Momentum and energy Definition and 161 Threads

Homework Statement This is my 'carrying out a practical investigation' assignment for Maths. I've attached the coursework (what I've wrote up to now) and my main concern is whether I've got the right differential equation to find 3 new velocity values throughout the pendulum trajectory...

Hi all - apologies, I'm starting a new thread here for something buried at the end of another thread - but I think the topic of that thread had changed sufficiently to warrant a more succinct top-level post. Thanks very much to PeterDonis for his very useful answers in the previous thread...

Two chunks of rock, each having a mass of 1.00 kg, collide in space. Just before the collision, an observer at rest in the reference frame of a nearby star determines that rock A is moving toward the star at 0.800 c and rock B is moving away from the star at 0.750 c . If the rocks stick...

If i have the momentum of the particle, could I measure their energy ? I'm talking about particles in a beam, they are moving in a relativistic speed.

Homework Statement A 10kg block moving at 1 m/s hits another 10kg stationary block. Those two blocks (now stuck together) collide with another 10kg stationary block. What percent of the original energy is lost after the two collisions? Homework Equations m1v1 + m2v2 = (m1+m2)v3 Kinetic energy...

1. Homework Statement A small mass m slides without friction on a surface making a quarter-‐circle with radius R, as shown. Then it lands on the top surface of a cart, mass M, that slides without friction on a horizontal surface. (In practice, this cart could be a slider on an air-‐track.)...

Homework Statement Homework Equations et Em and pm be the energy and momentum of the mass m after the collision. Let p and p' be the momentum of mass M before and after the collision. From conservation of 4 momentum: \begin{bmatrix}E+m \\ p\end{bmatrix}=\begin{bmatrix}E_m+E' \\...

I have some understanding of Liner Energy Transfrom (LET), but when I compare it with other terminologies such as momentum, then it gets little contradicting. For example, I know that if talk about particles and ions, then a gold ion (AU) has much higher LET than an Iron particle (Fe). And...

Homework Statement A .01kg bullet is fired into a 1.2kg block hanging from a 1m wire. The bullet exits the block with a speed of 200m/s and the block swings to a height of .2 meters. What is the original velocity of the bullet? What percentage of the original energy of the bullet is no longer...

Homework Statement Homework Equations Conservation of liner and angular momentum H1=H2 r x M1V1= r x M2V2 G1=G2 M1V1=M2V2 The Attempt at a Solution I've gotten an equation for the velocity of the block and clay after the impact, and I also know that when the block reaches the highest point...

Homework Statement Two identical particles of mass m travel towards each other at speed v; they combine and form a single new particle. By employing conservation of momentum and conservation of energy, what is the mass of this new particle in Homework Equations Relativistic momentum and total...

Homework Statement Okay there is 2 boxes. One mass has a spring attached to it. They undergo a collision. The spring then has a constant of 600N/m. M 1 = 1kg Vi1 = 4m/s Vf1 = 3m/s M 2 = 2.10kg Vi2 = 2.50m/s Determine Vf of M 2 and x value on impact. 2. Homework Equations The Attempt at a...

Homework Statement (a) A proton at rest has energy Eproton = mprotonc2 ≈ 938 MeV. (Its momentum is zero). The protons which circulated inside the Fermilab Bevatron had energies close to 1000 GeV (1GeV = 1000 MeV). What value of γ did a Tevatron proton have? (b) Somehow a Bevatron proton...

Homework Statement The masses of blocks A and B are 2 kg and 3 kg, respectively. Block A slides to the right on the smooth surface and strikes the spring attached to stationary block B. The spring deforms during the collision process. What quantity do the blocks have in common at the instant...

How can you determine if energy was conserve in a momentum problem? Let's say a small mass "m" hits a larger stationary mass "5m" where the smaller mass "m" flies bounces upward and the larger mass "5m" bounces in a negative downward direction. So from them bouncing off each other I know that...

Homework Statement Cross sectional area: 4.5x10^-2 m Speed: 3.5ms-1 Density of sea water: 1030 kg m-3 Calculate the mass of water propelled backwards in 1 s. Homework EquationsThe Attempt at a Solution Could someone just guide me through it, maybe give me a starting point like which equation...

