A particle of mass 2m is moving to the right in projectile motion. At the top of its trajectory, an explosion breaks the particle into two equal parts. After the explosion, one part falls straight down with no horizontal motion. What is the direction of the velocity of the other part in the instant after the explosion?
A) up and to the left
B) stops moving
C) up and to the right
D) straight up
E) down and to the right

Question

Quizplus · Accepted Answer

At the top of the projectile motion, the velocity is entirely horizontal; therefore, after the explosion, the horizontal motion of the second part remains unchanged. However, the vertical motion of the second part is upwards due to the conservation of momentum. Thus, the direction of velocity after the explosion is up and to the right (choice C).

A Particle of Mass 2m Is Moving to the Right