CBSE-XI-Physics
09: Centre of Mass, Linear Momentum, Collision
- #11If the total mechanical energy of a particle is zero, is its linear momentum necessarily zero? Is it necessarily nonzero?Ans : No. As the potential energy can have a negative value, the total energy of the system may sum up to zero.
For example:
Two masses A and B having masses 2 kg and 4 kg respectively move with a velocity of 4 ms-1 in opposite directions.
Kinetic energy of system (A and B)
`` =\frac{1}{2}\times 2\times {4}^{2}+\frac{1}{2}\times 4\times {4}^{2}``
`` =48\,\mathrm{\,J \,}``
If the gravitational potential energy of the system is -48 J, the total energy of the system will be zero. However, the linear momentum will be non-zero.
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