For a system to follow the law of conservation of linear momentum during a collision the condition is :

Question

(1) total external force acting on the sysyem is zero.

(2) total external force acting on the systyem is finite and time of collision is negligible.

(3) total internal force acting on the system is zero.

(a) (1) only

(b) (2) only

(c) (3) only

(d) (1) or (2)