Chapter 8: Momentum
It turns out that Σ Fnet = ma is a special case of Newton's second law. Newton determined that a net force was something that caused a time rate of change of momentum, Δp/Δt or dp/dt, where momentum is defined as p = mv. The two descriptions are the same if the mass of the object in question does not change. Therefore, if there is no net force acting on an object or a system of objects, the momentum does not change. This statement is called conservation of momentum. Conservation of momentum, along with conservation of energy, is used in analyzing collisions between objects.
Table of Contents
Illustrations
- Illustration 8.1: Force and Impulse.
- Illustration 8.2: The Difference between Impulse and Work.
- Illustration 8.3: Hard and Soft Collisions and the Third Law.
- Illustration 8.4: Relative Velocity and Collisions.
- Illustration 8.5: Zero-Momentum Frame.
- Illustration 8.6: Microscopic View of a Collision.
- Illustration 8.7: Center of Mass.
- Illustration 8.8: Moving Objects and Center of Mass.
Explorations
- Exploration 8.1: Understanding Conservation Laws.
- Exploration 8.2: An Elastic Collision.
- Exploration 8.3: An Inelastic Collision with Unknown Masses.
- Exploration 8.4: Elastic and Inelastic Collisions and Δp.
- Exploration 8.5: Two and Three Ball Collisions.
- Exploration 8.6: An Explosive Collision.
- Exploration 8.7: A Bouncing Ball.
Problems
- Problem 8.1: Determine momentum and its conservation.
- Problem 8.2: Determine Δp for two collisions.
- Problem 8.3: Determine Δp for two collisions.
- Problem 8.4: Determine mass of blue cart.
- Problem 8.5: Determine mass of small car.
- Problem 8.6: Two carts: determine if momentum is conserved.
- Problem 8.7: Three carts: determine if momentum is conserved.
- Problem 8.8: An explosive collision.
- Problem 8.9: Is the collision elastic or inelastic?
- Problem 8.10: Is the collision elastic, inelastic, or explosive?
- Problem 8.11: Determine Δp.
- Problem 8.12: Analyze several two-d collisions.
- Problem 8.13: Determine the center of mass.
- Problem 8.14: Using center of mass.
