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Why if total momentum is zero but kinetic energy is not equal to zero?
Wiki User
∙ 12y ago
This sounds like a trick question. Momentum has a sign (positive or negative), and if you have two masses that are going in opposite directions their total momentum is zero. But the sum of their kinetic energies is positive.
Wiki User
∙ 12y ago
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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.
What is the quantity that remains conserved in all types of collision?
Total mechanical energy
A collision in which kinetic energy may be transferred between the colliding particles but the total kinetic energy remains the same?
This is called an elastic collision. In this case both momentum and kinetic energy is conserved.
How did the elastic collision effect the total momentum and total kinetik energy in the system?
In a perfectly elastic collision total momentum and total energy remains constant. First law of physics - true everywhere even inside a black hole.
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.
Can potential energy ever be less than kinetic energy?
The answer to both of your questions lies in the different nature of both quantities, momentum and kinetic energy. Momentum is a vector, kinetic energy is a scalar. This means that momentum has a magnitude and a direction, while kinetic energy just has a magnitude. Consider the following system: 2 balls with equal mass are rolling with the same speed to each other. Magnitude of their velocities is the same, but the directions of their velocities are opposed. What can we say about the total momentum of this system of two balls? The total momentum is the sum of the momentum of each ball. Since masses are equal, magnitudes of velocities are equal, but direction of motion is opposed, the total momentum of the system of two balls equals zero. Conclusion: the system has zero momentum. What can we say about the total kinetic energy of this system? Since the kinetic energy does not take into account the direction of the motion, and since both balls are moving, the kinetic energy of the system will be different from zero and equals to the scalar sum of the kinetic energies of both balls. Conclusion: we have a system with zero momentum, but non-zero kinetic energy. Assume now that we lower the magnitude of the velocity of one of the balls, but keep the direction of motion. The result is that we lower the total kinetic energy of the system, since one of the balls has less kinetic energy than before. When we look to the total momentum of the new system, we observe that the system has gained netto momentum. The momentum of the first ball does not longer neutralize the momentum of the second ball, since the magnitudes of both velocities are not longer equal. Conclusion: the second system has less kinetic energy than the first, but has more momentum. If we go back from system 2 to system 1 we have an example of having more kinetic energy, but less momentum. I hope this answers your question Kjell
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.
When an action and reaction occur momentum is usually lost?
No. Total momentum before and after the collision is the same. Some kinetic energy can be lost - but not momentum.
What is the quantity that remains conserved in all types of collision?
Total mechanical energy
A collision in which kinetic energy may be transferred between the colliding particles but the total kinetic energy remains the same?
This is called an elastic collision. In this case both momentum and kinetic energy is conserved.
Two objects move separately after colliding with the same total momentum and kinetic energy?
Inelastic
Potential energy plus kinetic energy equal what?
Mechanical energy is equal to potential energy plus kinetic energy in a closed system. The total mechanical energy is conserved.
How did the elastic collision effect the total momentum and total kinetik energy in the system?
In a perfectly elastic collision total momentum and total energy remains constant. First law of physics - true everywhere even inside a black hole.
What in a closed system energy is equal to potential energy plus kinetic energy?
Mechanical energy is equal to potential energy plus kinetic energy in a closed system. The total mechanical energy is conserved.
In a closed system what energy is equal to potential energy plus kinetic energy.?
Mechanical energy is equal to potential energy plus kinetic energy in a closed system. The total mechanical energy is conserved.
In a closed system what energy is equal to potential energy plus kinetic energy?
Mechanical energy is equal to potential energy plus kinetic energy in a closed system. The total mechanical energy is conserved.
In a closed system energy is equal to potential energy plus kinetic energy?
Mechanical energy is equal to potential energy plus kinetic energy in a closed system. The total mechanical energy is conserved.
