Centre of Mass 2 Question 6
7. Two blocks and each of mass , are connected by a massless spring of natural length and spring constant . The blocks are initially resting on a smooth horizontal floor with the spring at its natural length, as shown in figure. A third identical block , also of mass , moves on the floor with a speed along the line joining and , and collides elastically with . Then
(1993, 2M)
(a) the kinetic energy of the
(b) the kinetic energy of the
(c) the maximum compression of the spring is
(d) the maximum compression of the spring is
Analytical & Descriptive Questions
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Answer:
Correct Answer: 7. (b, d)
Solution:
- After collision between
and stops while moves with speed of i.e. [in head on elastic collision, two equal masses exchange their velocities]. At maximum compression, and will move with same speed (From conservation of linear momentum).
Let
From conservation of mechanical energy in two positions shown in above figure