the 3 kg mass has a positive momentum of 6 kg m/sec; the 2 kg mass has a negative momentum of 6 kg m/sec; each mass is moving, but the total momentum of the system equals 0.
Momentum and inertia
Momentum and Inertia<br />8SCIENCE Thurs. May 12/Fri. May 13<br />
Matter in motion<br />Matter is what all things in the universe are made from – atoms etc.<br />The amount of matter is called mass<br />Usually in kilograms (kg)<br />Mass is important:<br />Objects with a lot of mass are hard to move and once they start moving, are difficult to stop<br />This ability to stay still or stay moving is called inertia<br />
Momentum<br />Sir Isaac Newton was a famous scientist who developed the ideas of gravity and many laws of physics <br />He decided mass and velocityare the two most important factors to know when describing motion<br />He called this momentum:<br />mass (m) x velocity (v) = momentum (p)<br />m x v = p (momentum)<br />
Momentum<br />Momentum includes velocity, which means it has a direction<br />ex: if a ball is hit from a tennis racket and coming towards you, you should move out of the way – even if you catch the ball, it will hurt your hand. This ball has momentum.<br />Momentum points in the direction of motion, and an object can have positive or negative momentum depending on the direction<br />Ex: What is the momentum of these balls?<br />B<br />
Conservation of Momentum<br />Law of conservation of momentum:<br />If no outside forces act on a group of objects, the momentum of the objects will never change<br />If an object slows down, its because it has hit another object and that hit object begins to move faster<br />Ex. Billiards:<br />When you hit the balls in a rack the main ball slows down when it hits the rest and the momentum is transferred, gaining an equal amount of momentum to travel across the pool table<br />