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Is it possible to have collision in which all the momentum is lost?
Wiki User
∙ 11y ago
In short no. Momentum is always conserved so you always end up with exactly the same amount you started off with.
One subtelty is that momentum is a vector quantity so direction matters. Thus if you have two balls of equal mass moving with the same speed in opposite directions their momenta are equal in magnitude (size) but oppositely directed so the total momemtum is p+(-p)=0 to start with.
A second subtelty emerges when we consider more complicated cases. If there are forces acting on the colliding bodies eg friction then we can 'lose' momentum to these forces (although really we just need to be more careful with the book-keeping).
Wiki User
∙ 11y ago
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Is it possible to have a collision in which all of the kinetic energy is lost?
A car driving into a very large rock. A collosion where all the things colliding (in the example the car and the rock) are no longer moving after the collision is one where all the kentic energy is lost. K.E. = 1/2 * m * v2 If v=0 then there is no kinetic energy.
How is momentum conserved after a collision?
Completely If you add all the energy of all the resultants of the collision together, you will arrive at the same value as the sum of the energies of all the components before the collision.
The momentum before a collision of three objects is always greater than the momentum after the collision?
Negative negative, and quite false as well.Regardless of how many objects are involved, and as long as the collisions are'elastic' ... meaning that no energy is lost in crushing, squashing, pulverizing, orheating any of the objects ... the grand total of all their momenta (momentums)after the collision is exactly the same as it was before the violence erupted.
The collision between two helium atoms is perfectly elastic so that momentum is conserved?
Momentum is always conserved in any type of collision. Energy conservation, however, is dependant on elasticity. In a perfectly elastic collision all energy is conserved.
A collision in which the total momentum and kinetic energy remain constant?
Kinetic energy is only conserved if the collision is elastic. All other collisions will have some loss of kinetic energy even when momentum is conserved.
Why are bumper cars an example of Newtons first law?
It points to the law of linear conservation of momentum, the total momentum after collision is the same as before the collision, say each car including driver has a mass of 200 kg, car A is moving at 5 metres / second, car B is stationary. Momentum of the moving car makes up all the momentum prior to collision and is = mass * velocity = 200 * 5 = 1000 kg.m/s, assuming an elastic(or perfect) collision, in which no energy is lost as heat or noise, the momentum after the collision will still be 1000 kg.m/s, but the mass will have increased to 400 kg (total of both cars), so the equation after collision: 1000 = 400 * velocity, velocity = 1000 / 400 = 2.5 metres / second
What is the quantity that remains conserved in all types of collision?
Total mechanical energy
A 0.490 kg hockey puck moving east with a speed of 5.20 ms has a head-on collision with a 0.830 kg puck initially at rest Assume a perfectly elastic collision?
I won't do all the algebra but here's the setup; Both momentum and kinetic energy are conserved in an elastic collision so you set the known momentum of puck 1, before the collision equal to the sum of the unknown momentum's of puck1 & puck2 after the collision. You then set the known kinetic energy of puck1 before collision to the sum of the kinetic energies of puck1 & puck2 after the collision. This gives you two equations in the unknown velocities after the collision. Solve for one velocity from the momentum equation, square it and substitute it in the KE equation. This will give you a quadratic equation in one unknown velocity. Solve for the two possible solutions. Try each solution back in the original momentum equation. One solution will give a non physical result so you discard it and use the one that gives you a physically possible solution. One possible nonphysical result is if puck2 remains at rest and puck1 continues East (positive velocity). I chose East as positive for convienence. So if an unknown velocity comes out negative it means its moving West.
Why in a collision momentum is not always conserved?
In principle momentum is always conserved. However what sometimes happens in a collision is that energy is released that is then no longer considered part of the system. For example if two cars collide energy could be dissipated via the air and ground (e.g. heat) and this can also carry away momentum. Often, these effects are not taken into account and in that way momentum conservation appears to be violated; but if one takes care and takes into account all collision products the total momentum after is equal to the total momentum prior. So in short, any violation can be traced back to a redefinition of the system.
Need an explanation why kinetic energy is always conserved during elastic collision what is meant by conserved?
In this context "conserved" means the total kinetic energy of all the objects is the same after the collision as before the collision. Note, the TOTAL is the same but the individual kinetic energies of each object may be different before and after. When two or more objects are about to collide they have a certain total kinetic energy. It is common that during the collision some of the kinetic energy is transformed into heat. So after the collision the total kinetic energy is less then before the collision. This is a non-elastic collision. There are some collisions, however, in which none of the kinetic energy is changed to heat. These are called ELASTIC collisions. So the total kinetic energy doesn't change, or is "conserved". There is another possible non-elastic collision. If during the collision there is an explosion, then its possible for the objects to have a larger total kinetic energy after the collision as they aquire some of the explosive energy. Finally note, that in all collisions the TOTAL vector momentum is the same just before and just after the collision. So in a collision momentum is always conserved.
Where does kinetic energy go after it is used?
If you're suggesting something like an auto accident, the energy of the collision is used to deform materials in the structural elements of the vehicle(s). It also heats them. The primary design features of cars includes a lot of thought to where the energy of a collision can go. Bumpers collapse, body panels and their strengthening members fold and become compressed, and a top or roof can collapse down. All this sinks ("sucks up") energy. And if it all works in an optimal way, you can climb out and walk away.
Which equation is a statement of the law of conservation of momentum?
One way to write it is: dp/dt = 0. That means that the rate of change of momentum over time is zero (using "p" as the symbol for momentum). Another way, which is often useful to calculate collisions, is: Ʃp(time 1) = Ʃp(time 2), which means that the sum of all momenta before the collision must be the same as the sum of all momenta after the collision.
