Question

Two object of the same mass travel in the same direction along a horiztonal surface. Object X has a speed of 5 m/s and object Y has a speed of 2 m/s, After a period of time, object X collides with object Y Object X Object Y 5 m/s 2 m/s

Consider the situation in which object X has a speed of 2 m/s and object Y has a speed of 5 m/s after the collision takes place. After the collision, both objects travel in the same direction. Which of the following predictions must be true about how the momentum p of the two-object system and the kinetic energy K of the two-object system change from before the collision to after the collision?

K Remains constant Remains constant Remains constant Decreases

a. Remains constant
c. Decreases
b. "Remains constant .

Answer 1

The system's momentum remains constant after the collision as the total mass and combined velocities of objects X and Y do not change. The change in kinetic energy cannot be determined without confirmation that the collision is elastic, making the question ambiguous as it stands.

Step-by-step explanation:

In the given scenario of a collision between objects of equal mass traveling in the same direction, one can analyze the change in the system's momentum and kinetic energy. Since momentum is conserved in all collisions, if objects X and Y exchange speeds after the collision while maintaining the same direction, the system's momentum remains constant. This is due to the fact that momentum is a vector quantity and depends on both mass and velocity; here, the mass is unchanged, and the total velocity of the system (sum of individual velocities) remains the same.

As for the kinetic energy, it is conserved only in elastic collisions. However, since the problem statement does not specify the nature of the collision and the simple exchange of velocities implies an elastic collision, one might infer that the kinetic energy also remains constant. However, without explicit confirmation that the collision is elastic, the kinetic energy conservation cannot be assumed. Often, after a collision, kinetic energy is converted into other forms of energy, such as heat or sound, resulting in a decrease in kinetic energy of the system.