Two blocks M1 and M2 having equal mass are free to move on a horizontal frictionless surface. M2 is attached to a massless spring as shown in Fig. 6.10. Initially M2 is at rest and M1 is moving toward M2 with speed v and collides head-on with M2. (a) While spring is fully compressed all the KE of M1 is stored as PE of spring. (b) While spring is fully compressed the system momentum is not conserved, though final momentum is equal to initial momentum. (c) If spring is massless, the final state of the M1 is state of rest. (d) If the surface on which blocks are moving has friction, then collision cannot be elastic.

Two blocks M₁ and M₂ having equal mass are free to move on a horizontal frictionless surface. M₂ is attached to a massless spring as shown in Fig. 6.10. Initially M₂ is at rest and M₁ is moving toward M₂ with speed v and collides head-on with M₂.

(a) While spring is fully compressed all the KE of M₁ is stored as PE of spring.

(b) While spring is fully compressed the system momentum is not conserved, though final momentum is equal to initial momentum.

(c) If spring is massless, the final state of the M₁ is state of rest.

(d) If the surface on which blocks are moving has friction, then collision cannot be elastic.

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Payal Gupta | Contributor-Level 10

8 months ago

This is a multiple choice answer as classified in NCERT Exemplar

(c) When M1 comes in contact with the spring. M1 is retarded by the spring force and M2 is accelerated by the spring force.

a) So spring will continue compress until the blocks moves with the same velocity.

b) As the surfaces are fri

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