Mechanics | 122494 - A particle or mass ma and momentum of magni-askIITians

Amit Saxena Grade: upto college level

        A particle or mass ma and momentum of magnitude 2mc strikes a particle of mass m, which is at rest. The two particles stick together after collision.
(a) The speed of the moving particle before the collision is
(A) less than c/2.                      (B) between c/2 and c.
(C) between c and 2c.             (D) 2c.
(b) The magnitude of the total momentum after the collision is
(A) less then 2mc.                     (B) equal to 2mc.
(C) between 2mc and 3mc.     (D) greater than 3mc.
(c) The speed of the two particles after collision is
(A) less than c/2.                        (C) equal to c/2.
(C) between c/2 and c.              (D) greater than c.

4 years ago

Answers : (1)

Navjyot Kalra

askIITians Faculty

654 Points

							(a) The correct option is (B).

Before collision, momentum of the first particle is 2mc and the second particle is 0(as the second particle is rest). So the total momentum of the system before collision will be 2mc. In accordance to the principle of conservation of linear momentum, the total momentum before collision will be equal to the total momentum after collision. Therefore the magnitude of the total momentum after the collision will be 2mc. From the above observation we conclude that, option (B) is correct.
(c) The correct option is (C).