Please enjoy this feature of Mr. Burns driving and colliding with everything!!

“Once a song gets momentum and gets away from you, that’s a good sign” – Dave Matthews.

“What?” – Darren

So let’s begin our discussion about momentum by defining a collision as any interaction where the internal forces dominate. If a hockey player checks another, the internal forces are strong enough to seriously injure the other player. The external forces of friction very minimal. Also evident in the tennis serve, the ball and the racquet forces are so large that the ball distorts noticeably. However, by comparison, the external forces of gravity on the ball and your hand on the racquet are very insignificant.

In summary, if the internal forces during a collision are much greater in magnitude than the external forces, the total momentum of the interacting objects has the same value just before as just after the collision. This means that momentum is conserved and leads us to one of the incredible fundamental laws that governs the interactions of all objects in the universe, the Law of Conservation of Momentum.

So, I wanted to give you a couple of problems to work on. This unit is all about practice and keeping track of your direction and your variables. Good luck!!

(1) Blythe and Bart are ice skating together. Blythe has a mass of 50 kg and Bart has a mass of 80 kg. Blythe pushes Bart in the chest when both are at rest, causing him to move away at a speed of 4 m/s. Determine Blythe’s speed after she pushes Bart?

(2) A 2 kg object is moving east at 4 m/s when it collided with a 6 kg object that is initially at rest. After the collision, the larger object moves east at 2.00 m/s. What is the final magnitude and direction of the velocity of the smaller object after the collision?

Thanks so much everyone!! You’re doing amazing!!