Question

1. when calculating the final velocity of an object after an explosion, what does it mean if the final velocity is negative?

the object is moving forward after the explosion.
the object is moving backward after the explosion.
the object was not at rest before the explosion.
the explosion did not obey the law of conservation of momentum.

Explanation:

Velocity is a vector quantity. The sign of velocity indicates its direction. If we assume a forward - moving direction as positive, then a negative velocity means the object is moving in the opposite (backward) direction.

• For the first option: Just because the final velocity is negative, we cannot say the object is moving forward.
• For the third option: The initial state (whether the object was at rest or not before the explosion) has no direct relation to the sign of the final velocity.
• For the fourth option: Explosions obey the law of conservation of momentum. The sign of velocity is about direction, not a violation of the law.

Answer:

The object is moving backward after the explosion.