Homework Statement A spring (k=4200N/m) and box A (mA=120kg) are on a frictionless incline, as shown below . Box A is pressed against the spring such that it is compressed 1.0m, and then released. Box A then hits, and sticks to box B, 1.0m farther up the ramp from the uncompressed position of...

Homework Statement [SIZE=13px][FONT=Helvetica]Q: A 3.000u object moving to the right through a laboratory at 0.8c collides with a 4.000u object to the left of the laboratory at 0.6c. Afterward, there are two objects, one of which is a 6.000u mass at rest. A) what are the mass and speed of the...

Hi, I have a problem understanding the particle in a box (V=0 inside, V=∞ outside), how is it possible that momentum can vary continuously while the energy spectrum is discrete? Aren't they related by E=p2/2m? What I am missing? Thanks!

Homework Statement Mass 2 collides with mass 1 as shown in the image, mass 1 is attached to the stick and it is initially stationary. Consider that the stick is massless and can rotate around the point O. The entire system is on a frictionless table. Which magnitudes are conserved in the system...

Hello, Could someone please provide me with a elastic collision problem where there are two objects one object with an initial velocity=0 m/s and the other object with a final velocity= 0 m/s. Thank you

Hi. I will give you a question I have looked at and then tell you where I am confused. The wavefunction for a particle of mass m is ψ(x) = sin(kx)exp(-iωt) where k is a constant. (i) Is this particle in a state of defined momentum ? If so , determine its momentum. (ii) Is this particle in...

Greetings, I was thinking about bouncing a tennis ball against a wall and how its momentum and kinetic energy would change. I asked a friend of mine and he answered that the ball would transfer more forward momentum than it had to the wall but its kinetic energy would remain constant. How is...

Is the law of conservation of momentum underpinned by the law of conservation of energy?

Homework Statement This is the question show that when one of the steel balls, suspended by strings next to each other (as in a Newton's cradle), is pulled to the left and released, only a single ball recoils to the right under ideal elastic-collision conditions. Assume that each ball has a...

1. A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle '2 = 41° from the neutron's initial direction. The neutron's initial speed is 5.6 105 m/s. Determine the angle at...

Homework Statement Given the parametric equations for a satellite in orbit around a spherical mass find angular momentum L in terms of ε, a, k, m, where k=GMm. Also, find the energy E in the same terms. Lastly, I can only use the equations provided and "fundamental definitions." Homework...

Lets say an archer shoots an arrow or a gun fires a bullet, why is it that a lighter objects (arrow and a bullet) gain larger kinetic energy than the heavier one's? Shouldn't it be Newtons 3rd law: force from the gun powder at the equal distance hence same gained kinetic energy?

Homework Statement An 8.20-kg object is sliding across the ice at 2.34 m/s. An internal explosion occurs, splitting the object into two equal chunks and adding 16 J of kinetic energy to the system. What is the average acceleration of the two chunks if the explosive separation takes...

Homework Statement A pendulum of 9.99 kg is initially at rest, just skimming the floor below. A bullet of mass 0.01kg is fired at the bob. The bullet collides with the bob and embeds itself, after which the pendulum begins to move. The bullet-bob pendulum reaches the maximum vertical...

Homework Statement The K0 meson is an uncharged member of the particle "zoo" that decays into two charged pions according to K0 ---> π+ + π-. The pions have opposite charges as indicated, and the same mass, mπ=140MeV/c^2. Suppose that a K0 at rest decays into two pions in a bubble chamber in...

A model car with a main body mass M and four wheels each with mass m is rolling down a track at velocity v, when it encounters a step of height b, which is less than the wheel radius r. The wheels are rolling, not sliding, and we know the moment of inertia around their respective centers and...

Homework Statement A mass m is laying on a frictionless table and is connected to a mass M with a nonelastic string going through the center of the table. At t=0 the m mass is at a r0 distance from the center of the table, and is moving at a v0 velocity in the tangent direction. Find the...

Homework Statement A man aims his gun vertically and shoots a 0.245 kg target, which is positioned on a telephone pole. The bullet has a mass of 0.055 kg and is traveling at a velocity of 850 m/s upwards just before it hits the target. The bullet passes through the target, emerging with a...

