Advanced/Notes 7.1
- 2. • How do we define momentum? • How is momentum related to force? • How can we apply the conservation of momentum? Momentum and its Relation to Force
- 3. • http://www.youtube.com/watch?v=0LnbyjOyEQ8&featur e=related Momentum
- 4. • Linear Momentum: the product of an objects mass and its velocity • Symbol is p • Units are kg·m/s Momentum
- 5. • Momentum
- 6. • A smaller football player can have the same momentum as a larger one, if… • Application? • Direction change? Momentum
- 7. • Relation to Newton’s 2nd
- 8. • For a top player, a tennis ball may leave the racket on the serve with a speed of 55 m/s (about 120 mph). If the ball has a mass of 0.060 kg and is in contact with the racket for about 4 x 10-3 s, estimate the average force on the ball. • Would this force be large enough to lift a 60 kg person? Force of a tennis serve
- 9. • Water leaves a hose at a rate of 1.5 kg/s with a speed of 20 m/s and is aimed at the side of a car, which stops it. What force is exerted by the water on the car? Water
- 10. • During a collision, measurements show that the total momentum does not change Conservation of Momentum
- 12. The total momentum of an isolated system remains constant
- 13. • A 10,000 kg railroad car, A, traveling at a speed of 24.0 m/s strikes an identical car, B, at rest. If the cars lock together as a result of the collision, what is their common speed just afterward? Railroad cars
- 14. • Only applies to an isolated system • Only forces are between objects in the system • System of rock falling by itself will not conserve momentum, because an external force, gravity • If we expand the system to include the Earth, then we can conserve momentum Systems
- 15. • Momentum conservation works for a rocket as long as we consider the rocket and its fuel to be one system, and account for the mass loss of the rocket. Systems
- 16. • Read Sections 7.1 and 7.2 • Do Problems # 1 – 12, Page 188 Homework