Final answer:
To find the mass of the second body involved in the collision, use the conservation of momentum and kinetic energy. Simultaneously solving these equations will provide the mass of the second body.
Step-by-step explanation:
The question involves solving a physics problem related to elastic collisions in one dimension. To find the mass of the second body, we'll need to use the conservation of momentum and the fact that in an elastic collision, kinetic energy is also conserved.
Let's denote the mass of the first body as m1 and the mass of the second body as m2. Since m1 is 2 kg and continues to move with a third of its original speed after the collision, and m2 is initially at rest, the conservation of momentum before and after the collision can be expressed as:
m1 × v1_initial = m1 × (v1_final) + m2 × v2_final,
where v1_final is one third of v1_initial and v2_final is the velocity of the second mass after the collision.
To solve this mathematical problem completely, we need another equation, which comes from the conservation of kinetic energy for an elastic collision:
½ × m1 × (v1_initial)^2 = ½ × m1 × (v1_final)^2 + ½ × m2 × (v2_final)^2
Solving these two equations simultaneously will give us the mass of the second body (m2).