Collisions!

Today was conservation of momentum or collisions, depending on the block. B and F Block worked on collisions with B Block getting perfectly inelastic, inelastic and elastic collisions in one gulp and F Block getting perfectly inelastic collisions in a small nibble. Collisions are categorized by how well they conserve kinetic energy. Elastics do a great job, perfectly inelastics do a poor job and inelastics are in between. Also, for perfectly inelastic collisions, the objects stick together and move as a unit after the interaction. In truth, most collisions are inelastic in nature, but for our purposes, we'll consider them either perfectly inelastic or elastic and go from there.

C Block worked on their Impulse-Momentum lab. Remember to take care in your calculations of momentum change that the signs for initial and final velocity are correct and used properly in the determination of Δp. We'll go over the lab on Monday, but make sure to consider the items I put on the board when framing your conclusion -what should we have seen for the agreement of impulse and momentum change/sources of error in experiment; how did time and magnitude of force compare for the thin and thick rubber band and how does that play into the impulse-momentum theorem.

E Block discussed the idea of conservation of momentum. Although a collision changes the momentum of each object involved, the total momentum of the system remains the same. We have Newton's 3^rd Law of Motion and impulse to thank for this and we examined how momentum conservation played out in different examples from real life. Keep these in mind as you approach problem-solving and setting up proper equations. We'll bring conservation of momentum with us Monday into our discussion of collisions and will see it again when we discuss rotational motion.