Homework Statement Choose the correct option (only one correct option) Two photons having A.) equal wavelengths have equal linear momenta B.) equal energies have equal linear momenta C.) equal frequencies have equal linear momenta D.) equal linear momenta have equal wavelengths...

Homework Statement A ball of mass m which is projected with speed vi into the barrel of a spring-gun of mass M initially at rest on a frictionless surface, as shown in the attached file below. The ball sticks in the barrel at the point of maximum compression of the spring. No energy is lost...

Homework Statement Two particles A and B each of mass m are attached by a light inextensible string of length 2l .The whole system lies on a smooth horizontal table with B initially at a distance l from A.The particle at end B is projected across the table with speed u perpendicular to...

Hi I was reading a book that introduced momentum and energy in integral forms and I had some confusion regarding what the terms meant. All integrals below are closed integrals For the momentum equation, the result was: F = d(mV)/dt = ∫∫ρ(V[dot]dS)V + ∫∫∫∂(ρV)/∂tdV From product rule...

In a collision the colliding particles will in general have different velocities at different instants of time. Overall this means that the particles can easily cover different distances during a collision and thus have different amounts of work done on them. My question is: Will the difference...

Hello guys, The question is: What is the momentum, in conventional SI units, of a proton of momentum 685 MeVc-1? So, I tried two methods which yielded slightly different answers, both proximate to the actual answer (3.66 x 10-19)What I first tried to do was to rearrange: ρ=γm0v To find the...

Homework Statement Hi. Just look at the picture, I will explain it: It says that a bullet impacts the rod as you can see (in the center of mass forming a 30 degree angle with the horizontal and keeps inside the rod) with a speed of: 25m/s. The bullet has a mass 0.1Kg, the rod 0.9Kg and the...

We know that the reason energy and momentum are conserved is b/c of Noether's theorem...time translational invariance implies energy conservation and space translational invariance implies momentum conservation. Now in a curved spacetime you can still form conserved quantities - energy and...

Homework Statement A 1.00kg block is attached to a horizontal spring with spring constant 2500N/m. The block is at rest on a frictionless surface. A 10g bullet is fired into the block, in the face opposite the spring, and sticks. a. What was the bullet's speed if the subsequent...

Homework Statement Suppose you have two bodies (assume a unit mass) approaching one another at the same speed, i.e., the velocities, v, have the same magnitude but are in opposite directions. Presumably the center of mass is half way between them, and it is not moving. It appears that the...

Suppose we have two objects and we're only talking about rectilinear motion. Initially, one object has mass m and is moving at velocity V. The other has mass M and is standing still. Then they hit each other and suppose that all kinetic energy is conserved and they stick together and move at...

I've noticed in several of my problems involving conservation of momentum, that the rotational kinetic energy of a system is often not conserved. Consider a merry-go-round spinning at a constant rate, until we drop a mass so that it lands on the rim of the merry-go-round. The rotational...

Homework Statement Homework Equations m1v1i + m2v2i = m1v1f + m2v2f (Conservation of momentum) (1/2)m2*(v2i)^2 + (1/2)m1*(v1i)^2 = (1/2)m2*(v2f)^2 + (1/2)m1*(v1f)^2 (Conservation of energy)The Attempt at a Solution I separated the momentum into x and y components and got 2 equations I used the...

Homework Statement A ballistic pendulum consisting of a heavy bob of mass M suspended form a fixed point by a thread of length l is at rest. A bullet of mass m and traveling horizontally at a speed v hits the bob and imbeds itself an the bob. As a result, the pendulum is deflected through a...

Could someone give me some deeper insight why we need to have momentum and energy to describe motion? Kinetic energy is only the square root of momentum divided by two times the mass of the particle. Why the need for this extra entity energy? I know that energy is a scalar and momentum is a...

Consider an ideal case of a mass m1 moving at constant velocity v1 on a frictionless surface, colliding with another masss m2 at rest. After collision, can someone tell me if it is possible for m1 to move off at -v1 while conserving the momentum and energy of the entire system? This is quite a...