The quantities remaining constant in colision are

Options

A. momentum, kinetic energy and temperature
B. momentum and kinetic energy but not temperature
C. momentum and temperature but not kinetic energy
D. momentum but neither kinetic energy nor temperature

Answer

To solve the question regarding the quantities that remain constant during a collision, we can break down the analysis into the following steps:

### Step 1: Understanding the System
In a collision, we typically analyze two bodies that collide with each other. During this interaction, they exert forces on each other, primarily through normal reactions.

**Hint:** Consider the forces acting on the bodies during the collision and identify whether they are internal or external.

### Step 2: Identifying External Forces
In an isolated system (where no external forces are acting), the only forces present are the internal forces between the colliding bodies. Since these forces are equal and opposite (according to Newton's third law), they do not affect the overall momentum of the system.

**Hint:** Think about Newton's laws and how they apply to the forces in a closed system.

### Step 3: Center of Mass and Momentum
The center of mass of the system will not accelerate if there are no external forces acting on it. This means that the velocity of the center of mass remains constant throughout the collision. Since momentum is defined as the product of mass and velocity, the total momentum of the system will also remain constant.

**Hint:** Recall the formula for momentum and how it relates to the center of mass.

### Step 4: Kinetic Energy Considerations
While momentum is conserved in all types of collisions, kinetic energy is not necessarily conserved. In elastic collisions, kinetic energy is conserved, but in inelastic collisions, some kinetic energy is transformed into other forms of energy (like heat or sound).

**Hint:** Differentiate between elastic and inelastic collisions regarding kinetic energy conservation.

### Step 5: Conclusion
From the analysis, we conclude that during a collision, the quantities that remain constant are:
- The momentum of the system (as long as no external forces act on it).

Kinetic energy and temperature may change due to the nature of the collision (elastic vs. inelastic).

**Final Answer:** The only quantity that remains constant in a collision is the momentum of the system.