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Which of the following statements correctly describes the conservation of momentum in an isolated system of interacting particles?
According to the NCERT text, 'The total momentum of an isolated system of interacting particles is conserved.' This means that in the absence of external forces, the total momentum of the system remains unchanged.
In a collision between two bodies A and B, with initial momenta $p_A$ and $p_B$, and final momenta $p_A'$ and $p_B'$ respectively, what relationship is established by Newton's Third Law when considering the forces during collision?
The NCERT text states: 'Since $F_{AB} = - F_{BA}$ by the third law, $(p_A' - p_A) = - (p_B' - p_B)$ i.e. $p_A' + p_B' = p_A + p_B$'. This shows that the total final momentum of the isolated system equals its initial momentum.
For an isolated system, the conservation of total momentum is applicable under which conditions?
The NCERT text explicitly states regarding the equality of total initial and final momentum: 'Notice that this is true whether the collision is elastic or inelastic.'
Which of the following quantities is NOT conserved in an inelastic collision of two bodies?
The NCERT text mentions that 'In an inelastic collision of two bodies, the quantities which do not change after the collision are the total linear momentum/total energy of the system of two bodies'. It also states 'In an inelastic collision, the final kinetic energy is always less than the initial kinetic energy of the system.' Therefore, total kinetic energy is not conserved in an inelastic collision.
Consider a bullet fired from a gun. If the bullet and gun system were initially at rest, and $p_b$ is the momentum of the bullet after firing and $p_g$ is the recoil momentum of the gun, what is the relationship between their momenta based on the law of conservation of momentum?
The NCERT states: 'Thus if $p_b$ is the momentum of the bullet after firing and $p_g$ is the recoil momentum of the gun, $p_g = -p_b$ i.e. $p_b + p_g = 0$. That is, the total momentum of the (bullet + gun) system is conserved.' This implies that the initial total momentum (zero) equals the final total momentum.
What is the primary reason why the total momentum of an isolated system is conserved?
The NCERT text explains: 'In an isolated system (i.e. a system with no external force), mutual forces between pairs of particles in the system can cause momentum change in individual particles, but since the mutual forces for each pair are equal and opposite, the momentum changes cancel in pairs and the total momentum remains unchanged.'
According to the Law of Conservation of Momentum, what happens to the total momentum of a system if there are no external forces acting on it?
The NCERT clearly states: 'The total momentum of an isolated system of particles is conserved.' An isolated system is one with no external force.
During a collision between two objects, is the total linear momentum conserved at every instant of the collision?
The NCERT states under 'POINTS TO PONDER': 'During a collision: (a) the total linear momentum is conserved at each instant of the collision; (b) the kinetic energy conservation (even if the collision is elastic) applies after the collision is over and does not hold at every instant of the collision.'
If a molecule in a gas container hits a horizontal wall and rebounds with the same speed but an angle of 30° with the normal, is momentum conserved in the collision at the wall, considering a single molecule and the wall?
The question asks 'Is momentum conserved in the collision?' If we consider just the molecule, its momentum changes in direction, so its momentum isn't conserved. However, for the system of the molecule and the wall, momentum is conserved. The NCERT implicitly refers to the 'system' being conserved. When a molecule hits a wall and rebounds, the wall experiences an impulse equal and opposite to the impulse on the molecule, ensuring conservation of momentum for the molecule-wall system. The text for the example problem 5.14 doesn't explicitly state the answer for the question posed within the problem statement, but general principle implies system momentum conservation.
The Law of Conservation of Momentum can be derived directly from which of Newton's Laws?
The NCERT text clearly states: 'The second and third laws of motion lead to an important consequence: the law of conservation of momentum.'
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