationary, I would assume that the initial and the final...

If you throw a baseball up on the moon, and it comes down, how is momentum conserved?

Homework Statement A 1200 kg car moving eastward at 8 m/s approaches an intersection where it unfortunately collides with an 1800 kg car going southward at 6 m/s. If they stick together, how fast do they move after the collision? The answer is 4.82 m/s Homework Equations a^2+b^2=c^2...

I’m confused about conservation of momentum. I remember learning that the momentum before a collision is the same as after it: Pinitial = Pfinal . So I do that for a mass M1 colliding with another mass M2 that’s initially at rest, M1 x V1initial + 0 = M1 x V1final + M2 x V2final...

Homework Statement If two objects of mass m1, m2 and velocity u1, u2 traveling along the same path collide and combine the total momentum before collision is equal to the total momentum after collision. But if one object collides at an angle of say 30o to the other how will this affect your...

So, here is my data: TRIAL 1 TRIAL 2 TRIAL 3 MASS OF CAR 1 7.5 N 7.5 N 7.5 N MASS OF CAR 2 7.5 N 7.5 N 7.5 N TIME FOR CAR 1 (s) 8.63 8.31 9.40 TIME FOR CAR 2 (s) 7.50 10.72 8.78 DISPLACEMENT FOR CAR 1 (m) 305.00 365.00 348.60 DISPLACEMENT FOR CAR 2 (m) 387.50...

I was thinking the other day about how conservation of momentum works in terms of a closed system consisting of a child and a swing and gravity. How does the child start moving on the swing? Does he need to push against the air to start going? Where does he extract the momentum from? If he...

I apologize if this is a silly question, but i swear it is not a homework assignment (or, it may be to someone somewhere, but that is no the reason i am interested in it). If you have a number of pins suspended through vertical platters such that they just touch, they will exhibit the...

I just learned that, in elastic collisions, the total momentum in the system is preserved while a certain amount of kinetic energy is lost. I know that kinetic is energy may be lost in the form of heat or sound. Isn't the same energy responsible for keeping the two objects in motion and...

Wow, I should really know this but I can't think of it. Let's assume (totally assume, haha) that I have a flanged cone with a flow through it. The flange is of course going to have a reaction force on it based on the flow. I know that summing forces, I have forces at the inlet and outlet (pA)_1...

A 10,000kg space shuttle moving east at 3000km/h wishes to change its course by 10°. It does so by ejecting an object at a speed of 5000km/h (South). Calculate the mass of the ejected object. Equations Momentum before = momentum after momentum is mass x velocity I am honesty pretty...

I had a squash ball going down a ramp, which collided with another squash ball of a slightly different mass at the bottom of the ramp. They then both went off the end of the ramp into a sand pit. However they both fell in the sand pit at different lengths, and so it appears that it is not a...

Homework Statement a robotic space probe of mass 7600 KG is traveling through space at 120 m/s. Mission control determines that a change in course of 30.0 degrees is necessary and instructs the probe to fire rockets perpendicular to its direction of motion. If the escaping gas leaves the...

Here's some homework True/False questions I got for homework, need some help making sure my answers are right. True/False: 1)In a collision between a laight hydrogen molecule and a heavy water molecule, the momentum lost by one molecule is exactly the same as the momentum gained by the other...

Homework Statement The frictionless track is made of a straight horizontal section and a quarter-circle with radius R = 5 m. A 1 Kg lump of putty is thrown toward the stationary 4 Kg block, and the block starts to slide with the putty stuck on it after the collision. If the normal force acting...

Homework Statement You are shooting cannonballs from a cannon. To achieve the maximum range of the ball, would you be better off fastening the cannon to the ground or letting it be free to recoil, or wouldn't it matter? Explain your reasoning Homework Equations Conservation of momentum...

We are currently learning about conservation of momentum and conservation of energy in my intro physics class @ berkeley. What must be true for me to use one of the other or both (I'd appreciate some common examples of when to use/when not to use them too, if possible)

Homework Statement You have been asked to design a “ballistic spring system” to measure the speed of bullets. A bullet of mass m is fired into a block of mass M. The block, with the embedded bullet, then slides across a frictionless table and collides with a horizontal spring whose spring...

Can someone care to explain the mathematics behind it? i initally thought that she'd go the full 15m, but because the cart does move slightly to the left as she runs it's just a bit less than the full 15m, can someone give me the maths to it...

If you are in a moving train and the train stops instantly would you hit the object ahead of you at the exact same speed the train was traveling or would there be some slight deceleration due to friction? Wouldn't the friction your body experiences with the seat you are sitting on and the air...

Homework Statement A 22.00 lead sphere is hanging from a hook by a thin wire 3.90 long, and is free to swing in a complete circle. Suddenly it is struck horizontally by a 4.50 steel dart that embeds itself in the lead sphere. What must be the minimum initial speed of the dart so that the...

Homework Statement Homework Equations 1.) m1*v1 + m2*v2 = m1'*v1' + m2'*v2' Where the ' denotes the velocity/mass after the event/whatever. 2.) 0.5m1(v1)^2 + 0.5m2(v2)^2 = 0.5m1'(v1')^2 + 0.5m1'(v1')^2 The Attempt at a Solution I know its a conservation of momentum style of problem...

Homework Statement Most geologists believe that the dinosaurs became extinct 65 million years ago when a large comet or asteroid struck the earth, throwing up so much dust that the sun was blocked out for a period of many months. Suppose an asteroid with a diameter of 2.0km and a mass of...

Homework Statement A 10.0 g marble slides to the left with a velocity of magnitude 0.500 m/s on the frictionless, horizontal surface of an icy, New York sidewalk and has a head-on elastic collision with a larger 30.0 g marble sliding to the right with a velocity of magnitude 0.150 m/s Find...

Homework Statement A projectile with a mass of 20 g has an initial horizontal velocity of 100 m/s when it hits and stops in a wood block of mass 0.402 kg. The block is sitting on a horizontal frictionless surface and is attached to a massless spring, initially relaxed, with spring constant 143...

A block of mass M is resting on a horizontal, frictionless table and is attached to a relaxed spring of spring constant k. A second block of mass 2M and initial speed vo collides with and sticks to the first block. Develop expressions for the following quantities in terms of M, k, and Vo. a)...

Homework Statement A 75-kg man sits in the back of a 120-kg canoe that is at rest in a still pond. If the man beings to move forward in the canoe at .50m|s relative to the shore, what happens to the canoe? Homework Equations The equation they gave me is m1v1+m2v2 = m1v1'+m2v2' I don't...